Comprehensive DescriptionRead full entry
Parmaturus lanatussp. nov.
Figs 8 and 9, Tables 1-3
Velvet Catshark (English), holbiche laineuse (French)
Parmaturus melanobranchus : Séret , 1993 (abstract of 4th IPFC, Bangkok)
Material. 1 specimen.
Indonesia . KARUBAR, stn 73, 8°29’S , 131°33’E (Tanimbar Isl.), 855-840 m depth, beam trawl, R.V. “ Baruna Jaya 1 ”, 2 November 1991 , juvenile male 360 mm TL ( MNHN 2007-1499: holotype ).
Diagnosis. A scyliorhinid catshark with the following combination of characters: soft body; velvety skin with long-cusped, tricuspidate denticles; plain brownish coloration; crests of small denticles (not enlarged) on upper and lower caudal fin and peduncle margins; teeth mainly quadricuspidate, in about 90 rows in both jaws; first dorsal fin forward of mid-length, pre-first dorsal length 44.4% TL; pelvic fins and vent well in front of mid-length, pre-pelvic length 40.0% TL and pre-vent length 44.2% TL; snout relatively short, prenarial length 4.7% TL; mouth relatively long, mouth length 5.0% TL; labial furrows rudimentary; head longer than abdomen, length 21.4% TL, pectoral-pelvic length16.9% TL; dorsal fins elevated, anterior margins of first and second dorsal fins 9.2% and 10.3% TL respectively; subterminal caudal lobe developed, subterminal margin length 4.7% TL, terminal margin length 5.3% TL; monospondylous centra 46; precaudal centra 85.
Description. Scyliorhinid catshark with flabby, soft, tadpole-shaped body; trunk slightly depressed; tail compressed and tapering to caudal fin; head very depressed, height 5.5% TL; abdomen shorter than head, pectoral to pelvic space 16.9% TL, 1.3 of head length; pelvic to anal space 1.6 times anal-fin base length. Caudal peduncle moderately deep, elongate, width 1.6 in its height, anal to caudal space 0.6 of anal-fin base; rather compressed, dorsal surface flattened, ventral surface interrupted by caudal crest. Snout short, rounded-parabolic in dorsoventral view; tip broadly rounded, bluntly pointed in lateral view; preoral length 5.8% TL, 1.6 times mouth width; prenarial snout 1.1 times eye length. Eye large, length 4.2% TL, 5.1 in head length; strongly dorsolateral on head, with well-developed subocular ridges. Mouth large, moderately long, semiangular, width 9.4% TL, 1.9 times its length; labial furrows rudimentary, reduced small slits at mouth corner. Nostrils large with tube-like incurrent apertures, anterior nasal flaps triangular, posterolateral tip forming a short lobe; well separated, internarial length 2.8% TL; falling short to mouth.
Teeth of both jaws exposed when mouth closed; mainly quadricuspidate, similar in size, typically with a pointed central cusp flanked with one/two slightly smaller lateral cusps; about 94 rows in upper jaw, about 92 rows in lower jaw (teeth in quincunx arrangement but cusps, particularly those near jaw angle, appear in oblique rows). Dermal denticles on side densely imbricate, erect; crown shield-like, tricuspidate, with very long, pointed, median cusp and variably developed lateral cusps. Caudal crests not well developed; dorsal crest confined to anterior portion of upper caudal margin; ventral crest more developed, extending well along caudal peduncle but not reaching anal-fin insertion, barely present on lower caudal margin; denticles hardly enlarged, smaller than or subequal in size to flank denticles; no distinct crest on preventral caudal margin.
First dorsal fin distinctly smaller than second dorsal; first originating slightly forward of middle of pelvicfin base; second originating over middle of anal-fin base; anterior margins of both dorsal fins convex; apex of first dorsal more narrowly rounded than apex of second dorsal; posterior margin of first dorsal very short, subtruncate, almost upright; posterior margin of second dorsal longer, subtruncate, directed slightly anterodorsally; rear corner of first dorsal obtuse, second dorsal almost forming right angle, corners rounded. Pectoral fins of moderate size, lobate, rounded, anterior margin 11.1% TL; anterior and posterior margins convex; apex and rear corners rounded. Pelvic fins small, subtriangular, apex broadly rounded, length 9.7% TL. Anal fin subtriangular, moderately developed, base 8.9% TL, 1.1 in interdorsal space; origin at about level of middle of interdorsal space, anal-fin height 2.9 in base length. Caudal fin relatively long, dorsal caudal margin length 27.8% TL; origins of upper and lower lobes obscured by caudal crests; lower lobe low; terminal caudal lobe fan-like with subtruncate posterior margin. Monospondylous centra 46; precaudal centra 85; total centra 134.
Coloration. (from preserved specimen). Body plain brown; gills and fins marginally darker; pelvic insertion whitish. Floor of mouth pale, roof of mouth greyish.
Size. Known only by the holotype, a juvenile male of 360 mm TL.
Distribution. Collected from the continental slope off Tanimbar Island in the Arafura Sea (Indonesia) in 840-855 m depth (Fig. 1).
Etymology. From the Latin “lanatus” meaning soft like wool in reference to the velvety feel of the skin.
Comparisons. Parmaturus lanatus can be distinguished from its congeners by the following:
Parmaturus albipenis differs from P. lanatus by: more tooth rows in jaws (130 versus about 90); longer pre-pelvic length (about 47% TL versus 40% TL); longer pre-vent length (52% TL versus 44% TL); shorter mouth (length 3.1% TL versus 5.0% TL); and head shorter than abdomen (rather than longer).
Parmaturus albimarginatus differs from P. lanatus by: crests of enlarged denticles well developed on caudal margins (crests without enlarged denticles in P. lanatus ); teeth mainly tricuspidate (rather than quadricuspidate); first dorsal fin after mid-length (before mid-length); much longer pre-pelvic (about 47% TL versus 40% TL) and pre-vent lengths (50% TL versus 44% TL); head shorter than abdomen (rather than longer); second dorsal fin larger than first dorsal (rather than subequal in size); and a much deeper head (ratio head height/ head width 1.0 versus 0.5).
Parmaturus bigus differs from P. lanatus by: crest of enlarged denticles well developed on caudal margins (crests without enlarged denticles in P. lanatus ); teeth mainly tricuspidate (rather than quadricuspidate); first dorsal fin after mid-length (before mid-length); much longer pre-pelvic (about 49% TL versus 40% TL) and pre-vent lengths (51% TL versus 44% TL); head shorter than abdomen (rather than longer); and second dorsal fin larger than first dorsal (rather than subequal in size).
Parmaturus melanobranchus differs from P. lanatus by: a well-developed crest of enlarged denticles on caudal margins (crests without enlarged denticles in P. lanatus ); mouth longer (about 7% TL versus 5% TL); and coloration darker with gill septa blackish (rather than brownish).
Parmaturus pilosus ZBK differs from P. lanatus by: a well-developed crest of enlarged denticles on caudal margins (crests without enlarged denticles in P. lanatus ); teeth with 5-7 cusps (versus 4); head shorter than abdomen (longer in P. lanatus ); and coloration plain reddish above, white below, with fin margins darker (rather than uniform brownish).
Parmaturus macmillani ZBK differs from P. lanatus by: a well-developed crest of enlarged denticles on caudal margins (crests without enlarged denticles in P. lanatus ); teeth with 5-6 cusps (versus 4); longer prepelvic (about 49% TL versus 40% TL) and prevent lengths (about 52% TL versus 44% TL); and head shorter than abdomen (pectoral-pelvic length about 29% TL versus 17% TL).