3.2. Doolia ara, sp. nov.
Type locality. Muddy sand substratum, station A5 (34°00′ N, 123°30′ E), off Jeju Island, the south west coast of Korea.
Material examined. Holotype 1♀ (NIBRIV0000862381) dissected on seven slides. Paratypes: three♀♀ and two♂♂; 2♀♀ (MABIK CR00246523 – 4) on five slides, 1♂ (MABIK CR00246525) on seven slides, 1♂ (NIBRIV0000862382) on six slides, and 1♀(NIBRIV0000862383) in 70% ethanol, all from the type locality, depth 66 m, collected by Y.H. Song and E.J. Nam during 24 September to 3 October 2002.
Etymology. The specific name refers to “Ara”, the research vessel of Jeju National University, in appreciation of the crew and Prof. Joon Baek Lee (Jeju National University). Gender, feminine.
. Total body length: 239 µm (measured from anterior margin of rostrum to posterior margin of caudal rami). Largest width measured at posterior margin of cephalic shield: 63 µm. Urosome gradually tapering posteriorly (Figure 2
Cephalothorax with serrulated posterior margin. Pleural areas rounded without lobate posterolateral angles. Entire surface covered with tiny denticles as illustrated [expressed as dots] in Figure 2
A,B. Sensilla and a few pores are present as illustrated in Figure 2
Rostrum triangular-shaped (Figure 2
A,C), broad at base, round anterior margin, clearly separated from cephalosome, and with a pair of sensilla and a row of long spinules along median anterior margin.
Pedigerous somites covered with minute denticles. Prosomites from P2-bearing to P4-bearing with well-developed, comb-shaped hyaline frills.
Urosome (Figure 2
A,B and Figure 3
B,D ) five-segmented, comprising P5-bearing somite, genital double-somite and three free abdominal somites. All urosomites covered with small denticles dorsally and ventrally and with well-developed hyaline frill along the hind margin. Genital double-somite (Figure 2
A,B and Figure 3
B) without distinct dorsal surface ridge but with a thick internal cuticle layer indicating original segmentation; completely fused internally and externally. Genital field located near anterior margin (Figure 3
B) with a large copulatory pore located in a median depression (Figure 3
B). P6 with a small protuberance bearing two bare setae, inner seta longer than outer seta, and with a small pore next to Inner seta. Anal somite (Figure 3
D) quadrate with well-developed operculum; opercular distal margin with a row of long spinules, and flanked by a pair of sensilla.
Caudal rami (Figure 3
B,D) long, cylindrical, three times longer than it is wide; each ramus with six setae: seta I bare, shortest; setae II bare and long; seta III absent, or presumably represented by one large pore on dorsal distal surface; setae IV and V separated basally; seta VI bare and small; seta VII tri-articulate at base. Each ramus with spinules on entire surface; additional spinular rows along distal margin.
Antennule (Figure 3
A) four-segmented. Segment 1 with a row of long spinules on anterior surface. Segment 2 the largest. Segment 3 with aesthetasc fused basally to one long plumose seta. Armature formula: 1-[1 pinnate], 2-[8 pinnate], 3-[6 pinnate + 2 bare + (1 pinnate + ae)], 4-[4 pinnate + 4 bare + trithek]. Apical trithek consisting of small aesthetasc fused basally to two setae (1 bare, and 1 pinnate).
Antenna (Figure 4
A) three-segmented, comprising coxa, allobasis, free one-segmented endopod and one-segmented exopod. Coxa small (not figured). Allobasis without distinct surface sutures marking original segmentation; with abexopodal pinnate seta on median inner margin and a row of setules along outer margin. Exopod small, about twice as longer as it is wide, with four well-developed pinnate setae and few spinules along outer margin. Endopod slightly shorter than allobasis, lateral armature arising in distal half, consisting of two strong pinnate spines; apical armature consisting of one strong pinnate spine, two pinnate, and two geniculate setae; with two rows of long spinules laterally; apical outer most spine basally fused to one tiny seta.
Mandible (Figure 4
B) with well-developed gnathobase bearing several multicuspidate teeth around distal margin and one slender spine at dorsal corner. Palp well-developed. Basis with one plumose seta. Endopod one-segmented, rectangular with one lateral plumose seta, four naked apical setae, and one row of spinules along apical margin. Exopod one-segmented, cylindrical with one naked apical seta.
Maxillule (Figure 4
D). Arthrite strongly developed, with two naked setae on anterior surface and eight spines/setae around distal margin and a row of spinules on posterior surface. Coxa with one short cylindrical endite bearing one long naked seta. Endopod and exopod incorporated into the basis, with three naked setae apically, and one plumose and four naked setae laterally.
Maxilla (Figure 4
C). Syncoxa with two endites and a row of long spinules along outer margin. Each coxal endite cylindrical; proximal endite with two pinnate spines; distal endite with one naked and two pinnate spines. Allobasis drawn out into strong, slightly curved claw; endopod represented by two naked setae on anterior surface.
Maxilliped (Figure 4
E) with one plumose seta and one row of spinules on syncoxa. Basis with one row of tiny spinules along palmar margin. Endopod one-segmented with long, curved, coarsely pinnate claw, and one naked slender seta.
Legs P1–P4 (Figure 5
A,B and Figure 6
A,B) with well-developed intercoxal plates and praecoxae bearing row of spinules along distal margin near borderline with each related coxa. Coxae and bases with surface ornamentations of spinules as figured. All legs P1–P4 with three-segmented exopods, and two-segmented endopods.
P1 (Figure 5
A). Coxa moderate, with long spinular rows as figured. Basis with one strong, bipinnate inner and one stout, unipinnate outer spines. Anterior surface covered with spinules as figured. Exopod longer than endopod; exp-1 and exp-2 with unipinnate spine, respectively; exp-3 longest with two unipinnate spines and two plumose setae. Enp-2 about three times longer than enp-1; enp-1 without spine or seta; enp-2 with row of long setules along outer and inner margins; two terminal plumose setae on enp-2 fused basally, inner one more than three times longer than the outer.
P2–P4 (Figure 5
B and Figure 6
A,B). Coxae and bases ornamented with spinular rows along outer or distal margins and anterior surface. Outer margin of basis producing a setophore armed with pinnate spine (P2) or naked seta (P3–P4) at each distal end. All segments with rows of spinules along inner and outer margins as figured. Endopod segments of P2–P3 with long setules or spinules alonge inner and outer margins. P4 endopod without setula ornamentations. P2 enp-2 three times longer than enp-1, endopod reaching to proximal area of exp-3, and exp-3 longest. P3 enp-2 2.5 times longer than enp-1, endopod reaching to middle of exp-2, and exp-1 largest. P4 endopod small, enp-2 2.3 times longer than enp-1, endopod reaching to middle of exp-1, and exp-3 longer than exp-1.
Spine and setal formulae as follows:
P1 0.0.022 0.020
P2 0.0.022 0.010
P3 0.0.022 0.010
P4 0.0.022 0.010
P5 (Figure 3
C) fused medially, and exopod and baseoendopod separate; each covered with minute spinules as figured. Baseoendopod with a long outer setophore bearing one plumose basal seta. Endopodal lobe only reaching to middle of exopod, with five pinnate setae; second outermost seta longest; a row of spinules along distal margin. Exopod small, slightly longer than wide and with one naked and three pinnate setae.
Male. Body length 243 µm. Largest width measured at about median area of cephalic shield: 61 µm. Urosome gradually tapering posteriorly (Figure 7
Cephalothorax with serrulated posterior margin. Pleural areas well-developed and rounded without lobate posterolateral angles. Entire surface covered with tiny denticles as in female. Sensilla present as illustrated in Figure 7
Rostrum triangular-shaped (Figure 7
A,E), broader than in female, smooth anterior margin, clearly separated from cephalosome, and with a pair of sensilla and a row of long spinules along entire anterior margin (only along median apical margin in female).
Urosome (Figure 7
A) six-segmented, comprising P5-bearing somite, genital somite and four abdominal somites. All urosomites covered with small denticles dorsally and ventrally and with well-developed hyaline frill along the hind margin.
Antennule (Figure 7
B) eight-segmented and subchirocer with geniculation between segments 5 and 6. Segment 1 with a row of coarse and widely spaced spinules. Segment 2 the largest. Segment 4 represented by a small sclerite along anterior margin of segment 3. Segment 5 swollen with one well-developed large aesthetasc. Segment 7 with three-dimensional process as figured in Figure 7
B. Segment 8 with triangular distal half. Armature formula: 1-[1pinnate], 2-[7 pinnate], 3-[5 pinnate], 4-[1 pinnate], 5-[1 + 6 pinnate + (1 pinnate + ae)], 6-, 7-[2 modified process], 8-[6 + 1 pinnate + trithek]. Apical trithek consisting of a minute aesthetasc and two naked setae.
P5 (Figure 7
D) fused medially, defined at base, and whole surface covered with minute spinules. Baseoendopod with a long, cylindrical setophore bearing one plumose outer basal seta. Exopod fused to endopod and represented by three pinnate setae. Minute and coarse spinules on anterior surface.
P6 (Figure 7
C) asymmetrical, represented on both sides by a small plate without any additional ornamentation: fused to ventral wall of supporting somite along right side, articulating at base and covering gonopore along left side.