Zootaxa

**The widespread chiton Stenosemus albus (Mollusca: Polyplacophora) is absent from the Pacific Ocean, and a new chiton species**

2025-12-10T13:32:01+13:00

Stenosemus albus (Linnaeus, 1767), previously considered widespread in the Northern Hemisphere, is absent from the northern Pacific. Instead, the new species Stenosemus magnidentis sp. nov., occurs there. This new species differs from S. albus in the shape of the central tooth and the head of the major lateral tooth of the radula.

**Disentangling the South American “Ceratomontia”: new genus, new combinations, and new species (Opiliones: Laniatores: Triaenonychidae)**

2025-12-10T13:32:56+13:00

Previous phylogenetic studies using morphological or molecular characters failed to recover the transcontinental triaenonychid genus Ceratomontia Roewer, 1915, as monophyletic, and pointed out the necessity to erect a new genus for the new world representatives. In this work we address this taxonomic claim and the genus Maurymontia gen. nov. is described to include the South American species. In addition to the proposed new combinations, we also provide a detailed redescription and illustrations for all the previously known species: Maurymontia argentina (Canals, 1939) comb. nov., Maurymontia brasiliana (Maury, 1999) comb. nov., Maurymontia centralis (Maury & Roig Alsina, 1985) comb. nov. and Maurymontia mendocina (Maury & Roig Alsina, 1985) comb. nov. Furthermore, we increase the genus composition with the description of three new species from Argentina: Maurymontia grismadoi sp. nov., Maurymontia mborore sp. nov. and Maurymontia trescerros sp. nov. Finally, we discuss some points regarding geographic distribution, the external and genital morphology.

**Towards the molecular resolution of the bird digenean Hyptiasmus oculeus complex (Cyclocoelidae)**

2025-12-10T13:33:54+13:00

Hyptiasmus Kossack, 1911 is a genus of cyclocoelid digeneans infecting the body cavity, air sacs, and lungs of mainly anseriform and gruiform birds. Some species of this genus have extensive ranges, spanning more than one continent. Therefore, this taxon is potentially of interest for studying patterns of genetic diversity and the associated problems of taxonomic delimitation of species. We focused on the examination of Hyptiasmus specimens initially identified as Hyptiasmus oculeus Kossack, 1911. These digeneans were collected from the nasal sinuses of specimens of Eurasian Coot Fulica atra Linnaeus, 1758 taken in both European and Asian parts of Russia. Phylogenetic analyses based on 28S rRNA, nd1, and cytb markers, in combination with morphological data, indicate that the newly collected digeneans are in fact members of H. oculeus complex represented by true H. oculeus and a putative new species Hyptiasmus sp. The morphological differences between these species appear to be the length of the postovarian space and the position of the genital pore. A detailed morphological study revealed the presence of rudimentary ventral and oral suckers in gravid specimens of H. oculeus complex. We did not find any geographic structuredness of the haplotype diversity in true H. oculeus. Our findings do not support the recent proposal to resurrect H. singilum Witenberg, 1923 and H. brumpti Dollfus, 1948. In addition, we hypothesise that Paracyclocoelum Vainutis, Andreev & Voronova, 2024 is a synonym of Cyclocoelum Brandes, 1892.

**Three newly discovered species of Amynthas earthworms (Oligochaeta: Megascolecidae) from Jiangxi Province and adjacent regions of China**

2025-12-10T13:34:44+13:00

This study describes three new earthworm species, namely, Amynthas yichunensis Sun & Jiang, sp. nov., A. huizhouensis Sun & Jiang, sp. nov., and A. shangraoensis Sun & Jiang, sp. nov. A. yichunensis sp. nov. exhibits variability in the number and position of spermathecal pores, with 0, 1, or 2 pairs located at intersegmental furrow 8/9 or spanning segments 7/8–8/9. A. huizhouensis sp. nov. possesses three pairs of spermathecal pores, located at intersegmental furrows 5/6–7/8, similar to other species within the A. gracilis group. A. shangraoensis sp. nov. features four pairs of spermathecal pores, which places it within the A. corticis group, with the pores located at intersegmental furrows 5/6–8/9. The genetic barcodes for the newly identified species have been submitted to the GenBank database.

Silent crickets: A new genus of Neometrypini from the Brazilian Atlantic Forest (Orthoptera: Oecanthidae: Tafaliscinae)

2025-12-10T13:35:42+13:00

A new genus of oecanthid cricket from the Neometrypini tribe is described here: Aphonodiacanthus Tonon & Campos gen. nov., comprising three new species: A. melanocephalus Tonon, Campos & Souza-Dias sp. nov., A. maculatus Tonon & Campos sp. nov., and A. chlorops Tonon & Campos sp. nov., from the Brazilian states of Paraná, Bahia, and São Paulo respectively. The combination of male genitalia characters, mainly the pointed shape of the pseudepiphallic lateral lobes, and other morphological features such as the short forewings and supra anal plate, supports the proposal of this new genus. A geographical distribution map and identification key to species are provided, along with an updated identification key to genera of Neometrypini. A brief discussion is also presented for traits such as the subgenual organ, the absence of acoustic communication, the metanotal glands, and highlight the presence of A. chlorops Tonon & Campos sp. nov. in a densely populated area within the São Paulo metropolitan region, inhabiting an urban fragment of Atlantic Forest.

Description of two new species of nereidids (Annelida: Nereididae) from West Bengal, India, Bay of Bengal

2025-12-10T13:36:36+13:00

Two new species of nereidids, Namalycastis solenotognatha sp. nov. and Nereis dhritiae sp. nov. are described in the present paper. These species were collected from two different locations along the intertidal zones, which are situated near mangrove habitats and sandy beaches, respectively. Namalycastis solenotognatha sp. nov. can be distinguished from its resembling congeners from Indian waters mainly by having heterogomph spinigers in supra-preacicular neurochaeta in anterior chaetigers, and lacking notochaetae. Other features related to the size (antennae, eyes, postero-dorsal tentacular cirri, and neuropodial superior lobe) and shape (heterogomph falcigers and spinigers’ blades, and pygidium) of several prostomial and parapodial structures, as well as the number of canals in the jaws, help distinguish the new species. Further, N. dhritiae sp. nov. differs from the three infra group I.B.2 species recorded from India by the presence of a distinct tendon in the blades of notopodial homogomph falcigers, one paragnath on area V, and an anterior row of area VII–VIII with only small paragnaths. Namalycastis solenotognatha sp. nov. and Nereis dhritiae sp. nov. increase the total number of Nereididae species to 73 from the Indian coast, five species belonging to Namalycastis and nine to Nereis.

Travisiid worms from deep water off Western Mexico with the establishment of a new species (Annelida: Travisiidae)

2025-12-10T13:37:24+13:00

Two species of travisiid worms are here reported from the continental slope of western Mexico. Travisia brevis Moore, 1923, a species reported in Mexican waters since 1972, was found off Guerrero to 880‒1928 m depth. A new species of Travisia is established for material collected off Jalisco, Colima and Guerrero, between 1050‒1992 m depth. Travisia pupa Moore, 1906 has been suggested to be present in Mexican waters and at first view it has some similarity with the new species described herein. Consequently, specimens of T. pupa from Puget Sound, Washington State, United States of America, were reviewed and analyzed for comparative purposes. Travisia hernandezalcantarai sp. nov., has a unique set of distinctive features: nuchal organs remarkably large, parapodial lappets absent, mid-ventral groove present, annulate branchiae from chaetiger 2 and peculiar rows of spherical papillae along body segments. Full descriptions and illustrations are provided for the three species. A key to species of Travisia from the North American Pacific is provided.

**Trypanorhynch cestodes of Mobula thurstoni (Lloyd) from Bali, Indonesia, including the description of Hemionchos arthanai sp. nov. (Cestoda: Eutetrarhynchidae Guiart, 1927)**

2025-12-10T13:38:30+13:00

Trypanorhynch cestodes were identified in the stomach and spiral valve of Mobula thurstoni (Lloyd) from Lombok Strait, Bali, Indonesia. This study includes the description of Hemionchos arthanai sp. nov. (Cestoda: Eutetrarhynchidae). New site and locality records were established for H. striatus Campbell and Beveridge, 2006, H. mobulae Campbell and Beveridge, 2006, Mobulocestus Campbell and Beveridge, 2006, Nybelinia balinensis Palm, Palm and Haseli, 2019, and Parachristianella campbelli Schaeffner and Marques, 2018. Hemionchos arthanai sp. nov. can be distinguished from the other Hemionchos species due to its smooth scolex surface lacking transverse annulations, the configuration of its five metabasal hooks per row where the hooks 1–4 (1´–4´) possess characteristic cavities, and its basal armature. The basal armature consists of two rows of enlarged uncinate hooks devoid of cavities, followed by three rows of slender uncinate to spiniform hooks without cavities, and three rows of conical, dorsoventrally flattened, falcate hooks with a strongly recurved mucronate tip. Although the life cycle of H. arthanai sp. nov. is unknown, euphausiaceans are expected to serve as intermediate hosts. This assumption is supported by the fact that H. mobulae has been detected in euphausiaceans, which are prey items for manta rays.

**A new species of Ichthyurus (Coleoptera: Cantharidae: Chauliognathinae) preying on tasar silkworm, Antheraea mylitta (Drury) from India**

2025-12-10T13:39:24+13:00

The Ichthyurini are a diverse and widespread tribe of Chauliognathinae (Cantharidae) comprising nearly 300 species, but, so far, their biological data are scarce, and nothing is known about their behaviour and feeding habits. Here, we describe and illustrate a new species, Ichthyurus antheraeanus Sreedevi, Reddy, and Biffi, sp. nov. from Jharkhand, India, and report for the first time the predatory behaviour of a species in the tribe. Males and females of I. antheraeanus sp. nov. were found preying on early instar larvae of the tasar silkmoth, Antheraea mylitta (Drury, 1773) (Lepidoptera: Saturniidae). Detailed descriptions and photographic illustrations of adult habitus and genitalia of both sexes of the species as well as their COI mtDNA barcode are provided. The potential harm that I. antheraeanus sp. nov. may have on the tasar silk production in India is discussed.

**Molecular Phylogenetic Assessment of Trimeresurus gunaleni Vogel, David & Sidik, 2014 (Serpentes: Viperidae: Crotalinae)**

2025-12-10T13:40:21+13:00