Taxonomy, Volume 5, Issue 2 (June 2025) – 6 articles

Four new dung beetle species of the genus Onthophagus Latreille from Côte d’Ivoire, Burkina Faso, Bénin, and Cameroon are described, and a fragment of their COI gene is sequenced. The coprophagous Onthophagus (Trichonthophagus) sylviae sp. nov. from Côte d’Ivoire and Burkina Faso is most similar to Onthophagus pallidus d’Orbigny from Cameroon, but it is more elongated, more silky than shiny, and has no dark spot on the third elytral interstria. Onthophagus odikpatra sp. nov. (18th group of d’Orbigny) from Côte d’Ivoire, Burkina Faso, and Cameroon feeds on carrion, including dead millipedes and fish, and dung. It is most similar to Onthophagus baloghi Balthasar from Central Africa but has simple punctures on the sides of the pronotum. Onthophagus chinonophilus sp. nov. from Côte d’Ivoire and Burkina Faso, which feeds on freshly dead millipedes and is attracted by their quinonous defensive secretions; it also belongs to the 18th group in d’Orbigny’s classification. Small and medium individuals resemble small Onthophagus latigibber d’Orbigny but differ in shape and sculpture of the pronotum. Small individuals are also similar to Onthophagus tschadensis Balthasar (19th group) but differ in the shape of the aedeagus. The generalist feeder Onthophagus (Tiaronthophagus) necneavius sp. nov. (24th group) from Côte d’Ivoire, Burkina Faso, and Bénin is most similar to Onthophagus naevius from Zambia, DR Congo, and Tanzania, but it is smaller, shiny all over; the sides of pronotum behind anterior angles are almost straight, not distinctly emarginate, and the frons is densely covered with fine punctures. COI barcode sequences were provided for all four new species, but the poor sampling of Onthophagus in GenBank prevents meaningful analysis of species relationships on the basis of COI barcodes at this point. Full article

In this study, we provide a comprehensive description of a newly identified eutardigrade species, Mesobiotus longiconicus sp. nov., based on an integrative approach combining morphological and genetic data. The species was discovered at Lajuma Research Centre, Republic of South Africa, and is classified within the harmsworthi group. It can be differentiated from its closest relatives—Meb. barabanovi, Meb. ethiopicus, Meb. harmsworthi, Meb. reinhardti, and Meb. skorackii—by distinct morphological and morphometric characteristics of the bucco-pharyngeal apparatus, claws, and eggs. These morphological differences are further validated by genetic analyses using four molecular markers: 28S rRNA, 18S rRNA, COI, and ITS2. Additionally, two other tardigrade species were identified in the same locality, including Minibiotus pentannulatus, which is now recorded for the second time outside its type locality. With this discovery, the total number of tardigrade taxa reported from South Africa reaches 101, including Meb. longiconicus sp. nov. Full article

The Neotropical genus Nudopeza (Micropezidae, Taeniapterinae) is described for a group of 41 species, including Nudopeza tapanti sp. nov. (type species) and Nudopeza pronigra (Hennig) n. comb. for Grallipeza pronigra Hennig 1934, Nudopeza arcuata (Hennig) n. comb. for Grallipeza arcuata Hennig 1934, and the following 38 additional new species: N. cegex sp. nov, N. cura sp. nov, N. duplitheca sp. nov, N. gilli sp. nov., N. glypha sp. nov., N. gracei sp. nov., N. hansoni sp. nov., N. horologia sp. nov., N. laselva sp. nov., N. mephitis sp. nov., N. mexicana sp. nov., N. micromephitis sp. nov., N. nigrivertex sp. nov., N. nigriscutellum sp. nov., N. nudarcuata sp. nov., N. penai sp. nov., N. palenque sp. nov., N. paramephitis sp. nov., N. peruviensis sp. nov., N. quadrivitta sp. nov., N. ruficincta sp. nov., N. rutilans sp. nov, N. sirena sp. nov., N. sumaco sp. nov., N. trinidadensis sp. nov., N. uniseta sp. nov., N. variterga sp. nov., N. venezuelensis sp. nov., N. verpa sp. nov., N. versivitta sp. nov., N. viriola sp. nov., N. viva sp. nov., N. yungasensis sp. nov., N. zarza sp. nov., N. zostera sp. nov., N. zumera sp. nov., N. zygoma sp. nov., and N. zytha sp. nov. Full article

We describe a new species of snake of the genus Tachymenoides using molecular and morphological evidence. The description is based on 21 specimens (4 females, 17 males) obtained in the regions of Pasco, Junín, and Puno between 2190 and 3050 m elevation. A maximum likelihood phylogenetic tree based on two mitochondrial (12S and cyt-b) genes and one nuclear (c-mos) gene shows that the new species is the sister taxon of T. affinis and distinct from Galvarinus tarmensis, which we transfer back to Tachymenis. The new species has smooth dorsal scales without apical pits usually in 19/17/15 series, 1 preocular, 2 postoculars, 1 loreal undivided nasal scale, 8 supralabials (4th and 5th in contact with the eye), 9 infralabials, 1–2+2–3 temporals, 139–157 ventrals, 52–67 subcaudals, and a divided cloacal scale. The longest specimen, a male, had a total length of 559 mm. Two females contained six and five eggs with small embryos. In life, the dorsum and flanks are olive brown to pale grayish brown with scattered black and cream flecks and no longitudinal stripes. Ventral coloration is highly variable, nearly uniformly black, mottled gray and dark-gray, mottled pale gray and tan, or pale grayish tan. Usually, three irregularly shaped, narrow, longitudinal ventral stripes are present. The iris is brown with a distinct yellowish-tan ringlet. Full article

In this study on diatoms, which are unicellular microalgae with a siliceous cell wall, images obtained by electron microscopy were used to compare three taxa from East Asia that were referred as Cyclotella hubeiana, Discostella guiyangensis and “Cyclotella fottii” in the original studies. Morphometrical and morphological analyses indicate that these three taxa are conspecific. The distinctive morphological features of this species are the following: one rimoportula located on the valve mantle within the ring of marginal fultoportulae, marginal fultoportulae situated on costae with internally two satellite pores positioned circumferentially (laterally) and externally long tubular opening, biseriate striae and branching costae. A comparison of these morphological features with those of Discostella and Cyclotella species and a re-assessment of the existing molecular data suggest that this species could be separated from both these genera. On this basis, we describe the new genus Discocyclus gen. nov. with Discocyclus hubeianus comb. nov. as the type species. Full article

The freshwater cyanobacterium Raphidiopsis raciborskii is an invasive species that was originally described as tropical and is now widely distributed in temperate regions. The current taxonomic position was established based on a multilevel approach with the morphological description of natural populations as well as their ultrastructural, physiological and molecular characterization. The practical problem in identifying this species is that the morphology of the trichome in the natural environment can vary considerably during population growth. The aim of this study was to investigate the morphological variability of R. raciborskii during its blooming in a temperate floodplain lake on the Middle Danube (Europe). In both cases, only straight trichomes were found. Young trichomes with one or two acuminate ends and without heterocytes, referred to as primary filaments, can be exclusively monodominant at the beginning of bloom formation and remain dominant throughout the year, leading to taxonomic confusion. In mature populations, the different morphological forms of secondary filaments may differ in the size of the filaments and in the number and size of akinetes and heterocytes formed in the trichomes. The correct taxonomic identification and early detection of R. raciborskii in natural freshwaters is extremely important for the successful control of the spread of this potentially toxic species. Full article