Elasmobranchii (sharks and rays) > Rajiformes
(Skates and rays) > Rajidae
Etymology: Dipturus: Greek, di = two + Greek, pteryx = fin (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Marine; bathydemersal; depth range 253 - 761 m (Ref. 11228). Deep-water; 20°S - 32°S, 30°E - 38°E (Ref. 114953)
Western Indian Ocean: southern Mozambique to Plettenberg Bay, South Africa.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 101 cm TL male/unsexed; (Ref. 114953)
Morphology | Morphometrics
An all-dark longnose skate with a greatly elongated, broadly triangular snout, and a stout tail - shorter than body and with mid-section swollen and triangular-shaped; disc with angular corners and smooth underside; small thorn at nape (Ref. 5578). Uniform dark grey above and below with black mucous pores on the underside (Ref. 2708, 5578).
Found on upper and mid-continental slope (Ref. 114953). Oviparous (Ref. 50449). Eggs have horn-like projections on the shell (Ref. 205). Males reaches maturity at ca. 83-98 cm TL; smallest known specimen at 24 cm TL; hatching size possibly at ca. 24 cm TL (Ref. 114953).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Oviparous, paired eggs are laid. Embryos feed solely on yolk (Ref. 50449). Eggs have horn-like projections on the shell (Ref. 205).
McEachran, J.D. and K.A. Dunn, 1998. Phylogenetic analysis of skates, a morphologically conservative clade of elasmobranchs (Chondrichthyes: Rajidae). Copeia 1998(2):271-290. (Ref. 27314)
IUCN Red List Status (Ref. 123251)
CITES (Ref. 118484)
Threat to humans
Fisheries: of no interest
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates based on models
Preferred temperature (Ref. 115969
): 9.7 - 12.9, mean 11.5 °C (based on 27 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00316 (0.00147 - 0.00681), b=3.22 (3.04 - 3.40), 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 (Fec assumed to be <100).
Vulnerability (Ref. 59153
): High vulnerability (59 of 100) .