Etmopterus benchleyi Vásquez, Ebert & Long, 2015
Ninja lanternshark

Family:  Etmopteridae (Lantern sharks)
Max. size:  32.5 cm TL (male/unsexed); 51.5 cm TL (female)
Environment:  pelagic-oceanic; marine; depth range 836 - 1443 m
Distribution:  Eastern Pacific Ocean: from Nicaragua south to Panama.
Diagnosis:  This moderately large species is distinguished by the following set of characters: short snout with pre-narial length 2.9% TL (2.9-4.0%) and pre-oral length 7.8% TL (6.9-9.0%); broad mouth strongly arched, width 1.2 (1.0-1.5) times into pre-oral length; dentition show strong disjunct dignathic heterodonty with upper teeth comprised of single median cusp, flanked by 1-2 pairs of lateral cusplets, where lower teeth with low, distally-inclined cusps lacking serrations and a low posterior blade; dermal denticles are short, slender, with slightly hook-like conical crowns; denticles below second dorsal fin in irregular patch densities and align into rows along the ceratotrichia of the fins; denticles dense around the eyes and gill openings, sparse to bare on ventrum of snout tip and around mouth; first and dorsal fins similar in size; the second-dorsal-fin spine 1.7 (1.6-2.3) times longer than first-dorsal-fin spine; the second-dorsal-fin spine height greater than second-dorsal-fin apex; interdorsal-fin space is moderately long, 23.1% TL (19.2-21.4%); body color uniformly black, the anteroposteriorly oblong narrow pineal window apparent (Ref. 106129)
Biology:  The larger individuals of this species were collected at greater depth than smaller specimens, suggesting a positive relationship between size and depth, as has been observed in E. princeps. The largest paratype (51.5 cm TL) contains five ova ranging from 25.6 to 34.2 mm, with no embryos apparent. The immature male paratype has claspers at the earliest stage of development, suggesting that maturity for males is attained at a greater size. Viviparous with litter sizes apparently consist of at least 5 pups with post-partum lengths less than 177 mm TL (Ref. 106129).
IUCN Red List Status: Least Concern (LC); Date assessed: 08 February 2019 Ref. (130435)
Threat to humans:  harmless


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