Teleostei (teleosts) >
Gadiformes (Cods) >
Macrouridae (Grenadiers or rattails)
Etymology: Hymenocephalus: Named for its transparent membrane-like head covering (‘‘hymen head’’) and fragile nature of head bones (Ref. 100825); yamasakiorum: Named for Ms. Yasuko Yamasaki and her family; a fishing trawler operator in Tosa Bay and adjacent waters and provider of a large number of fish specimens to the BSKU collection.
Eponymy: Yasuko Yamasaki and her family operate a fishing trawler in Tosa Bay, Japan and nearby waters. They provide a large number of fish specimens to Kochi University. (Ref. 128868), visit book page.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Marine; bathydemersal; depth range 380 - 420 m (Ref. 100825). Temperate
Distribution
Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri
Northwest Pacific: Japan.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 15.1 cm TL male/unsexed; (Ref. 100825)
Short description
Identification keys | Morphology | Morphometrics
This species is distinguished by the following characters: 9 pelvic-fin rays; chin barbel 55 % HL, its tip extending beyond vertical through hind margin of orbit when laid back; moderately high snout, not depressed, length 28 % HL; orbit diameter 33 % HL; interorbital width 24 % HL; preopercular supporter broad, short (5 % HL); D1 II,10; pectoral-fin rays i16-i17; gill rakers on first arch (outer/inner) 14/20, on second arch 20/19; pyloric caeca 15; when fresh the ventral two-thirds of head and body are silvery; dorsal half of posterior part of tail prominently dark; ventral half of tail completely immaculate; OL:OH = 1.15; ostial and caudal colliculi not fused; TCL:PCL = 2.3 (Ref. 100825).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Nakayama, N., H. Endo and W. Schwarzhans, 2015. A new grenadier of the genus Hymenocephalus from Tosa Bay, southern Japan (Actinopterygii: Gadiformes: Macrouridae). Ichthyol. Res. (Ref. 100825)
IUCN Red List Status (Ref. 130435: Version 2024-1)
Threat to humans
Harmless
Human uses
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Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00214 (0.00109 - 0.00421), b=3.20 (3.03 - 3.37), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.3 ±0.4 se; based on size and trophs of closest relatives
Resilience (Ref.
120179): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref.
59153): Low vulnerability (10 of 100).