[Ichthyology • 2026] Hippocampus amandavincentae • A New Species of Spiny Seahorse (Syngnathiformes: Syngnathidae) from Indian Ocean, with Redescription of H. histrix and H. jayakari

 

Hippocampus amandavincentae  

Shalu, Short, Raghavan, Ramvilas & Ranjeet, 2026

DOI: doi.org/10.11646/zootaxa.5862.2.4  

 facebook.com/RajeevRAGHAVAN98

 

Abstract

The thorny seahorse, Hippocampus histrix Kaup, 1856, has long been treated as a single, widely distributed species ranging from the Red Sea and western Indian Ocean to the western Pacific. Morphological and molecular evidence now demonstrate that this broad concept encompasses at least three diagnosable species. Examination of Indian Ocean specimens combined with mitochondrial COI sequence analysis reveals a new lineage herein described as Hippocampus amandavincentae sp. nov., based on material from southeastern India and corroborated by published sequences from Madagascar, Mozambique, the Seychelles, and the northern Red Sea. The new species is diagnosed by a shorter snout, five coronet spines, and spines present on all principal trunk and tail ridges. A published COI sequence from the northern Red Sea places H. amandavincentae in apparent sympatry with Hippocampus jayakari Boulenger, 1900, in that region, indicating that the distributional boundary between these two species requires targeted field investigation. Hippocampus histrix sensu stricto is redescribed and its distribution restricted to the Pacific Ocean, including Japan, Indonesia, and the Philippines, based on direct examination of type material. Hippocampus jayakari, described from the Gulf of Oman, is confirmed as a distinct species of the northwestern Indian Ocean, readily distinguished by four cleithral spines with the ventral-most bifurcate, a shorter and deeper snout, and spines confined to alternating tail rings. Together, these three species represent geographically coherent lineages whose delineation resolves over a century of misidentification in museum collections and online databases, stabilises the application of long-used names, and provides a practical framework for regional conservation assessment and future systematic research on spiny seahorses across the Indo-Pacific.

Pisces, barcoding, India, species complex, taxonomy, thorny seahorse

Hippocampus amandavincentae sp. nov.

Hippocampus amandavincentae sp. nov.

Kannan SHALU, Graham SHORT, Rajeev RAGHAVAN, Ghosh RAMVILAS and Kutty RANJEET. 2026. A New Species of Spiny Seahorse, Hippocampus amandavincentae, with Redescription of H. histrix and H. jayakari (Teleostei: Syngnathidae).  Zootaxa. 5862(2); 271-292. DOI: doi.org/10.11646/zootaxa.5862.2.4 [2026-08-05] 

  facebook.com/RajeevRAGHAVAN98/posts/10162487911550938

[Ichthyology • 2026] Nanosphronemus gemma • A remarkable New Genus and Species of miniature osphronemid (Anabantoidei: Osphronemidae) from Vietnam

Nanosphronemus gemma

 Britz, Tan & Rüber, 2026

Raffles. Bull. Zool. 74; 

Abstract

 A new genus and species of miniature labyrinth fish of the family Osphronemidae, Nanosphronemus gemma, is described from Vietnam. It differs from all other genera of anabantoids by a unique dorsal- and anal-fin ray count, a unique colour pattern and a number of unique or highly unusual skeletal characters. Our molecular phylogenetic analysis indicates that Nanosphronemus is the sister group of the genus Trichopsis, the croaking gouramis. 

Key words. Anabantoidei, labyrinth fishes, miniaturisation, gourami

Nanosphronemus gemma, live colouration, not preserved, all ca. 16 mm SL in lateral view.
a, putative female above, note absence of red stripe in dorsal half; b, putative male in normal colouration, note presence of red stripe above and darker pigmentation below midlateral stripe; c, putative male in breeding colouration, note overall darker colouration of body and also fins, presence of bright red stripe and highly iridescent scales in mid-lateral stripe and below on head and body.

Nanosphronemus gemma, not preserved, all ca. 18 mm SL.
a, mature female with eggs; b, in breeding colouration and typical oblique courtship position, c, approaching bubble nest under plant leaf; d, adding air bubbles and embedding eggs into bubble nest.

Nanosphronemus, new genus  

Diagnosis. Nanosphronemus differs from all other genera in the suborder Anabantoidei by its unique count of XIX– XXI+2–3 dorsal-fin rays (vs. I–XVIII+ 4–14, rarely XIX in some specimens of Macropodus ocellatus) and XX– XXIV+4–5 anal-fin rays (vs. I–XVII+8–38, rarely XX–XXII in some specimens of Macropodus spp.), the presence (vs. absence) of a series of anteroventrally directed processes off the distal part of caudal haemal arches, Baudelot’s ligament ...

Etymology. The new genus name is derived from the Ancient Greek word, νάνος, meaning dwarf, combined with the name Osphronemus, the type genus of the family Osphronemidae, to which this new genus belongs. Gender: masculine. The name alludes to the tiny size of this new fish, which makes it one of the smallest anabantoids known to date.

Nanosphronemus gemma, new species 

 Suggested common name. Jewel Gourami.

Distribution. Unclear at present: reported from undisclosed area near Huế in Central Vietnam. 

Etymology. The species name is derived from the Latin word for jewel, ‘gemma’, alluding to the stunning colouration of sexually mature males. A noun in apposition.

 

Ralf BRITZ, Heok Hui TAN and Lukas RÜBER. 2026. Nanosphronemus gemma, A remarkable New Genus and Species of miniature osphronemid from Vietnam (Teleostei: Anabantoidei: Osphronemidae). Raffles. Bull. Zool. 74; 606–623. 

 

[Ichthyology • 2026] Acrossocheilus zhangjiajiensis • Integrative Taxonomy reveals A New Species of Acrossocheilus (Cypriniformes: Cyprinidae) from Hunan Province, China

Acrossocheilus zhangjiajiensis

in Cao, Deng, Xiang, Xie, Wang, Li, Hu, Wei et Jiang, 2026.

张家界光唇鱼  ||  DOI: doi.org/10.3897/zse.102.195486

Abstract

The genus Acrossocheilus (Cyprinidae), which occurs in Southeast Asia and southern China, is of significant ecological and economic importance. A new species, Acrossocheilus zhangjiajiensis sp. nov., is described from the upper Lishui River Basin, a tributary of the Yangtze River, in Sangzhi County, Zhangjiajie City, Hunan Province, China. The description is based on an integrative taxonomic approach combining morphological examination, DNA barcoding, and mitogenomic analyses. This new species is distinguished from all congeners by the following combination of characters: a maxillary barbel extending to the midline of the eye; a slightly hardened last unbranched dorsal-fin ray with a smooth posterior margin; dorsal-fin membranes with black stripes; the second primary vertical bar (PVB2) positioned anterior to the origin of the dorsal fin; juveniles and adults possessing six distinct vertical black bars on the flank; and fewer than 40 lateral line scales. Notably, it further differs from its sister species, A. jishouensis, in several morphometric traits, as well as the texture of the last unbranched dorsal-fin ray and the persistence of vertical flank bars throughout all life stages. The complete mitogenome of A. zhangjiajiensis sp. nov. is 16,592 bp in length. Phylogenetic analyses based on the mitochondrial COI gene and the 13 protein-coding genes (PCGs) support a sister-species relationship between A. zhangjiajiensis sp. nov. and A. jishouensis, with genetic distances of 3.1%​ (COI) and 3.3% (13 PCGs). A COI-based haplotype network and species delimitation analyses further support the distinctiveness of the new species. This discovery increases the total number of valid Acrossocheilus species to 25 and provides critical data for the systematics, evolution, and conservation of this genus.

Key Words: Cyprinid, integrative taxonomy, morphology, mitogenome, Yangtze River

Live specimens of Acrossocheilus zhangjiajiensis sp. nov.
A. Lateral view of body; B. Lateral view of head; C. Ventral view of head; D. Dorsal view of head.

 

Acrossocheilus zhangjiajiensis sp. nov.

Etymology. The specific epithet zhangjiajiensis is derived from Zhangjiajie City, where the type locality of this species is located. Currently, this taxon is known only from this type locality, and its Chinese name is “Zhāng jiā jiè guāng chún yú (张家界光唇鱼)”.

 Jianhan Cao, Zhiyong Deng, Hongmei Xiang, Yixing Xie, Cheng Wang, Hong Li, Yang Hu, Ying Wei and Wansheng Jiang. 2026. Integrative Taxonomy reveals A New Species of Acrossocheilus (Cypriniformes, Cyprinidae) from Hunan Province, China. Zoosystematics and Evolution. 102(3): 869-883. DOI: doi.org/10.3897/zse.102.195486 [25-06-2026]

[Ichthyology • 2026] Brachygobius jennie • A New bumblebee goby (Gobiiformes: Oxudercidae) from Hengqin Island, Guangdong Province, China

Brachygobius jennie  

 Tian, Wu, Lan, Lavoué & Huang, 2026. 

 DOI: doi.org/10.3897/zse.102.184142

Abstract

A new species of bumblebee goby, Brachygobius jennie sp. nov. (Teleostei, Oxudercidae), is described based on 31 specimens collected from the Hengqin Island, Guangdong Province, China. This new species is distinguished from all other valid species of Brachygobius by its extreme small size (SL < 9 mm) and distinctive number, position, size and shape of its black bars. It possesses four complete (forming ring) or nearly complete post-cephalic, relatively narrow bars, two of which are located posterior to the base of the anal fin. The first bar behind the head extends pigmentation to the first dorsal fin but does not reach the midventral line. The second bar, chevron-shaped and located below the second dorsal fin, extends pigmentation onto that fin and ventrally reaches the midventral line and the anal fin. Cytochrome oxidase subunit I-based analyses, including six out of the eight valid species of Brachygobius, show Brachygobius jennie sp. nov. to be more than 10% genetically divergent from other species, supporting the morphological diagnosis and confirming its distinct taxonomic status. With a maximum size of less than 9 mm SL (based on observations of 106 specimens), the new species is not only the smallest species of Brachygobius, but also one of the smallest known gobioid fishes.

Key Words: Fish, Gobioidei, integrative taxonomy, new species, miniature vertebrates

Diagnostic marking pattern comparison among all species of Brachygobius having four post-cephalic black bands, the last two located posterior to the base of the anal fin. Left column: schematic drawings highlighting diagnostic marking patterns based on information from type material and original descriptions; from top to bottom: 
Brachygobius jennie sp. nov. based on its description (this study); B. aggregatus, based on a drawing of a type specimen (plate 4 in Herre 1940); B. kabiliensis, based on the drawing of the holotype (fig. 19 in Inger 1958); and B. nunus, based on the drawing of a specimen of Gobius alcockii Annandale, 1906 (fig. 1 in Annandale 1906), a junior synonym of B. nunus, and the description of B. nunus by Hamilton (1822). Red arrowheads indicate diagnostic differences. Right column: photographs of live non-type specimens illustrating the corresponding left schematic patterns (all photos from the authors).

Live photographs of four paratypes of Brachygobius jennie sp. nov., illustrating intra-specific marking pattern.

Photographed by Mr. Haocong Yang and Mr. Danyang Zhou.

Brachygobius jennie sp. nov. 

 Jiangyan Tian, Jianyong Wu, Chunliu Lan, Sébastien Lavoué and Jianrong Huang. 2026. Brachygobius jennie, A New bumblebee goby (Teleostei, Oxudercidae) from Hengqin Island, Guangdong Province, China. Zoosystematics and Evolution. 102(3): 853-863.  DOI: doi.org/10.3897/zse.102.184142 [17 Jun 2026]

[Ichthyology • 2026] Characidium lilloi • A New Species of Characidium (Characiformes: Crenuchidae) from the Northwestern La Plata Basin in Argentina

Characidium lilloi

Terán, Méttola, Alonso, Montes, Méndez-López, Miranda, Aguilera & Mirande, 2026

DOI: doi.org/10.1643/i2025064  

 x.com/IchsAndHerps

Abstract

Using an integrative approach that combines molecular and morphological analyses, we describe Characidium lilloi, a new species from the Andean portion of the northwestern La Plata basin, specifically from the upper Bermejo and Juramento River basins in Argentina. Specimens were examined for morphometric, meristic, and osteological traits. Genetic analyses based on COI and CYTB sequences were conducted to infer its phylogenetic relationships. The new species is distinguished by a unique combination of morphological characters including an unscaled isthmus, absence of dark stripes or spots on fins, 7–13 regular transversal bars, 14 scales around the caudal peduncle, 35–37 scales in longitudinal series, and highly developed nasal flaps; and molecular evidence. Characidium lilloi, new species, was found to be closely related to C. fasciatum and C. gomesi and represents the first known member of the C2 Clade in the northwestern La Plata basin. Ecologically, C. lilloi, new species, inhabits fast-flowing mountain rivers within the Yungas and Chacoan. This discovery underscores the northwestern La Plata basin as a biogeographic hotspot of endemism and reinforces its importance as a high-priority area for freshwater conservation.

Lateral views of live paratypes of Characidium lilloi.
 CI-FML 8196, 36.8–49.1 mm SL,
Argentina, El Rey National Park, Río Popayán.

Scale bar = 1 cm. 

Characidium lilloi, new species

Etymology.—This species is named in honor of the Argentine naturalist Miguel Lillo (1862–1931), a pioneer who recognized the importance of public investment in science and education. In his commitment to advancing these fields, Lillo donated his personal assets before his death, ensuring the continuity of his legacy through several key institutions. These include the Facultad de Ciencias Naturales e Instituto Miguel Lillo, the Fundación Miguel Lillo, and the Unidad Ejecutora Lillo–CONICET, all of which have played significant roles in the development of science and education in Argentina. The specific name lilloi, thus, not only pays tribute to Lillo’s contributions but also honors the dedication of public workers in Argentina who promote and contribute to the progress of science, education, and technology.   

Guillermo E. Terán, V. Ezequiel Méttola, Felipe Alonso, Martín M. Montes, Alejandro Méndez-López, Guido Miranda, Gastón Aguilera and J. Marcos Mirande. 2026. A New Species of Characidium (Characiformes: Crenuchidae) from the Northwestern La Plata Basin in Argentina. Ichthyology & Herpetology. 114(2):283-298 DOI: doi.org/10.1643/i2025064 [23 June 2026]

  x.com/IchsAndHerps/status/2069532500280381641

Utilizando un enfoque integrador que combina análisis moleculares y morfológicos, se describe Characidium lilloi, una nueva especie proveniente del sector andino del noroeste de la cuenca del Plata, específicamente de las cuencas altas de los ríos Bermejo y Juramento en Argentina. Los ejemplares fueron examinados en cuanto a caracteres morfométricos, merísticos y osteológicos. Se realizaron análisis genéticos basados en las secuencias de los genes mitocondriales COI y CYTB con el fin de inferir sus relaciones filogenéticas. La nueva especie se distingue por una combinación única de caracteres morfológicos incluyendo el istmo sin escamas, ausencia de bandas oscuras o manchas en las aletas, presencia de 7 a 13 barras transversales regulares, 14 escamas alrededor del pedúnculo caudal, 35 a 37 escamas en la serie longitudinal, y lóbulos nasales altamente desarrollados; y evidencia molecular. Characidium lilloi, nueva especie, se encuentra estrechamente relacionada con C. fasciatum y C. gomesi, y representa el primer miembro conocido del Clado C2 en el noroeste de la cuenca del Plata. Desde el punto de vista ecológico, C. lilloi, nueva especie, habita ríos de montaña de corriente rápida, dentro de las ecorregiones de las Yungas y el Chaco. Este hallazgo resalta al noroeste de la cuenca del Plata como un hotspot biogeográfico de endemismos, y refuerza su importancia como una región de alta prioridad para la conservación de ambientes dulceacuícolas.

[Ichthyology • 2026] Rhinogobius mengyangensis • A New Species of Freshwater Goby (Gobiiformes: Gobiidae) from Sichuan Province, southwestern China

 

Rhinogobius mengyangensis 

X. Liu, Chen, Shu, Huang, K. Liu & Yu, 2026

濛阳吻虾虎鱼  ||  DOI: doi.org/10.3897/zookeys.1280.188225

Abstract

A new species of freshwater goby, Rhinogobius mengyangensis sp. nov., is described from the upper Changjiang River basin in Sichuan Province, China, based on comparative morphology and molecular phylogeny. The new species is sister to Rhinogobius szechuanensis Tchang, 1939 and can be distinguished from its congeners by the following combination of characters: absence of sensory canals and pores on head; cheeks and operculum without spots or stripes; second dorsal fin with 9–11 longitudinal rows of inverted V-shaped or dash-like brown markings; incomplete brownish edges on flank scales below second dorsal fin; branchiostegal membrane bright yellow.

Key words: Biodiversity, freshwater, phylogeny, taxonomy

Rhinogobius mengyangensis sp. nov. alive. 

A. Male, Tuojiang River basin (holotype, IHB 0202506006); B. Female, Tuojiang River basin (Paratype, IHB 0202506007); 

C. Male, Qingyijiang River basin; D. Female, Qingyijiang River basin.

Rhinogobius mengyangensis sp. nov.

 

Diagnosis. Rhinogobius mengyangensis sp. nov. can be distinguished from all congeners except R. szechuanensis by the following combination of features: absence of sensory canals and sensory pores on head; cheeks and operculum without spots or stripes (Fig. 3). It can be distinguished from R. szechuanensis in having the second dorsal fin with 9–11 longitudinal rows of inverted V-shaped or dash-like brown markings (vs with blue spots, some coalescing into vertical bars), incomplete brownish edges on flank scales below second dorsal fin (vs with complete edges), and a bright-yellow branchiostegal membrane (vs white or blue) (Fig. 4).

 Xin Liu, Zhong-Guang Chen, Yi-Fan Shu, Jun-Hao Huang, Kai Liu and Yi Yu. 2026. Rhinogobius mengyangensis : A New Species of Freshwater Goby (Teleostei, Gobiidae) from Sichuan Province, southwestern China. ZooKeys. 1280: 333-347. DOI: doi.org/10.3897/zookeys.1280.188225

[28 May 2026]

[Ichthyology • 2026] Solenostomus snuffleupagus • A hairy Ghost Pipefish (Syngnathiformes: Solenostomidae) from the Southwest Pacific, with an integrative comparison to S. paegnius

Solenostomus snuffleupagus

Short & Harasti, 2026   

DOI: doi.org/10.1111/jfb.70497

 

Abstract

A new species of ghost pipefish, Solenostomus snuffleupagus sp. nov., is described from the Coral Sea based on specimens (18–34 mm SL) collected from coral reef habitats in Queensland, Australia. The species is diagnosed by the following combination of characters: abundant elongate integumentary filaments imparting a conspicuously shaggy appearance; 36 total vertebrae (vs. 32–34 in all congeners); compact body form with a short, deep pretrunk (11%–14% SL); sexually dimorphic supraoccipital crests (moderately elevated in females, strongly developed in males); and two modified anchor-like ossicles spanning the pterygiophores in both soft dorsal and anal fins. Micro-CT imaging reveals distinctive pretrunk ossicle configuration characterized by deep angular interspaces and absence of a ventral ossicle series. Mitochondrial COI sequences indicate an uncorrected p-distance of 22.0% from the superficially similar S. paegnius, a species with which it has long been confused in museum collections and citizen science databases. Field observations document consistent association with dense filamentous red macroalgae, with body coloration closely matching host substrate. The species is currently known from the southwest Pacific, including northeastern Australia (Coral Sea), Papua New Guinea, New Caledonia, Fiji and Tonga, representing a southwestern Pacific distribution.

Solenostomus snuffleupagus, in situ, Great Barrier Reef, Australia, 2022: (a) adult individual; (b) female specimen used for genetic analysis; (c) male specimen used for genetic analysis (photographs by David Harasti).

Micro-CT reconstructions (lateral view) of Solenostomus snuffleupagus:
(a) holotype, female, AMS I.33751-047; (b) paratype, male, NTM S.13600–047. DF, dorsal-fin; PF, pectoral-fin; sAF, soft anal-fin; sDF, soft dorsal-fin. Numbers 1 and 2 indicate the respective pterygiophores supporting the soft dorsal- and anal-fins.

 Taxonomy

Family Solenostomidae 

Genus Solenostomus Lacépède 1803 

 Solenostomus snuffleupagus, Short and Harasti, new species

Diagnosis: A species of Solenostomus distinguished from its congeners by the following combination of characters: body compact and vertically deep anteriorly; pretrunk deep (24.4%–29.2% SL); abundant, elongate integumentary filaments conferring a conspicuously shaggy appearance, particularly dense on snout, jaws, head and fin extremities; pretrunk ossicles are narrow and elongated, separated by deep angular interspaces, forming a distinctive compact lattice; There are total 36 vertebrae. The supraoccipital crest is elevated and rounded in females, but strongly pronounced in males. There are two modified anchor-like ossicles spanning the pterygiophores in both the soft dorsal fin (19–20 rays) and anal fin (18–19 rays). The soft dorsal fin has 19–20 rays, the anal fin has 18–19 rays, the pectoral fin has 27 rays, the caudal fin has 15 rays.

Etymology: The specific epithet snuffleupagus refers to the shaggy character Mr. Snuffleupagus, also known as ‘Snuffy’, from the children's television series Sesame Street™, in allusion to the species' distinctly shaggy, filamentous appearance and snout reminiscent of the character's covering and trunk. The name is treated as a noun in apposition (ICZN Article 31.1.2).

Solenostomus paegnius, in situ: (a) Indonesia (photograph by Richard Smith); (b) Philippines, male–female pair with the female positioned above the male in the water column (photograph by Lynn Funkhouser); (c) Philippines, male–female pair with the female positioned above the male in the water column (photograph by Alex Tyrrell @dive4photos).

 

Graham Short and David Harasti. 2026. Solenostomus snuffleupagus sp. nov., A hairy Ghost Pipefish (Teleostei: Solenostomidae) from the Southwest Pacific, with an integrative comparison to S. paegnius. Journal of Fish Biology. DOI: doi.org/10.1111/jfb.70497 [10 May 2026]

 

[Ichthyology • 2026] Hemigrammus serrazul • A New Hemigrammus (Characiformes: Acestrorhamphidae) from the rio Cuiabazinho Drainages, upper rio Paraguai Basin, Mato Grosso, Brazil

   

Hemigrammus serrazul  

Ferreira, Ribeiro & Carvalho, 2026

DOI: doi.org/10.1590/1982-0224-2025-0157

 

Abstract

A new species of Hemigrammus is described from tributaries of the rio Cuiabazinho, upper rio Paraguai basin, Mato Grosso State, Brazil. It can be readily distinguished from all its congeners by a unique combination of characters, including a distinctive body coloration pattern without spots, the number of perforated lateral-line scales (12–15), the number of branched rays on anal fin (21–25), and the presence of small bony hooks at the tips of the lepidotrichia of the second to fourth branched rays of the pelvic fins, which are absent in the anal fin. We also provide a brief discussion on the recent taxonomic reconfiguration of Hemigrammus.

Keywords: Freshwater fish; Rio Cuiabá drainage; Serra Azul; Serrana Province of Mato Grosso; Taxonomy

 Color pattern variations in live specimens of Hemigrammus serrazul: A. Male; B. Female.

Photo by Alexandre C. Ribeiro.  

Hemigrammus serrazul, new species

Diagnosis. Hemigrammus serrazul can be distinguished from most congeners (except of H. apiaka (Esguícero& Castro, 2017), H. erythrozonus Durbin, 1909, H. gracilis (Lütken, 1875), H. mimus Böhlke, 1955, and H. tupebas (Esguícero& Castro, 2017) by flank uniformly colored, without spots, i.e., no humeral and caudal spots, just a tiny and narrow longitudinal stripe (vs. species with spots in humeral and/or caudal peduncle). From H. apiaka, H. erythrozonus, H. gracilis, H. mimus, and H. tupebas, H. serrazul differs by premaxillary teeth in two rows: outer with three to five tricuspid teeth, inner with five ...

Etymology. The specific epithet serrazul refers to the type locality where the new species was collected, the Serra Azul, the local portion of the so-called Serrana Province of Mato Grosso, a range of escarped relief that serves as a watershed divide between the rio Cuiabá, Paraguai, and Arinos basins. A noun in apposition.

Hemigrammus serrazul, live specimen in aquarium, photographed just after capture in córrego Cocal (CPUFMT 8218), upper rio Paraguai basin, municipality of Rosário Oeste, Mato Grosso State, Brazil. Inserir:

Photo by Alexandre C. Ribeiro.

Katiane Mara Ferreira, Alexandre Cunha Ribeiro and Fernando Rogério Carvalho. 2026. A New Hemigrammus (Characiformes: Acestrorhamphidae) from the rio Cuiabazinho Drainages, upper rio Paraguai Basin.  Neotrop. ichthyol. 24 (01); DOI: doi.org/10.1590/1982-0224-2025-0157

[Ichthyology • 2026] Redefinition of Stemonosudis intermedia (Ege, 1933) (Aulopiformes: Paralepididae) and Description of Stemonosudis dianea, A New Species from the western Atlantic Ocean

[A-B] Stemonosudis dianea  Ho & Bemis, 2026 
Stemonosudis intermedia  (Ege, 1933)

 

DOI: doi.org/10.1111/jfb.70342

 

Abstract

We examined specimens of slender barracudina in the genus Stemonosudis collected from the western Atlantic Ocean. Investigation revealed that seven specimens represent the first adult records of Stemonosudis intermedia (Ege, 1933), previously known only from juveniles. We redescribed S. intermedia based on the holotype and newly recognized adult and juvenile specimens, and using this ontogenetic series, we document changes in coloration from light-brown juveniles to black adults. We also determined that some specimens from the western Atlantic Ocean previously identified as S. intermedia represent a new species, which we describe herein based on three adults and five juvenile specimens. The new species differs from congeners by having 43–44 anal-fin rays, 117–121 total vertebrae and a pale mouth, gill chamber and gill arches, among a combination of other characters. We also provide information on the lectotype of S. similis (Ege, 1957), which remains known only from the type series.

Keywords: biodiversity, biogeography, Ichthyology, nomenclature, taxonomy

Stemonosudis dianea sp. nov., fresh coloration.
(a) Holotype USNM 407498, 332 mm SL, photograph by Cristina Castillo.
(b) Paratype USNM 407509, 348 mm SL, photograph by Sandra Raredon.

 Stemonosudis dianea sp. nov.

English name: Diane's Slender Barracudina

Stemonosudis intermedia (Ege, 1933), fresh coloration of adults. Right side photographed, reflected to face left. USNM 407096, 277 mm SL. (a) Lateral view of body. (b) Close up of head.

Photographs by Ross Robertson.

Hsuan-Ching Ho and Katherine E. Bemis. 2026. Redefinition of Stemonosudis intermedia (Ege, 1933) and Description of A New Species from the western Atlantic Ocean (Aulopiformes: Paralepididae). Journal of Fish Biology. DOI: doi.org/10.1111/jfb.70342 [30 March 2026]

https://www.fisheries.noaa.gov/feature-story/ferocious-predator-and-important-prey-new-barracudina-species-named-smithsonian

[Ichthyology • 2021] Lethrinus mitchelli • A New Species of Emperor Fish (Acanthuriformes: Lethrinidae) from Milne Bay Province, Papua New Guinea

Lethrinus mitchelli

Allen, Victor & Erdmann, 2021

DOI: doi.org/10.5281/zenodo.5172763 

Abstract 

A new species of emperor fish, Lethrinus mitchelli, is described on the basis of three specimens, 109.4–111.3 mm SL, collected from 20 m at the East Cape region of Milne Bay Province, Papua New Guinea. It is similar to the sympatric relatives L. semicinctus and L. rubrioperculatus, but differs in color pattern and has a narrower cheek (cheek height 3.2–3.6 in head length vs. 2.4–2.9). Other diagnostic features include head length (2.7 in SL) greater than body depth (3.0–3.1 in SL); the snout excluding the lip 1.3–1.4 in cheek height; the snout profile nearly straight, without a prominent hump, and about 55° to the upper jaw; conical lateral jaw teeth; the interorbital area nearly flat or convex; the fourth dorsal-fin spine longest; lateral-line scales 47; transverse scale rows below and above the lateral line 15 and 4.5 rows; and a fully-scaled area adjacent to the prominent bony spine at the posteriormost margin of the opercle (excluding fleshy flap). The new species has a distinctive color pattern: brown dorsally, whitish ventrally, with a broad, brown, posteriorly tapering band on the midlateral body, partially split anteriorly by a relatively broad, ascending diagonal white band. Lethrinus mitchelli is 6.11% sequence divergent (pairwise) in the mtDNA COI marker from its nearest relative, L. semicinctus, also from the East Indies. A table of COI divergences among mtDNA lineages assigned to 27 of the 28 known species of Lethrinus shows a set of distinctly different lineages, from 3.32% to 20.85% divergent from each other (minimum interspecific distances). 

Key words: taxonomy, ichthyology, phylogenetics, coral reef fishes, Indo-Pacific, DNA barcodes, mtDNA COI 

Lethrinus mitchelli n. sp.
blotchy pattern on rubble bottom, about 200 mm SL, East Cape Region, Milne Bay Province, Papua New Guinea
 preserved holotype, 110.1 mm SL, East Cape Region, Milne Bay Province, Papua New Guinea.

photos: G.R. Allen.

Lethrinus mitchelli n. sp.
[upper] about 200 mm SL, East Cape Region, Milne Bay Prov., Papua New Guinea; 
[lower] blotchy pattern on rubble bottom, about 200 mm SL, East Cape Region, Milne Bay Province, Papua New Guinea.

photos: G.R. Allen

 Allen, G.R., Victor, B.C. and Erdmann, M.V. 2021. Lethrinus mitchelli, A New Species of Emperor Fish (Teleostei: Lethrinidae) from Milne Bay Province, Papua New Guinea. Journal of the Ocean Science Foundation. 38, 66–77. DOI: doi.org/10.5281/zenodo.5172763 

[Ichthyology • 2026] Claea dafangensis (Cypriniformes: Nemacheilidae) • A New Cave-dwelling Fish from the upper Wujiang River, Guizhou Province, China

(A) Claea dafangensis Wang, Luo & Zhou, sp. nov. 

(F) Habitat of C. dafangensis sp. nov.

(B) C. dabryi (E) C. scet (Lei et al. 2025). 

in J.-J. Wang, Luo, M.-Y. Xiao, Xie, Y.-L. Wang, Deng, N. Xiao et Zhou, 2026.  

大方山鳅  ||  DOI: doi.org/10.3897/zse.102.172325

 Abstract

A new species of the genus Claea, Claea dafangensis sp. nov., is described from Yuchong Township, Dafang County, Guizhou Province, China. This species can be distinguished from its four congeners by a combination of the following characteristics: body pigmentation present; normal eyes with a diameter of 10.9–21.0% of head length (HL); processus dentiformis prominent, covering the lower jaw when the mouth is shut; 8–9 branched pectoral-fin rays; 16 branched caudal-fin rays; caudal-peduncle depth 6.1–8.7% of standard length (SL); interorbital width 23.6–39.0% HL; tip of maxillary barbel reaching the posterior margin of the eyes; outrostral barbel extending backward beyond the anterior nostrils; and anal-fin base length 4.0–5.5% SL. Mitochondrial Cyt b analysis further supports the distinctiveness of this population, revealing that it forms an independent phylogenetic lineage with a minimum genetic distance of 2.6% from C. wulongensis. The description of this new species suggests that Claea dabryi represents a species complex containing multiple distinct lineages, the diversity of which requires further evaluation.

Key Words: Mitochondrial, morphology, taxonomy, Wujiang basin

Holotype GZNU20241204001 (A–K) of Claea dafangensis sp. nov. in preservative.
 (A) Lateral view. (B) Dorsal view. (C) Ventral view. (D) Dorsal-fins view. (E) Anal-fins view. (F) Pectoral-fins view. (G) Pelvic-fins view. (H) Dorsal view of head. (I) Lateral view of head. (J) Ventral view of head. (K) Anterior chamber and posterior chamber. (Cephalic lateral line system highlighted as yellow dots)

Claea dafangensis Wang, Luo & Zhou, sp. nov.

Diagnosis. Comparative data between new species and all four known species within the genus Claea are provided in Table 3. Claea dafangensis sp. nov. can be distinguished from C. scet by the processus dentiformis prominent, covering lower jaw when mouth shut (vs.reduced, not covering lower jaw when mouth shut), body pigmentation present (vs. reduced), eyes normal, with diameter 10.9–21.0% of head length (HL) (vs. eyes reduced, 3.8–5.9% HL); from C. minibarba by tip of maxillary barbel reaching the posterior margin of eyes (vs. extending to the middle of eye), 8–9 branched pectoral-fin rays (vs. 10), and caudal-peduncle depth 6.1–8.7% SL (vs. 9.5–11.7%); from C. wulongensis by tip of maxillary barbel reaching the posterior margin of eye (vs. extending to ansterior margin of eye), 16 branched caudal-fin rays (vs. 18), and interorbital width 23.6–39.0% HL (vs. 38.5–43.1%); from C. dabryi (Fig. 6) by outrostral barbel backward extending beyond the anterior nostrils (vs. reaching or beyond to ansterior margin of eye), tip of maxillary barbel reaching the posterior margin of eye (vs. beyond the posterior margin of eye), and anal fin base length 4.0–5.5% SL (vs. 2.8–3.4%).

Lateral view of species in the genus Claea during life and the habitat of the new species.
(A) Claea dafangensis sp. nov. (B) C. dabryi (C) C. wulongensis (Chen et al. 2021). (D) C. minibarba (Zhang et al. 2024). (E) C. scet (Lei et al. 2025). (F) Habitat of Claea dafangensis sp. nov.

Etymology. The specific epithet “dafangensis” refers to the type locality of the new species, distributed in Dafang County. We propose the common English name “Dafang mountain loach” and the Chinese name “Dà Fānɡ Shān Qīu (大方山鳅).”

Jia-Jia Wang, Tao Luo, Ming-Yuan Xiao, Xin Xie, Yu-Ling Wang, Huai-Qing Deng, Ning Xiao and Jiang Zhou. 2026. Claea dafangensis (Cypriniformes, Nemacheilidae), A New Cave-dwelling Fish from the upper Wujiang River, Guizhou Province, China. Zoosystematics and Evolution. 102(2): 519-531.  DOI: doi.org/10.3897/zse.102.172325 [26 Mar 2026]

[Ichthyology • 2025] Hyphessobrycon ribeiroi • A New Hyphessobrycon (Characiformes: Acestrorhamphidae) from the Central Amazon Basin, Brazil

Hyphessobrycon ribeiroi

Lima, Silva-Oliveira, Oliveira & Faria, 2025

 

Papéis Avulsos De Zoologia. 65;  

scielo.br/j/paz 

Researchgate.net/publication/388856173

Abstract

A new species of Hyphessobrycon is described from the region of the lower rioTapajós basin, state of Pará, and tributaries of the northern bank of the Amazon River from the rio Itapiranga basin westward to the lower rio Negro basin, states of Amazonas and Roraima, Brazil. The new species exhibits a color pattern consisting in a conspicuous single humeral blotch and a conspicuous caudal peduncle blotch, a pattern shared with several congeners. It can be diagnosed from those congeners by some other pigmentary features, and from some of them by maxillary teeth, and/or branched anal-fin rays counts, anal-fin morphology, and fin hooks arrangement in matures males.The new species is most similar morphologically to a non-congener, Hemigrammus schmardae, with which it was found syntopically at the lower rio Negro but can be distinguished from it by some color pattern features. An analysis based on the cytochrome c oxidase I gene indicates that the new species is closely related to Hyphessobrycon ericae.

Keywords: Barcoding; Hemigrammus schmardae ; Hyphessobrycon ericae ; rio Tapajós; rio Negro

Hyphessobrycon ribeiroi, new species, living aquarium specimens, no locality data.

Hyphessobrycon ribeiroi, new species  

 Diagnosis: Hyphessobrycon ribeiroi can be distinguished from most species currently assigned to the genera Hyphessobrycon and Hemigrammus, except He. hyanuary, He. levis, He. melanochrous, He. schmardae, He. vorderwinkleri, Hy. duragenys, Hy. eos, Hy. ericae, Hy. frankei, Hy. langeanii, Hy. santae, Hy. reticulatus, Hy. rutiliflavidus, Hy. tenuis, Hy. tropis, Hy. uaiso, Hy. wosiackii, and Hy. zoe by the presence of single humeral blotch and a caudal peduncle blotch extending into the basis of the middle caudal fin rays (vs. two humeral blotches or absence of a blotch in the humeral region or caudal peduncle). It can be distinguished from aforementioned species, except Hy. ericae and Hy. wosiackii, by possessing a vertically elongated humeral blotch with a posterior backward extension (vs. humeral blotch never presenting a posterior backward extension). The new species can be diagnosed from ...

Etymology: The specific epithet is a homage to Frank Raynner Ribeiro, professor of the Universidade Federal do Oeste do Pará, as a recognition of its contribution to the knowledge of South American Siluriformes and also the fishes from the rio Tapajós basin.

Flávio C.T. Lima, Cárlison Silva-Oliveira, Claudio Oliveira and Tiago C. Faria. 2025. A New Hyphessobrycon (Characiformes: Acestrorhamphidae) from the Central Amazon Basin, Brazil. Papéis Avulsos De Zoologia. 65; e202565011. DOI: 10.11606/1807-0205/2025.65.011

  https://www.scielo.br/j/paz/a/nfFVZnYpfgBPdnt9KBQTJ6H

 Researchgate.net/publication/388856173_A_new_Hyphessobrycon_from_the_Central_Amazon_basin_Brazil

  x.com/PAZ_journal/status/2026326260490678454