Chimaeroid taxonomy and distribution

Description of a new species of chimaeroid fish from the Galápagos Islands, Ecuador (Holocephali, Chimaeriformes, Chimaeridae) 

A new species of chimaeroid, Hydrolagus mccoskeri sp. nov., is described from the Galápagos Islands. This species represents the second member of the family Chimaeridae known from the eastern equatorial Pacific. It can be distinguished from its congeners by a combination of the following characters: small head with short, blunt snout; preopercular and oral lateral line canals branching from the same node off the infraorbital canal and sharing a short common branch; dorsum medium brown with numerous narrow, sharply delineated circular and elongate white blotches; ventrum white to tan with extremely fine brown mottling. The species is compared to Hydrolagus novaezealandiae and Hydrolagus colliei, the most similar congeners in color pattern and morphology.


Barnett, L.A.K., Didier, D.A., Long, D.J. & D.A. Ebert.  2006.  Hydrolagus mccoskeri sp. nov., a new species of chimaeroid fish from the Galápagos Islands (Holocephali: Chimaeriformes: Chimaeridae).  Zootaxa 1328:27-38.



Distribution of chimaeroid fishes of the Pacific Ocean (Holocephali, Chimaeriformes, Chimaeridae) 

Video footage from submersible and remotely operated vehicle (ROV’s) surveys in the Pacific Ocean were analyzed for the presence of chimaeroid fishes.  Individuals were identified to species when possible.  We found that the published bathymetric and geographic range of these species were not accurate.  Of the species observed, many were located in regions previously believed to be outside of their respective distributional ranges.  Several individuals differed in morphology and coloration from known species.  These specimens likely represent an undescribed species that has yet to be captured by fishing gear.  Footage was provided by the Monterey Bay Aquarium Research Institute.