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); trolli: In honor of American artist Ray Troll (b. 1954), Ketchikan, Alaska (USA), “one of the few true chimaeroid lovers of the world ... for his valiant efforts to increase ratfish awareness worldwide”. (See ETYFish).
Environment: milieu / climate zone / depth range / distribution range
Marine; bathydemersal; depth range 612 - 1707 m (Ref. 45071). Deep-water
Western Pacific: New Caledonia and New Zealand.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 112 cm TL male/unsexed; (Ref. 45071); 120.4 cm TL (female); max. published weight: 8.8 kg (Ref. 122636)
Morphology | Morphometrics
Body blue-gray with a dark line around the orbit and dark shadowing along edges of lateral-line canals. Snout pointed. Preopercular and oral lateral-line canals sharing a common branch. D1 concave with pale margin. Males with frontal tenaculum deeply curved, upturned distally with spines along dorsal upturned edge. Prepelvic tenacula deeply indented along distal margin. Pelvic claspers with pale fleshy distal lobes, divided distally for 1/3 their length, tips usually extending beyond distal edge of pelvic fins. Ventral caudal fin not deeply indented at its origin to form a separate anal fin.
Oviparous (Ref. 205). Eggs are encased in horny shells (Ref. 205). Reported sexual maturity at 550-65.0 cm BDL or body length (Ref. 116866).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Didier, D.A. and B. Séret, 2002. Chimaeroid fishes of New Caledonia with description of a new species of Hydrolagus (Chondrichthyes, Holocephali). Cybium 26(3):225-233. (Ref. 45071)
IUCN Red List Status (Ref. 125652)
Threat to humans
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Preferred temperature (Ref. 123201
): 3.4 - 6.9, mean 4.8 °C (based on 322 cells).
Phylogenetic diversity index (Ref. 82804
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00309 (0.00126 - 0.00759), 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
): 3.9 ±0.6 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): Low, minimum population doubling time 4.5 - 14 years (Assuming Fec <100).
Fishing Vulnerability (Ref. 59153
): High to very high vulnerability (72 of 100).