Zootaxa

**A review of the chitons of the genus Stenosemus (Mollusca: Polyplacophora) of the southern hemisphere**

2026-05-21T12:39:36+12:00

A revision of the chitons of the genus Stenosemus was carried out, as a result of which new localities of the species S. perforatus, S. exaratus and S. simplicissimus are identified, the species status of S. dallii and S. johnstoni is restored and two new species are described: S. neozelandicus sp. nov. and S. minisulcus sp. nov. A new family Stenosemusidae is also erected on the basis of morphological and ecological peculiarities for members of Stenosemus and Carinichiton Sirenko, 2026. In total, 17 species of chitons of the genus Stenosemus are currently known in the southern hemisphere and 18 species in the northern hemisphere. Of these, two species inhabit both hemispheres. The Gondwanan origin of the genus Stenosemus is assumed.

**Two new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from the Yunnan border region, Southwest China**

2026-05-21T12:41:04+12:00

Two new species of the genus Dugesia from the Yunnan border region, Southwest China, are described by applying an integrative approach, using morphological, histological, and molecular data. Dugesia repanda Chen & Dong, sp. nov. is characterized by the following features: symmetrical openings of the oviducts into the bursal canal; an upward curving, highly asymmetrical penis papilla; highly elongated and muscularised seminal vesicle of which the major portion is located considerably anterior to the root of the penis papilla; a long connecting duct between the seminal vesicle and diaphragm; a dorsally located penial fold; ejaculatory duct opening subterminally through the dorsal wall of the penis papilla. Dugesia laterocalceata Chen & Dong, sp. nov. is characterized by the following features: hyperplastic ovaries; symmetrical openings of the oviducts; a boot-shaped penis papilla; penis papilla with a dorsal bulge; a connecting duct between the seminal vesicle and diaphragm; ejaculatory duct consistently opening through the right lateral wall of the penis papilla. In the molecular phylogenetic tree, the two new species belong to distinct and independent lineages. Dugesia laterocalceata Chen & Dong, sp. nov. is nested within the Oriental-Australasian clade, whereas D. repanda Chen & Dong, sp. nov. is recovered as a distinct lineage that is sister to the entire Eastern Palearctic-Oriental-Australasian clade.

**Taxonomic revision of the genus Cryptochetum Rondani, 1857 (Diptera: Cryptochetidae) from Pakistan with a new country record**

2026-05-21T12:42:55+12:00

The polyphagous mealybug genus Drosicha Walker, 1858 is currently represented by three species in Pakistan: D. mangiferae (Stebbing, 1903), D. stebbingii (Stebbing, 1902), and D. turkestanica Archangelskaya, 1931. Among these, D. turkestanica is recorded herein for the first time from Pakistan, with its distribution restricted to the northern regions of the country, Gilgit-Baltistan. Its endoparasitic fly, Cryptochetum turanicum Nartshuk, 1979, is also newly recorded from Pakistan, confirmed through adult morphology, male and female terminalia, DNA barcoding, and biogeographical evidence. These results expand the known geographical range of both the parasitoid and its host toward the southeastern Palaearctic distribution, contributing significant evidence for the Palaearctic regional fauna in Gilgit-Baltistan. We also provide an updated global checklist of Cryptochetum species, including comparative notes, host associations, diagnostic characters, distribution data, and a taxonomic identification key to the species known from Pakistan. Furthermore, Cryptochetum jorgepastori Cadahia, 1984 syn. nov. is proposed as a junior synonym of C. turanicum Nartshuk, 1979.

**Redescription of Pterygotrigla guezei Fourmanoir, 1963 (Perciformes, Triglidae, Pterygotriglinae), a senior synonym of Pterygotrigla cajorarori Richards & Yato, 2012**

2026-05-21T12:44:33+12:00

Pterygotrigla guezei Fourmanoir, 1963, a triglid fish of the subgenus Pterygotrigla, was previously known only from islands in the Western Indian Ocean. Additional specimens of P. guezei were collected during surveys conducted by the research vessel Dr. Fridtjof Nansen off Mozambique and Tanzania in 2023. This material extends the known distribution of the species westward to the eastern coast of Africa and enables comparison of specimens from the Western Indian Ocean with those of Pterygotrigla cajorarori Richards & Yato, 2012 from the Philippines (type locality), using both morphological and genetic data. Previously, P. guezei had been distinguished from other members of the subgenus by the presence of 11 membranous pectoral-fin rays rather than 12. However, examination of the holotype and additional specimens from the Western Indian Ocean shows that all specimens possess 12 pectoral-fin rays. Comparison of type material of P. guezei and P. cajorarori, together with additional specimens from the Western Indian Ocean, the Philippines, and Australia reveal no consistent differences between the two species. This conclusion is supported by a phylogenetic analysis of the COI gene region, in which specimens from both areas form a single lineage, supporting their conspecificity, making P. cajorarori a junior synonym of P. guezei. The latter species is redescribed here, including its incorporation into a phylogenetic framework for the first time.

**Two new species of the genus Polypedilum Kieffer (Chironomidae, Diptera) with unique volsella from China**

2026-05-21T12:45:57+12:00

Two new species of the genus Polypedilum Kieffer, 1912, P. arcuatile Zhang sp. nov. and P. protuberans Zhang sp. nov., are described from China based on adult male specimens collected in Yunnan Province. Polypedilum arcuatile sp. nov. can be distinguished from its congeners by the pad-shaped superior volsella covered with microtrichia, the convex inner margin of its basal portion bearing six setae, and the presence of a distinct lateral projection extending from the outer margin of the superior volsella. Polypedilum protuberans sp. nov. is characterized by a pad-shaped superior volsella covered with microtrichia, with the inner apical region of the basal portion distinctly protruding and bearing three setae. The morphology of the superior volsella and the subgeneric placement of both new species are discussed. A preliminary checklist of Chinese Polypedilum species is provided, accompanied by illustrations of the two new species.

**Two new species of the genus Incisocalliope (Crustacea, Amphipoda, Pleustidae) from Korean waters, with a taxonomic reevaluation of the genus**

2026-05-21T12:47:12+12:00

This study aims to discover and document amphipods from Korea, contributing to the clarification of the taxonomy of Korean amphipod species. As part of this effort, two new species of the pleustid genus Incisocalliope, I. rotundus sp. nov. and I. truncatus sp. nov. (Parapleustinae, Pleustidae), are described from Korean waters. These two new species are morphologically similar to other species of the genus Incisocalliope. However, although they generally conform to Incisocalliope, they show certain differences from previously described species in the following features: the length of antenna 1 peduncular article 1, the number of marginal setae on mandibular palp article 2, the absence of robust setae on the hind margin of coxa 1, and the setation pattern on the hind margin of gnathopod 2 propodus. These differences are considered non-binary traits that are influenced by the generally larger body size of the two new species. Therefore, we propose an expansion and refinement of the current diagnosis of the genus Incisocalliope to accommodate these variations. Photographs of the two new species in their living state, full illustrations, detailed morphological descriptions, and a revised identification key to the world species of the genus Incisocalliope are provided.

**On recognizing Paracalanus indicus Wolfenden, 1906 from P. tropicus Andronov, 1977 (Copepoda, Calanoida, Paracalanidae) off the Iranian coast**

2026-05-21T12:48:27+12:00

In the present study, we re-evaluated the presence of a row of denticles on the posterior margin of the genital double-somite as one of the morphological diagnostic characters used to distinguish Paracalanus indicus Wolfenden, 1906, from P. tropicus Andronov, 1977. The results demonstrated that these denticles are present in both dorsal and lateral margins in these two species. Consequently, the previously reported absence of denticles from the dorsal surface of P. indicus can no longer be regarded as a reliable diagnostic character to separate Paracalanus indicus from P. tropicus. Molecular analyses further confirmed that the specimens collected from Chabahar Bay, Iran, belong to P. indicus. In this species, the row of denticles along the posterior margin of the genital double-somite is arranged in a clustered pattern, with the lateral denticles being larger and more distinct than the dorsal ones. In contrast, P. tropicus exhibits a continuous row of relatively larger denticles. Therefore, the distribution pattern of the denticles along the posterior margin of the genital somite is considered a reliable diagnostic character to recognize these two species, but it can hardly be observed with light microscopy. A key to the females of Paracalanus species reported from off the Iranian coasts is also provided

**A review of the net-winged beetle genus Benibotarus Kôno, 1932 (Coleoptera: Lycidae: Erotinae), with description of a new species from central China**

2026-05-21T12:49:39+12:00

The net-winged beetle genus Benibotarus Kôno, 1932 (Erotinae: Dictyopterini) is reviewed. Currently, the genus includes two subgenera, Benibotarus s. str. and B. subgen. Sibetarus Bocak et Bocakova, 1991, and three species. Benibotarus is known to occur only in the Palaearctic, from central Europe and the Caucasus (subgen. Sibetarus) to East Asia (subgen. Benibotarus s. str.), with a considerable gap between distribution ranges of its subgenera. A fourth species of the genus, B. (s. str.) rubrohumeralis sp. nov., is described from central China. B. (S.) taygetanus (Pic) is reported from Montenegro for the first time. Photographs of Benibotarus and of some morphological details are presented, with the female copulatory organs of B. arnoldii (Barovskij, 1932) and B. spinicoxis (Kiesenwetter, 1874) illustrated for the first time. An identification key to the Benibotarus subgenera and species is provided.

**A new species of Xya Latreille, 1809 from Xinjiang, China (Orthoptera, Tridactyloidea, Tridactylidae)**

2026-05-21T12:50:49+12:00

A new species, Xya bortalaensis sp. nov., from Xinjiang, China, is described. The new species is similar to Xya huidongensis Cao, Chen & Yin, 2025, but differs from the latter in having the following characteristics: a Y-shaped yellowish-white stripe along the inner margin of the eye, a yellowish-white band on the posterolateral margin of the eye, a symmetrical, subtriangular yellowish-white pattern on the pronotum, and yellowish-white stripes on the tegmina and metafemur. Type specimens are deposited in the College of Life Sciences, Hebei University (HBU), Baoding, China.

“Morphological compatibility” or subjective expectation? A response to Cadena-Castañeda (2026) and Braun (2026)

2026-05-21T12:52:07+12:00