Etmopterus joungi

KNUCKEY, EBERT & BURGESS, 2011



Classification: Elasmobranchii Squaliformes Etmopteridae

Reference of the original description
KNUCKEY, J.D.S. & EBERT, D.A. & BURGESS, G.H. (2011)
Etmopterus joungi n. sp., a new species of lanternshark (Squaliformes: Etmopteridae) from Taiwan. Aqua, International Journal of Ichthyology, 17 (2): 61–72

Image of the original description
Image in copyright.

Types
Etmopterus joungi
Holotype: CAS: 227957; Paratype: UF: 159703;


Description :


Citation: Etmopterus joungi KNUCKEY, EBERT & BURGESS, 2011: In: Database of modern sharks, rays and chimaeras, www.shark-references.com, World Wide Web electronic publication, Version 09/2019

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Shortfin Smooth Lanternshark, Etmopterus joungi, Knuckey, Ebert & Burgess, 2011 © Pacific Shark Research Center at Moss Landing Marine Laboratories (MLML)
Common names
Shortfin smooth lanternshark

Short Description
This species is distinguished by the following characters: short preoral snout 8.0% TL (8.2-8.7); broad and strongly arched mouth; upper teeth differ from lower teeth with each tooth in first functional row with single median cusp and flanked by one or two lateral cusplets on either side; lower teeth in single series, forming blade-like edge with slender, non-erect cusps; relatively short head, 15.9% TL (15.3-16.0); dermal denticles truncate, low, with block-like crowns, irregularly arranged over majority of body, extending onto dorsal fins; pectoral to pelvic fin space large, 29.0% TL (25.3-27.30); very narrow pectoral fins, posterior portion square-shaped, posterior margin acutely angular at anterior and inner margins, with no expanded corners of fins; second dorsal fin located relatively posteriorly along body, second dorsal fin spine long and strongly recurved, 0.5 (0.3-0.5) into dorsal fin height; interdorsal space about three times distance between first dorsal fin spine origin and pectoral fins; inconspicuous suprapelvic flank marking lacking posterior branch; dorsal caudal fin margin short, 15.4% TL (15.3-19.4); posterior end of lateral line becoming open groove, with the ventral edge darkly colored; caudal fin short; monospondylous vertebrae 48 (38-41), diplospondylous vertebrae 17 (21-24), dorso-caudal vertebrae 24 (22-25), and total vertebrae 89 (84-88); spiral valve with 11 turns; color in life dusky grey dorsally, black to dark grey ventrally [13058].

Distribution
Northwest Pacific: Taiwan. Source: www.gbif.org

Biology
Occurs along the upper continental slope and caught by bottom trawl at a depth greater than 300m. Sexual maturity in males likely achieved between 31.9 and 40.6 cm TL, and in females, larger than 45.6 cm TL. A cymothiod isopod Elthusa raynaudi was found attached to the roof of the mouth of the holotype (normally occurs in the gill chambers of fishes) [13058]. Deep-water

Size / Weight / Age
Max length : 40.6 cm TL male/unsexed; [13058]; 45.6 cm TL (female)

Habitat
Pelagic; marine; depth range 300 - ? m [13058]

Dentition
Diagnosis: Upper teeth dissimilar to lower teeth, each tooth in first functional row with single median cusp and flanked by one or two lateral cusplets on either side; lower teeth in single series, forming blade-like edge with slender, non-erect cusps; Description: Teeth dissimilar in upper and lower jaws; upper teeth multicuspid, first row with one to two lateral cusplets on either side of single, pointed median cusp; teeth in lower jaw unicuspid, in single series, not erect, overlapping, with blade-like edge; upper tooth counts numbering 27 (25-30); lower tooth counts numbering 42 (33-36). Comparisons: Etmopterus joungi possesses an upper jaw dentition with a relatively slender medial cusp and robust lateral cusplets (but not as large as the medial cusp) on either side. Etmopterus pusillus generally possesses an upper jaw dentition with a slender medial cusp with slender lateral cusplets, whereas E. bigelowi generally possesses an upper jaw dentition with a significantly more robust medial cusp with robust lateral cusplets on either side. The lower jaw dentition of E. joungi is also different in that the cusps are significantly more oblique and relatively slender than those found in E. pusillus and E. bigelowi of similar sizes and sexes [13058];

Remarks
shark-references Species-ID=11011;

Parasites (arranged by Jürgen Pollerspöck)
Isopoda