A new species of nine-spined stickleback, Pungitius modestus (Gasterosteiformes, Gasterosteidae), from northern Honshu, Japan

A new species of nine-spined stickleback, Pungitius modestus, is described based on the holotype and 17 paratypes (38.7–51.7 mm standard length) collected from the inland area of Yamagata Prefecture, northern Honshu, Japan. The new species is distinguished from the other species of Pungitius by the following combination of characters: 30–32 small unconnected lateral plates; dorsal-fin rays VIII–X (usually IX)+9–11; anal-fin rays 7–10 (usually 8); pectoral-fin rays 10; a short spiny dorsal fin base (26.5%–29.8% SL); the first spiny dorsal fin spine behind the pectoral-fin base; a long pre-anal fin (59.9%–67.4% SL); the anal-fin spine below the 1st–3rd dorsal-fin rays; a short pelvic-fin spine (6.3%–9.1% SL); a short anal-fin spine (4.1%–6.0% SL); a long caudal peduncle (14.3%–19.7% SL); no body markings; membranes of the dorsal-fin spines dark brown with black pigments; the entire male body, and soft dorsal and anal fins, becoming black in the breeding season; the anteroventral process of the ectocoracoid present; and the dorsal extension of the ascending process of the pelvis level with the dorsal-most actinost.

A new species of Pseudione sensu lato (Isopoda: Bopyridae) on a squat lobster host from the deep South-West Atlantic

A new bopyrid, Pseudione chiesai n. sp., is herein described based on an ovigerous female and an adult male found in the right branchial chamber on a specimen of Munida spinosa Henderson, 1885. This parasite was collected in the Mar del Plata submarine canyon at 819 m depth during the expedition “Talud Continental I” carried out by the Argentine RV Puerto Deseado in 2012. P. chiesai n. sp. belongs to the Pseudione “crénelés” group sensu Bourdon (1972, 1976), which currently contains seven species, all of which have galatheoid crabs as hosts. P. chiesai n. sp. can be separated from the other species in the Pseudione “crénelés” group by the following combination of characters: (1) both sides of the body convex, (2) frontal lamina with a few, shallow indentations, (3) coxal plates 1–4 and tergal projections 1–4 with distinct irregular margins, mainly on the right side, (4) pereomeres 5–7 with single/branched lateral digitations, (5) maxilliped palp well-developed and setose, and (6) pleon with lateral plates 1–5 distally rounded and directed laterally. The taxonomic position of this new species is briefly discussed.

Claxtonia goni, a new species of Tardigrada (Heterotardigrada, Echiniscidae) from the island of Maui (Hawaiian Islands, U.S.A., North Pacific Ocean), with notes to the genus Claxtonia Gąsiorek & Michalczyk, 2019

A new Tardigrada species, Claxtonia goni sp. nov. is described from specimens collected in the central area of the Haleakalā National Park, the island of Maui, Hawaii, U.S.A. The new species and Clx. pardalis (Degma & Schill, 2015) together with several examples of Clx. wendti (Richters, 1903) are the only known Claxtonia species with the plates having an intracuticular pattern resembling that on a leopard’s fur. Claxtonia goni sp. nov. differs from Clx. pardalis in the absence of pores on leg plates, in smaller and uniform pores on dorso-lateral plates, in very unequally spaced teeth in the dentate collar, in lesser ratio of internal cephalic cirrus and lateral cirrus A lengths, and in relatively shorter claws in fourth pair of legs. The differences between the new species and the other congeners as well as Echiniscus species with the same cirri composition and similar cuticular sculpture are also defined. The diagnosis of the genus Claxtonia is amended and three Echiniscus species are transferred into the genus with the proposed new combinations: Claxtonia aliquantilla (Grigarick, Schuster & Nelson, 1983) comb. nov., Clx. mosaica (Grigarick, Schuster & Nelson, 1983) comb. nov. and Clx. nigripustula (Horning, Schuster & Grigarick, 1978) comb. nov..

A new species of the genus Henricia (Asteroidea, Spinulosida, Echinasteridae) from South Korea

A new species of the genus Henricia Gray, 1840 that belongs to the family Echinasteridae is described from South Korea. Henricia epiphysialissp. nov. has epiphyseal ossicles at the ends of the abactinal and lateral plates, and the abactinal and lateral spines form a hooked crown. The partial sequence of the mitochondrial COXI gene (537 bp) of H. epiphysialissp. nov. was obtained, and the new species was morphologically and genetically compared with other related Henricia species.

Three new species of abdominal shrimp parasites (Crustacea: Isopoda: Bopyridae: Hemiarthrinae) from the Indo-West Pacific

Three new species of the parasitic isopod subfamily Hemiarthrinae Markham, 1972 are described. Allodiplophryxus unilateralis n. sp. is described from Western Australia, infesting the palaemonid shrimp Jocaste lucina (Nobili, 1901), and females differ from the only other species in the genus in possessing six pleomeres, an asymmetrical first oostegite and pleopods restricted to the short side of the body. Loki athanus n. sp. is described from Madagascar, infesting the alpheid shrimp Athanas parvus de Man, 1910, and females differ from the only other species in the genus in possessing well-developed lateral plates on pleomere 4 and four pairs of uniramous pleopods. Hemiarthrus alphei n. sp. is described from French Polynesia, infesting the alpheid shrimp Alpheus crinitus Dana, 1852, and females differ from the four other known Hemiarthrus species in having pleomeres with well-developed, symmetrical lateral plates, a barbula with three pairs of projections and a pointed pleotelson. Keys to species of Hemiarthrus and all genera of the Hemiarthrinae are presented.

Spatial, sexual, and rapid temporal differentiation in neuromast expression on lateral plates of Haida Gwaii threespine stickleback (Gasterosteus aculeatus)

Lateral lines, a major sensory modality in fishes, are diverse among taxa, but their intraspecific variation has received limited attention. We examined numbers of superficial neuromasts on the buttressing lateral plates (LP) of 1910 threespine stickleback (Gasterosteus aculeatus Linnaeus, 1758) from 26 ecologically and morphologically diverse populations on the Haida Gwaii archipelago, western Canada. Extending from previous studies, we predicted that (i) highly stained dystrophic localities would have threespine stickleback with elevated numbers of neuromasts per plate due to a greater reliance on non-visual sensory modalities and (ii) that LP count and neuromast numbers per plate would functionally covary with predatory assemblage. We found that there were no differences in neuromast count across major habitats (marine, lake, stream), but clear-water populations and those with predatory fish had significantly more neuromasts per plate than most populations in highly stained dystrophic lakes, the effects being accentuated on the first buttressing plate (LP4). We also report the first evidence that neuromast counts per plate are sexually dimorphic, with males having a greater density of neuromasts in most populations. Two transplant experiments between ecologically opposite habitats indicate that within 12 generations, neuromast counts per plate can rapidly shift in response to a change in habitat.

A new species of Pomponema Cobb, 1917 (Nematoda: Cyatholaimidae) from Northeast of Brazil, with reference to the taxonomic status of the genera Parapomponema Ott, 1972 and Propomponema Ott, 1972

A new species of free-living marine nematode is described from Itapuã beach, northeast of Brazil. Pomponema veronicae sp. n. differs from other species of Pomponema by having buccal cavity with large pointed dorsal tooth, two subventral teeth and pairs of denticles, gubernaculum with two L-shaped lateral plates and having a membrane at its distal end that connects to L-shaped plate, and presence of a ventral orifice at distal end of L-shaped plates. It also differs from other species in the size of spicules and gubernaculum. The new species is considered most closely related to Parapomponema species because of the L-shaped lateral plates of gubernaculum, but the taxonomic status of Parapomponema was reviewed and Parapomponema and Propomponema are now synonymized with Pomponema. Pomponema cyatholaimoides is considered as a species inquirendum and Pomponema carinatum is accepted as Pomponema loticum. An updated identification key to species of Pomponema is included.

A new species of Pomponema Cobb, 1917 (Nematoda: Cyatholaimidae) from Northeast of Brazil, with reference to the taxonomic status of the genera Parapomponema Ott, 1972 and Propomponema Ott, 1972

A new species of free-living marine nematode is described from Itapuã beach, northeast of Brazil. Pomponema veronicae sp. n. differs from other species of Pomponema by having buccal cavity with large pointed dorsal tooth, two subventral teeth and pairs of denticles, gubernaculum with two L-shaped lateral plates and having a membrane at its distal end that connects to L-shaped plate, and presence of a ventral orifice at distal end of L-shaped plates. It also differs from other species in the size of spicules and gubernaculum. The new species is considered most closely related to Parapomponema species because of the L-shaped lateral plates of gubernaculum, but the taxonomic status of Parapomponema was reviewed and Parapomponema and Propomponema are now synonymized with Pomponema. Pomponema cyatholaimoides is considered as a species inquirendum and Pomponema carinatum is accepted as Pomponema loticum. An updated identification key to species of Pomponema is included.

New genus of the family Delphacidae (Homoptera: Cicadina) from North America

A new genus, Euryburnia gen. nov. (type species: Megamelus magnifrons Crawford, 1914) is erected to accommodate the group of Nearctic species of the family Delphacidae erroneously placed by Hamilton (2002) in the genus Eurybregma Scott, 1875. The new genus differs from Eurybregma by narrower metope without intermediate carinae on eumetope (only median carina is developed). According to male genitalia structure the new genus is close to the genera Unkanodes Fennah, 1956 and Chilodelphax Vilbaste, 1968, but distinguished by angular (not rounded) latero-ventral lobes of pygofer and by pygofer phragme without teeth and processes. From the genus Eurybregma the new genus differs by the presence of latero-ventral lobes of male pygofer. According to presence of unique, well developed beak-shaped basal lobes of dorso-lateral plates of ovipositor (first valvifers) the new genus is distinguished within all Delphacidae. New combinations proposed: Euryburnia magnifrons (Crawford, 1914), comb. nov. (=Megamelus magnifrons Crowford, 1914), Euryburnia montana (Beamer, 1952), comb. nov., (=Eurysa montana Beamer, 1952), Euryburnia obesa (Beamer, 1952), comb. nov. (=Eurysaobesa Beamer, 1952), Euryburnia eurytion (Hamilton, 2002), comb. nov. (=Eurybregma eurytion Hamilton, 2002).