Elasmobranchii (sharks and rays) > Torpediniformes
(Electric rays) > Narkidae
Etymology: Narke: Greek, narke = numbness (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Marine; demersal; depth range 100 - ? m (Ref. 114953). Tropical; 42°N - 0°N, 55°E - 143°E (Ref. 114953)
Indo-West Pacific: Oman and the Arabian Sea eastward to Japan and south to Singapore and Indonesia.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 18.0 cm TL male/unsexed; (Ref. 9913); common length : 20.0 cm TL male/unsexed; (Ref. 114953)
Found in continental waters, both inshore and offshore (Ref. 9913). Mainly feeds on crustaceans and polychaetes (Ref. 114953). Biology little known (Ref. 9913) but reported to produce 4-6 young each gestation (Ref. 114953). Adult males and females known at 15 cm TL; common size reported to reach 35 cm TL (Ref. 114953). The electric organs present on disc are used to stun the prey.
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Compagno, L.J.V. and P.R. Last, 1999. Narkidae. Sleeper rays. p. 1443-1446. In K.E. Carpenter and V.H. Niem (eds.) FAO identification guide for fishery purposes. The living marine resources of the Western Central Pacific. FAO, Rome. (Ref. 9913)
IUCN Red List Status (Ref. 119314)
CITES (Ref. 115941)
Fisheries: minor commercial
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Preferred temperature (Ref. 115969
): 19 - 28.2, mean 26.4 (based on 992 cells).
Phylogenetic diversity index (Ref. 82805
= 0.6252 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.2 ±0.3 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): Low, minimum population doubling time 4.5 - 14 years (Assuming fecundity<100).
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .