Astyanax cocibolca Bussing, 2008

Family:  Characidae (Characins; tetras), subfamily: Stethaprioninae
Max. size:  5.36 cm SL (male/unsexed)
Environment:  pelagic; freshwater; depth range - 2 m
Distribution:  Central America: endemic to Lake Nicaragua.
Diagnosis:  The semipelagial Astyanax cocibolca can be readily separated from the A. aeneus that inhabits some of the same habitats in Lake Nicaragua by its slender body 29.1-36.4% SL (vs. 33.9-39.3% SL); with slightly upturned mouth; high total gill raker count 23-34, mean 28.9 (vs. 22-26, mean 24.1); reduced size of dentary teeth; fewer scale rows above lateral line 6-8, mean 7.2 (vs. 8-9, mean 8.3); more intense black midlateral band; smaller size, maximum 54.3 (vs. greater than 80 mm SL); conical teeth in outer row of premaxillary bone (vs. only tricuspid outer row teeth) (Ref. 83537).
Biology:  This filter-feeding specialist utilizes the open-water habitat, at least as a nursery where young can feed on the rich plankton population. Two small adults from the open water habitat contained 90% copepoda and cladocera while inshore specimens contained 90% fruit, 5% cladocera, 5% seed, algae. The adult female from open water contained ripe eggs, although 10 adult females from inshore sites contained only undeveloped eggs (Ref. 83537).
IUCN Red List Status: Data deficient (DD); Date assessed: 08 November 2019 Ref. (130435)
Threat to humans:  harmless


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