Paralepis elongata ( Brauer, 1906 )

Ho, Hsuan-Ching & Iwamoto, Tomio, 2024, Description of a large specimen of Paralepis elongata (Brauer, 1906) from Angola, southeastern Atlantic Ocean (Aulopiformes: Paralepididae), Zootaxa 5415 (2), pp. 333-338 : 334-336

Paralepis elongata ( Brauer, 1906)

Figure 1

Omosudis elongatus Brauer, 1906: 140 , fig. 68 (type locality: Gulf of Guinea).

Paralepis elongata ( Brauer, 1906) : Maul, 1962: 539 (north of Dakar, Senegal). Post, 1972:156 (type catalog). Post, 1986: 277 ( South Africa, but needs confirmation). Post, 1987: 122 (revision).

Paralepis danae Ege, 1933: 223 (type locality off Cape Verde, Senegal). Ege, 1953: 20, fig. 2.6. Homonym of Paralepis pseudosphyraenoides danae Ege, 1930 .

Paralepis egei Harry, 1948: 221 (replacement name for P. danae Ege, 1933 ).

Material examined. CAS 222645 , 1 specimen, 314 mm SL , R / V Dr. FridtJof Nansen, 10°49’S, 13°16’E, off Angola, southeastern Atlantic , 501‒504 m depth (1250 m wired out), 6 Apr. 2005, field no. NANSEN 3656, coll . T. Iwamoto.

Description of CAS 222645. Morphometrics: standard length (SL) 314 mm; head length (HL) 70.8 (22.5% SL); body depth at pectoral fin 24.1 (7.7%); predorsal length 200 (63.7%); prepelvic length 190 (60.5%); preanal length 250 (79.6%). Eye diameter 8.8 (12.4% HL); interorbital width 7.9 (11.2%); snout length 31.9 (45.1%); head depth 18.4 (26.0%); head width 11.8 (16.7%); pre-nostril length 22.1 (31.2%); upper jaw 26.0 (36.7%); lower jaw 36.1 (51.0%); pectoral-fin length 28.0 (39.5%); dorsal-fin base 12.2 (17.2%); anal-fin base 40.7 (57.5%); caudalpedunclular depth (12.4%); caudal-peduncular length 20.1 (28.4%).

Meristics: dorsal-fin rays 11; pectoral-fin rays 18 (both sides); anal-fin rays 26; lateral-line scales 33/32 before pelvic fin; 35 before dorsal fin; 50/51 before anal fin; 63 in total, no small scales on rear end of lateral line. Gill rakers 4 on epibranchial, 12 on ceratobranchial and 7 on hypobranchial, 23 in total. Vertebrae: 36 prepelvic; 38 predorsal; 42 prehaemal; 54 preanal; and total 79.

Body relatively slender compared to congeners, compressed, depth at pectoral fin 13.0 times in SL. Caudal peduncle moderately long, its length 2.3 times eye diameter. No ventral adipose fin (v iz, a bdominal ridge, or carina, between pectoral and pelvic fins and between anus and anal fin). Anus situated slightly behind tip of appressed pelvic fin (pelvic fin damaged distally), distance from VFO to anus 3.5 times in distance between pelvic- and anal-fin origins.

Head relatively long, its length 4.4 in SL; snout long and pointed anteriorly, its length 2.2 in HL. Mouth terminal, large, its gape extending to about 1.5 times eye diameter in front of eye when mouth opened. Lower jaw slightly upturned at tip, with small distal tab of fleshy tissue. Eye large, its diameter 8.0 in HL. No light organ around eye. First suborbital bone slender, fifth and sixth bones large and well-expanded posteriorly, and seventh suborbital small. Interorbital space narrow, its width 9.0 in HL; some straight ridges present on top of head and snout. Two nostrils located about 1.0 eye diameter before eye and before posterior end of maxilla, the latter extending to about 0.6 eye diameters before anterior margin of eye. Numerous sensory canals presumed present, but most integument on head damaged.

Dorsal fin situated well behind mid-length, predorsal length 1.6 in SL. Pectoral-fin base behind posterior margin of gill cover, upper end of fin base well below horizontal of lower margin of eye; a small pocket behind fin base. Pectoral fin small, upper rays of pectoral fin slightly longer than lower rays, its length 2.5 in HL. Pelvic fin situated slightly before dorsal-fin origin and behind mid-length, pre-pelvic fin length 1.7 in SL. No axial scale behind pelvic-fin base (probably lost during trawl operation). Anal fin originating in posterior fifth of body, preanal length 1.3 in SL. Dorsal adipose fin over rear portion of anal-fin base, its base length slightly smaller than eye diameter.

Single row of small, retrorse teeth anteriorly (about 60 in number) on premaxillary, the slender conical teeth abruptly transforming into broad, flattened, bladelike teeth over posterior half or more of bone. Vomerine teeth absent. Two or three fangs (either depressible or fixed) at front end of each lower jaw, followed by a single row of small, depressible teeth, then two rows of fangs arranged in 6 tooth pairs; those of inner row long with knife-like tip and depressible; those in outer row slightly shorter, curved, and fixed, slightly embedded in tissue. Two or three small teeth at front of palatine, followed by two rows of fangs forming 3 tooth pairs, those in inner row long and depressible, those in outer row small and fixed, followed by single row of 17 widely-spaced teeth. Single irregular row of 12 teeth on each side of tongue.

Gill rakers present on epibranchial, ceratobranchial, and hypobranchial parts of each gill arch, each raker with 3‒5 short to very slender teeth, these teeth extending upward well beyond margin of gill arch. Teeth on pharyngeal arch forming a long band of slender teeth, arranged in about 3 rows at middle, on fourth arch with similar teeth arranged in oval patch with about 6 rows in middle. Long band of needle-like teeth on fifth ceratobranchial, arranged in about 3 rows at middle.

Gill filaments present on all four gill arches. Fourth arch mostly connected to gill chamber wall by membranes. Pseudobranchs present, their anterior halves included in a deep pocket.

Body covered with small scales (almost all lost with but scale pockets remained), except for a single row of large lateral-line scales extending from above pectoral girdle to point above approximately 2/3 length of anal-fin base. Morphology of lateral-line scales as described by Post (1987); no small scales at rear end of lateral line.

No light organ and luminescent duct.

Coloration. Body overall brown-gray after long-term preservation, assumed darker originally. Black pigments on snout, chin, around eye, gill cover, fins and lateral line. Melanophores unevenly distributed in mouth cavity and gill chamber; tongue black; gill arches pale without pigmentation. Peritoneal membrane black.

Figures

FIGURE 1. Paralepis elongata (Brauer, 1906).A. Drawing of a 190.5 mm specimen, from Post (1987). B‒C. CAS 222645, 314 mm SL, large adult male, preserved. D. Radiograph of CAS 222645. B‒D. taken by J. Fong.