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| Chromis veneta Rekha, Jayakumar, Abhilash, Ahamed Rasheeq, Saikrishnan, Vallarasu, Gladston, Chakraborty & Ajithkumar, 2026 |
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
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| Caption Male of Chromis veneta sp. nov. (64.51 mm SL) in live breeding coloration. |
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]
















































