Common names
Negrito, Tollo lucero liso, Sagre nain, Slender lantern shark, Slender lanternshark, Smooth lantern shark, Smooth lanternshark, Gata-preta, Lixinha da fundura, Lixinha-de-fundura lisa, Quelmazinha, Xarinha-preta

Short Description
Field marks and Diagnostic Features after EBERT & STEHMANN, 2013 [17836]: A moderately large, slender, broad–headed, long–tailed, lanternshark with a short thick flat snout. Upper teeth with a slender cusp and one or more pairs of cusplets, lower teeth compressed and knife–like, with a cusp and blade. Lateral trunk denticles cuspless, truncated, and wide–spaced, giving the body a smooth texture, not in longitudinal rows on head, body or tail. Two dorsal fins with fin spines, first dorsal fin smaller than second dorsal fin, first dorsal–fin spine slender and lower than fin, second dorsal–fin spine slightly recurved and pointing posterodorsally. No anal fin. Flank and caudal photomarks present and inconspicuous. Diagnostic Features: Head flattened and moderately broad, not deep and conical; head relatively long, 22 to 26% of total length and 2.2 to 2.8 times in snout–vent length; head width 0.9 to 1.4 times preoral snout; head low, height 6 to 9% of total length. Prespiracular length 1.2 to 1.4 times spiracle–pectoral space. Snout flattened and broadly rounded, not bulbous; preoral length moderately long and 9 to 11% of total length. Eyes narrow and elongated–oval; upper eyelid with a pale naked patch. Gill openings slightly wider than spiracle; width of third gill opening one–third eye length or less. Mouth relatively broad and 1.2 to 1.7 times eye length. Total tooth row counts upper jaw 23 to 30, lower jaw 35 to 44; upper teeth generally with less than 3 pairs of cusplets, with cusps greatly expanded, over twice as high as adjacent cusplets; upper teeth of mature males large with a cusp and a pair of long cusplets. Body moderately firm, slightly compressed, and moderately slender. Predorsal spine length about 36 to 39% of total length; interdorsal space about 1.2 to 1.5 times prebranchial length, subequal to head length; pectoral–pelvic space about 1.1 to 1.4 times head length in adults; snout tip to rear flank marking base about 103–106% of snout tip to second dorsal spine origin; dorso–caudal space 9 to 11% of total length, about 1.8 to 2.9 in interdorsal space; pelvic–caudal space 15 to 18% of total length, about 1.8 to 2.3 times first dorsal–fin length, about 1.1 to 1.6 in interdorsal space, subequal or somewhat shorter than prebranchial length, and about 1.5 to 2.0 times in pectoral–pelvic space. No rows of greatly enlarged denticles on flanks above pectoral fins; denticles covering underside of snout; denticles on head, flanks and tail not in regular longitudinal rows; denticles present on second dorsal fin, densely covering base but absent from posterior margin; lateral trunk denticles short, robust, close–set but not overlapping, with truncated, hollow, sessile, low crowns, not thorn or bristle–like. Distal margins of fins not fringed with naked ceratotrichia. Pectoral fin small with anterior margin length 8 to 9% of total length, rounded–angular in shape. First dorsal–fin origin just behind pectoral–fin free rear tips, base much closer to pectoral–fin bases than pelvic fins; first dorsal–fin spine stout, short, and usually lower than first dorsal–fin apex, spine origin nearer to snout tip than upper caudal–fin origin. Second dorsal fin much larger than first and nearly or quite twice its area, height 32 to 39% of second dorsal–fin length, apex more or less pointed or narrowly rounded, posterior margin usually deeply concave; second dorsal–fin spine stout and recurved, with its tip diagonally vertical. Dorsal caudal–fin margin about 0.8 of head length. Vertebral counts: total vertebral counts 82 to 88, precaudal vertebral counts 59 to 66, monospondylous vertebral counts 47 to 53. Intestinal valve counts 10 to 13. Size moderate with adults to about 48 cm. Colour: pale or dark brown to blackish on dorsal surface, underside of snout and abdomen abruptly black, dorsal surface dark in life, conspicuously lighter in preservative, ventral surface conspicuously dark; precaudal fins light distally, no conspicuous dark bands at tip and through middle of caudal fin; a small conspicuous round white pineal blotch on dorsal surface of head. No conspicuous photolines on body. Suprapelvic photomark present but not running behind pelvic fins. Flank photomarks present; flank photomark base opposite and behind second dorsal–fin spine; anterior branch of flank photomark long and broad, much longer than posterior branch, posterior branch about 10% of anterior branch and truncate, merging ventrally with post–pelvic photomark, and not extending behind free rear tip of second dorsal fin. Ventral saddle–shaped precaudal photomark absent from middle of caudal peduncle. Caudal photomarks present; caudal–base photomark present, with anterior branch broad, partly enveloping ventral surface of caudal peduncle but not extending onto its sides; caudal–base photomark with elongated, blunt–tipped posterior branch over 7% of total length. No central caudal photomark. Upper caudal photomark present and straight.

Distribution
Western Atlantic: northern Gulf of Mexico; southern Brazil to Argentina [518] [1388]. One specimen collected off the Guianas [2445]. Eastern Atlantic: Portugal to Namibia. Also occurs in oceanic waters between Argentina and South Africa. Western Indian Ocean: South Africa. Western Pacific: Australia [1388], New Zealand [578], and Japan. Southeast Pacific: Amber Seamount, Nasca and Sala-y-Gomez. Source: www.gbif.org

Human uses
fisheries: minor commercial; price category: not marketed/unknown; price reliability:

Biology
Ovoviviparous [518]. Distinct pairing with embrace [17086]. Found on or near the bottom of continental and insular slopes at depths from 275 to 1,000 m (possibly to 2,000 m); also oceanic in the south Atlantic from the surface to 710 m [1388]. Benthopelagic at 200-1000 m (possibly to 1998 m) [17640]. Feeds on fish eggs, lanternfish, squid, and other small dogfish [536].

Size / Weight / Age
50.0 cm TL (male/unsexed; (Ref. 36731))

Habitat
benthopelagic; oceanodromous [17660]; marine; depth range 0 - 1070 m [578], usually 400 - 700 m (Ref. 36731)

Remarks
shark-references Species-ID=2184; Links:

digital version of the original description of E. pusillus: LOWE, R.T. 1839: A supplement to a synopsis of the fishes of Madeira. Proceedings of the Zoological Society of London, 7: 76-92"

digital version of the original description of E. nigra: LOWE, R.T. 1834: Characters of a new genus Leirus, and of several new species of fishes from Madeira. Proceedings of the Zoological Society of London, 1833 (pt 1): 142-144"

Parasites (arranged by Jürgen Pollerspöck)
Cestoda

• Aporhynchus pickeringae Noever, Caira, Kuchta & Desjardins, 2010 [17721] [20495]

Copepoda

• Eudactylina epaktolampter Deets, 1994 [17867]

Isopoda

• Elthusa raynaudii (Milne Edwards, 1840) [8698] [13058]