Elasmobranchii (sharks and rays) >
Torpediniformes (Electric rays) >
Narcinidae (Numbfishes)
Etymology: Narcine: Greek, narke = numbness (Ref. 45335).
Eponymy: Ignacio Riera Julia was Chief of the Spanish Fisheries Office and adviser to the General Direction of International Fisheries Relations, Ministry of Agriculture and Fisheries, Mahé, Seychelles (1989). He was a good friend of the senior author Lloris. (Ref. 128868), visit book page.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Marine; bathydemersal; depth range 170 - 500 m (Ref. 114953). Deep-water; 2°N - 20°S, 35°E - 48°E (Ref. 114953)
Western Indian Ocean: central Somalia to at least Mozambique.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 30.1 cm TL male/unsexed; (Ref. 11228)
Short description
Identification keys | Morphology | Morphometrics
Shovel-shaped disc with a long tail (much longer than disc length); a longer-than-wide nasal curtain; slender tooth bands that are subtriangular in shape (Ref. 49866). Uniform light brown or golden-brown dorsally (Ref. 49866).
Known based on 11 specimens. Males mature at 26 cm TL; born at ca. 9 cm TL. Low fecundity based on two mid-term embryos (each just over 7 cm) found in right uterus of large female (Ref. 114953).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Heemstra, P.C., 1995. Additions and corrections for the 1995 impression. p. v-xv. In M.M. Smith and P.C. Heemstra (eds.) Revised Edition of Smiths' Sea Fishes. Springer-Verlag, Berlin. (Ref. 11228)
IUCN Red List Status (Ref. 130435: Version 2024-1)
Threat to humans
Harmless
Human uses
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Special reports
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Internet sources
Estimates based on models
Preferred temperature (Ref.
123201): 13.8 - 15.9, mean 15.1 °C (based on 7 cells).
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01175 (0.00470 - 0.02937), b=2.88 (2.66 - 3.10), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.1 ±0.3 se; based on size and trophs of closest relatives
Resilience (Ref.
120179): Low, minimum population doubling time 4.5 - 14 years (Assuming fecundity<100).
Fishing Vulnerability (Ref.
59153): Low vulnerability (20 of 100).