CGSS Cristian Ghia Shrimp Studio

06/09/2026

Nuovo progetto 💙

28/08/2026

28/08/2026

Giretto veloce in serra 💙💙💙

02/08/2026

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Researchers presents an inventory of the ichthyofauna from the blackwater habitats of the Coastal Plain in northern Santa Catarina, southern Brazil. In total, 30 species were recorded, representing 13 families and five orders. The authors found the entire study area is highly fragmented, with restinga remnants surrounded by urban zones and industrial infrastructure. This pattern of fragmentation reduces population connectivity, impairs gene flow, and increases the risk of local extinctions.

"The continued degradation of riparian vegetation, combined with climate change, poses an additional threat to the persistence of these communities. These findings underscore the urgent need to expand conservation actions targeting blackwater ecosystems along the southern Brazilian coastal plain."

Ichthyofauna checklists and rapid assessments are important tools for biologists, researchers, conservationists, and government bodies/NGOs. They provide critical baselines for the conservation and management of regional fish fauna. Our understanding of species composition in a territory evolves due to species movements across borders, extinctions, introductions, and new taxonomic evidence.

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Fish assemblages and endemism in blackwater aquatic habitats of the Coastal Plain in northern Santa Catarina, southern Brazil

Open-access - https://www.scielo.br/j/bn/a/hCWmq8GcxYnGmtQLbpNBHfJ/

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Dalcin, R. H., Lima, A. O. de S., Laaf, Y. de O., Ossa-Guerra, L. E. D. la ., Dallabona, J. A., Costa, V. S. C. da ., Abilhoa, V., Pinheiro, P. C., Feltrin, C. R., & Cionek, V. de M.. (2026). Fish assemblages and endemism in blackwater aquatic habitats of the Coastal Plain in northern Santa Catarina, southern Brazil. Biota Neotropica, 26(3), e20251834. https://doi.org/10.1590/1676-0611-BN-2025-1834

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
Blackwater streams are unique environments characterized by dark, acidic, and nutrient-poor waters, supporting highly specialized aquatic communities.

This study presents an inventory of the ichthyofauna of such systems in the northern region of Santa Catarina state, based on surveys conducted between 2020 and 2024. A total of 22 sites were sampled, including perennial rivers, intermittent streams, and temporary pools, located both within and outside protected areas. In total, 30 fish species were recorded, representing 13 families and five orders. The order Characiformes showed the highest richness and was represented mainly by small-characins of the family Acestrorhamphidae. Nine species were identified as endemic to blackwater environments of the Atlantic Forest, five of which officially listed as threatened. The guppy 𝑃𝑜𝑒𝑐𝑖𝑙𝑖𝑎 𝑟𝑒𝑡𝑖𝑐𝑢𝑙𝑎𝑡𝑎 was recorded for the first time in blackwater environments of the region, as well as 𝐵𝑟𝑎𝑐ℎ𝑦ℎ𝑦𝑝𝑜𝑝𝑜𝑚𝑢𝑠 𝑐𝑓. 𝑑𝑟𝑎𝑐𝑜, representing the first record of Hypopomidae (knifefish) in the region. DNA barcoding (using COI) provided molecular information, in addition to the morphological identification of 12 species, providing new local sequences for them. Results indicated a high similarity between the ichthyofauna of this region and that of blackwater streams in the southern coast of São Paulo. Endemic and threatened species were recorded both inside and outside legally protected areas, highlighting gaps in current conservation efforts. Furthermore, intermittent streams and temporary pools proved to be critical habitats for maintaining species with extremely restricted distributions.

The continued degradation of riparian vegetation, combined with climate change, poses an additional threat to the persistence of these communities. These findings underscore the urgent need to expand conservation actions targeting blackwater ecosystems along the southern Brazilian coastal plain.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Top left - Representative species of the order Characiformes recorded in the blackwater streams of northern Santa Catarina, Brazil. (A) Astyanax lacustris. (B) Deuterodon ribeirae. (C) Hollandichthys multifasciatus. (D) Hyphessobrycon igneus. (E) Hyphessobrycon griemi. (F) Hyphessobrycon reticulatus. (G) Oligosarcus hepsetus; (H) Psalidodon laticeps. (I) Rachoviscus crassiceps. (J) Characidium lanei. (K) Hoplias malabaricus. (L) Spintherobolus ankoseion. ( M ) Mimagoniates lateralis. ( N ) Mimagoniates microlepis. The white scale bar below each photograph corresponds to 1 cm.
Top right - Representative species of the order Cichliformes and Cyprinodontiformes recorded in the blackwater streams of northern Santa Catarina, Brazil. (A) Geophagus iporangensis. (B) Saxatilia lepidota. (C) Phalloceros cf. circummontanus (male). (D) Phalloceros cf. circummontanus (female). (E) Phalloceros spiloura (male). (F) Phalloceros spiloura (female). (G) Poecilia reticulata (male). (H) Poecilia reticulata (female). (I) Atlantirivulus haraldsiolii (male). (J) Atlantirivulus haraldsiolii (female). (K) Atlantirivulus luelingi (male). (L) Atlantirivulus luelingi (female). ( M ) Campellolebias chrysolineatus (male); ( N ) Campellolebias chrysolineatus (female). The white scale bar below each photograph corresponds to 1 cm.
Bottom - Examples of sampling sites visited during fieldwork activities. (A) Saí Mirim River, Itapoá. (B) Tributary of the Saí Mirim River. (C) Temporary pool on the margins of the Saí Mirim River during the rainy season. ( D ) Temporary pool on the margins of the Saí Mirim River during the dry season. (E) Acaraí River, São Francisco do Sul. (F) Tributary of the Acaraí River. (G) Temporary pool on the margins of the Acaraí River. (H) Pernambuco River, Barra do Sul. (I) Tributary of the Pernambuco River. (J) Perequê River, Barra do Sul. (K) Tributary of the Perequê River. ( L ) Temporary pool on the margins of the Perequê River. (M) Tributary of the Itapocu River, Araquari. ( N ) Temporary pool on the margins of a tributary of the Itapocu River. (O) Cardoso Stream, tributary of the Itapocu River, Araquari. (P) Tributary of the Cardoso Stream.

© 2026 the Author(s). Published in the journal Biota Neotropical. An open-access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) deed. https://creativecommons.org/licenses/by/4.0/

30/07/2026

New Specie 💙💙💙

𝑅𝑎𝑘𝑡ℎ𝑎𝑚𝑖𝑐ℎ𝑡ℎ𝑦𝑠 𝑎𝑛𝑐ℎ𝑖, a new species of phreatobitic swamp eel (Synbranchidae), is described from wells in a small village in Goalpara District, Assam, northeast India.

"The discovery of 𝑅. 𝑎𝑛𝑐ℎ𝑖 from wells in the same village in which 𝐺𝑖𝑡𝑐ℎ𝑎𝑘 𝑛𝑎𝑘𝑎𝑛𝑎 Britz et al. was recently described highlights the presence of a formerly unknown and highly dynamic subterranean habitat: the groundwater aquifers in alluvial deposits in northeast India."

Phreatobitic refers to organisms (phreatobites) that live exclusively within the phreatic zone, which is the subterranean area of groundwater aquifers completely saturated with water.

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
𝑅𝑎𝑘𝑡ℎ𝑎𝑚𝑖𝑐ℎ𝑡ℎ𝑦𝑠 𝑎𝑛𝑐ℎ𝑖, a new species of phreatobitic synbranchid eel from Assam

Paywall - https://www.mapress.com/zt/article/view/zootaxa.5857.3.3

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Britz, R., Pinion, A.K., Marak, W.K., Velentina, K. & Lokeshwor, Y. (2026) 𝑅𝑎𝑘𝑡ℎ𝑎𝑚𝑖𝑐ℎ𝑡ℎ𝑦𝑠 𝑎𝑛𝑐ℎ𝑖, a new species of phreatobitic synbranchid eel from Assam. Zootaxa, 5857 (3), 462–482. https://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. was recently described highlights the presence of a formerly unknown and highly dynamic subterranean habitat: the groundwater aquifers in alluvial deposits in northeast India.

𝗘𝘁𝘆𝗺𝗼𝗹𝗼𝗴𝘆
The species name is derived from the Garo word ‘an·chi’, meaning ‘blood’ alluding to its blood-red colouration in life.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Top (Fig. 3) - 𝑅𝑎𝑘𝑡ℎ𝑎𝑚𝑖𝑐ℎ𝑡ℎ𝑦𝑠 𝑎𝑛𝑐ℎ𝑖, paratypes, KUFOS.F.50–52.1.1., 255–318 mm TL, India: Assam: Goalpara District, illustrating colouration in life. A, Three paratypes, shortly after collection. B, Paratype, KUFOS.F.50.1.1., 318 mm TL in lateral view. C, Same individual, close-up of head region. D, Paratype, KUFOS.F.52.1.1., 255 mm TL, close-up of head region
Bottom (Fig. 4) - Abandoned well from which paratypes were collected. A, Overview of well. B, View into the well illustrating algae and moss-covered upper loamy-sandy and vegetation-free lower loamy part.

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

22/07/2026

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The Gymnotiformes are an abundant, diverse, and ecologically significant component of the nocturnal ichthyofauna of most major Neotropical freshwater habitats. The authors in this study present a taxonomically inclusive molecular phylogeny of Gymnotiformes, with analyses that provide strong support for a concordant species-level phylogenetic arrangement and propose a revised classification of Gymnotiformes, including new suprageneric names and reassignments of some taxa and species.

"We found support for six monophyletic families, including Electrophoridae (electric eels). We propose two new suborders corresponding to electric signal type: Pulseoidei (pulse-type) and Sinusoidei (wave-type), an arrangement that does not allow determination of whether a pulse or wave-type signal was ancestral."

"Our study provides a robust phylogenetic framework for Gymnotiformes and establishes a foundation for future work on systematics, biogeography, trait evolution, and comparative neurobiology."

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Molecular phylogenetics and a new taxonomy of the neotropical electric fishes (Actinopterygii: Otophysi: Gymnotiformes)

Open-access - https://www.sciencedirect.com/science/article/pii/S105579032600148X

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Francesco H. Janzen, Mark H. Sabaj, William G.R. Crampton, Nathan R. Lovejoy, Molecular phylogenetics and a new taxonomy of the neotropical electric fishes (Actinopterygii: Otophysi: Gymnotiformes), Molecular Phylogenetics and Evolution, 2026, 108678, ISSN 1055-7903, https://doi.org/10.1016/j.ympev.2026.108678

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
The order Gymnotiformes—Neotropical electric eels and knifefishes—comprise a distinctive lineage of freshwater fishes characterized by electrogenesis and electroreception. Despite their ecological, evolutionary, and neurobiological significance, phylogenetic relationships within the order remain incompletely resolved.

We present the most taxonomically inclusive molecular phylogeny of Gymnotiformes to date, based on two mitochondrial and seven nuclear genes from 202 species representing 31 of 36 extant genera. Maximum likelihood and Bayesian inference analyses provide strong support for a concordant species-level phylogenetic arrangement that we use to propose a revised classification of Gymnotiformes, including new suprageneric names and reassignments of some taxa and species.

We found support for six monophyletic families, including Electrophoridae (electric eels). We propose two new suborders corresponding to electric signal type: Pulseoidei (pulse-type) and Sinusoidei (wave-type), an arrangement that does not allow determination of whether a pulse or wave-type signal was ancestral. In Apteronotidae, the subfamilies Sternarchorhamphinae and Apteronotinae are supported; within Apteronotinae, we establish the tribe Steatogenini to include 𝑃𝑜𝑟𝑜𝑡𝑒𝑟𝑔𝑢𝑠, 𝑆𝑡𝑒𝑟𝑛𝑎𝑟𝑐ℎ𝑒𝑙𝑙𝑎, and close relatives.

We resolve the non-monophyly of 𝐴𝑝𝑡𝑒𝑟𝑜𝑛𝑜𝑡𝑢𝑠 with generic reassignments. For Sternopygidae, we support the monophyletic subfamilies Sternopyginae and Eigenmanniinae and resolve polyphyly in 𝑅ℎ𝑎𝑏𝑑𝑜𝑙𝑖𝑐ℎ𝑜𝑝𝑠 and 𝐸𝑖𝑔𝑒𝑛𝑚𝑎𝑛𝑛𝑖𝑎 via generic reassignments. Within 𝐺𝑦𝑚𝑛𝑜𝑡𝑢𝑠, we support six species groups.

We confirm the sister-group relationship between Hypopomidae and Rhamphichthyidae and clarify their internal structure, including support for six species groups within the diverse genus 𝐵𝑟𝑎𝑐ℎ𝑦ℎ𝑦𝑝𝑜𝑝𝑜𝑚𝑢𝑠.

Our study provides a robust phylogenetic framework for Gymnotiformes and establishes a foundation for future work on systematics, biogeography, trait evolution, and comparative neurobiology.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Representatives of the six gymnotiform families Apteronotidae (A), Sternopygidae (S), Gymnotidae (G), Electrophoridae (E), Hypopomidae (H), and Rhamphichthyidae (R). Top to bottom, and left to right, are: 𝑅ℎ𝑎𝑚𝑝ℎ𝑖𝑐ℎ𝑡ℎ𝑦𝑠 𝑟𝑜𝑠𝑡𝑟𝑎𝑡𝑢𝑠 (R), 𝐴𝑟𝑐ℎ𝑜𝑙𝑎𝑒𝑚𝑢𝑠 𝑗𝑎𝑛𝑒𝑎𝑒 (S), 𝑆𝑡𝑒𝑟𝑛𝑎𝑟𝑐ℎ𝑜𝑟ℎ𝑎𝑚𝑝ℎ𝑢𝑠 𝑚𝑢𝑒𝑙𝑙𝑒𝑟𝑖 (A), 𝐸𝑖𝑔𝑒𝑛𝑚𝑎𝑛𝑛𝑖𝑎 𝑚𝑎𝑔𝑜𝑖 (S), 𝐺𝑦𝑚𝑛𝑜𝑡𝑢𝑠 𝑐𝑎𝑟𝑎𝑝𝑜 (G), 𝑆𝑡𝑒𝑟𝑛𝑎𝑟𝑐ℎ𝑜𝑟ℎ𝑦𝑛𝑐ℎ𝑢𝑠 𝑠𝑝. (A), 𝐴𝑝𝑡𝑒𝑟𝑜𝑛𝑜𝑡𝑢𝑠 𝑔𝑎𝑙𝑣𝑖𝑠𝑖 (A), 𝑂𝑟𝑡ℎ𝑜𝑠𝑡𝑒𝑟𝑛𝑎𝑟𝑐ℎ𝑢𝑠 𝑡𝑎𝑚𝑎𝑛𝑑𝑢𝑎 (A), “𝐴𝑝𝑡𝑒𝑟𝑜𝑛𝑜𝑡𝑢𝑠” (Genus B) 𝑐𝑢𝑐ℎ𝑖𝑙𝑙𝑒𝑗𝑜 (A), 𝐴𝑝𝑡𝑒𝑟𝑜𝑛𝑜𝑡𝑢𝑠 𝑒𝑠𝑐ℎ𝑚𝑒𝑦𝑒𝑟𝑖 (A), 𝐴𝑝𝑡𝑒𝑟𝑜𝑛𝑜𝑡𝑢𝑠 𝑐𝑓. 𝑎𝑙𝑏𝑖𝑓𝑟𝑜𝑛𝑠 (A), 𝐺𝑦𝑚𝑛𝑜𝑟ℎ𝑎𝑚𝑝ℎ𝑖𝑐ℎ𝑡ℎ𝑦𝑠 𝑠𝑝. (R), 𝑆𝑡𝑒𝑟𝑛𝑎𝑟𝑐ℎ𝑜𝑟ℎ𝑦𝑛𝑐ℎ𝑢𝑠 𝑚𝑎𝑟𝑟𝑒𝑟𝑜𝑖 (A), 𝑆𝑡𝑒𝑟𝑛𝑜𝑝𝑦𝑔𝑢𝑠 𝑎𝑒𝑞𝑢𝑖𝑙𝑎𝑏𝑖𝑎𝑡𝑢𝑠 (S), 𝐴𝑑𝑜𝑛𝑡𝑜𝑠𝑡𝑒𝑟𝑛𝑎𝑟𝑐ℎ𝑢𝑠 𝑑𝑒𝑣𝑒𝑛𝑎𝑛𝑧𝑖𝑖 (A), 𝑆𝑡𝑒𝑎𝑡𝑜𝑔𝑒𝑛𝑦𝑠 𝑑𝑢𝑖𝑑𝑎𝑒 (R), 𝐵𝑟𝑎𝑐ℎ𝑦ℎ𝑦𝑝𝑜𝑝𝑜𝑚𝑢𝑠 𝑜𝑐𝑐𝑖𝑑𝑒𝑛𝑡𝑎𝑙𝑖𝑠 (H), 𝐻𝑦𝑝𝑜𝑝𝑜𝑚𝑢𝑠 𝑎𝑟𝑡𝑒𝑑𝑖 (H), and 𝐸𝑙𝑒𝑐𝑡𝑟𝑜𝑝ℎ𝑜𝑟𝑢𝑠 𝑚𝑢𝑙𝑡𝑖𝑣𝑎𝑙𝑣𝑢𝑙𝑢𝑠 (E). Photos by M. Sabaj.

© 2026 the Author(s). Published in the journal Molecular Phylogenetics and Evolution. An open-access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) deed. https://creativecommons.org/licenses/by/4.0/

01/07/2026

💙

𝑁𝑒𝑜𝑝𝑙𝑒𝑐𝑜𝑠𝑡𝑜𝑚𝑢𝑠 𝑎𝑧𝑒𝑣𝑒𝑑𝑜𝑠𝑎𝑛𝑡𝑜𝑠𝑖, a new species of small-sized loricariid catfish (Hypoptopomatinae), is described from the Neotropical Atlantic coastal drainages, in southeast Brazil.

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
A new sexually dimorphic species of the armoured catfish genus 𝑁𝑒𝑜𝑝𝑙𝑒𝑐𝑜𝑠𝑡𝑜𝑚𝑢𝑠 (Siluriformes: Loricariidae) from Neotropical Atlantic coastal drainages

Open-access - https://onlinelibrary.wiley.com/doi/10.1111/jfb.70547

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Uzeda, P. L. C., Pessali, T. C., Katz, A. M., Ottoni, F. P., Langeani, F., & Silva, P. C. (2026). A new sexually dimorphic species of the armoured catfish genus 𝑁𝑒𝑜𝑝𝑙𝑒𝑐𝑜𝑠𝑡𝑜𝑚𝑢𝑠 (Siluriformes: Loricariidae) from Neotropical Atlantic coastal drainages. Journal of Fish Biology, 1–10. https://doi.org/10.1111/jfb.70547

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
A new species of the small-sized armoured catfish genus 𝑁𝑒𝑜𝑝𝑙𝑒𝑐𝑜𝑠𝑡𝑜𝑚𝑢𝑠 is described from Neotropical Atlantic coastal drainages, in southeast Brazil. The new species can be readily diagnosed from all congeners by having the first plates of the ventral series reduced in size, rounded and ventrally displaced, resulting in a naked band between the mid-ventral and ventral series of plates. Additionally, the species exhibits marked sexual dimorphism in dentition: Females possess numerous slender teeth, while males have fewer, more robust teeth. We report the second known case of sympatry between congeneric species of 𝑁𝑒𝑜𝑝𝑙𝑒𝑐𝑜𝑠𝑡𝑜𝑚𝑢𝑠, a rare condition for the genus, and provide insights into its biogeographic and ecological patterns.

𝗘𝘁𝘆𝗺𝗼𝗹𝗼𝗴𝘆
The specific epithet ‘𝑎𝑧𝑒𝑣𝑒𝑑𝑜𝑠𝑎𝑛𝑡𝑜𝑠𝑖’ is in honour of Valter M. Azevedo-Santos, Brazilian ichthyologist and dear friend, for his outstanding contributions to freshwater ecology and conservation biology. A noun in the genitive case.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Left - 𝑁𝑒𝑜𝑝𝑙𝑒𝑐𝑜𝑠𝑡𝑜𝑚𝑢𝑠 𝑎𝑧𝑒𝑣𝑒𝑑𝑜𝑠𝑎𝑛𝑡𝑜𝑠𝑖, holotype, DZSJRP 25391, male, 113.8 mm SL, Brazil, Minas Gerais, Espera Feliz, Ribeirão São Domingos, tributary of the Preto River, Itabapoana River basin. Dorsal, lateral and ventral views.
Right - Ontogenetic variation in dorsal colouration of 𝑁𝑒𝑜𝑝𝑙𝑒𝑐𝑜𝑠𝑡𝑜𝑚𝑢𝑠 𝑎𝑧𝑒𝑣𝑒𝑑𝑜𝑠𝑎𝑛𝑡𝑜𝑠𝑖, MCNIP 5072, paratypes. From left to right: juvenile (51.5 mm SL), early adult (59.0 mm SL), adult (77.5 mm SL).

© 2026 the Author(s). Published in the Journal of Fish Biology. An open-access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) deed. https://creativecommons.org/licenses/by/4.0/

26/06/2026

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𝐴𝑐𝑟𝑜𝑠𝑠𝑜𝑐ℎ𝑒𝑖𝑙𝑢𝑠 𝑧ℎ𝑎𝑛𝑔𝑗𝑖𝑎𝑗𝑖𝑒𝑛𝑠𝑖𝑠, a new species of cyprinid is described from the upper Lishui River Basin, a tributary of the Yangtze River, in Sangzhi County, Zhangjiajie City, Hunan Province, China.

"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."

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Integrative taxonomy reveals a new species of 𝐴𝑐𝑟𝑜𝑠𝑠𝑜𝑐ℎ𝑒𝑖𝑙𝑢𝑠 (Cypriniformes, Cyprinidae) from Hunan Province, China

Open-access - https://zse.pensoft.net/article/195486/

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Cao J, Deng Z, Xiang H, Xie Y, Wang C, Li H, Hu Y, Wei Y, Jiang W (2026) Integrative taxonomy reveals a new species of 𝐴𝑐𝑟𝑜𝑠𝑠𝑜𝑐ℎ𝑒𝑖𝑙𝑢𝑠 (Cypriniformes, Cyprinidae) from Hunan Province, China. Zoosystematics and Evolution 102(3): 869-883. https://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.

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)”.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
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.

© 2026 the Author(s). Published in the journal Zoosystematics and Evolution. An open-access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) deed. https://creativecommons.org/licenses/by/4.0/

26/06/2026

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An interesting study on microhabitat use by fishes from the mountainous headwaters of the northwestern La Plata Basin, Argentina, a freshwater region of conservation priority with a highly endemic ichthyofauna. Researchers, after more than two decades of fieldwork in the Andean headwaters of the Bermejo and Juramento river basins, compiled over 81 hours of direct observations and nearly eighteen hours of underwater video recordings to document how these fishes live in their natural environments.

Results from this fieldwork reveal patterns of habitat partitioning, nursery areas, mixed-species shoals, altitudinal segregation, predatory behaviour, aggressive mimicry, commensal feeding, and the relationship between colouration and habitat use, providing new insights into the ecology and evolution of these unique freshwater fishes.

𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Habitat use, coloration, and behavioral observations of fishes from mountainous headwaters of the northwestern La Plata basin

Open-access - https://www.lillo.org.ar/journals/index.php/acta-zoologica-lilloana/article/view/2380

𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Alonso, F., Irigoyen, A. J., Aguilera, G., Terán, G. E., Serra Alanis, W. S., Mettola, V. E., Waldbilling, M. M., Merlo, P. J., Trobbiani, G., Méndez López, A., Avigliano, E., Montes, M. M. ., Pandolfi, M., & Mirande, J. M. (2026). Habitat use, coloration, and behavioral observations of fishes from mountainous headwaters of the northwestern La Plata basin. Acta Zoológica Lilloana, 413–450. https://doi.org/10.30550/j.azl/2380

𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
We describe microhabitat use and provide observations on the coloration and behavior of fishes from the mountainous headwaters of the northwestern La Plata Basin, a highly endemic freshwater region of high conservation priority.

Using underwater observations, video recordings, and in situ photography, we documented habitat associations, school formation, species interactions, and the potential ecological role of coloration patterns. In watercourses of the Bermejo and Juramento river basins we accumulated approximately 81.5 h of direct observations and 17 h 36 min of underwater video recordings. Fish assemblages showed marked habitat partitioning: benthic specialists (e.g., 𝑇𝑟𝑖𝑐ℎ𝑜𝑚𝑦𝑐𝑡𝑒𝑟𝑢𝑠 𝑠𝑝𝑒𝑔𝑎𝑧𝑧𝑖𝑛𝑖𝑖, 𝑅𝑖𝑛𝑒𝑙𝑜𝑟𝑖𝑐𝑎𝑟𝑖𝑎 𝑠𝑝𝑝., 𝐶ℎ𝑎𝑟𝑎𝑐𝑖𝑑𝑖𝑢𝑚 𝑠𝑝𝑝., and 𝑃𝑎𝑟𝑜𝑑𝑜𝑛 𝑐𝑎𝑟𝑟𝑖𝑘𝑒𝑟𝑖) were concentrated in riffles and high-velocity microhabitats, whereas many characiforms were more frequent in pools and moderate-flow sections. Shallow vegetated secondary arms frequently functioned as nursery habitats by concentrating juveniles. Size-based altitudinal segregation observed in 𝐴𝑐𝑟𝑜𝑏𝑟𝑦𝑐𝑜𝑛 𝑡𝑎𝑟𝑖𝑗𝑎𝑒 (adults upstream; juveniles downstream) suggests a life cycle linked to elevation gradients and a possible reproductive migration.

We also recorded notable behaviors, including aggressive mimicry in 𝑂𝑙𝑖𝑔𝑜𝑠𝑎𝑟𝑐𝑢𝑠 𝑏𝑜𝑙𝑖𝑣𝑖𝑎𝑛𝑢𝑠, contrasting predatory strategies of 𝑆𝑎𝑙𝑚𝑖𝑛𝑢𝑠 𝑏𝑟𝑎𝑠𝑖𝑙𝑖𝑒𝑛𝑠𝑖𝑠, and commensal feeding by small characiforms following substrate-disturbing individuals of 𝑆𝑡𝑒𝑖𝑛𝑑𝑎𝑐ℎ𝑛𝑒𝑟𝑖𝑛𝑎 𝑏𝑟𝑒𝑣𝑖𝑝𝑖𝑛𝑛𝑎.

These results highlight the importance of structural habitat heterogeneity and the need for conservation measures to mitigate anthropogenic impacts such as river canalization.

𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Top left - Catfish species recorded: A) 𝐻𝑒𝑝𝑡𝑎𝑝𝑡𝑒𝑟𝑢𝑠 𝑚𝑢𝑠𝑡𝑒𝑙𝑖𝑛𝑢𝑠; B) 𝑇𝑟𝑖𝑐ℎ𝑜𝑚𝑦𝑐𝑡𝑒𝑟𝑢𝑠 𝑠𝑝𝑒𝑔𝑎𝑧𝑧𝑖𝑛𝑖𝑖, C) 𝑈𝑟𝑘𝑢𝑚𝑎𝑦𝑢 𝑔𝑙𝑎𝑑𝑦𝑠𝑎𝑒, D) 𝑈𝑟𝑘𝑢𝑚𝑎𝑦𝑢 𝑚𝑖𝑐𝑟𝑎𝑐𝑎𝑛𝑡ℎ𝑢𝑠, E) 𝐻𝑦𝑝𝑜𝑠𝑡𝑜𝑚𝑢𝑠 𝑐𝑜𝑐ℎ𝑙𝑖𝑜𝑑𝑜𝑛, F) 𝑅𝑖𝑛𝑒𝑙𝑜𝑟𝑖𝑐𝑎𝑟𝑖𝑎 𝑠𝑡𝑒𝑖𝑛𝑏𝑎𝑐ℎ𝑖, G) 𝑅𝑖𝑛𝑒𝑙𝑜𝑟𝑖𝑐𝑎𝑟𝑖𝑎 𝑐𝑎𝑡𝑎𝑚𝑎𝑟𝑐𝑒𝑛𝑠𝑖𝑠.
Top right - Study sites. Bermejo river basin: A) Stream in Lesser (-24.682152°, -65.476162°, 762 m asl), Salta province, B) an unnamed stream along National Route 50 (-23.055411°, -64.343825°, 351 m asl), C) Bermejo River (-23.192536°, -64.183119°, 306 m asl), D) Parque Nacional El Rey at Popayán River (-24.730694°, -64.575028°, 786 m asl), E) Geiser Mollinedo (-24.416999°, -63.990999°, 357 m asl), and F) Laguna La Quinta (-23.884175°, -64.467428°, 627 m asl), G) Aguas Calientes (-23.744398°, -64.519017°, 411 m asl); and in the Juramento River Basin: H) the Calchaquí River near Payogasta (-25.050156°, -66.105744°, 2433 m asl).
Bottom - Characiforme species recorded: A) 𝑃𝑎𝑟𝑜𝑑𝑜𝑛 𝑐𝑎𝑟𝑟𝑖𝑘𝑒𝑟𝑖, B) 𝐶ℎ𝑎𝑟𝑎𝑐𝑖𝑑𝑖𝑢𝑚 𝑏𝑜𝑟𝑒𝑙𝑙𝑖𝑖, C) 𝑃𝑟𝑜𝑐ℎ𝑖𝑙𝑜𝑑𝑢𝑠 𝑙𝑖𝑛𝑒𝑎𝑡𝑢𝑠, D) 𝑆𝑡𝑒𝑖𝑛𝑑𝑎𝑐ℎ𝑛𝑒𝑟𝑖𝑛𝑎 𝑏𝑟𝑒𝑣𝑖𝑝𝑖𝑛𝑛𝑎, E) 𝐻𝑜𝑝𝑙𝑖𝑎𝑠 𝑎𝑟𝑔𝑒𝑛𝑡𝑖𝑛𝑒𝑛𝑠𝑖𝑠, F) 𝐴𝑟ℎ𝑖𝑛𝑜𝑙𝑒𝑚𝑢𝑟 𝑜𝑏𝑡𝑢𝑠𝑖𝑑𝑒𝑛𝑠.

© 2026 the Author(s). Published in the journal Acta Zoológica Lilloana. An open-access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC-BY-NC-ND-4.0) deed. https://creativecommons.org/licenses/by-nc-nd/4.0/

18/06/2026