Fish in the News

Everything about the fishes we love.
Aquarium hobby, science and conservation.

[Fish in the News @FishInTheNews]

@iprimaa Generally this species is found across estuaries, tidal rivers, and mangrove habitats.

[Fish in the News @FishInTheNews]

The spotted scat, 𝑆𝑐𝑎𝑡𝑜𝑝ℎ𝑎𝑔𝑢𝑠 𝑎𝑟𝑔𝑢𝑠, is a commercially important euryhaline fish widely distributed in the Indo-West Pacific, yet its systematics and evolutionary history remain poorly understood. Here, researchers investigated the genetic diversity, phylogeography, and demographic history of 𝑆. 𝑎𝑟𝑔𝑢𝑠 from across its range. Haplotype network analysis identified four major haplogroups: two predominantly distributed in the Indian Ocean, one in the West Pacific, and one in Australia.

A haplogroup is a genetic population group of similar haplotypes that share a common direct maternal or paternal ancestor. These groups are defined by specific, slowly accumulating genetic mutations—most commonly single-nucleotide polymorphisms (SNPs)—passed down through generations without being recombined or shuffled like regular autosomal DNA.

"Demographic analyses indicated late Pleistocene population expansion in Haplogroup I, whereas Haplogroups II and IV showed no clear expansion signal. The coexistence of three lineages of 𝑆. 𝑎𝑟𝑔𝑢𝑠 within Thai waters highlights this region as a critical zone of genetic diversity for future research. These findings underscore the need to uncover hidden diversity for effective fisheries management and conservation."

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Cryptic diversity and phylogeography of the spotted scat 𝑆𝑐𝑎𝑡𝑜𝑝ℎ𝑎𝑔𝑢𝑠 𝑎𝑟𝑔𝑢𝑠 (Acanthuriformes, Scatophagidae) across the Indo-West Pacific

Open access: https://t.co/GeNj00Cguo

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Seesan K, Janekitkarn S, Ratmuangkhwang S, Chamason O, Liu S-YV, Lavoué S, Zeng C, Muangmai N (2026) Cryptic diversity and phylogeography of the spotted scat 𝑆𝑐𝑎𝑡𝑜𝑝ℎ𝑎𝑔𝑢𝑠 𝑎𝑟𝑔𝑢𝑠 (Acanthuriformes, Scatophagidae) across the Indo-West Pacific. ZooKeys 1297: 131-152. https://t.co/u3lkYMi3vm

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
The spotted scat, 𝑆𝑐𝑎𝑡𝑜𝑝ℎ𝑎𝑔𝑢𝑠 𝑎𝑟𝑔𝑢𝑠, is a commercially important euryhaline fish widely distributed in the Indo-West Pacific, yet the systematics and evolutionary history of this species remain poorly understood.

We investigated the genetic diversity, phylogeography, and demographic history of 𝑆. 𝑎𝑟𝑔𝑢𝑠 using 239 mitochondrial COI sequences (129 newly determined for this study) from across its range. Haplotype network analysis identified four major haplogroups: two predominantly distributed in the Indian Ocean, one in the West Pacific, and one in Australia. Mean K2P distances among haplogroups (5.08–7.72%) greatly exceeded those within haplogroups (0.45–0.91%), indicating deeply divergent mitochondrial lineages and possible species-level cryptic diversity.

The distributions of the West Pacific and Indian haplogroups overlap in the Thai-Malay Peninsula region. Whereas Pleistocene exposure of the Sunda Shelf may have driven the divergence of these haplogroups by restricting gene flow between the Indian and Pacific Oceans, their secondary contact appears to have been facilitated by the recent inundation of the Sunda Shelf, enabling range expansion and lineage admixture. Demographic analyses indicated late Pleistocene population expansion in Haplogroup I, whereas Haplogroups II and IV showed no clear expansion signal. The coexistence of three lineages of 𝑆. 𝑎𝑟𝑔𝑢𝑠 within Thai waters highlights this region as a critical zone of genetic diversity for future research.

These findings underscore the need to uncover hidden diversity for effective fisheries management and conservation.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Lateral views of fresh specimens of 𝑆𝑐𝑎𝑡𝑜𝑝ℎ���𝑔𝑢𝑠 𝑎𝑟𝑔𝑢𝑠 representing each haplogroup. Scale bars indicate 1 cm. Haplogroup I: A. CHB01 (Chonburi), 126.41 mm SL; B. SK04 (Songkhla), 168.33 mm SL; Haplogroup II: C. CT01 (Chanthaburi), 95.45 mm SL; D. PTN02 (Pattani), 121.42 mm SL; E. KS01 (Kaohsiung), 148.27 mm SL; F. KS06 (Kaohsiung), 166.02 mm SL; Haplogroup IV: G. RN06 (Ranong), 119.00 mm SL; H. RN09 (Ranong), 114.98 mm SL.

© 2026 the Author(s). Published in the journal ZooKeys. An open access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) licence. https://t.co/5IYEkz4Rwi

#Scatophagus #Acanthuriformes #Scatophagidae #Scat #Ichthyology #Taxonomy #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank #Phylogeography #CrypticSpecies #Brackish #BrackishWater #Mangroves #BrackishAquarium #SpottedScat #Euryhaline

[Fish in the News @FishInTheNews]

Cypriniformes, the most species-rich order of freshwater fishes (∼5,000 species), represents a key lineage for understanding vertebrate diversification in freshwater ecosystems.

🔓 https://t.co/KheTv6932H

Here, researchers present the first phylogenomic analysis of Cypriniformes with complete family-level representation, encompassing 316 species (comprising ∼30% of all described genera).

"Our results strengthen the evolutionary relationships of several miniaturized lineages, while identifying recalcitrant relationships shaped by both biological processes and model artifacts that can yield superficially similar patterns of phylogenetic conflict. Our study substantially expands genomic representation and establishes a phylogenomic foundation for future comparative, developmental, and evolutionary research in this freshwater radiation."

Lead author Hiranya Sudasinghe has made available an A0 poster, print-size image file, 'The Cypriniformes Tree of Life' - https://t.co/ePWVB9kD89

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Phylogenomics of Cypriniformes, the most diverse order of freshwater fishes: consensus, challenges, and limitations

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Hiranya Sudasinghe, Ralf Britz, Michael Matschiner, Kevin W Conway, Heok Hui Tan, Maurice Kottelat, Rajeev Raghavan, Neelesh Dahanukar, Vasudevan Komalavally Anoop, Jörg Bohlen, Kerstin Howe, Richard Durbin, Walter Salzburger, Catherine L Peichel, Lukas Rüber, Phylogenomics of Cypriniformes, the most diverse order of freshwater fishes: consensus, challenges, and limitations, Molecular Biology and Evolution, Volume 43, Issue 11, November 2026, msag261, https://t.co/ATDalqxeaY

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
Cypriniformes, the most species-rich order of freshwater fishes (∼5,000 species), represents a key lineage for understanding vertebrate diversification in freshwater ecosystems. This clade includes several highly miniaturized and understudied lineages whose phylogenetic placements have long remained contentious.

Here, we present the first phylogenomic analysis of Cypriniformes with complete family-level representation and broad genus-level coverage, encompassing 316 species comprising ∼30% of all described genera. Our dataset integrates 257 newly assembled genomes with publicly available resources and analyzes multiple sets of genome-wide markers using both concatenation-based and coalescent-aware approaches. The general concordance among analytical frameworks indicates that the backbone topology of Cypriniformes is now established, allowing clear identification of well-supported clades and regions of persistent conflict.

Our results strengthen the evolutionary relationships of several miniaturized lineages, while identifying recalcitrant relationships shaped by both biological processes and model artifacts that can yield superficially similar patterns of phylogenetic conflict.

Our study substantially expands genomic representation and establishes a phylogenomic foundation for future comparative, developmental, and evolutionary research in this freshwater radiation.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
a) ASTRAL-IV species tree showing the hypothesis of phylogenomic relationships of Cypriniformes inferred from 335 species and 1,167 loci (total alignment length: 541,983 bp), based on combined first and second codon positions of BUSCO.NT.C12 and UCE nucleotide dataset. The numbers indicate the different Cypriniformes families. The major conflicting zones of phylogenetic relationships are highlighted in gray (see Fig. 2; Figures S11 and S12). Simplified family-level topologies are shown for (b) the ASTRAL-IV species tree and (c) the IQ-TREE2 concatenated phylogeny for the same dataset. Fish illustrations by Nadeela Hirimuthugoda.

© 2026 the Author(s). Published in the journal Molecular Biology and Evolution. An open access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) licence. https://t.co/5IYEkz4Rwi

#Phylogenomics #Cypriniformes #Ichthyology #Taxonomy #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank

[Fish in the News @FishInTheNews]

@mtanichthys Thank you, updated post so that's clearer at the beginning.

[James Albert 🐟 🇺🇦 @JamesAl0410008]

Research by Donovan German and Nathan Lujan shows that "wood eating" catfishes don’t digest wood itself but rather the nutrient-rich microbial biofilm, algae, and fungi growing on the surface. They skim the good stuff and poop out the rest.

https://t.co/zBbU4RLn2l

[Maxwell Bernt @mjbernt]

Recently published with Melanie Stiassny a revision of the African auchenoglanidid catfishes.
https://t.co/7NN4wTPwhr

[Fish in the News @FishInTheNews]

#NewSpeciesAlert - 𝐸𝑥𝑜𝑠𝑡𝑜𝑚𝑎 𝑛𝑎𝑠𝑖𝑏𝑎𝑟𝑏𝑎𝑡𝑢𝑚, a new species of sisorid catfish (Glyptosterninae), is described from Bupal stream, a tributary of the Dujang River in the Chindwin River system of Manipur, northeastern India.

🔒 https://t.co/rFqUnvYhoF

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
𝐸𝑥𝑜𝑠𝑡𝑜𝑚𝑎 𝑛𝑎𝑠𝑖𝑏𝑎𝑟𝑏𝑎𝑡𝑢𝑚, a new species of glyptosternine catfish from Manipur, northeastern India

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Torisha, P., & Shangningam, B. (2026). 𝐸𝑥𝑜𝑠𝑡𝑜𝑚𝑎 𝑛𝑎𝑠𝑖𝑏𝑎𝑟𝑏𝑎𝑡𝑢𝑚, a new species of glyptosternine catfish from Manipur, northeastern India. Journal of Natural History, 60(45–48), 2251–2263. https://t.co/r8Ihk68n0L

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
A new species of glyptosternine catfish of the genus 𝐸𝑥𝑜𝑠𝑡𝑜𝑚𝑎 is described from the Bupal stream, a tributary of the Dujang River, Chindwin River system in Manipur, northeastern India.

𝐸𝑥𝑜𝑠𝑡𝑜𝑚𝑎 𝑛𝑎𝑠𝑖𝑏𝑎𝑟𝑏𝑎𝑡𝑢𝑚 Torisha & Shangningam sp. n. can be easily distinguished from congeners of the Chindwin-Irrawaddy by the following combination of characters: possessing a long nasal barbel extending beyond the posterior margin of orbit, adipose fin confluent (vs. separate) with the upper procurrent caudal fin rays except in 𝐸. 𝑐ℎ𝑎𝑢𝑑ℎ𝑢𝑟𝑖𝑖, 𝐸. 𝑑𝑢𝑙𝑜𝑛𝑔𝑒𝑛𝑠𝑒, 𝐸. 𝑑𝑢𝑗𝑎𝑛𝑔𝑒𝑛𝑠𝑒 and 𝐸. 𝑣𝑖𝑛𝑐𝑖𝑔𝑢𝑒𝑟𝑟𝑎𝑒, rounded and parallel striae on the anterolateral surfaces of the lips (vs. parallel) in 𝐸. 𝑐ℎ𝑎𝑢𝑑ℎ𝑢𝑟𝑖𝑖 and 𝐸. 𝑑𝑢𝑙𝑜𝑛𝑔𝑒𝑛𝑠𝑒, (vs. rounded) in 𝐸. 𝑑𝑢𝑗𝑎𝑛𝑔𝑒𝑛𝑠𝑒 and 𝐸. 𝑣𝑖𝑛𝑐𝑖𝑔𝑢𝑒𝑟𝑟𝑎𝑒.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
𝐸𝑥𝑜𝑠𝑡𝑜𝑚𝑎 𝑛𝑎𝑠𝑖𝑏𝑎𝑟𝑏𝑎𝑡𝑢𝑚, preserved specimen.

© 2026 the Author(s). Published in the Journal of Natural History.

#NewSpecies #Ichthyology #Taxonomy #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank #Exostoma #India #Manipur #Catfishes #Glyptosternine #Glyptosterninae #Sisoridae

[Fish in the News @FishInTheNews]

#NewSpeciesAlert - 𝐿𝑎𝑢𝑏𝑢𝑘𝑎 𝑐𝑎𝑒𝑟𝑢𝑙𝑒𝑜𝑠𝑡𝑟𝑖𝑎𝑡𝑎, a new species of danionid (Cypriniformes: Danionidae), is described from the Yangon and Pyapon rivers, distributaries of the Irrawaddy River system in Myanmar.

🔒 https://t.co/D3Bou6OYrz

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
A new species of 𝐿𝑎𝑢𝑏𝑢𝑘𝑎 (Cypriniformes: Danionidae) from the Irrawaddy River System, Myanmar

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Htay, K.Y., Song, X.-Y., Thu, M.M., Paing, A.K., Naing, N.H., Oo, T.N. & Chen, X.-Y. (2026) A new species of 𝐿𝑎𝑢𝑏𝑢𝑘𝑎 (Cypriniformes: Danionidae) from the Irrawaddy River System, Myanmar. Zootaxa, 5897 (2), 152–166. https://t.co/LSnjRipONU

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
A new species of the genus 𝐿𝑎𝑢𝑏𝑢𝑘𝑎 Bleeker, 1859 is described from the Yangon and Pyapon rivers, distributaries of the Irrawaddy River system in Myanmar.

𝐿𝑎𝑢𝑏𝑢𝑘𝑎 𝑐𝑎𝑒𝑟𝑢𝑙𝑒𝑜𝑠𝑡𝑟𝑖𝑎𝑡𝑎 sp. nov. can be distinguished from its congeners by the following combination of features: (1) two blue and golden longitudinal stripes extending from pectoral-fin base to caudal-fin base; (2) swim bladder visible through transparent area beneath blue longitudinal stripe; (3) dorsal-fin base length less than half anal-fin base length; (4) pectoral fin long, reaching beyond tip of pelvic fin; and (5) 21–22 predorsal scales. Phylogenetic analysis of mitochondrial genes using Maximum Likelihood (ML) and Bayesian Inference (BI) indicates that the new species represents an independent evolutionary lineage, with p-distances of 16–19% for COI and 19–22% for Cytb relative to its congeners.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Cover image from the study.

© 2026 the Author(s). Published in the journal Zootaxa.

#NewSpecies #Ichthyology #Taxonomy #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank #Laubuka #Cypriniformes #Danionidae #IrrawaddyRiver #Myanmar #Burma #YangonRiver #PyaponRiver

[James Albert 🐟 🇺🇦 @JamesAl0410008]

Over half of vertebrate species are teleost fishes, with over 35,000 species. Why so many species? The answer is complex, but certainly involves the origin and turnover of multiple sex chromosomes, evolving at about the pace of speciation and extinction.

https://t.co/hHKQLsxRrQ

[Fish in the News @FishInTheNews]

#FishBook - 'Fishes of the Genus 𝑁𝑜𝑡ℎ𝑜𝑏𝑟𝑎𝑛𝑐ℎ𝑖𝑢𝑠' by Béla Nagy and Brian R. Watters is a comprehensive reference guide to the remarkable seasonal fishes of Africa, bringing together decades of field observations from more than sixty expeditions across Africa, research, aquarium experience, taxonomy and conservation, in a richly illustrated 600-page volume, with many hundreds of full-colour photographs, over 150 habitats including 50 type localities, maps covering all species, phylogenetic diagrams, and detailed accounts of every species.

Available to preorder now (link below) and expected to ship 10th November 2026.

𝗣𝘂𝗯𝗹𝗶𝘀𝗵𝗲𝗿'𝘀 𝗱𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻:
'Fishes of the Genus 𝑁𝑜𝑡ℎ𝑜𝑏𝑟𝑎𝑛𝑐ℎ𝑖𝑢𝑠' presents a comprehensive account of Africa’s remarkable seasonal fishes, which complete their entire life cycle in ephemeral wetlands that appear and vanish with the rains.
​
Drawing on decades of field exploration, scientific research, and aquarium observations, Béla Nagy and Brian R. Watters explore the ecology, life history, reproduction, diversity, classification, and conservation of these extraordinary fishes. From the seasonal wetlands they inhabit to the remarkable adaptations that allow them to survive months of drought as dormant embryos, the book reveals a unique group of fishes living at the edge of time.
​
The book brings together extensive field observations from across Africa with detailed habitat descriptions, distribution and dispersal patterns, life-history studies, maintenance and breeding techniques, and modern approaches to classification and systematics. The final chapter provides comprehensive species accounts covering identification, taxonomy, habitat, distribution, conservation status, reproduction, and maintenance.

Richly illustrated throughout, the book includes hundreds of full-colour photographs, biotope images, maps, phylogenetic diagrams, historical illustrations, and detailed drawings. It is both a scientific reference and a visual exploration of the extraordinary diversity of 𝑁𝑜𝑡ℎ𝑜𝑏𝑟𝑎𝑛𝑐ℎ𝑖𝑢𝑠.

Written for researchers, conservationists, ichthyologists, killifish enthusiasts, and dedicated aquarists, this book offers an authoritative and accessible synthesis of one of Africa’s most fascinating groups of freshwater fishes.

600 pages ​| over 650 full-colour photos | 102 species accounts | 30 maps covering all species | 14 phylogenies | 7 x 10 in - 17.8 x 25.4 cm

𝗢𝗿𝗱𝗲𝗿𝗶𝗻𝗴 𝗱𝗲𝘁𝗮𝗶𝗹𝘀:
A limited number of softcover and hardcover books printed on premium 115gsm coated paper will be available directly from the authors (while supplies last) for 60 and 80 euros, respectively, plus shipping. Available via the website contact form.

https://t.co/vGqcCpWK77

The book will also be available through online distributors worldwide when launched. Online prices via online distributors will start at approximately 90 EUR / 96 USD for the softcover and 110 EUR / 130 USD for the hardcover, plus shipping.

#AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank #Killifish #Killifishes #Books #AquariumBook #AquariumBooks #AnnualKillifish #SeasonalKillifish #Killifische #Nothobranchius #Nothobranchiidae

[Fish in the News @FishInTheNews]

#NewSpeciesAlert - 𝐵𝑢𝑛𝑜𝑐𝑒𝑝ℎ𝑎𝑙𝑢𝑠 𝑔𝑎𝑟𝑐𝑖𝑎𝑖, a new species of banjo catfish (Aspredinidae), is described from the Tocantins-Araguaia River basin, Brazil.

🔒 https://t.co/2kiWxMR4Vh

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Description of new species of 𝐵𝑢𝑛𝑜𝑐𝑒𝑝ℎ𝑎𝑙𝑢𝑠 Kner 1855 (Siluriformes: Aspredinidae) from the Tocantins-Araguaia River basin, using an integrative approach

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Crispim, J.L., Frisoni, W.J.M., Costa, N.S., Sabaj, M.H. & Oliveira, C. (2026) Description of new species of 𝐵𝑢𝑛𝑜𝑐𝑒𝑝ℎ𝑎𝑙𝑢𝑠 Kner 1855 (Siluriformes: Aspredinidae) from the Tocantins-Araguaia River basin, using an integrative approach. Zootaxa, 5894 (1), 65–83. https://t.co/CeU5eE1m1r

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
𝐵𝑢𝑛𝑜𝑐𝑒𝑝ℎ𝑎𝑙𝑢𝑠 currently comprises 14 valid species and is the most species-rich genus within the banjo catfish family (Aspredinidae), occurring widely across major trans- and cis-Andean drainages of South America. Despite this broad distribution, no species has yet been described from the Tocantins-Araguaia basin, a region recognized for its high level of endemism.

Here, we describe a new species of 𝐵𝑢𝑛𝑜𝑐𝑒𝑝ℎ𝑎𝑙𝑢𝑠 from the Tocantins–Araguaia basin using an integrative taxonomic approach, applied for the first time in the genus. We also discuss the molecular and morphological diversity within a lineage previously represented by a single valid species, 𝐵𝑢𝑛𝑜𝑐𝑒𝑝ℎ𝑎𝑙𝑢𝑠 𝑎𝑙𝑒𝑢𝑟𝑜𝑝𝑠𝑖𝑠. Species delimitation analyses based on the cytochrome c oxidase subunit I (COI) marker recovered additional distinct Molecular Operational Taxonomic Units (MOTUs), suggesting the presence of further undescribed species within 𝐵𝑢𝑛𝑜𝑐𝑒𝑝ℎ𝑎𝑙𝑢𝑠.

𝗘𝘁𝘆𝗺𝗼𝗹𝗼𝗴𝘆
The specific epithet “𝑔𝑎𝑟𝑐𝑖𝑎𝑖” honours the Peruvian ichthyologist Dr James Raúl Garcia Ayala, of the Laboratório de Biologia e Genética de Peixes (LBP-UNESP), who helped collect part of the type series, in recognition of his research on Neotropical fishes, especially the taxonomy of the subfamily Stethaprioninae.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Holotype of 𝐵𝑢𝑛𝑜𝑐𝑒𝑝ℎ𝑎𝑙𝑢𝑠 𝑔𝑎𝑟𝑐𝑖𝑎𝑖 (LBP 37103, 92.2 mm SL) in dorsal (top), lateral (middle) and ventral (bottom) views. Scale bar = 10 mm. Photographed by J. L. Crispim.

© 2026 the Author(s). Published in the journal Zootaxa.

#NewSpecies #Ichthyology #Taxonomy #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank #Bunocephalus #Catfishes #BanjoCatfish #Siluriformes #Aspredinidae #Brazil #rioTocantins #rioAraguaia

[Fish in the News @FishInTheNews]

Researchers delve into the evolutionary distribution of axillary and pectoral spine glands in Corydoradinae catfishes, showing the presence of axillary glands across all genera in the subfamily, though the venom gland associated with the pectoral spine is restricted to a clade comprising 𝑂𝑠𝑡𝑒𝑜𝑔𝑎𝑠𝑡𝑒𝑟, 𝐵𝑟𝑜𝑐ℎ𝑖𝑠, and 𝐻𝑜𝑝𝑙𝑖𝑠𝑜𝑚𝑎.

🔓 https://t.co/hQ0T10fvN5

"This pattern is congruent with phylogenetic relationships and implies that mimicry rings may involve Müllerian, quasi-Batesian, and Batesian components depending on their species composition and the degree of defense exhibited by the species present."

"The presence of venom-associated pectoral spine glands only in the clade comprising 𝐵𝑟𝑜𝑐ℎ𝑖𝑠, 𝐻𝑜𝑝𝑙𝑖𝑠𝑜𝑚𝑎, and 𝑂𝑠𝑡𝑒𝑜𝑔𝑎𝑠𝑡𝑒𝑟 supports a single origin of these glands in the Corydoradinae. Further, our histological analyses indicate that these glands are absent in 𝐶𝑜𝑟𝑦𝑑𝑜𝑟𝑎𝑠, 𝐴𝑠𝑝𝑖𝑑𝑜𝑟𝑎𝑠, 𝑆𝑐𝑙𝑒𝑟𝑜𝑚𝑦𝑠𝑡𝑎𝑥, and 𝐺𝑎𝑠𝑡𝑟𝑜𝑑𝑒𝑟𝑚𝑢𝑠. Interestingly, several species from both venom-bearing and non-venom-bearing lineages have been reported to participate in mimicry rings, often forming mixed-species shoals and exhibiting highly convergent color patterns. Alexandrou et al. (2011) identified 52 Corydoradinae species forming 24 putative Müllerian mimicry rings, with more than 90% of these rings composed of species from different genera that, nonetheless, share strikingly similar coloration. Classical Müllerian mimicry requires that all participating species are defended, contribute to predator deterrence, and share the costs associated with predator learning a common warning signal (Ruxton et al., 2018). Our results partially support this interpretation, as all examined Corydoradinae possess at least some combination of mechanical and glandular defenses. However, the additional presence of venom-associated pectoral spine glands in only some genera suggests that defensive effectiveness may not be equivalent among lineages."

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Morphological diversification of defensive glands in Corydoradinae catfishes indicates a mixed Müllerian-Batesian mimicry system

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Jiménez-Vergara, C. R., Thomaz, A. T., Garzón-Restrepo, A. J., Malabarba, L. R., & Monroy, M. (2026). Morphological diversification of defensive glands in Corydoradinae catfishes indicates a mixed Müllerian-Batesian mimicry system. Neotropical Ichthyology, 24(3), e260051. https://t.co/9f3V2W01Fh

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
Axillary and pectoral-fin spine glands play a central role in the defensive biology of Siluriformes by releasing toxic secretions; however, their distribution, structural diversity, and evolutionary significance within Corydoradinae remain poorly understood.

Here, we present the first comparative histological analysis of these glands across seven genera of Corydoradinae. Axillary glands were present in all examined genera and exhibited a conserved lobular organization consistent with a holocrine secretion type as described previously in other Siluriformes.

In contrast, venom-associated pectoral spine glands were restricted to a clade comprising 𝐻𝑜𝑝𝑙𝑖𝑠𝑜𝑚𝑎, 𝐵𝑟𝑜𝑐ℎ𝑖𝑠, and 𝑂𝑠𝑡𝑒𝑜𝑔𝑎𝑠𝑡𝑒𝑟. In these genera, gland position and cellular morphology closely match venom glands described in other siluriform lineages, supporting a lineage-specific derived condition. Conversely, 𝐶𝑜𝑟𝑦𝑑𝑜𝑟𝑎𝑠, 𝐴𝑠𝑝𝑖𝑑𝑜𝑟𝑎𝑠, 𝑆𝑐𝑙𝑒𝑟𝑜𝑚𝑦𝑠𝑡𝑎𝑥, and 𝐺𝑎𝑠𝑡𝑟𝑜𝑑𝑒𝑟𝑚𝑢𝑠 lacked true venom-associated pectoral spine glands and instead displayed abundant epidermal granular cells and club cells, consistent with the retention of a non-venomous ancestral state.

This pattern is congruent with phylogenetic relationships and implies that mimicry rings may involve Müllerian, quasi-Batesian, and Batesian components depending on their species composition and the degree of defense exhibited by the species present.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Mimicry ring involving 𝐶𝑜𝑟𝑦𝑑𝑜𝑟𝑎𝑠 𝑠𝑖𝑚𝑢𝑙𝑎𝑡𝑢𝑠 and the venomous 𝐻𝑜𝑝𝑙𝑖𝑠𝑜𝑚𝑎 𝑚𝑒𝑡𝑎�� co-occurring in the Meta River basin. Although both possess axillary glands of similar morphology, they differ in the presence of venom spine glands.

© 2026 the Author(s). Published in the journal ZooKeys. An open access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) licence. https://t.co/5IYEkz4Rwi

#Corydoradinae #Corydoras #Aspidoras #Scleromystax #Gastrodermus #Brochis #Hoplisoma #Osteogaster #Ichthyology #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank #Mimicry #Venom #ToxicSecretions #Müllerian #VenomGlands #PectoralSpine

[Fish in the News @FishInTheNews]

#NewSpeciesAlert - 𝑀𝑜𝑒𝑛𝑘ℎ𝑎𝑢𝑠𝑖𝑎 𝑛𝑎𝑛𝑎ℎ, a new species of tetra (Acestrorhamphidae), is described from tributaries of the rio Tapajós basin at Serra do Cachimbo, Pará State, Brazil.

🔓 https://t.co/wk5lUDdasL

"This new taxon represents the fifth species of this putative group described from the Serra do Cachimbo, whose members are likely endemic to the region, indicating that the Serra do Cachimbo may represent an important region of endemism for small-bodied freshwater fishes and underscoring the need for continued taxonomic and biogeographic studies in Amazonian shield headwaters."

"The currently known geographic distribution of 𝑀𝑜𝑒𝑛𝑘ℎ𝑎𝑢𝑠𝑖𝑎 𝑛𝑎𝑛𝑎ℎ is highly restricted, encompassing an upper tributary of the rio Teles Pires within the Serra do Cachimbo. The other putative closely related species, 𝑀. 𝑐𝑎𝑚𝑏𝑎𝑐𝑖𝑐𝑎, 𝑀. 𝑐ℎ𝑙𝑜𝑟𝑜𝑝ℎ𝑡ℎ𝑎𝑙𝑚𝑎, 𝑀. 𝑝𝑒𝑡𝑦𝑚𝑏𝑢𝑎𝑏𝑎, 𝑀. 𝑝𝑙𝑢𝑚𝑏𝑒𝑎, 𝑀. 𝑝𝑎𝑟𝑒𝑐𝑖𝑠, and 𝑀. 𝑠𝑜𝑙𝑎𝑟𝑖𝑠, also exhibit narrow distributions, being endemic to elevated areas of the Brazilian Shield."

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Description of a new species of 𝑀𝑜𝑒𝑛𝑘ℎ𝑎𝑢𝑠𝑖𝑎 (Characiformes: Acestrorhamphidae) from tributaries of rio Tapajós basin at Serra do Cachimbo, Pará State, Brazil

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Camelier, P., & Marinho, M. M. F. (2026). Description of a new species of 𝑀𝑜𝑒𝑛𝑘ℎ𝑎𝑢𝑠𝑖𝑎 (Characiformes: Acestrorhamphidae) from tributaries of rio Tapajós basin at Serra do Cachimbo, Pará State, Brazil. Neotropical Ichthyology, 24(3), e260067. https://t.co/4hIQnKUd0r

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
A new species of 𝑀𝑜𝑒𝑛𝑘ℎ𝑎𝑢𝑠𝑖𝑎 is described from a tributary of the rio Teles Pires, upper rio Tapajós basin, Serra do Cachimbo, Pará State, Brazil.

The new species is diagnosed by a distinctive body coloration pattern consisting of dark blotches on the anterior portion of scales of the second to seventh longitudinal series, a conspicuous horizontally elongate, drop-shaped blotch on the caudal peduncle, and a unique eye coloration in life, with the dorsal portion of the iris reddish and the ventral portion bright golden, as well as five or six branched pelvic-fin rays. The new species is morphologically similar to a group of Amazonian congeners that share unusual body coloration and colored eyes in life, all of which exhibit restricted distributions associated with upland areas of the Brazilian crystalline shield.

This new taxon represents the fifth species of this putative group described from the Serra do Cachimbo, whose members are likely endemic to the region, indicating that the Serra do Cachimbo may represent an important region of endemism for small-bodied freshwater fishes and underscoring the need for continued taxonomic and biogeographic studies in Amazonian shield headwaters.

𝗘𝘁𝘆𝗺𝗼𝗹𝗼𝗴𝘆
The specific name, 𝑛𝑎𝑛𝑎ℎ, is in honour of the esteemed ichthyologist Dr Naércio Aquino Menezes in recognition of his significant contributions to the knowledge of ichthyofauna. Naércio, whom we affectionately call “Naná”, trained many new ichthyologists with respect and kindness and was our PhD advisor. Dr Menezes also coordinated the “South American Characiformes Inventory” project, which supported the expedition in which the new species was collected. A noun in apposition.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
𝑀𝑜𝑒𝑛𝑘ℎ𝑎𝑢𝑠𝑖𝑎 𝑛𝑎𝑛𝑎ℎ, live specimen, paratype, MZUSP 124117, 48.6 mm SL, Brazil, Pará State, Novo Progresso, rio Teles Pires basin, upper rio Tapajós basin.

© 2026 the Author(s). Published in the journal Neotropical Ichthyology. An open access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) licence. https://t.co/5IYEkz4Rwi

#NewSpecies #Ichthyology #Taxonomy #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank #Tetra #Tetras #Characiforme #Acestrorhamphidae #Characin #rioTelesPires #rioTapajós #SerraDoCachimbo #ParáState #Brazil #Neotropical #Endemism #Amazon

[Fish in the News @FishInTheNews]

Researchers in this study provide genomic and additional morphological data supporting the continued recognition of the Halloween darter, 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑐𝑟𝑦𝑝𝑡𝑎, as a valid species distinct from sympatric 𝑃. 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 𝑠𝑒𝑛𝑠𝑢 𝑙𝑎𝑡𝑜.

🔓 https://t.co/OJUF7FkQAr

"Additionally, we provide preliminary genomic, meristic, and morphological data that suggest populations of the 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 complex in the Apalachicola, Altamaha, and Savannah basins, which have recently been collectively referred to under the epithet “𝑤𝑒𝑠𝑡𝑓𝑎𝑙𝑙𝑖” (Fowler), comprise at least two distinct species.

We treat Apalachicola populations as an undescribed form, 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑠𝑝. 𝑐𝑓. 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎, that occurs sympatrically with 𝑃. 𝑐𝑟𝑦𝑝𝑡𝑎. Our conclusion that 𝑃. 𝑐𝑟𝑦𝑝𝑡𝑎 is a valid species supports conservation status for the species in Georgia and Alabama. Ongoing work by the present authors aims to elucidate patterns of speciation in this group and to clarify taxonomy of the eastern populations of the 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 complex."

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Genomic and morphological data corroborate 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑐𝑟𝑦𝑝𝑡𝑎 (Percidae: Etheostomatinae) as a valid taxon and reveal undescribed diversity in the 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 complex

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Hilburn, B.G., Freeman, M.C., Bennett, J., Petersen, K.N., Bayona-Vásquez, N.J., Wares, J.P. & Freeman, B.J. (2026) Genomic and morphological data corroborate 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑐𝑟𝑦𝑝𝑡𝑎 (Percidae: Etheostomatinae) as a valid taxon and reveal undescribed diversity in the 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 complex. Zootaxa, 5890 (4), 527–541. https://t.co/h1re4EwP9f

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑐𝑟𝑦𝑝𝑡𝑎 Freeman, Freeman & Burkhead, the Halloween Darter, was described in 2008 as a new species endemic to the Chattahoochee and Flint River systems in the Apalachicola Basin, Georgia and Alabama, USA. The description illustrated phenotypic differences between 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑐𝑟𝑦𝑝𝑡𝑎 and sympatric 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 (Agassiz) 𝑠𝑒𝑛𝑠𝑢 𝑙𝑎𝑡𝑜 (𝑠.𝑙.) (the Blackbanded Darter) but lacked genetic data. Because of certain morphological similarities with syntopic 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 𝑠.𝑙. and anecdotal evidence suggesting low genetic differentiation between the two forms, recent authors have noted the need for additional investigations to assess the taxonomic validity of 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑐𝑟𝑦𝑝𝑡𝑎.

To examine whether 𝑃. ���𝑟𝑦𝑝𝑡𝑎 represents a valid species separate from 𝑃. 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 𝑠.𝑙., we used 3RAD reduced-representation genomic data and expanded phenotypic comparisons between 𝑃. 𝑐𝑟𝑦𝑝𝑡𝑎 and 𝑃. 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 𝑠.𝑙. from the Apalachicola basin and three adjacent river basins. Genome-wide sequence data show that 𝑃. 𝑐𝑟𝑦𝑝𝑡𝑎 is reciprocally monophyletic with respect to 𝑃. 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 𝑠.𝑙. in every basin examined. Meristic and morphometric data also resolve 𝑃. 𝑐𝑟𝑦𝑝𝑡𝑎 and 𝑃. 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 𝑠.𝑙. as distinct clusters in principal component analyses, and pigmentation patterns provide diagnostic characters that allow easy identification of 𝑃. 𝑐𝑟𝑦𝑝𝑡𝑎 in the field.

Additionally, we provide preliminary genomic, meristic, and morphological data that suggest populations of the 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 complex in the Apalachicola, Altamaha, and Savannah basins, which have recently been collectively referred to under the epithet “𝑤𝑒𝑠𝑡𝑓𝑎𝑙𝑙𝑖” (Fowler), comprise at least two distinct species.

We treat Apalachicola populations as an undescribed form, 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑠𝑝. 𝑐𝑓. 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎, that occurs sympatrically with 𝑃. 𝑐𝑟𝑦𝑝𝑡𝑎. Our conclusion that 𝑃. 𝑐𝑟𝑦𝑝𝑡𝑎 is a valid species supports conservation status for the species in Georgia and Alabama. Ongoing work by the present authors aims to elucidate patterns of speciation in this group and to clarify taxonomy of the eastern populations of the 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 complex.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
A) 3RAD sample locations for 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 𝑠.𝑙. and B) 3RAD sample locations for 𝑃𝑒𝑟���𝑖𝑛𝑎 𝑐𝑟𝑦𝑝𝑡𝑎. Grey shading represents the respective ranges of each taxon. C) Midpoint-rooted maximum likelihood phylogeny constructed in IQ-TREE using 3RAD SNP data depicting the reciprocal monophyly of 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑐𝑟𝑦𝑝𝑡𝑎 and geographic structure in the 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 complex. Bootstrap support values are displayed on the major nodes. The Flint clade also includes a single individual from a tributary of the Apalachicola River proper. Photos from top to bottom: 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑐𝑟𝑦𝑝𝑡𝑎 from the Chattahoochee watershed, 𝑃. 𝑠𝑝. 𝑐𝑓. 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 from the Chattahoochee watershed, 𝑃𝑒𝑟𝑐𝑖𝑛𝑎 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 from the Upper Coosa watershed, and 𝑃. 𝑠𝑝. 𝑐𝑓. 𝑛𝑖𝑔𝑟𝑜𝑓𝑎𝑠𝑐𝑖𝑎𝑡𝑎 from the Savannah watershed. Photos by B.G.H.

© 2026 the Author(s). Published in the journal Zootaxa. An open access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) licence. https://t.co/5IYEkz4Rwi

#Ichthyology #Taxonomy #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #Percina #Percidae #Etheostomatinae #FishTank #USA #HalloweenDarter #Darter #Darters #Apalachicola #Georgia #Alabama #Altamaha #Savannah #BlackbandedDarter #Chattahoochee