Elasmobranchii (sharks and rays) >
Squaliformes (Sleeper and dogfish sharks) >
Somniosidae (Sleeper sharks)
Etymology: Scymnodon: scymnus, an ancient name for some kind of shark, derived from a Greek word meaning young animal, cub or whelp; odon (Gr.), tooth, referring to large, triangular cutting teeth on lower jaw of S. ringens (See ETYFish); macracanthus: macro-, from makros (Gr.), long or large; acanthus (L.), from akantha (Gr.), thorn, referring to stout, prominent dorsal-fin spines (See ETYFish).
More on author: Regan.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Marine; bathydemersal; depth range 219 - 1550 m (Ref. 6871), usually 550 - 732 m (Ref. 247). Deep-water; 50°S - 54°S
Indo-Pacific: southern distribution, discontinuous across Pacific and Indian Oceans.
Length at first maturity / Size / Weight / Age
Maturity: Lm 149.5, range 129 - 170 cm
Max length : 131 cm TL male/unsexed; (Ref. 247); 170.0 cm TL (female)
Dorsal spines (total): 2; Anal spines: 0. Dark brown or blackish in color, dorsal fins with fairly prominent fin spines, moderately long snout, lanceolate upper teeth and bladelike lower teeth with short, oblique cusps, stocky body that tapers abruptly from pectoral region, and moderately large tricuspidate and tricarinate lateral trunk denticles (Ref. 247).
A rare species inhabiting lower continental slopes (Ref. 26346), also on insular slopes in large schools near the bottom which are segregated according to size and sex, and feeds on cephalopods and bony fishes (Ref. 247). Up to 36 young in a litter, ths size at birth between 32 and 36 cm (Ref. 247). Used for fishmeal and liver oil (Ref. 6871). Minimum depth from Ref. 247. Ovoviviparous (Ref. 205).
Ovoviviparous (Ref. 26346). Distinct pairing with embrace (Ref. 205).
Compagno, L.J.V., 1984. FAO Species Catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 1 - Hexanchiformes to Lamniformes. FAO Fish. Synop. 125(4/1):1-249. Rome, FAO. (Ref. 247)
IUCN Red List Status (Ref. 130435: Version 2024-1)
Threat to humans
Harmless
Human uses
Fisheries: of no interest
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Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5313 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00372 (0.00220 - 0.00627), b=3.12 (2.98 - 3.26), in cm total length, based on LWR estimates for this species & (Sub)family-body (Ref.
93245).
Trophic level (Ref.
69278): 4.5 ±0.59 se; based on food items.
Resilience (Ref.
120179): Low, minimum population doubling time 4.5 - 14 years (Fec assumed to be <100).
Fishing Vulnerability (Ref.
59153): Very high vulnerability (90 of 100).