Holocephali (chimaeras) > Chimaeriformes
(Chimaeras) > Chimaeridae
(Shortnose chimaeras or ratfishes)
Etymology: Hydrolagus: hydro-, combining form of hydor (Gr.), water; lagos (Gr.), hare, i.e., “water rabbit,” probably referring to three pairs of tooth plates, which tend to protrude from the mouth like a rabbit’s incisors. (See ETYFish); mccoskeri: In honor of American ichthyologist John E. McCosker (b. 1945), California Academy of Sciences, who collected and supplied holotype to the authors. (See ETYFish).
Environment: milieu / climate zone / depth range / distribution range
Marine; bathydemersal; non-migratory (Ref. 57880); depth range 396 - 506 m (Ref. 57880). Deep-water; 1°N - 2°S, 92°W - 89°W (Ref. 57880)
Eastern Central Pacific: Galapagos Is. (Fernandina, Española, Marchena, San Cristóbal Is.).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 38.1 cm TL (female)
Morphology | Morphometrics
Hydrolagus with head small with short, blunt snout; second dorsal fin only slightly indented along its length; 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 irregular circular and elongate white blotches; ventrum white to tan with extremely fine brown mottling.
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Barnett, L.A.K., D.A. Didier, D.J. Long and 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. (Ref. 57880)
IUCN Red List Status (Ref. 126983)
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82804
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00282 (0.00118 - 0.00673), b=3.10 (2.89 - 3.31), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.7 ±0.6 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): Low, minimum population doubling time 4.5 - 14 years (Deep-water species with large eggs and low fecundity).
Fishing Vulnerability (Ref. 59153
): Low to moderate vulnerability (28 of 100).