3.2. Taxonomic Account
Phylum Platyhelminthes Minot, 1985
Subphylum Rhabditophora Ehlers, 1985
Order Polycladida Lang, 1884
Suborder Acotylea Lang, 1884
Superfamily Stylochoidea Poche, 1926
Family Hoploplanidae Stummer-Traunfels, 1933
Genus Hoploplana Laidlaw, 1902
Hoploplana cf. divae Marcus, 1950
Material examined: CBUMAG:PLA:00152, a single specimen preserved in 70% EtOH, immature, 2.2 mm × 1.27 mm.
Distribution: Originally described from São Paulo, Brazil [
23], this species was later recorded in Curaçao [
25], as well as in northeastern and southeastern Brazil [
32,
36], and the Gulf of Mexico [
9]. This is the first record for Colombia.
Remarks: Only a single juvenile specimen was found beneath rocks. Although this species is typically associated with bryozoans, no individuals were found among the bryozoan colonies inspected during our study. Its presence in multiple regions could suggest that it may be widely distributed across the Tropical Atlantic. The specimen collected exhibited the characteristic dorsal papillae, eyespot arrangement, and coloration previously described for
H. divae (
Figure 2). However, given that it was an immature specimen, no molecular sequences were obtained, and the genus
Hoploplana includes 15 species with similar morphological traits, 6 having dorsal papillae [
14,
31,
37], we consider that the presence of
H. divae on the Caribbean Coast of Colombia still requires further confirmation.
Figure 2.
Hoploplana cf. divae Marcus, 1950. (A) Photograph of live specimen; (B) Detail of tentacles and eyespot organization; (C) Detail of the dorsal papillae. ce: cerebral eyespots; pa: papillae; te: tentacles; ten: tentacular eyespots.
Figure 2.
Hoploplana cf. divae Marcus, 1950. (A) Photograph of live specimen; (B) Detail of tentacles and eyespot organization; (C) Detail of the dorsal papillae. ce: cerebral eyespots; pa: papillae; te: tentacles; ten: tentacular eyespots.
Family Idioplanidae Dittman, Cuadrado, Aguado, Noreña and Egger, 2019
Genus Idioplana Woodworth, 1898
Idioplana atlantica (Bock, 1913)
Synonyms:
Idioplanoides atlantica (Bock, 1913)
Idioplanoides atlanticum Bock, 1913
Woodworthia atlantica Bock, 1913
Distribution: Described from St. Thomas, US Virgin Islands [
38]. It has also been reported from Cuba [
8] and the Yucatán Peninsula, Mexico [
9]. This is the first formal record for Colombia.
Remarks: This species was not collected during the present study, but it was previously identified as
Acotylea sp. 2 from Playa Cristal in Neguanje Bay, Santa Marta by Quiroga et al. [
11]. It exhibits a rounded body shape, short nuchal tentacles, and a distinctive dorsal pattern of brown rings on a white or cream background (
Figure 3). Only three species have been described within this genus [
31], and this is the only one in the region known to display such a unique color pattern. Although the specimen collected by Quiroga et al. [
11] was immature, additional photographs provided by the authors were used to support the identification (
Figure 3).
Figure 3.
Idioplana atlantica (Bock, 1913). (A) Photograph of live specimen; (B) Detail of tentacles and eyespot organization. ce: cerebral eyespots; me: marginal eyespots; te: tentacles; ten: tentacular eyespots.
Figure 3.
Idioplana atlantica (Bock, 1913). (A) Photograph of live specimen; (B) Detail of tentacles and eyespot organization. ce: cerebral eyespots; me: marginal eyespots; te: tentacles; ten: tentacular eyespots.
Family Latocestidae Laidlaw, 1903
Genus Latocestus Plehn, 1896
Latocestus brasiliensis Hyman, 1955
Material examined: CBUMAG:PLA:00104, mature specimen as sagittal sections and a whole mount, 17 mm × 2 mm. CBUMAG:PLA:00082, mature specimen as a whole mount, only anterior part of the body, 19 mm × 2 mm. AMNH 682, one specimen as a whole mount.
Distribution: Described from São Francisco do Sul Island in southeastern Brazil [
39,
40], and later recorded from northeastern Brazil [
40]. This is the first record for Colombia and the Caribbean Sea.
Remarks: The reproductive morphology seen in our histological sections corresponds with the original description and illustration provided by Hyman [
39] and the sections published by Bahia et al. [
40], by having a broad penis papilla, slightly muscular spermiducal bulbs, and a vagina running anteriorly a short distance and then to the posterior, ending in an oval Lang’s vesicle. Hyman [
39] described the species based on fixed material and therefore did not report the coloration of live specimens. Bahia et al. [
40] described their specimens as “greyish beige”, while those collected in the present study have a whitish translucent body with a central green or yellow region, likely due to the gut content (
Figure 4A). The posteriorly positioned pharynx is pink, as also noted in the photograph published by Bahia et al. (2015) [
40]. Additionally, the arrangement of the eyespots from our specimens matches (
Figure 4B) that of the paratype (AMNH 682). We provide the first 28S rDNA and COI mtDNA sequences for the species (
Table 1). Although we could not confirm the species identity through molecular comparison due to the absence of previously available sequences for this species, BLAST analysis of the 28S sequences showed high similarity (>97%) with other latocestid sequences deposited in GenBank. To date, no COI sequences have been published for any member of this family.
Figure 4.
Latocestus brasiliensis Hyman, 1955. (A) Photograph of live specimen; (B) Detail of the eyespot arrangement from whole mount (CBUMAG:PLA:00104); (C) Detail of the far posterior, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00104); am: male atrium; b: brain; ce: cerebral eyespots; fe: frontal eyespots; fp: female pore; i: intestine; lv: Lang’s vesicle; m: mouth; me: marginal eyespots; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; spb: spermiducal bulb; v: vagina.
Figure 4.
Latocestus brasiliensis Hyman, 1955. (A) Photograph of live specimen; (B) Detail of the eyespot arrangement from whole mount (CBUMAG:PLA:00104); (C) Detail of the far posterior, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00104); am: male atrium; b: brain; ce: cerebral eyespots; fe: frontal eyespots; fp: female pore; i: intestine; lv: Lang’s vesicle; m: mouth; me: marginal eyespots; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; spb: spermiducal bulb; v: vagina.
Latocestus sp.
Material examined: CBUMAG:PLA:00083, immature specimen as a whole mount, far posterior damaged, 30 mm × 4 mm. CBUMAG:PLA:00173, mature specimen as sagittal sections and a whole mount, 20 mm × 2.5 mm. CBUMAG:PLA:00223, mature specimen as sagittal sections and a whole mount, 30 mm × 3.74 mm. CBUMAG:PLA:00268, mature specimen preserved in 70% EtOH.
Distribution: Collected in the present study from Bahía Concha, Inca Inca Bay and Neguanje Bay.
Remarks: The dorsal surface is covered with brown to orange dots, resembling
Enchiridium evelinae Marcus, 1949; however, the pigment is concentrated towards the posterior and less noticeable anteriorly (
Figure 5A). This pattern is preserved after fixation and clearing, although it becomes much less noticeable compared to live specimens. Marginal eyes are more densely distributed in the anterior region, becoming fewer and smaller posterior to the level of the brain. The region between the brain and the anterior margin is filled with eyespots organized in a fan-like pattern (
Figure 5B). The pharynx is located at the far posterior portion of the body (
Figure 5C), as typical of Latocestidae [
14]. Additionally, we observed what appears to be a sclerotized structure similar to bristle worms’ chaetae inside the intestine in the slides of one of the specimens (
Figure 5E). According to Faubel [
14], the genera within the family can be distinguished based on the interior lining in the prostatic vesicle. Our specimens exhibit a ridged prostatic lining, well-developed spermiducal bulbs, and an oval Lang’s vesicle, which are diagnostic characters of the genus
Latocestus (
Figure 5D,E). We provide the 28S rDNA and COI mtDNA sequences for this morphospecies (
Table 1). The BLAST analysis shows high similarity with
Latocestus sp. (MH700317 = 98.9%; MH700318 = 99.1%); however, the reproductive morphology of this species is not available. Due to the lack of documentation on the live coloration of species within the genus and the scarcity of DNA sequences available for the family, we assigned our specimens only to the generic level until additional morphological and molecular data become available.
Figure 5.
Latocestus sp. (A) Photograph of live specimen; (B) Detail of the eyespot arrangement from whole mount (CBUMAG:PLA:00083); (C) Detail of the far posterior, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00223). am: male atrium; b: brain; ce: cerebral eyespots; fe: frontal eyespots; fp: female pore; i: intestine; lv: Lang’s vesicle; m: mouth; me: marginal eyespots; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; spb: spermiducal bulb; v: vagina.
Figure 5.
Latocestus sp. (A) Photograph of live specimen; (B) Detail of the eyespot arrangement from whole mount (CBUMAG:PLA:00083); (C) Detail of the far posterior, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00223). am: male atrium; b: brain; ce: cerebral eyespots; fe: frontal eyespots; fp: female pore; i: intestine; lv: Lang’s vesicle; m: mouth; me: marginal eyespots; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; spb: spermiducal bulb; v: vagina.
Latocestidae sp.
Material examined: CBUMAG:PLA:00130, mature specimen as sagittal sections and an anterior mount, 26 mm × 7.9 mm.
Distribution: Found in the present study only in Bahía Concha.
Figure 6.
Latocestidae sp. (A) Photograph of live specimen; (B) Detail of the eyespot arrangement from whole mount; (C) Detail of the far posterior, ventral view; (D,E) sagittal sections of reproductive structures. am: male atrium; b: brain; ce: cerebral eyespots; fe: frontal eyespots; gp: gonopores; lv: Lang’s vesicle; m: mouth; me: marginal eyespots; mp: male pore; ph: pharynx; pp: penis papilla; pv: prostatic vesicle; spb: spermiducal bulbs; v: vagina.
Figure 6.
Latocestidae sp. (A) Photograph of live specimen; (B) Detail of the eyespot arrangement from whole mount; (C) Detail of the far posterior, ventral view; (D,E) sagittal sections of reproductive structures. am: male atrium; b: brain; ce: cerebral eyespots; fe: frontal eyespots; gp: gonopores; lv: Lang’s vesicle; m: mouth; me: marginal eyespots; mp: male pore; ph: pharynx; pp: penis papilla; pv: prostatic vesicle; spb: spermiducal bulbs; v: vagina.
Remarks: The external appearance and the organization of the male apparatus place it in the family Latocestidae (
Figure 6). The reproductive system corresponds to that of the genus
Latocestus (
Figure 6D,E); however, our specimens present a distinctive broad band of marginal eyes around the entire body. This type of marginal eye arrangement has so far only been reported in the genus
Nonatona Marcus, 1952, which possesses a typical
Latocestus reproductive system, except for the presence of a ductus vaginalis [
24]. Our specimen external appearance and reproductive anatomy agree with the characters of
Nonatona, which only has the species
Nonatona euscopa Marcus, 1952; however, while our specimen has the broad marginal band of eyes, these are not that densely grouped, nor is the band that broad, as mentioned by Marcus for
N. euscopa [
24]. Additionally, our specimen also differs by having a more pronounced conical penis papilla than
N. euscopa (
Figure 6E). Furthermore, due to our only specimen posterior not being in good shape after the histology, we were not able to clearly distinguish the existence of a ductus vaginalis or a female pore (
Figure 6D,E). Finally, we believe that, while similar to the only member of
Nonatona, more material is needed to accurately place this morphospecies inside the family Latocestidae. We provide a 28S rDNA sequence for the morphospecies, which shows high similarity with other Latocestid sequences in GenBank (
Latocestus sp. MH700318 = 97.2%;
Latocestus sp. MK299377 = 97.4%), and a COI mtDNA sequence (
Table 1).
Family Stylochidae Stimpson, 1857
Genus Stylochus Ehrenberg, 1831
Stylochus sp.
Material examined: CBUMAG:PLA:00134, mature specimen as a whole mount, 20.6 mm × 13 mm. CBUMAG:PLA:00293, mature specimen as sagittal sections and a whole mount, 20 mm × 14 mm. CBUMAG:PLA:00316, mature specimen preserved in 70% EtOH, 27.8 mm × 17.3 mm.
Distribution: Inca Inca Bay, Taganga Bay, and Neguanje Bay. This represents the first record of the genus Stylochus and family Stylochidae in Colombia.
Remarks: Specimens were found beneath rocks, and one was collected in the swash zone of a cliff. Specimens exhibited a relatively large body size and firm consistency. Cream coloration with orange/pinkish dots on the dorsal surface, a pattern shared with several stylochids (
Figure 7A). Our specimens possess a tripartite, anchor-shaped seminal vesicle and a prostatic vesicle with extravesicular polyglandular glands, features typical of several
Stylochus species [
14] (
Figure 7D,E). In terms of body shape, coloration, and reproductive anatomy, our specimens resemble
Stylochus oculifera (Girard, 1853) as described by Hyman [
28], Marcus and Marcus [
25], and later from Bulnes et al. [
41]. However, our 28S rDNA sequences do not closely match those available in GenBank for this species (HQ6590007 = 94.9%; MH700311 = 93.94%), having a higher similarity with a sequence identified as
Imogine sp. (=
Stylochus sp.) (MH700312 = 99.47%). This discrepancy suggests that the specimens may represent a different species. Therefore, we assign them to the genus
Stylochus only. It is important to note that the reference sequences in GenBank lack associated detailed morphological descriptions, which limits the ability to make definitive comparisons. We provide both 28S rDNA and COI mtDNA sequences for our species (
Table 1).
Family Stylochocestidae Bock, 1913
Genus Chatziplana Faubel, 1983
Chatziplana grubei (Graff, 1892)
Synonyms:
Hoploplana grubei (Graff, 1892)
Planocera grubei Graff, 1892
Material examined: CBUMAG:PLA:00627, mature specimens as a whole mount, 7 mm × 4 mm. CBUMAG:PLA:00631, mature specimen as sagittal sections. Measurement from fixed specimen.
Distribution: Described from specimens found floating in algae from the Atlantic [
42]. Subsequent records from Canada [
43], St. Thomas, US Virgin Islands [
38], the Sargasso Sea and the Gulf of Mexico [
26,
44], the Mexican Caribbean [
45], and the Colombian Caribbean [
13].
Remarks: We inspected the
Sargassum associated with the rocky shores of the Santa Marta region, but we did not find this species. Using additional tissue samples from deposited at the Centro de Colecciones Científicas de la Universidad del Magdalena, obtained from floating
Sargassum collected in the Parque Nacional Natural Corales de Profundidad, located in the Bolívar department [
13], we generated the first COI mtDNA sequences for the species, along with an additional 28S rDNA sequence (
Chatziplana grubei PQ962884 = 97.6%) (
Table 1).
Figure 8.
Chatziplana grubei (Graff, 1892). (A,B) CBUMAG:PLA:00627. (A) Photograph of a specimen in whole mount; (B) Detail of the eyespot organization from whole mount; (C) sagittal sections of reproductive structures (CBUMAG:PLA:00631). ce: cerebral eyespots; mb: muscle bulb; ov: oviduct; pv: prostatic vesicle; spb: spermiducal bulbs; st: stylet; te: tentacles; ten: tentacular eyespots; v: vagina.
Figure 8.
Chatziplana grubei (Graff, 1892). (A,B) CBUMAG:PLA:00627. (A) Photograph of a specimen in whole mount; (B) Detail of the eyespot organization from whole mount; (C) sagittal sections of reproductive structures (CBUMAG:PLA:00631). ce: cerebral eyespots; mb: muscle bulb; ov: oviduct; pv: prostatic vesicle; spb: spermiducal bulbs; st: stylet; te: tentacles; ten: tentacular eyespots; v: vagina.
Superfamily Leptoplanoidea Faubel, 1984
Family Gnesiocerotidae Marcus and Marcus, 1966
Genus Gnesioceros Diesing, 1862
Gnesioceros sargassicola (Mertens, 1833)
Synonyms:
Gnesioceros floridana (Pearse, 1938)
Gnesioceros mertens (Diesing, 1850)
Gnesioceros mertensi (Diesing, 1850)
Gnesioceros verrilli Hyman, 1939
Imogine oculifera Verrill, 1892
Pelagoplana sargassicola (Mertens, 1833)
Planaria sargassicola Mertens, 1833
Planocera sargassicola (Mertens, 1833)
Stylochoplana floridana Pearse, 1938
Stylochoplana oculifera Pearse and Walker, 1939
Stylochoplana sargassicola (Mertens, 1833)
Stylochus mertensi Diesing, 1850
Stylochus pelagicus Moseley, 1877
Stylochus sargassicola (Mertens, 1833)
Figure 9.
Gnesioceros sargassicola (Mertens, 1833). (A) Photograph of live specimens. (B,C) CBUMAG:PLA:00265. (B) Detail of the eyespot organization from whole mount; (C) Detail of the posterior portion of the body, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00266). am: male atrium; ce: cerebral eyespots; ci: cirrus; fp: female pore; lv: Lang’s vesicle; mp: male pore; o: ovaries; pv: prostatic vesicle; spt: spermatophore; te: tentacle; ten: tentacular eyespots; v: vagina; vb: vagina bulbosa.
Figure 9.
Gnesioceros sargassicola (Mertens, 1833). (A) Photograph of live specimens. (B,C) CBUMAG:PLA:00265. (B) Detail of the eyespot organization from whole mount; (C) Detail of the posterior portion of the body, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00266). am: male atrium; ce: cerebral eyespots; ci: cirrus; fp: female pore; lv: Lang’s vesicle; mp: male pore; o: ovaries; pv: prostatic vesicle; spt: spermatophore; te: tentacle; ten: tentacular eyespots; v: vagina; vb: vagina bulbosa.
Material examined: CBUMAG:PLA:00265, one mature specimen as whole mount, 10 mm × 3 mm, and 3 mature specimens in 70% EtOH. CBUMAG:PLA:00266, one mature specimen as sagittal sections, 7 mm × 3 mm, and 6 mature and immature specimens in 70% EtOH. CBUMAG:PLA:00288, 5 immature specimens in 70% EtOH. CBUMAG:PLA:00348, 5 mature and immature specimens in 70% EtOH. CBUMAG:PLA:00404, one mature specimen in 70% EtOH. Measurements from fixed material.
Distribution: Widely distributed across the Tropical Western Atlantic, recorded as clinging fauna and found in littoral environments. Records from floating habitats include the Sargasso Sea [
46], the Caribbean Sea [
43], the Gulf of Mexico [
47], and the North Atlantic Ocean [
44,
48,
49]; additionally, the species has been recorded in the littoral from Bermuda [
26], St. Thomas, from Texas to Massachusetts [
25,
50], Cape Verde [
51], Cayman Islands [
48], Curaçao, Bonaire, Puerto Rico, St. Barthelemy [
25], Canary Islands [
52], and in Colombia [
11,
13].
Remarks: We found specimens both beneath rocks and associated with
Sargassum on the rocky shores. Some specimens were also found in floating remains of a water hyacinth, a plant that is usually carried out to the sea by rivers. Our whole mount preparations also reveal the crescent-shaped Lang’s vesicle noted by Hyman [
26] and observed by Merchán-Mayorga et al. [
13] (
Figure 9E). Similarly, we also observed the presence of spermatophores attached to the female system in some of our specimens, likely deposited after mating, as noted also by Hyman [
26], Marcus and Marcus [
25], and Merchán-Mayorga et al. [
13] (
Figure 9C). Although the species is recurrently documented in the Tropical Western Atlantic, only a few studies, including this one, have reported the presence of spermatophores. However, the mating behavior associated with them remains unknown, requiring further investigation.
Hyman [
50] distinguished the pelagic
G. sargassicola from the “shore-associated”
Gnesioceros floridana Hyman, 1939 based on the presence of a ring-shaped musculo-glandular fold in the former and an incomplete ring fold in the latter. However, in a subsequent work, it was suggested that both might represent the same species [
47]. Marcus and Marcus [
25] examined several specimens from floating
Sargassum and from shore algae, and found no significant differences in the female reproductive structures, subsequently synonymizing
G. floridana with
G. sargassicola. Our specimens from rocky shores, as well as specimens from floating
Sargassum [
13], show no anatomical differences. The molecular sequences obtained from our specimens were nearly identical to each other (97–99.4%) and showed high similarity with those reported by Merchán-Mayorga et al. [
13] (PQ962885 = 99.6%) and Litvaitis et al. [
53] (MH700309 = 99.6%). This strong genetic similarity, together with the lack of distinguishing morphological differences between the specimens found on the rocky shore and those from floating
Sargassum, potentially supports the synonymy of
G. floridana and
G. sargassicola as proposed by Marcus and Marcus [
25]. We provide additional 28S rDNA and the first COI mtDNA sequences both from our specimens and from additional samples already deposited at the Centro de Colecciones Científicas de la Universidad del Magdalena [
13] (
Table 1).
Genus Styloplanocera Bock, 1913
Styloplanocera fasciata (Schmarda, 1859)
Synonyms:
Stylochoplana fasciata (Schmarda, 1859)
Stylochus fasciatus Schmarda, 1859
Styloplanocera papillifera Bock, 1913
Figure 10.
Styloplanocera fasciata (Schmarda, 1859). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00640); (C) Detail of the posterior, ventral view; (D) (INVPLA0025) and (E) (CBUMAG:PLA:00640) sagittal sections of reproductive structures. af: female atrium; am: male atrium; ce: cerebral eyespots; ci: cirrus; fp: female pore; lv: Lang’s vesicle; mk: marginal knobs; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; te: tentacle; ten: tentacular eyespots; u: uterus; v: vagina; vb: vagina bulbosa.
Figure 10.
Styloplanocera fasciata (Schmarda, 1859). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00640); (C) Detail of the posterior, ventral view; (D) (INVPLA0025) and (E) (CBUMAG:PLA:00640) sagittal sections of reproductive structures. af: female atrium; am: male atrium; ce: cerebral eyespots; ci: cirrus; fp: female pore; lv: Lang’s vesicle; mk: marginal knobs; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; te: tentacle; ten: tentacular eyespots; u: uterus; v: vagina; vb: vagina bulbosa.
Material examined: CBUMAG:PLA:00088, one mature specimen in 70% EtOH, 18 mm × 10 mm. CBUMAG:PLA:00089, one mature specimen in 70% EtOH. CBUMAG:PLA:00334, one mature specimen in 70% EtOH, 32 mm × 13.67 mm. CBUMAG:PLA:00417, one mature specimen in 70% EtOH, 34.4 mm × 9.4 mm. CBUMAG:PLA:00551, one immature specimen in 70% EtOH, 18.1 mm × 6.2 mm. CBUMAG:PLA:00640, one mature specimen as sagittal sections of the reproductive structures and an anterior mount, 20 mm × 9 mm. CBUMAG:PLA:00641, one mature specimen as a whole mount, 15 mm × 5 mm. INVPLA0025, mature specimen as sagittal sections of the reproductive structures.
Distribution: Aruba, Curaçao, Bonaire, Barbados, St. Croix, Virgin Islands [
25], Puerto Rico [
29], Jamaica [
54], Cuba [
8], and Colombia [
11].
Remarks:
Styloplanocera fasciata is probably one of the most common polyclads in the Caribbean Sea [
7]. Based on our field observations, although the species was commonly encountered throughout the sampling, it was more frequently observed on rocky shores with exposure to strong wave action, whereas its presence was notably reduced on more sheltered shores characterized by greater accumulation of coral rubble. All our specimens showed the characteristic dorsal coloration pattern with grey or brown blotches and dots, as well as the presence of marginal papillae [
25] (
Figure 10A,C). Additionally, they showed the cuticular cirrus armed with spines as described by Faubel [
14] (
Figure 10D). We provide additional 28S rDNA sequences that were nearly identical to each other (PX093744 vs. PX093745 = 99%), and which show high similarity with the available sequences of the species (e.g., MH700408 = 99.6%), and the first COI mtDNA sequences for the species (
Table 1).
Family Notoplanidae Marcus and Marcus, 1966
Genus Amyris Marcus and Marcus, 1968
Amyris hummelincki Marcus and Marcus, 1968
Synonyms:
Amyris ujara Marcus and Marcus, 1968
Material examined: CBUMAG:PLA:00183, one mature specimen in 70% EtOH, 14 mm × 3 mm. CBUMAG:PLA:00225, one mature specimen as sagittal sections and preserved in 70% EtOH, 23.7 mm × 2 mm. CBUMAG:PLA:00426, one mature specimen as a whole mount, 24.7 mm × 2.5 mm. CBUMAG:PLA:00513, one mature specimen in 70% EtOH, 16.6 mm × 2.5 mm. CBUMAG:PLA:00539, one mature specimen in 70% EtOH, 11.4 mm × 2.5 mm. CBUMAG:PLA:00547, one mature specimen in 70% EtOH, 11.7 mm × 1.4 mm. CBUMAG:PLA:00549, one mature specimen in 70% EtOH, 21 mm × 3.2 mm.
Distribution: Curaçao and Bonaire [
25]. This study provides the first formal record for Colombia.
Remarks: We observed the presence of cirrus spines from our slides and whole mount (
Figure 11C,D). Marcus and Marcus [
25] did not observe a spinous cirrus; however, our observations are consistent with the comment by Litvaitis et al. [
53] of
Amyris possessing an armed penis papilla. Faubel [
14] assigned the genus
Amyris to the family Notoplanidae, a placement that was later supported by both molecular and morphological evidence [
53]. However,
Amyris was transferred erroneously to Faubelidae Özdikmen, 2010, along with other genera, after a misunderstanding of it being considered part of Notocirridae Faubel, 1983 [
55]. A more detailed discussion of this taxonomic misclassification is provided by Ramos-Sánchez et al. [
56]. We continue to follow the classification of
Amyris hummelincki in Notoplanidae. We provide additional 28S rDNA sequences for the species that show high similarity with the previously available sequences (e.g., MH700271 = 98.5%) (
Table 1).
Figure 11.
Amyris hummelincki Marcus and Marcus, 1968. (A) Photograph of live specimen; (B,C) CBUMAG:PLA:00426. (B) Detail of the eyespot organization from whole mount; (C) Detail of the cirrus, ventral view from whole mount; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00225). b: brain; ce: cerebral eyespots; ci: cirrus; cs: cirrus spines; fp: female pore; lv: Lang’s vesicle; mp: male pore; ov: oviduct; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; v: vagina.
Figure 11.
Amyris hummelincki Marcus and Marcus, 1968. (A) Photograph of live specimen; (B,C) CBUMAG:PLA:00426. (B) Detail of the eyespot organization from whole mount; (C) Detail of the cirrus, ventral view from whole mount; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00225). b: brain; ce: cerebral eyespots; ci: cirrus; cs: cirrus spines; fp: female pore; lv: Lang’s vesicle; mp: male pore; ov: oviduct; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; v: vagina.
Genus Notoplana Laidlaw, 1903
Notoplana queruca Marcus and Marcus, 1968
Material examined: INVPLA0011, mature specimen in sagittal sections.
Distribution: Curaçao, St. Martin, Florida Keys (US) [
25], and Colombia [
11].
Remarks: We confirm the identification by Quiroga et al. [
11] after examining their sectioned specimen and additional photographs provided by the authors. From the sections, it is possible to distinguish the “carrot-shaped” seminal vesicle interpolated with the prostatic vesicle with a proximal conical projection of the ejaculatory duct (
Figure 12B), as well as the long-folded male antrum. In addition, the vagina runs almost horizontally, as mentioned in the species description [
25]. This species was not encountered during our sampling; however, we provide a photograph of the live specimen and sagittal sections of reproductive structures from Quiroga et al. [
11] material.
Figure 12.
Notoplana queruca Marcus and Marcus, 1968. (A) Photograph of live specimen, taken by Quiroga and Bolaños in 2002; (B,C) sagittal sections of reproductive structures. e: eyespots; ph: pharynx; ov: oviduct; pv: prostatic vesicle; sv: seminal vesicle; u: uterus; v: vagina; vd: vas deferens.
Figure 12.
Notoplana queruca Marcus and Marcus, 1968. (A) Photograph of live specimen, taken by Quiroga and Bolaños in 2002; (B,C) sagittal sections of reproductive structures. e: eyespots; ph: pharynx; ov: oviduct; pv: prostatic vesicle; sv: seminal vesicle; u: uterus; v: vagina; vd: vas deferens.
Notoplana insularis Hyman, 1939
Material examined: USNM 20423, anterior mount and sagittal sections of the holotype, 9 mm × 3 mm [
27]. USNM 24633–24635, whole mounts.
Distribution: Providencia Island, Colombia [
27], Florida (US), St. Thomas (VI), Puerto Rico, and Trinidad [
29].
Remarks:
Notoplana insularis was originally described by Hyman [
27] from a specimen collected on Providencia Island (=Old Providence). In a later study, Hyman [
29] reported the species from additional localities, suggesting that it may be a common species throughout the Caribbean and Antillean Arc. However, we did not encounter this species along the Santa Marta coast.
After reviewing the type material (USNM 20423,
Figure 13), we found that the histological sections are in poor condition, hindering a thorough evaluation. Further sampling from the type locality and other sites is required. Photographic documentation of the type material is provided (
Figure 13).
Figure 13.
Notoplana insularis Hyman, 1939. (A,B) Holotype USNM20423, (C) Paratype USNM24634. (A) Photograph of the anterior mount. (B) sagittal section of reproductive structures. (C) Whole mount. e: eyespots; ph: pharynx; pv: prostatic vesicle; st: stylet; sv: seminal vesicle.
Figure 13.
Notoplana insularis Hyman, 1939. (A,B) Holotype USNM20423, (C) Paratype USNM24634. (A) Photograph of the anterior mount. (B) sagittal section of reproductive structures. (C) Whole mount. e: eyespots; ph: pharynx; pv: prostatic vesicle; st: stylet; sv: seminal vesicle.
Notoplana cf. tipuca Marcus and Marcus, 1968
Material examined: CBUMAG:PLA:00215, mature specimen as sagittal sections of reproductive structures and anterior mount, 27 mm × 4 mm. CBUMAG:PLA:00408, mature specimen preserved in 70% EtOH, 17.6 mm × 4.9 mm. CBUMAG:PLA:00409, mature specimen as sagittal sections and preserved in 70% EtOH, 21.5 mm × 3 mm. CBUMAG:PLA:00470, mature specimen as whole mount, 14.4 mm × 2.8 mm.
Distribution: Previously only known from the type locality, Piscadera Bay, Curaçao [
25]. We found our specimens in Bahía Concha and Neguanje Bay.
Remarks: Found mostly under coral rubble. Our specimens possess an interpolated prostatic vesicle, with the ejaculatory duct of the seminal vesicle entering proximally into the prostatic vesicle (
Figure 14D). The penis papilla is armed with a long slender stylet. The female gonopore is located far from the male pore; the vagina extends anteriorly from the pore and then coils posteriorly to end in a long Lang’s vesicle (
Figure 14E). Cerebral eyespots are arranged in two groups (
Figure 14B), and a band of marginal eyes encircles the body. These characters resemble those of
Notoplana tipuca. However, in our specimens, the distance between the gonopores is significantly greater, ranging from 0.7 to 2 mm in fixed specimens, compared to the 0.4 mm measured by Marcus and Marcus [
25] from their mounted specimen. Although these measurements are relative to specimen size, the representation of the reproductive organs indicates comparatively shorter distances than those observed in our sagittal sections (
Figure 14D,E). This discrepancy may be attributed either to fixation artifacts in the original material examined by Marcus and Marcus [
25] or to natural variation within the population from Curaçao. Additionally, due to the lack of photographs of the type material and absence of DNA sequences, the identity remains uncertain and requires further confirmation.
Marcus & Marcus [
25] originally established the genus
Igluta Marcus and Marcus, 1968 (with
I.
tipuca as its only species) within the family Cryptocelidae. The only other cryptocelid genus exhibiting a penis with armature and Lang’s vesicle is
Amemiyaia Kato, 1944; however, contrary to
Igluta, this genus has a tripartite seminal vesicle, has a coiled ejaculatory duct within the prostatic vesicle, and a vagina bulbosa [
25,
57]. Faubel [
14] later synonymized
Igluta with
Notoplana based on the organization of the male apparatus, while Prudhoe [
16] retained
Igluta as valid, the same status is given in the Turbellarian taxonomic database [
1]. Given that our molecular data show higher similarity to cryptocelid sequences than to notoplanid ones (e.g.,
Phaenocelis peleca MH700345 = 97.5% and
Amemiyaia pacifica LC508143 = 97% vs.
Notoplana sp. MH700334 = 92.6%), the reinstatement of
Igluta may be necessary once additional material from the type locality becomes available. We provide 28S rDNA and COI mtDNA sequences for this morphospecies (
Table 1).
Figure 14.
Notoplana cf. tipuca Marcus and Marcus, 1968. (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00470); (C) Detail of the posterior portion of the body, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00409). b: brain; ce: cerebral eyespots; fp: female pore; lv: Lang’s vesicle; mp: male pore; ph: pharynx; pv: prostatic vesicle; spb: spermiducal bulbs; st: stylet; ten: tentacular eyespots; v: vagina.
Figure 14.
Notoplana cf. tipuca Marcus and Marcus, 1968. (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00470); (C) Detail of the posterior portion of the body, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00409). b: brain; ce: cerebral eyespots; fp: female pore; lv: Lang’s vesicle; mp: male pore; ph: pharynx; pv: prostatic vesicle; spb: spermiducal bulbs; st: stylet; ten: tentacular eyespots; v: vagina.
Family Notocomplanidae Litvaitis, Bolaños and Quiroga, 2019
Genus Notocomplana Faubel, 1983
Notocomplana ferruginea (Schmarda, 1859)
Synonyms:
Discocelis binoculata Verrill, 1901
Leptoplana ferruginea (Schmarda, 1859)
Melloplana ferruginea (Schmarda, 1859)
Notoplana bahamensis Bock, 1913
Notoplana binoculata (Verrill, 1901)
Notoplana caribbeana Hyman, 1939
Notoplana ferruginea Schmarda, 1859
Polycelis ferruginea Schmarda, 1859
Figure 15.
Notocomplana ferruginea (Schmarda, 1859). (A) Photograph of live specimen. (B,D,E) CBUMAG:PLA:00211. (B) Detail of the eyespot organization from whole mount; (C) Detail of the posterior end, ventral view; (D,E) sagittal sections of reproductive structures. am: male atrium; ce: cerebral eyespots; fp: female pore; lv: Lang’s vesicle; m: mouth; mp: male pore; ov: oviduct; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; v: vagina; vd: vas deferens.
Figure 15.
Notocomplana ferruginea (Schmarda, 1859). (A) Photograph of live specimen. (B,D,E) CBUMAG:PLA:00211. (B) Detail of the eyespot organization from whole mount; (C) Detail of the posterior end, ventral view; (D,E) sagittal sections of reproductive structures. am: male atrium; ce: cerebral eyespots; fp: female pore; lv: Lang’s vesicle; m: mouth; mp: male pore; ov: oviduct; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; v: vagina; vd: vas deferens.
Material examined: CBUMAG:PLA:00211, mature specimen as sagittal sections and as a whole mount, only anterior part, 27.2 mm × 9.9 mm; CBUMAG:PLA:00212, mature specimen in 70% EtOH, 30.2 mm × 12 mm; CBUMAG:PLA:00214, mature specimen in 70% EtOH, 37.7 mm × 12 mm; CBUMAG:PLA:00240, mature specimen in 70% EtOH, 50.8 mm × 13 mm; CBUMAG:PLA:00241, mature specimen in 70% EtOH, 32.1 mm × 15.2 mm.
Distribution: Jamaica [
54], Curaçao, Bonaire, Bahamas, Puerto Rico, Providencia Island, Colombia [
25,
29], the Gulf of Mexico [
9] and the Colombian Caribbean coast [
11].
Remarks: This was one of the most common polyclads encountered during our sampling and it is likely distributed throughout the entire Tropical Western Atlantic. While the body coloration is reported as milky white [
25,
27], our specimens have a clear brown tinge, especially towards the anterior margin and center of the body (
Figure 15A). Additionally, after inspecting all live specimens, it was possible to distinguish a faint marginal reddish line along the anterior margin. One of the specimens exhibited markedly enlarged tentacular eyes compared to others, a variation that was once used to distinguish a separate species,
Notoplana binoculata (Verrill, 1901). However, this taxon was later synonymized with
N. ferruginea [
29], and our examination of the reproductive structures supports this synonymy. We provide additional 28S rDNA sequences similar between each other (97.4–99%) and that show high similarity with previously available sequences (e.g., PX093753 vs. MH700322 = 97.2% and PX093754 vs. MH700323 = 99.3%), and the first COI mtDNA sequences for the species (
Table 1).
Notocomplana martae (Marcus, 1948)
Synonyms:
Notoplana martae Marcus, 1948
Figure 16.
Notocomplana martae (Marcus, 1948). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount; (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures. am: male atrium; b: brain; ce: cerebral eyespots; gp: gonopores; i: intestine; p: penis; ph: pharynx; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; u: uterus; v: vagina; vb: vagina bulbosa.
Figure 16.
Notocomplana martae (Marcus, 1948). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount; (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures. am: male atrium; b: brain; ce: cerebral eyespots; gp: gonopores; i: intestine; p: penis; ph: pharynx; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; u: uterus; v: vagina; vb: vagina bulbosa.
Material examined: CBUMAG:PLA:00252, one mature specimen as sagittal sections and whole mount only of the anterior portion of the body, 5.2 mm × 0.7 mm.
Distribution: Described from Ilha de São Sebastião and Ilha de Palmas, São Paulo state in southeastern Brazil [
32,
58]. This study presents the first record of this species for Colombia and the Caribbean Sea.
Remarks: A single specimen was collected from
Sargassum in the intertidal zone of Taganga Bay. Histological sections of the reproductive structures are consistent with the original description of
N. martae by Marcus [
58] (
Figure 16D,E), and the organization of the cerebral eyespots (
Figure 16B) matches that observed in the type specimen photographs published by Bahia and Schrödl [
32]. Our specimen differs only by having an additional brown coloration in contrast to the white coloration mentioned by Marcus [
58] (
Figure 16A); however, this difference may result from feeding on other organisms inhabiting the
Sargassum mats. Marcus [
58] also reported this species from algae in the upper littoral zone. Here we provide the first photographs of a live specimen (
Figure 16), as well as the first 28S rDNA and COI mtDNA sequences (
Table 1).
Notocomplana sp.
Material examined: CBUMAG:PLA:00136, mature specimen as sagittal sections and preserved in 70% EtOH, 33.6 mm × 14.4 mm; CBUMAG:PLA:00406, mature specimen as sagittal sections and preserved in 70% EtOH, 26.9 mm × 8.3 mm; CBUMAG:PLA:00453, mature specimen as sagittal sections and anterior mount, 25.7 mm × 6.4 mm.
Distribution: Found in Bahía Concha and Neguanje bay.
Remarks: This morphospecies was less common than
N. ferruginea during our sampling. Internally, this species is characterized by the presence of a bigger conical penis papilla and a small oval Lang’s vesicle (
Figure 17D,E). Additional characters include gonopores far from each other, interpolated prostatic vesicle with a projection of the ejaculatory duct, and a seminal vesicle relatively of similar size and ventral to the prostatic vesicle (
Figure 17D). The vagina shows various folds, runs anteriorly and then turns towards the posterior (
Figure 17E).
Our specimens are externally similar in size and coloration to
N. ferruginea and could easily be mistaken for that species. However, they lack the marginal reddish line that characterizes
N. ferruginea. Internally, there are some differences from other
Notocomplana species present in the West Atlantic, including the presence of a small and oval Lang’s vesicle, which is bigger and longer in
N. ferruginea (
Figure 15E) and
Notocomplana lapunda Marcus and Marcus, 1968 [
25], and absent in
N. martae (
Figure 16E).
Notocomplana evelinae Marcus, 1947 has a similar Lang’s vesicle but a smaller prostatic vesicle [
21]. Nevertheless, due to the lack of available sequences for our specimens, we could not determine whether this morphospecies represents a different species from those previously reported for the region, and therefore we have identified it only to the genus level. This morphospecies could represent an undescribed species, but we prefer to be conservative until molecular data are available.
Family Stylochoplanidae Faubel, 1983
Genus Armatoplana Faubel, 1983
Armatoplana divae (Marcus, 1947)
Synonyms:
Stylochoplana divae Marcus, 1947
Figure 18.
Armatoplana divae (Marcus, 1947). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00264); (C) Detail of the posterior portion of the body, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00110). ce: cerebral eyespots; ed: ejaculatory duct; fp: female pore; gp: gonopores; i: intestine; lv: Lang’s vesicle; mp: male pore; ph: pharynx; pv: prostatic vesicle; st: stylet; sp: sperm; te: tentacle; ten: tentacular eyespots; u: uterus; v: vagina; vd: vas deferens.
Figure 18.
Armatoplana divae (Marcus, 1947). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00264); (C) Detail of the posterior portion of the body, ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00110). ce: cerebral eyespots; ed: ejaculatory duct; fp: female pore; gp: gonopores; i: intestine; lv: Lang’s vesicle; mp: male pore; ph: pharynx; pv: prostatic vesicle; st: stylet; sp: sperm; te: tentacle; ten: tentacular eyespots; u: uterus; v: vagina; vd: vas deferens.
Material examined: CBUMAG:PLA:00110, one mature specimen as sagittal sections and preserved in 70% EtOH, 18 mm × 6 mm; CBUMAG:PLA:00255, one mature specimen preserved in 70% EtOH, 7.2 mm × 3 mm; CBUMAG:PLA:00263, one mature specimen preserved in 70% EtOH, 20 mm × 8 mm; CBUMAG:PLA:00264, one mature specimen as a whole mount, 15.5 mm × 6 mm; CBUMAG:PLA:00537, one mature specimen in 70% EtOH, 14.1 mm × 4.6 mm.
Distribution: Originally recorded from São Paulo and Rio de Janeiro, Brazil [
21,
32]. Also reported from Colombia [
11].
Remarks: All morphological characteristics observed in our specimens match the original description by Marcus [
21], such as the presence of nuchal tentacles and the dorsal color pattern, which may be darker depending on the gut content. We provide additional 28S rDNA that shows similarity between each other (97.4%) and to previously available sequences (
Armatoplana divae MH700274 = 97.56%;
Armatoplana divae MH700273 = 97.66%), and the first COI mtDNA sequences for the species (
Table 1).
Armatoplana colombiana Bolaños, Quiroga and Litvaitis, 2006
Material examined: CBUMAG:PLA:00095, one mature specimen in 70% EtOH, 12 mm × 4.6 mm; CBUMAG:PLA:00427, one mature specimen in 70% EtOH, 6.8 mm × 3 mm; CBUMAG:PLA:00491, one mature specimen as a whole mount, 3 mm × 1 mm (from fixed specimen); CBUMAG:PLA:00492, one mature specimen as a whole mount, 4 mm × 2 mm (from fixed specimen); CBUMAG:PLA:00493, one mature specimen in 70% EtOH, 5.95 mm × 2.36 mm; CBUMAG:PLA:00525, one mature specimen in 70% EtOH, 5 mm × 2.4 mm; CBUMAG:PLA:00531, one mature specimen as whole mount and one as sagittal sections, 5 mm × 3 mm and 5 mm × 2 mm (from fixed material).
Distribution: Previously known only from the type locality, Inca Inca Bay, Colombia [
11,
12]. In this study, we report additional specimens from Taganga Bay.
Remarks: Specimens were found forming aggregations beneath smooth rocks and appear to be common in the type locality. Examination of our whole mounts and histological slides, together with the original description, show the diagnostic curved prostatic vesicle, the extremely long and curved stylet, and the small marginal knobs (
Figure 19). However, while the original description of
A. colombiana illustrates an oval Lang’s vesicle [
12], our whole mounts reveal a crescent-shaped vesicle (
Figure 19C); this difference may be a result of the difficulty of reconstructing the reproductive structures from the histological slides of such small specimens and the lack of whole mount preparations in the original description [
12]. Additionally, the prostatic vesicle has a more pronounced curvature than shown by Bolaños et al. [
12] (
Figure 19D). We provide the first 28S rDNA and COI mtDNA sequences for the species (
Table 1).
Armatoplana leptalea (Marcus, 1947)
Synonyms:
Stylochoplana leptalea Marcus, 1947
Figure 20.
Armatoplana leptalea (Marcus, 1947). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00156); (C) Detail of the ventral view; (D) (CBUMAG:PLA:00120) and (E) (CBUMAG:PLA:00156) sagittal sections of reproductive structures. am: male atrium; ce: cerebral eyespots; ed: ejaculatory duct; fp: female pore; gp: gonopores; lv: Lang’s vesicle; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; sv: seminal vesicle; st: stylet; ten: tentacular eyespots; v: vagina; vb: vagina bulbosa; vd: vas deferens.
Figure 20.
Armatoplana leptalea (Marcus, 1947). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00156); (C) Detail of the ventral view; (D) (CBUMAG:PLA:00120) and (E) (CBUMAG:PLA:00156) sagittal sections of reproductive structures. am: male atrium; ce: cerebral eyespots; ed: ejaculatory duct; fp: female pore; gp: gonopores; lv: Lang’s vesicle; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; sv: seminal vesicle; st: stylet; ten: tentacular eyespots; v: vagina; vb: vagina bulbosa; vd: vas deferens.
Material examined: CBUMAG:PLA:00119, one mature specimen as sagittal sections and preserved in 70% EtOH, 13.8 mm × 4.4 mm; CBUMAG:PLA:00120, one mature specimen as sagittal sections of reproductive structures and preserved in 70% EtOH, 20.2 mm × 6 mm; CBUMAG:PLA:00156, one mature specimen as sagittal sections and as an anterior mount, 17.2 mm × 4.1 mm; CBUMAG:PLA:00175, one mature specimen as sagittal sections and preserved in 70% EtOH, 33 mm × 8 mm. CBUMAG:PLA:00407, one mature specimen as a whole mount, 17.7 mm × 4 mm.
Distribution: Antigua, Curaçao, Florida Keys [
25], southeastern and northeastern Brazil [
21,
25,
32,
40]. This study provides the first formal record for Colombia.
Remarks: Our specimens resemble externally and internally both the type material and additional Brazilian specimens pictured in Bahia and Schördl [
32]. The phylogenetic analysis by Litvaitis et al. [
53] showed that the DNA sequences of
A. leptaleta from Brazil and the Caribbean show two distinct clades. Our sequences exhibit high similarity to the Caribbean clade (MH700275 = 99.1%; MH700276 = 99.4%). Based on the morphological agreement with the original description, we classified our specimens as
A. leptalea sensu stricto, while acknowledging the need for further taxonomic investigation to determine whether this taxon represents a species complex.
Genus Interplana Faubel, 1983
Interplana evelinae (Marcus, 1952)
Synonyms:
Stylochoplana evelinae Marcus, 1952
Figure 21.
Interplana evelinae (Marcus, 1952). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount; (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures. ce: cerebral eyespots; cu: cuticular protrusion; gp: gonopores; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; st: stylet; te: tentacle; ten: tentacular eyespots; u: uterus; v: vagina; vb: vagina bulbosa; vd: vas deferens.
Figure 21.
Interplana evelinae (Marcus, 1952). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount; (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures. ce: cerebral eyespots; cu: cuticular protrusion; gp: gonopores; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; st: stylet; te: tentacle; ten: tentacular eyespots; u: uterus; v: vagina; vb: vagina bulbosa; vd: vas deferens.
Material examined: CBUMAG:PLA:00111, mature specimen as sagittal sections of the reproductive structures and anterior mount, 15.9 mm × 8.6 mm.
Distribution: Described from southeastern Brazil [
24,
32]. This study provides the first record for Colombia and the Caribbean Sea.
Remarks: We collected only a single specimen in our sampling, found alongside individuals of
Phaenocelis peleca, a species with which it may be easily confused due to its similar white coloration with brown spots over the pharynx region (
Figure 21A). Marcus [
24] also reported finding two light pink worms. Nonetheless,
I. evelinae can be distinguished externally by the presence of small, pointed tentacles and internally by a markedly different organization of the reproductive structures, including a complex stylet and a cuticular protrusion in the vagina bulbosa [
24] (
Figure 21A–E). The observation of the reproductive structures from our sagittal sections (
Figure 21D,E) agrees with the description of Marcus [
24]; however, they differ in that the cuticular nature of the vagina bulbosa does not have such a big protrusion as was pictured in the species description [
24]. We provide the first photographs of a living specimen, as well as detailed images of its reproductive anatomy. This contribution is particularly relevant given that
I. evelinae is the type species of the genus
Interplana.
Genus Phaenoplana Faubel, 1983
Phaenoplana longipenis (Hyman, 1953)
Synonyms:
Stylochoplana longipenis Hyman, 1953
Figure 22.
Phaenoplana longipenis (Hyman, 1953). (A,B) Holotype USNM 365. (A) Photograph of anterior mount; (B) Detail of the eyespot organization from anterior mount; (C) sagittal section of reproductive structures (INVPLA007). ce: cerebral eyespots; lv: Lang’s vesicle; mp: male pore; p: penis; sv: seminal vesicle; ten: tentacular eyespots; v: vagina.
Figure 22.
Phaenoplana longipenis (Hyman, 1953). (A,B) Holotype USNM 365. (A) Photograph of anterior mount; (B) Detail of the eyespot organization from anterior mount; (C) sagittal section of reproductive structures (INVPLA007). ce: cerebral eyespots; lv: Lang’s vesicle; mp: male pore; p: penis; sv: seminal vesicle; ten: tentacular eyespots; v: vagina.
Material examined: INVPLA007, mature specimen as sagittal sections of reproductive structures; USNM 365.1–365.3, holotype as sagittal sections of reproductive structures and anterior mount.
Distribution: Guaymas, Sonora, Mexico; San Pedro, Santa Catalina Island, and Newport Bay, California [
59]. Also reported for the Caribbean Coast of Colombia [
11].
Remarks: Although we did not encounter this species during our sampling, examination of the specimen reported by Quiroga et al. [
11] (INVPLA007) corroborated its identity as
P. longipenis. Originally described from the Pacific coast of North America, its occurrence in the Colombian Caribbean may be incidental, potentially linked to maritime traffic, given the proximity of Santa Marta to major shipping routes. No additional records have been published for either the Pacific or the Caribbean. Nonetheless, given the confirmed identity of the Colombian specimen, it is prudent not to dismiss the possibility of
P. longipenis occurring in other parts of the Caribbean. Further molecular and morphological studies are recommended to clarify its true distribution and to determine whether it represents an amphiamerican species.
Superfamily Discoceloidea Dittman, Cuadrado, Aguado, Noreña and Egger, 2019
Family Cryptocelidae Laidlaw, 1903
Genus Phaenocelis Stummer-Traunfels, 1933
Phaenocelis medvedica Marcus, 1952
Material examined: CBUMAG:PLA:00162, one mature specimen as sagittal sections and preserved in 70% EtOH, 21.6 mm × 4.8 mm; CBUMAG:PLA:00169, one mature specimen as sagittal sections and preserved in 70% EtOH, 23 mm × 3.8 mm; CBUMAG:PLA:00261, one mature specimen as a whole mount, 27 mm × 5.4 mm.
Distribution: Described from southeastern Brazil [
24]. It has been recorded in Rio de Janeiro and northeastern Brazil [
32,
40], on the Caribbean Coast of Colombia [
11], and recently in the Gulf of Mexico [
9].
Remarks: The specimens examined display the pink coloration described by Marcus [
24]; however, we also observed individuals with a more pale coloration, suggesting that the characteristic pink color may result from ingested food. The internal morphology matches that reported in the original description [
24].
P. medvedica was the most frequently encountered species in our sampling and is likely among the most common polyclads in the Caribbean Sea [
7]. We provide a new 28S rDNA sequence that shows high similarity to previously available ones (e.g., KY263706 = 99.69%), and the first COI mtDNA sequences for the species (
Table 1).
Phaenocelis peleca Marcus and Marcus, 1968
Synonyms:
Phaenocelis pelica Marcus and Marcus, 1968
Phaenoplana peleca (Marcus and Marcus, 1968)
Material examined: CBUMAG:PLA:00142, mature specimen as a whole mount, 9 mm × 6 mm; CBUMAG:PLA:00185, mature specimen as sagittal sections of the reproductive structures and preserved in 70% EtOH, 15.3 mm × 7 mm; CBUMAG:PLA:216, mature specimen as sagittal sections of the reproductive structures and preserved in 70% EtOH, 9.7 mm × 4.9 mm; CBUMAG:PLA:00511, mature specimen as a whole mount, 9.6 mm × 5.5. mm. INVPLA0012; INVPLA0013, mature specimen as sagittal sections of the reproductive structures.
Distribution: Described from Curaçao [
25] and recorded recently from the Gulf of Mexico [
9]. This study provides the first formal record for Colombia.
Remarks: This study constitutes the first formal record of
Phaenocelis peleca as a nominal species for Colombia. Quiroga et al. [
11] had previously reported a specimen as
Notocomplana sp. (INVPLA0012; INVPLA0013), which, upon reexamination, corresponds to
P. peleca. Our sampled specimens match the description of the external appearance and of the reproductive structures provided by Marcus and Marcus [
25]. As mentioned by Cuadrado et al. [
9], our specimens are smaller than those from the Gulf of Mexico; however, this size difference does not appear to correlate with maturity. We recorded this species exclusively in Bahía Concha and Neguanje Bay, both within the Tayrona National Natural Park, where the substrate is predominantly composed of coral rubble. Most specimens were found aggregated under rocks and rubble. Notably, a specimen of
I. evelinae was found within one of these aggregations. Our 28S sequences show relatively low similarity to previously available ones (PX093765 vs. MH700345 = 94.8%; PX093764 vs. MH700343 = 97.2%). We provide 28S rDNA sequences from our specimens and the first COI mtDNA sequence for the species (
Table 1).
Figure 24.
Phaenocelis peleca Marcus and Marcus, 1968. (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00142); (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00185). am: male atrium; b: brain; ce: cerebral eyespots; fp: female pore; gp: gonopores; lv: Lang’s vesicle; m: mouth; mp: male pore; ov: oviduct; ph: pharynx; pp: penis papillae; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; u: uterus; v: vagina; vs: vas deferens.
Figure 24.
Phaenocelis peleca Marcus and Marcus, 1968. (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00142); (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00185). am: male atrium; b: brain; ce: cerebral eyespots; fp: female pore; gp: gonopores; lv: Lang’s vesicle; m: mouth; mp: male pore; ov: oviduct; ph: pharynx; pp: penis papillae; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; u: uterus; v: vagina; vs: vas deferens.
Phaenocelis cf. purpurea (Schmarda, 1859)
Synonyms:
Comprostatum veneris Hyman, 1944
Comprostatum insularis Hyman, 1944
Leptoplana purpurea Schmarda, 1859
Phaenocelis insularis (Hyman, 1944)
Material examined: CBUMAG:PLA:00181, mature specimen as anterior mount, 17.3 mm × 6 mm; CBUMAG:PLA:00182, mature specimen as sagittal sections of the reproductive structures and preserved in 70% EtOH, 22.1 mm × 6.5 mm; CBUMAG:PLA:516, mature specimen as sagittal sections of the reproductive structures and anterior mount, 14.6 mm × 3.3 mm; CBUMAG:PLA:00540, mature specimen preserved in 70% EtOH, 41.2 mm × 5.5 mm.
Distribution: Jamaica [
54], Florida [
60] and Curaçao [
25]. The specimens were found exclusively in Neguanje Bay.
Remarks: The genus
Phaenocelis currently comprises only three recognized species [
31]. This morphospecies resembles
P. medvedica and
P. purpurea (Schmarda, 1859) in external appearance; however, it may be distinguished from
P. medvedica by its darker coloration, less noticeable cerebral eyes and smaller pharynx (
Figure 25A,B). Internally, it differs from
Phaenocelis medvedica and
P. peleca by having a short ejaculatory duct and relatively long and slender male atrium that accommodates a slightly curved rod-like penis, a less conspicuous prostatic vesicle than
P. medvedica, and a simpler vagina leading to a globular Lang’s vesicle (
Figure 25D,E). However, our sequences do not match those publicly available for the species (MH700348 = 97.5%, MH700347 = 97.8%), showing higher similarity to an unidentified
Phaenocelis (MH700355 = 98.1%, MH700356 = 99.5%), which were not accompanied by a detailed morphological description. We regard that the species identity needs further confirmation until additional material from the type locality and additional locations where it was recorded is available. We provide 28S rDNA and COI mtDNA sequences from our specimens (
Table 1).
Figure 25.
Phaenocelis cf. purpurea (Schmarda, 1859). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:516); (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00182). am: male atrium; b: brain; ce: cerebral eyespots; ed: ejaculatory duct; gp: gonopores; lv: Lang’s vesicle; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; v: vagina; vd: vas deferens.
Figure 25.
Phaenocelis cf. purpurea (Schmarda, 1859). (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:516); (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00182). am: male atrium; b: brain; ce: cerebral eyespots; ed: ejaculatory duct; gp: gonopores; lv: Lang’s vesicle; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; sv: seminal vesicle; ten: tentacular eyespots; v: vagina; vd: vas deferens.
Genus Triadomma Marcus, 1947
Triadomma curvum Marcus, 1949
Material examined: CBUMAG:PLA:00386, mature specimen as anterior mount, 6.7 mm × 1.5 mm; CBUMAG:PLA:00489, mature specimen as sagittal sections, 5.7 mm × 1.3 mm; CBUMAG:PLA:00533, mature specimen as a whole mount, 6.9 mm × 2.4 mm. Measurements refer to live specimens.
Distribution: Originally described from Ilha de São Sebastião, Saõ Paulo [
22]. This study provides the first record for Colombia and the Caribbean Sea.
Remarks: Our specimens display two groups of cerebral and tentacular eyespots that extend anteriorly towards the margin (
Figure 26B), a long curved stylet and a true seminal vesicle in the male apparatus (
Figure 26D,E), consistent with the species description [
22]. Marcus [
21] established the genus
Triadomma within Cryptocelidae Laidlaw, 1903, based on the presence of minute anterior marginal eyespots, also observed in our specimens (
Figure 27B). Later, Faubel [
14] transferred both species described by Marcus [
21,
22] to Notoplanidae due to the presence of an interpolated prostatic vesicle with tubular interior lining, a feature also observed in our specimens (
Figure 27D). Prudhoe [
16], however, retained the original family assignment proposed by Marcus [
21]. The genus was subsequently and erroneously moved to Faubelidae [
32,
55] (see the comment under
A. hummelincki). Given that our molecular data show relatively low similarity with other sequences of acotyleans (e.g.,
Gnesioceros sargassicola MH700309 = 94.7%;
Comoplana agilis MN384685 = 94.5%), including those of Notoplanidae and Cryptocelidae (e.g.,
Notoplana sp. MH700334 = 94.4% vs.
Phaenocelis sp. MH700350 = 92.5%), we continue to follow the placement of Marcus [
22] and Prudhoe [
16], retaining
Triadomma in Cryptocelidae until additional material from the type locality and from the type species becomes available to better assess its systematic position within Acotylea. This study provides, for the first time, live photographs as well as 28S rDNA and COI mtDNA sequences for the species (
Table 1).
Figure 26.
Triadomma curvum Marcus, 1949. (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00386); (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00489). am: male atrium; ce: cerebral eyespots; fp: female pore; gp: gonopores; me: marginal eyespots; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; st: stylet; sv: seminal vesicle; ten: tentacular eyespots; u: uterus; vb: vagina bulbosa; vd: vas deferens.
Figure 26.
Triadomma curvum Marcus, 1949. (A) Photograph of live specimen; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:00386); (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00489). am: male atrium; ce: cerebral eyespots; fp: female pore; gp: gonopores; me: marginal eyespots; mp: male pore; ov: oviduct; ph: pharynx; pv: prostatic vesicle; st: stylet; sv: seminal vesicle; ten: tentacular eyespots; u: uterus; vb: vagina bulbosa; vd: vas deferens.
Family Discocelidae Laidlaw, 1903
Genus Adenoplana Stummer-Traunfels, 1933
Adenoplana evelinae Marcus, 1950
Material examined: CBUMAG:PLA:158, mature specimen as a whole mount, 26.5 mm × 9.2 mm; CBUMAG:PLA:00535, mature specimens as sagittal sections of the reproductive structures and whole mount, 28.4 mm × 12.2 mm.
Distribution: Southeastern and northeastern Brazil [
23,
32,
40]. This study provides the first record for Colombia and the Caribbean Sea.
Figure 27.
Adenoplana evelinae Marcus, 1950. (A) Photograph of live specimens; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:158); (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00535). am: male atrium; ce: cerebral eyespots; ed: ejaculatory duct; fp: female pore; lv: Lang’s vesicle; m: mouth; mp: male pore; ph: pharynx; po: prostatoid organ; ten: tentacular eyespots; u: uterus; v: vagina.
Figure 27.
Adenoplana evelinae Marcus, 1950. (A) Photograph of live specimens; (B) Detail of the eyespot organization from whole mount (CBUMAG:PLA:158); (C) Detail of the ventral view; (D,E) sagittal sections of reproductive structures (CBUMAG:PLA:00535). am: male atrium; ce: cerebral eyespots; ed: ejaculatory duct; fp: female pore; lv: Lang’s vesicle; m: mouth; mp: male pore; ph: pharynx; po: prostatoid organ; ten: tentacular eyespots; u: uterus; v: vagina.
Remarks: We provide photographs of both juveniles and adult specimens (
Figure 27A). In both stages, the marginal eyespots form a complete band encircling the body margin. Our observations and molecular data suggest that
A. evelinae may have a transparent body during early stages, which becomes opaque as the animals grow and feed, rather than representing two distinct color morphs, as previously suggested by Bahia and Schrödl [
32]. The reproductive anatomy is typical of
Adenoplana (
Figure 27D,E), with
A. evelinae distinguished primarily by the presence of a continuous band of marginal eyespots [
23]. We provide 28S rDNA sequences (
Adenoplana evelinae MH700268 = 99.7%; KY263647 = 100%) and the first COI mtDNA sequence for the species (
Table 1).
Adenoplana obovata (Schmarda, 1859)
Synonyms:
Leptoplana obovata (Schmarda, 1859)
Polycelis obovata (Schmarda, 1859)
Material examined: INVPLA001; INVPLA002. Preserved specimen and sagittal sections.
Distribution: Described from Jamaica [
54]. It was also recorded from the Colombian Caribbean coast [
11].
Remarks: We did not encounter this species in our sampling. However, the available material from Quiroga et al. [
11] and additional photographs shows the diagnostic marginal eyespots extending only up to the level of the pharynx. The reproductive anatomy is typical of the genus
Adenoplana (
Figure 28B,C).
Figure 28.
Adenoplana obovata (Schmarda, 1859). (A) Photograph of live specimen, taken by Quiroga and Bolaños in 2002; (B) Detail of the ventral view; (C) sagittal section of reproductive structures. am: male atrium; fp: female pore; m: mouth; me: marginal eyespots; mp: male pore; ph: pharynx; po: prostatoid organ; ten: tentacular eyespots; vd: vas deferens.
Figure 28.
Adenoplana obovata (Schmarda, 1859). (A) Photograph of live specimen, taken by Quiroga and Bolaños in 2002; (B) Detail of the ventral view; (C) sagittal section of reproductive structures. am: male atrium; fp: female pore; m: mouth; me: marginal eyespots; mp: male pore; ph: pharynx; po: prostatoid organ; ten: tentacular eyespots; vd: vas deferens.
Family Ilyplanidae Faubel, 1983
Genus Ilyella Faubel, 1983
Ilyella yrsa (Marcus and Marcus, 1968)
Synonyms:
Zygantroplana yrsa Marcus and Marcus, 1968
Material examined: CBUMAG:PLA:00157, mature specimen as a whole mount, 9.7 mm × 2.1 mm; CBUMAG:PLA:00237, mature specimen as an anterior mount, 8.26 mm × 3 mm; CBUMAG:PLA:00247, mature specimen as a whole mount, 6 mm × 3 mm; CBUMAG:PLA:00642, a mature specimen as sagittal sections, 4 mm × 3 mm; CBUMAG:PLA:00643, a mature specimen as sagittal sections, 5 mm × 4 mm.
Distribution: Aruba, Curaçao, Bonaire; Los Frailes, Isla Coche and Isla de Aves (VE); Antigua, Grenada and Barbuda [
25]. This study provides the first record for Colombia.
Remarks: We found this species on the algae
Dictyota, on the hydrozoan
Pennaria disticha Goldfuss, 1820, and under rocks. In all specimens, we observed the cerebral eyespots arranged in two distinct groups, a posterior notch, and paired uteri located posterior to the pharynx. The reproductive system is situated close to the posterior end, allowing to distinguish both the Lang’s vesicle and the duct of the vagina, which opens at the far posterior end (
Figure 29). Whole mounts of our specimens are consistent with the description and illustrations of the species and its reproductive anatomy provided by Marcus and Marcus [
25]. In the original description, the species was assigned to the genus
Zygantroplana Laidlaw, 1906, and later transferred to
Ilyella by Faubel [
14]; however, our sequences show a higher similarity to leptoplanids (e.g.,
A. hummelincki MH70027 = 96.6% and
N. ferruginea MT677877 = 96.4%) than to
Ilyella gigas (Scharmda, 1859) (LC508139 = 92%), the type species of the genus. No sequences of the two species of
Zygantroplana are available. This discrepancy highlights the need for a revision of the systematics of the family and its members [
61]. We provide the first live photographs and detailed images of the reproductive structures, as well as the first 28S rDNA and COI mtDNA sequences for this species (
Table 1).
Figure 29.
Ilyella yrsa (Marcus and Marcus, 1968). (A) Photograph of live specimen; (B,C) CBUMAG:PLA:00247. (B) Detail of the eyespot organization from whole mount; (C) Detail of the posterior portion of the body, ventral view; (D) (CBUMAG:PLA:00642) and (E) (CBUMAG:PLA:00643) sagittal sections of reproductive structures. am: male atrium; b: brain; ce: cerebral eyespots; lv: Lang’s vesicle; ov: oviduct; u: uterus; v: vagina; vd: vas deferens.
Figure 29.
Ilyella yrsa (Marcus and Marcus, 1968). (A) Photograph of live specimen; (B,C) CBUMAG:PLA:00247. (B) Detail of the eyespot organization from whole mount; (C) Detail of the posterior portion of the body, ventral view; (D) (CBUMAG:PLA:00642) and (E) (CBUMAG:PLA:00643) sagittal sections of reproductive structures. am: male atrium; b: brain; ce: cerebral eyespots; lv: Lang’s vesicle; ov: oviduct; u: uterus; v: vagina; vd: vas deferens.