[Ichthyology • 2026] Tridensimilis magnus • A New Species of Tridensimilis (Siluriformes: Trichomycteridae) from Tapajós Basin, Brazil: the Largest translucent Catfish Species of Tridentinae

 Tridensimilis magnus

Colares Canto, Datovo, Ohara, de Pinna & Ribeiro, 2026.  

DOI: doi.org/10.1590/1982-0224-2025-0209 

Abstract

A new species of translucent catfish of the genus Tridensimilis is described from the upper and middle rio Tapajós basin, states of Pará and Mato Grosso, Brazil. In addition, we redefine the taxonomic limits of the genus Tridensimilis and present evidence that questions the current generic placement of Tridentopsis tocantinsi. The new species is distinguished from congeners by a set of morphological features, in combination: number of vertebrae, anal-fin rays, opercular and interopercular odontodes; eyes positioned laterally and oriented ventrally, slightly more visible in ventral than in dorsal view; and basipterygia fused at midline. Live specimens of the new species display ex situ atmospheric air capture at the water surface, resulting in the filling of the digestive cavity with air bubbles, a behavior recorded for the first time in any representative of Tridentinae. The new species is the largest currently known of the subfamily Tridentinae, with analyzed specimen reaching 34 mm of standard length. The new taxon likely increases the list of endemism in the rio Tapajós basin.

Keywords: Amazon basin; Behavior; Biodiversity; Conservation; Taxonomy

 

Live specimens of Tridensimilis magnus:
 UFOPA-I 1773, 29.0 mm SL (A) and INPA-ICT 62042, not mensured (B-D). Arrows indicate swallowed air bubbles in stomach and intestines.

Tridensimilis magnus, new species

Diagnosis. Tridensimilis magnus differs from all other Tridentinae in having the largest body length, reaching 34 mm SL (vs. 27 mm in Tridens, 25 mm in Tridentopsis Myers, 1925, 17 mm in Miuroglanis Eigenmann & Eigenmann, 1889, 18 mm in Rhinotridens, and 23 mm in Tridensimilis). The new species is further distinguished from all tridentines, except Rhinotridensbritskii, by having 39–41 post-Weberian vertebrae (vs. 34–38 in Miuroglanis, Rhinotridens chromocaudatus, Tridentopsis and Tridensimilis, and 45–52 in Tridens). Tridensimilis magnus additionally differs from Tridensimilisvenezuelae and T. tocantinsi LaMonte, 1939,in having longer maxillary barbels that surpass the opercular odontophore (vs. not extending beyond pupil); externally visible rictal barbels reaching the base of interopercular odontophores (vs. rictal barbels not externally visible or reaching at most one-third of distance from their base to anterior margin of eyes); 7 or 8 dorsal-fin rays (vs. 8–11); and pelvic-fin base vertically aligned with the 13th or 14th vertebra (vs. with the 11th vertebra). The new species is additionally distinguished from T. tocantinsi in having 6 or 7 opercular odontodes (vs. 10); from T.venezuelae by having 7 or 8 interopercular odontodes (vs. 4–6).

Etymology. The specific epithet magnus derives from Latin meaning “large” or “great”, in allusion to the longer length of the species in comparison to its congeners, emphasizing one of the distinctive morphological traits that diagnose the species. An adjective.

 

 André L. Colares Canto, Aléssio Datovo, Willian M. Ohara, Mário C. C. de Pinna and Frank Raynner V. Ribeiro. 2026. A New Species of Tridensimilis (Siluriformes: Trichomycteridae) from Tapajós Basin: the Largest translucent Catfish Species of Tridentinae. Neotropical Ichthyology. 24(02); DOI: doi.org/10.1590/1982-0224-2025-0209  [20 July 2026]

[Ichthyology • 2025] Pseudogastromyzon putienensis • A New Species of Pseudogastromyzon Nichols (Teleostei: Balitoridae) from Fujian Province, Southeastern China

Pseudogastromyzon putienensis 

Chen & Li, 2025

莆田擬腹吸鰍 | DOI: doi.org/10.11646/zootaxa.5738.1.22

Abstract

In this study, a new species of balitorid loach from Fujian Province was collected and described herein, namely Pseudogastromyzon putienensis. The new species can be identified by having dorsal fin iii, 7, anal fin ii, 5, pectoral fin i, 17–18, pelvic fin i, 9, lateral line scales 65–71 and vertebrae counts 38–39. For body and fin colourations, male possess greyish brown with metallic sheen, straight pale bars, and conspicuous rows of large dorsal-fin spots while females with ivory base color and distinct Y-shaped or curved bars, and transparent paired and caudal fins with striped rows. The new species was collected from the Mulan River system and is closely related to Pseudogastromyzon fasciatus; comparisons of the two species are provided herein with comments upon the taxonomy of related congeners in southeastern China.

 Pisces, Pseudogastromyzon, Balitoridae, new species, Fujian Province, China 

Pseudogastromyzon putienensis sp. nov.
Fresh coloration of adult male (A, NTOUP-2023-09-001, holotype, 66.7 mm SL), and juvenile (B, NTOUP-2023- 09-003, paratype, 40.3 mm SL) 

Pseudogastromyzon Nichols, 1925 

Pseudogastromyzon putienensis sp. nov.

(莆田擬腹吸鰍)

 I-SHIUNG CHEN and HSIEN-EN LI. 2025. A New Species of Pseudogastromyzon Nichols (Teleostei: Balitoridae) from Fujian Province, Southeastern China.  Zootaxa. 5738(1); 183-189. DOI: doi.org/10.11646/zootaxa.5738.1.22 [2025-12-30]

[Ichthyology • 2024] Turcinoemacheilus ekmekciae • A New dwarf loach (Cypriniformes: Nemacheilidae) from upper Tigris and Euphrates

Turcinoemacheilus ekmekciae

Kaya, Yoğurtçuoğlu, Aksu, Bayçelebi & Turan, 2024

DOI: doi.org/10.1111/jfb.15578 

 

Abstract

Turcinoemacheilus ekmekciae, new species, from upper Euphrates and Tigris drainages is distinguished from other species of Turcinoemacheilus in Western Asia by having a dark stripe broader than the eye diameter along the lateral line, rarely possessing roundish blotches, 5–6 mandibular pores in mandibular canal, a comperatvely smaller head, a deeper body, and a greater pre-pelvic distance. Our specimens collected from the upper Great Zab, near the type locality of Turcinoemacheilus kosswigi, showed notable genetic divergence (a minimum K2P of 3.3%) from sequences reported as T. kosswigi in previous studies. Despite morphological similarities, this molecular difference suggests that the populations analysed in previous studies may represent a potential new species of Turcinoemacheilus, which we tentatively named as Turcinoemacheius cf. kosswigi. Molecular data also suggest that T. ekmekciae is characterized by a minimum K2P distance of 3.5% from Turcinoemacheilus minimus and T. cf. kosswigi. The three methods for species delimitation (assemble species by automatic partitioning [ASAP], Poisson tree processes [PTP], and multi-rate PTP [mPTP]) that were utilized for testing species assignments consistently identified our test group as a distinct species.

Keywords: cytochrome c oxidase I, freshwater, fish, taxonomy, Western Asia

Turcinoemacheilus ekmekciae,
from the top, FFR 3608, holotype, 36 mm standard length (SL); Kaynarca stream, Euphrates:
FFR 3616, paratype, 41 mm SL, Nerduş stream, Tigris:
Not preserved, ~35 mm SL; not preserved, ~40 mm SL; not preserved, ~40 mm SL; Kaynarca stream, Euphrates.

 Turcinoemacheilus ekmekciae, new species

Diagnosis: Turcinoemacheilus ekmekciae is distinguished from its congeners from upper Tigris and Euphrates drainages by a combination of characters. The new species is distinguished from T. minimus from Göksu and Kahta drainages by having a deeper caudal peduncle (7%–9% SL v. 6–7), and 5–6 mandibular pores in mandibular canal (v. 4–5). T. ekmekciae is distinguished from T. kosswigi from upper Greater Zab by having a greater pre-pelvic distance (50%–53% SL v. 47–50), a shorter upper caudal fin lobe (14%–18% SL v. 18–21), and a shorter maxillary barbel (15%–21% HL v. 21–26). The new species is further distinguished from T. kosswigi by having a dark stripe broader than the eye diameter along the lateral line, only in one population possessing roundish blotches (v. a dark-brown mid-lateral stripe narrower than the eye diameter).

Turcinoemacheilus ekmekciae is distinguished from the two Iranian Turcinoemacheilus, T. bahaii and T. hafezi, by the position of the ...

Etymology: The species is named for Fitnat Güler Ekmekçi for her contribution to the knowledge of the ichthyofauna of Türkiye. A noun in genitive, indeclinable.

 

Cüneyt Kaya, Baran Yoğurtçuoğlu, İsmail Aksu, Esra Bayçelebi and Davut Turan. 2024. Turcinoemacheilus ekmekciae, A New dwarf loach from upper Tigris and Euphrates (Teleostei: Nemacheilidae). Journal of Fish Biology. DOI: doi.org/10.1111/jfb.15578 [10 October 2023]

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[Ichthyology • 2026] Prognathodes thanatos • A New Deepwater Species of Butterflyfish (Teleostei: Chaetodontidae: Prognathodes) from Mozambique, Africa, with a Systematic Review of Chaetodontid Relationships on the Basis of Osteology

 Prognathodes thanatos

 Tea, Blum, Rocha, Parkinson & Stanley, 2026 

DOI: doi.org/10.1643/i2025038  

  x.com/IchsAndHerps

 Abstract 

Prognathodes thanatos, new species, is described on the basis of the holotype from Mozambique, Africa. The new species is readily distinguished from congeners in having the following combination of live coloration details and morphological characters: head and body silvery white with three broad, dark brown bands; pelvic fin including spine black; dorsal-fin rays XIII,19; anal-fin rays III,15; lateral line short and incomplete with 26–29 pored scales; gill rakers 4 + 12–13 = 16–17; snout length 12.6% SL; and angle of preopercle finely serrate. The new species appears to be most closely related to Prognathodes guyotensis, a poorly known, deepwater species of butterflyfish known from very few specimens. The assignment of both species to the genus Prognathodes is accompanied by a critical reassessment and discussion of the currently inadequate definition of the genus.

Prognathodes thanatos, new species, SAIAB 80277, holotype, 100.3 mm SL, off Bazaruto Archipelago, Mozambique, Africa in (A) fresh and (B) preserved coloration.
Photographs by (A) P. Heemstra, South African Institute of Aquatic Biology, copyright 2025, used with permission, and (B) C. Phan, Australian Museum Research Institute, copyright 2025.  x.com/IchsAndHerps

Underwater photographs of Prognathodes thanatos, new species, taken using remotely operated submersibles.
(A–B) 200 m, Comoro Islands; (C) depth unknown, off the coast of KwaZulu-Natal, South Africa; (D) depth unknown, likely >100 m, Leadsman Canyon, Sodwana Bay, off the coast of KwaZulu-Natal, South Africa

Yi-Kai Tea, Stanley D. Blum, Luiz A. Rocha, Kerryn Parkinson and Edward L. Stanley. 2026. A New Deepwater Species of Butterflyfish (Teleostei: Chaetodontidae: Prognathodes) from Mozambique, Africa, with a Systematic Review of Chaetodontid Relationships on the Basis of Osteology. Ichthyology & Herpetology. 114(3); 474-494. DOI: doi.org/10.1643/i2025038 (15 September 2026)  

 x.com/IchsAndHerps/status/2103540682904199366

 www.instagram.com/p/DdZv3B9E20t

[Ichthyology • 2026] Peckoltia kahxi • A New Species of Peckoltia (Siluriformes: Loricariidae) from the rapids of rio Trombetas Basin, Brazi

 

 Peckoltia kahxi

Dopazo, Araújo, Akama & Wosiacki, 2026

 

DOI: doi.org/10.1590/1982-0224-2026-0053

Abstract

A new species of Peckoltia is described from the rio Trombetas basin, Pará State, Brazil. The new species was investigated by morphological and molecular dataset and it can be distinguished from its congeners by: (1) mottled appearance, without defined spots or patches on the head and body, (2) partially naked abdomen with clusters of plates on the lateral sides of the abdomen from the pectoral to the pelvic region, (3) higher numbers of teeth on both jaws, (4) short odontodes in the cheek, (5) dark spots on the interradial membranes on all fins, (6) four saddles along the body, (7) lower lips with rounded papillae, (8) yellow stripes of the head obliquely positioned on head, not larger than eye orbit, (9) upper lip completely dark, and (10) dorsal margin of the hyomandibula concave. Genetic analysis revealed a genetic divergence of 2.3 to 15% between the new species and other species of the genus. Additionally, phylogenetic analysis based on a mitochondrial gene (Cytb) was conducted and the species was recognized as a monophyletic unit. The description of the new species contributes to the knowledge of the Trombetas River basin, a little-known tributary on the left bank of the Amazon River.

Keywords: Amazon basin; Ancistrini; Armoured catfish; Rheophilic species; Taxonomy

 Peckoltia kahxi, new species

 Manuela Dopazo, lFelipe Arian de Andrade Araújo, Alberto Akama and Wolmar Benjamin Wosiacki. 2026. A New Species of Peckoltia (Siluriformes: Loricariidae) from the rapids of rio Trombetas Basin, Brazil. Neotrop. ichthyol. 24(3); DOI: doi.org/10.1590/1982-0224-2026-0053

 

[Ichthyology • 2026] Hypomasticus rectangulatus • A New Species of Hypomasticus (Characiformes: Anostomidae) from the Vila Nova River, State of Amapá, Brazil

Hypomasticus rectangulatus

Ito, Gama, Sabaj & Birindelli, 2026

DOI: doi.org/10.1643/i2025102 

 Abstract  

A new species of Hypomasticus is described from the Vila Nova River, a left-bank tributary to the lower Amazon in the state of Amapá, Brazil. The new taxon belongs to the Hypomasticus granti group, a clade recently corroborated by molecular phylogenetics, and is diagnosed by a color pattern distinctive among anostomids: midlateral side with dusky rectangular blotch extending from the opercle to near vertical through dorsal-fin origin and followed by three dark oblong (vertically elongated) blotches well separated on posterior half of body, and (in adults) scales in anterior portion of lateral line and flanking rows with a dark spot at their base, forming three longitudinal rows within the dusky rectangular blotch. It further differs from congeners by having 32–34 perforated lateral-line scales and 12 circumpeduncular scale rows. Osteological examination revealed polymorphism in the number of dentary teeth regarding the presence of a fifth tooth, a condition previously observed in other members of the H. granti group. Sexual dimorphism was recorded with males exhibiting hypertrophy of the first pair of ribs, a condition previously unknown within this clade.

Hypomasticus rectangulatus.
(A) IEPA 5637, holotype, 213.3 mm SL and (B) IEPA 5417, paratype, 89.84 mm SL. Brazil, Amapa´ state, municipality of Mazaga˜o, rio Vila Nova. Photos by M. Sabaj. Scale = 1 cm.

Hypomasticus rectangulatus sp. nov. 

Etymology.—The specific epithet rectangulatus is derived from the Latin word meaning rectangular or right-angled, in reference to the distinctive rectangular blotch present on the anterior midlateral region of the body. An adjective.

 

Ian Solon Bortoloci Ito, Cecile de Souza Gama, Mark Henry Sabaj and José Luís Olivan Birindelli. 2026. A New Species of Hypomasticus (Characiformes: Anostomidae) from the Vila Nova River, State of Amapá, Brazil. Ichthyology & Herpetology. 114(3); 507-519. DOI: doi.org/10.1643/i2025102 (22 September 2026)

[Ichthyology • 2026] Parachiloglanis gurungi • A New Species of Torrent Catfish (Siluriformes: Sisoridae) from western Bhutan

 Parachiloglanis gurungi

Thoni & Gurung, 2026

 DOI: doi.org/10.11646/zootaxa.5881.3.9 

 facebook.com: Ryan Thoni

 

Abstract

A new species of Parachiloglanis is described, based on specimens collected from the Kalikhola stream, a tributary of the Jaldhaka River, Samtse Dzongkhag, Bhutan. Parachiloglanis gurungi, new species, differs from its congeners in having a white bar on anterior flanks on dorsum of the body, white spot at the upper caudal-peduncle base, short and deep caudal peduncle, long predorsum, and differences in vomerine toothplate shape. Phylogenetic analysis of the cytochrome oxidase subunit B (cytb) gene sequences reveal lineage independence, corroborating its distinct status and establishing it as a sibling species to Parachiloglanis hodgarti.

 Pisces, Glyptosterninae, Teesta River, Samtse, Siluriformes

Parachiloglanis gurungi sp. nov. 

RYAN J. THONI and MER MAN GURUNG. 2026. Parachiloglanis gurungi, A New Species of Torrent Catfish (Teleostei: Sisoridae) from western Bhutan.  Zootaxa. 5881(3); 437-444. DOI: doi.org/10.11646/zootaxa.5881.3.9 [2026-09-22] 

  facebook.com/RyanThoni7/posts/10175905154200623

[Ichthyology • 2026] Neolamprologus labrosus • A New Species of the Genus Neolamprologus (Cichliformes: Cichlidae) from Lake Tanganyika

Neolamprologus labrosus

Takahashi, Snoeks & Satoh, 2026

 

DOI: doi.org/10.1111/jfb.70640  

  x.com/Discusshuki

Abstract

Lake Tanganyika harbours an exceptionally diverse fauna of cichlids that has arisen through explosive adaptive radiation. During a recent survey at Kasenga and Kombe, Zambia, we discovered an undescribed species of the genus Neolamprologus. The new species is readily distinguished from its congeners by its uniquely developed upper lip, which protrudes conspicuously beyond the lower lip, along with several additional morphological characters. Phylogenetic analysis of the mitochondrial NADH dehydrogenase subunit 2 gene showed that specimens of the new species were not recovered as monophyletic; instead, they formed a clade together with Neolamprologus mustax. Nevertheless, the new species is morphologically clearly distinct from N. mustax despite their sympatric occurrence. This discovery highlights the still underestimated diversity of cichlids in Lake Tanganyika and underscores the importance of documenting its fauna in the face of increasing anthropogenic pressures on the lake's ecosystem.

 Keywords: freshwater, biodiversity, mitochondrial ND2, morphology, phylogeny

Neolamprologus labrosus

Tetsumi Takahashi, Jos Snoeks and Shun Satoh. 2026. A New Species of the Genus Neolamprologus (Cichliformes: Cichlidae) from Lake Tanganyika. Journal of Fish Biology. DOI: doi.org/10.1111/jfb.70640 [15 September 2026]

  x.com/Discusshuki/status/2099862874617520532

[Ichthyology • 2026] Opsarius geminus • A New danionid fish (Cypriniformes: Danionidae) from the Western Ghats, India and Revalidation of Barilius papillatus Day 1869

 

 Opsarius geminus

Vijayakrishnan, Nallathambi, Jayasimhan, & Knight, 2026

Barilius papillatus Day 1869

DOI: doi.org/10.11646/zootaxa.5878.4.7

Abstract

Opsarius geminus, a new species of danionid fish is described from the Krishna River, Western Ghats, India. It can be distinguished from its congeners in the Western Ghats by possessing a combination of the following characters: unique colour pattern consisting of 9–11 blue bars that are 2–3 scales wide; 46–51 lateral-line scales; 20–23 pre-dorsal scales; barbels absent; length of last dorsal-fin ray almost equal to, or greater than length of first dorsal-fin ray; 7 ½–8½ dorsal-fin branched rays and 10½–11½ anal-fin branched rays. Barilius papillatus Day 1869, currently a synonym of Opsarius barna (Hamilton, 1822) is redescribed, based on the syntype and fresh specimens, and a lectotype is designated to fix its identity. Opsarius papillatus can be diagnosed from all its congeners in India, by possessing a combination of the following characters: colour pattern consisting of 7–9 blue bars that are 1–2 scales wide; 39–41 lateral-line scales; 15–18 pre-dorsal scales; barbels absent; length of last dorsal-fin ray shorter than length of first dorsal-fin ray; 7½ dorsal-fin branched rays and 10½ anal-fin branched rays.

Pisces, new species, Opsarius barna, Krishna River, Mahanadi River, Eastern ghats

 

 

BALAJI VIJAYAKRISHNAN, MOULITHARAN NALLATHAMBI, PRAVEENRAJ JAYASIMHAN, J.D. MARCUS KNIGHT. 2026. Opsarius geminus, A New danionid fish from the Western Ghats, India and Revalidation of Barilius papillatus Day 1869 (Teleostei: Danionidae).  Zootaxa. 5878(4); 589-600. DOI: doi.org/10.11646/zootaxa.5878.4.7 [2026-09-16]

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[Ichthyology • 2026] Chromis veneta • Resolving Cryptic Diversity in the Chromis viridis species complex (Blenniiformes: Pomacentridae): a multilocus phylogenetic and morphometric reassessment of species boundaries

 

Chromis veneta 

Rekha, Jayakumar, Abhilash, Ahamed Rasheeq, Saikrishnan, Vallarasu, Gladston, Chakraborty & Ajithkumar, 2026

  

DOI: doi.org/10.3389/fmars.2026.1922804

Abstract

The blue-green damselfish, Chromis viridis (Cuvier, 1830), is widely distributed across Indo-Pacific coral reefs and is among the most heavily traded marine ornamental fishes. Recent molecular studies have suggested the presence of cryptic diversity within the C. viridis complex, but species boundaries remain unresolved. Multilocus phylogenetic analyses incorporating three mitochondrial markers—cytochrome c oxidase subunit I (COI), cytochrome b (cytb), and the mitochondrial control region (D-loop)—and two nuclear markers, recombination-activating gene 1 (RAG1) and recombination-activating gene 2 (RAG2), were performed to assess lineage diversification within the Chromis viridis species complex. Specimens collected from the Lakshadweep Archipelago and the Gulf of Mannar, India, formed a distinct and well-supported lineage that was clearly separated from C. viridis sensu stricto and other congeners in phylogenetic reconstructions and genetic distance analyses. Multiple species-delimitation approaches consistently supported the recognition of this lineage as an independently evolving taxon, and morphometric analyses revealed corresponding differences in body proportions and meristic characters. Based on the concordance of molecular and morphological evidence, a new species, Chromis veneta sp. nov., is herein described from the Indian Ocean. The new species differs from C. viridis in having a relatively elongate body, narrower caudal peduncle, distinctive body pigmentation, yellowish to orangish distal fin margins, and a deeply forked caudal fin with elongate lobe tips. Additional diagnostic features include differences in dentition, gill-raker counts and sagittal otolith morphology. The discovery of C. veneta sp. nov. highlights underestimated diversity within the C. viridis complex and underscores the importance of integrative taxonomy in revealing cryptic reef-fish diversity.

Keywords: Chromis veneta sp. nov., Chromis viridis complex, cryptic species diversity, species delimitation, multilocus phylogenetics, integrative taxonomy, morphometric analysis, Pomacentridae

 

Chromis veneta sp. nov., freshly collected holotype, NBFGR/POMCVEN, 52.0 mm SL, Agatti Island.

Caption Male of Chromis veneta sp. nov. (64.51 mm SL) in live breeding coloration.

Chromis veneta sp. nov. in its natural coral reef habitat at Agatti Island, Lakshadweep, associated with branching Acropora corals and occurring sympatrically with Chromis viridis, Pomacentrus pavo, and Dascyllus aruanus.

Chromis veneta sp. nov.

 Diagnosis: Chromis veneta sp. nov. is distinguished from its congeners by the following combination of characters: dorsal-fin rays XII, 9–10 (usually 10); anal-fin rays II, 9–10 (usually 10); pectoral-fin rays 16–17 (usually 17); pelvic-fin rays I, 5; principal caudal-fin rays 8 + 7; spiniform caudal rays 3; tubed lateral-line scales 15–16; gill rakers 9–10 + 23–26 (usually 9 + 24), total 33–35 (usually 33); body depth 2.27–2.56 in SL; caudal-peduncle depth 0.63–0.77 in head length; and caudal-peduncle length 0.51–0.73 in head length. In life, the body is bright aquamarine-green with a subtle iridescent blue-green sheen. Each scale on the upper and middle flanks is narrowly edged with yellow-green, forming a fine reticulate pattern that becomes more conspicuous under illumination. The ventral surface is pale silvery white. A diffuse black patch is present at the upper base of the pectoral fin and is more conspicuous in live specimens. A fine, continuous blue-green stripe extends from the tip of the snout to the anterior margin of the orbit. Reproductively active individuals further exhibit distinct yellowish to amber pigmentation along the distal margins of the dorsal and anal fins.

Etymology: The specific epithet, veneta is derived from the Latin venetus, meaning “sea-blue” or “azure,” referring to the characteristic of blue green to turquoise coloration exhibited by the species in live condition. The name is treated as an adjective in agreement with the generic name Chromis.

 

M. U. Rekha, Teena Jayakumar T. K., Abhilash C. P. Ahamed Rasheeq A., Saikrishnan K. R., Vallarasu R., Gladston Y., Kajal Chakraborty and Ajithkumar T. T. 2026. Resolving Cryptic Diversity in the Chromis viridis species complex (Pomacentridae): a multilocus phylogenetic and morphometric reassessment of species boundaries. Front. Mar. Sci. 13; 1922804. DOI: doi.org/10.3389/fmars.2026.1922804 [04 September 2026]

[Ichthyology • 2026] Petulanos jasteri • A New Species of Petulanos (Characiformes: Anostomidae) from the Rio Araguari, Amapá State, Brazil

 

Petulanos jasteri

Birindelli, Lima & Gama, 2026

 DOI: doi.org/10.1643/i2025080

Abstract

The Neotropical family Anostomidae comprises over 150 valid species, though its true diversity remains underestimated. The genus Petulanos currently includes four species distributed across northern South America, all characterized by upturned mouths, compressed multicuspid dentition, and distinctive color patterns. In this study, we describe Petulanos jasteri, a new species apparently endemic to the rio Araguari, Amapá state, Brazil. Despite hosting extensive protected areas, Amapá remains poorly surveyed, and its ichthyofauna is still insufficiently documented. The new species is readily distinguished from congeners by its color pattern, consisting of three vertically elongated dark blotches on the posterior half of the trunk (without pale margins) combined with eight to ten dark vertical bars. It lacks the horizontal stripes that characterize P. brevior, as well as the rounded blotch above the pectoral fin present in P. intermedius, P. plicatus, and P. spiloclistron, and has 38 or 39 lateral-line scales (vs. 40 to 42 in P. spiloclistron). Osteological characters confirm its assignment to Petulanos, sharing synapomorphies such as four branchiostegal rays, bicuspid symphyseal premaxillary tooth, symplectic with a distinctive triangular ventral lamina, and open cranial fontanel. Petulanos jasteri, new species, is the first species of the genus reported from the rio Araguari. Its discovery emphasizes the underestimated diversity of the Anostomidae and highlights the need for further surveys and integrative studies in poorly explored basins of northern Brazil.

Petulanos jasteri.
(A) Holotype, IEPA 6078, 72.9 mm SL, Amapá, Ferreira Gomes, rio Mutum, tributary to rio Araguari, at Parque Nacional Montanhas do Tumucumaque.
(B) Paratype, ZUEC 14774, 83.7 mm SL, Amapá, Ferreira Gomes, rio Araguari.
(C) Paratype, ANSP 211099 (ex. IEPA 6079), 64.1 mm SL, rio Mutum, tributary to rio Araguari, at Parque Nacional Montanhas do Tumucumaque, photographed alive.

Scale bar = 10 mm. 

Petulanos jasteri, a new species 

Etymology.—The specific name jasteri honors Dr. Christoph Bernhard Jaster, formerly chief of the Tumucumaque National Park and the Amapá National Forest, for having made possible many field expeditions in these Conservation Units for the IEPA Ichthyology team, being a great supporter of basic science and biological surveys at Amapá State.

José L. O. Birindelli, Flávio C. T. Lima, Cecile S. Gama. 2026. New Species of Petulanos (Characiformes, Anostomidae) from the Rio Araguari, Amapá State, Brazil. Ichthyology & Herpetology. 114(3):451-460. DOI: doi.org/10.1643/i2025080 [28 August 2026]

[Ichthyology • 2026] Glyptothorax jiwanae • A New Species of the Sisorid Catfish Genus Glyptothorax (Siluriformes: Sisoridae) from Nepal

 

 Glyptothorax jiwanae

Haggard, Ng, Edds & Conway, 2026

DOI: doi.org/10.1643/i2025050  

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Abstract

Glyptothorax jiwanae, new species, is described in this study based on 42 specimens, 41–133 mm SL, from Nepal. It is distinguished from congeners by a combination of characters, including presence of longitudinal striae on the gular region, presence of adhesive papillae on the lower lip, premaxillary teeth hidden when the mouth is closed, nasal barbel reaching posterior to eye, skin flaps along the posterior edges of the maxillary and inner and outer mandibular barbels extending for half or less of barbel length, round eye, thoracic adhesive apparatus (TAA) consisting only of longitudinally oriented striae, an elongate, oval depression within the medial pit of the TAA, finely tuberculate skin, pelvic origin at a vertical through or slightly anterior to the base of the last dorsal-fin ray, length of adipose-fin base 14.9–18.4% SL, i,7,8,i caudal-fin rays, caudal-fin lobes approximately equal in length, and slightly asymmetrical procurrent rays.

 Glyptothorax jiwanae, KU 28638, holotype, 55.4 mm SL, Nepal, Rautahat/Sarlahi, Bagmati River. Scale bar = 5 mm.

Glyptothorax jiwanae, new species 

Etymology.— This species is named after Dr. Jiwan Shrestha, for her pioneering work on elucidating the ichthyofaunal diversity of Nepal. A noun in the genitive.

 

Angela Haggard, Heok Hee Ng, David R. Edds and Kevin W. Conway. 2026. A New Species of the Sisorid Catfish Genus Glyptothorax from Nepal (Siluriformes: Sisoridae). Ichthyology & Herpetology. 114(3):439-450. DOI: doi.org/10.1643/i2025050 [20 August 2026]

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[Ichthyology • 2026] Laimosemion laranja • A New killifish of the Genus Laimosemion (Cyprinodontiformes: Rivulidae) from Rio Cajari in the Brazilian Amazon

Laimosemion laranja 

Abrantes, Lima, Nielsen, de Lira, da Silva & Berbel-Filho, 2026

 

DOI: doi.org/10.3897/zse.102.187659

Abstract

Based on morphological and molecular evidence, this study describes a new species of rivulid of the genus Laimosemion from the lower Rio Amazonas Basin in the south of the state of Amapá in northern Brazil. The new species, Laimosemion laranja sp. nov., exhibits a color pattern characteristic of the L. geayi species group, consisting of longitudinal rows of spots on the anterior portion of flank and oblique chevron-shaped bars on the posterior portion of flank. It can be distinguished from its congeners by unique combination of characters, including position of dorsal-fin origin relative to anal-fin rays, frontal squamation pattern of head, counts of transverse and longitudinal scale series, fin-ray counts, vertebral count, osteology of caudal fin, and number of neuromasts in infraorbital series. Partial sequences of the mitochondrial cytochrome c oxidase subunit I (cox1) gene indicates that the new species diverges genetically by 5.3% from its closest relatives, L. agilae and L. strigatus, by 9.2% from L. dibaphus, and 12.3% from L. geayi. We further discuss the systematic relationships within the L. geayi species group and the conservation status of the new species based on IUCN criteria, including recommendations for its conservation.

Key Words: Amapá State, Amazonas Estuary and Coastal Drainages Ecoregion, Amazonian ichthyofauna, conservation

Laimosemion laranja new species
 Holotype [INPA–ICT 062600], male, 26.8 mm SL; 
 Paratype [INPA–ICT 062601], female, 20.1 mm SL 
Brazil, Amapá, Laranjal do Jari, Rio Cajari, Amazonas Basin.

photos: Y. Abrantes. 

 

Laimosemion laranja sp. nov.

Diagnosis. Laimosemion laranja differs from the six congeners of the L. geayi group by having eight scales in transverse series (vs.7 in L. dibaphus and L. strigatus, 9 in L. geayi, 9–10 in L. agilae and L. cladophorus, and 9–11 in L. mabura). It can be distinguished from all other congeners of the L. geayi group, except L. agilae and L. cladophorus, by dorsal-fin origin positioned on transversal plane through bases of 4th–6th anal-fin rays in both sexes (vs. of 7th–8th anal-fin rays). It differs from L. agilae by frontal squamation pattern of head (E squamation vs. F squamation) and from ...

Etymology. The specific epithet ‘laranja’ is a name with a dual allusion. It refers to the bright orange color pattern on males of the new species (‘laranja’ means the color, as it also means the fruit in Portuguese), and is also an homage to the municipality of Laranjal do Jari, founded on December 17, 1987, in the south of Amapá State, Brazil, from where the species is currently only found. A noun in apposition.

Sampling localities of Laimosemion laranja new species.
 Localities one and two (A, B), and the type locality (C). Brazil, Amapá, Laranjal do Jari, Rio Cajari, Amazonas Basin.

 Photos: W.M. Berbel-Filho.

Yuri Gomes Abrantes, Sergio Maia Queiroz Lima, Dalton Tavares Bressane Nielsen, Fabio Origuela de Lira, Márcio Joaquim da Silva, Waldir Miron Berbel-Filho. 2026. A New killifish of the Genus Laimosemion (Cyprinodontiformes, Rivulidae) from Rio Cajari in the Brazilian Amazon. Zoosystematics and Evolution. 102(4): 1079-1088. DOI: doi.org/10.3897/zse.102.187659 [20 Aug 2026]

[Ichthyology • 2026] Rakthamichthys anchi • A New Species of phreatobitic synbranchid eel (Synbranchiformes: Synbranchidae) from Assam, India

 

Rakthamichthys anchi 

Britz, Pinion, Marak, Velentina & Lokeshwor, 2026 

 

DOI: doi.org/10.11646/zootaxa.5857.3.3

Abstract

Rakthamichthys anchi, a new species of phreatobitic synbranchid is described from wells in a small village in Goalpara District, Assam, Northeast India. It is distinguished from the northeastern Indian R. rongsaw, and the Western Ghats congeners R. roseni, R. digressus, and R. mumba by absence of lateral-line canal pores in the frontal. From R. roseni, R. digressus, and R. mumba, it is further distinguished by more preanal vertebrae (90–100 vs. 76–88 in) and from R. indicus by more vertebrae (159 vs.162–169). It is also distinguished from the Western Ghats species by an uncorrected p-distance of ~15–20% in the barcoding gene. From R. roseni, the only Western Ghats species for which detailed osteological information is available, R. anchi is distinguished by several anatomical characters. The discovery of R. anchi from wells in the same village in which Gitchak nakana Britz et al. [2026] was recently described highlights the presence of a formerly unknown and highly dynamic subterranean habitat: the groundwater aquifers in alluvial deposits in northeast India.

Pisces, swamp eels, groundwater, well, subterranean fishes, micro-CT, skeleton

Ralf BRITZ, Amanda K. PINION, Wimarithy K. MARAK, Kangjam VELENTINA and Yumnam LOKESHWOR. 2026. Rakthamichthys anchi, A New Species of phreatobitic synbranchid eel from Assam.  Zootaxa. 5857(3); 462-482. DOI: doi.org/10.11646/zootaxa.5857.3.3 [2026-07-30]

[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  

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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] 

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