Uranoscopus brunneus, Fricke, 2018

Fricke, Ronald, 2018, Two new species of stargazers of the genus Uranoscopus (Teleostei: Uranoscopidae) from the western Pacific Ocean, Zootaxa 4476 (1), pp. 157-167 : 159-161

Uranoscopus brunneus , new species

Dark-finned stargazer

( Figures 1 , 2 A–B , 3 ; Table 1)

ZooBank: urn:lsid:zoobank.org:act: BD717215 - DEC9-40 A1-9FBB-546ADC551BBA

Uranoscopus sp. 2: Kishimoto 2001: 3529.

Material. Holotype: NTUM 12716 , 125.8 mm SL, Solomon Sea , Papua New Guinea, West New Britain Province, off southwestern New Britain, 6°06.08’S 149°12.209’E ̄ 6°07.639’S 149°12.107’E, 315̄ 625 m depth, St. CP 4330- 26, MADEEP Expedition, R / V Alis, 6 May 2014 .

Diagnosis. A moderately-sized species of Uranoscopus with a moderately large head (head length 3.2 in SL); lower edge of preopercle with 8 spines; labial fimbriae poorly-developed; anterior nostril with a long tubiform valve, posterior nostril a slit-like pore; supracleithrum with a sharp spine at rear end and five small spines inside; dorsoposterior margin of pectoral fin concave; 62 oblique scale-rows along the sides of the body in adult; pectoralfin membranes dark brown.

Description. Morphometric and meristic data are presented in Table 1.

Dorsal fin V + ii,11; anal fin i,11; pectoral fin i,10,vi (total 17); pelvic fin I,5; caudal fin (iii),i,9,ii,(iii). Vertebrae 11 + 14.

Head moderate, anterior part of body moderately broad, depressed, body tapering and becoming compressed posteriorly. Body scales arranged in 62 oblique rows. Head, breast and belly naked. Anterodorsal area between lateral lines densely covered with scales just behind skull. Tubiform scales embedded along lateral line. Lateral line positioned dorsally, slightly bending down on caudal peduncle to continue in an extension on the sixth branched caudal-fin ray (counted from above), extending along the basal half of that ray. Spines 1–4 in first dorsal fin well developed, connected by membranes; rudimentary 5th element covered by skin. First two elements of second dorsal fin segmented and unbranched. Membranes of anal and paired fins fleshy and thickened. Pectoral fin broad, dorsoposterior margin concave, forming an angle of about 30° between upper edge and middle ray, remainder of distal margin nearly straight, 11th ray longest ( Fig. 2 A ). Soft dorsal and anal-fin bases long, height of soft dorsalfin 3.0 in second dorsal-fin base length, height of anal fin 3.4 in anal-fin base length. Caudal fin distally slightly convex. Pelvic fins situated on isthmus; distance between pelvic fin bases about one pelvic-fin base length. Pelvic spine feeble, closely connected to 1st soft-ray by connective tissue.

Head flattened dorsolaterally, dorsal and lateral surfaces almost entirely encased in minutely sculptured bones. Externally apparent bones of head very slightly concave along mid-dorsal line. Preorbital spines 3, the uppermost spine forming a knob near anterior margin of orbit ( Fig. 2 B ). Single pair of basipterygial processes widely separated. Joints of head bone elements marked by narrow grooves. Post-interorbital knobs absent from frontal bone. Two parietal lobes developed. Preopercular limb not joined with opercle over most of its length, but contacts opercle posteriorly. Eye moderate, positioned dorsally, not telescopic, without membranous tentacle or grainy row. Interorbital fossa semi-oval, longer than broad, including anterior three-fifths of interorbital space, reaching to level of posterior end of pupil. Supracleithrum with a sharp spine at rear end and five small spines inside. Nasal bone weakly ossified, not exposed, covered by skin of snout. Frontal bones not forming a supraorbital tubercule. Anterior nostril with a wide, rounded flap, posterior nostril a slit-like pore ( Fig. 2 B ). No chin barbel or cirri on branchiostegal membrane. Prelingual filament reduced to a triangular velum. Opercle distinctly shorter than deep; subopercle without ventral thickening. Preopercle with a slight horizontal, oblique, ventro-lateral thickening. Lower edge of preopercle with 8 spines. Respiratory valve rudimentary. Dentary without a ventromedial flange. Teeth in jaws small, conical, in two series; one series of widely separated caniniform teeth on premaxillary and dentary; labial fimbriae poorly-developed, barely recognisable.

Colour in life (see Fig. 3 ). Dorsal parts of head and body dark brown, back scattered with irregular small rosy blotches. Sides of head and body dark brown, with irregular slightly larger rosy blotches. Belly and thorax rose, pectoral-fin base dark grey. Eye greenish. First dorsal fin black, base of first and second spines pale. Rays of second dorsal and anal fins grey, membranes spotted. Caudal-fin rays and membranes dark reddish brown. Pectoral fin black, distal margin reddish. Pelvic fin rose.

Colour in preservative. Head brown; upper half of body dark brown, with numerous, closely set, pale blotches; ventral half of body yellowish, belly rose. Eyes dark grey. First dorsal fin jet black; second dorsal fin pale, rays spotted with brown. Anal fin yellowish. Caudal-fin rays yellow, spotted with brown, membranes pale. Pectoral-fin rays yellow, spotted with brown, membranes dark brown, tips of lower rays pale yellow. Pelvic fins dark grey, distal one-third of rays and membranes yellow.

Etymology. “Brunneus” (Latin) means brown; the name refers to the overall brown colouration of the species, and especially to its brown pectoral fin membranes.

Distribution. Papua New Guinea (New Britain), Philippines, Indonesia (see Kishimoto 2001: 3529; updated). Found on soft bottoms of lower continental shelf; known depth range 315̄ 625 m.

Comparisons. This new species is a member of a species group which is characterised by a supracleithrum with a sharp spine at rear end and one or more spines inside, and the dorsoposterior margin of the pectoral fin distinctly concave (forming an angle of about 30–40° between upper edge and middle ray). The group is here named Uranoscopus albesca species-group; other species in this group are U. albesca , U. bauchotae , U. dollfusi and U. kishimotoi n. sp., which are compared in Tab. 2. Uranoscopus brunneus n. sp. exclusively possesses within the group a total of 12 anal-fin rays (other species 13–14), a very high number of 62 oblique scale rows along the sides of the body (other species 47–59), 8 spines on the lower margin of the preopercle (other species 3–6), and dark brown pectoral-fin membranes (other species: pale to light brown).

Remarks. This species was briefly described from the Philippines and Indonesia by Kishimoto (2001: 3529) as Uranoscopus sp. 2.

Uranoscopus brunneus n. sp. lives relatively deep, at a known depth range of 315̄625 metres. Kishimoto (2001) reports a maximum total length of 26 cm, which would equal a maximum standard length of about 20 cm. The new species is close to U. kishimotoi n. sp. in having a high number of lateral scale rows and a very long cleithral spine.

Figures

FIGURE 1. Uranoscopus brunneus n. sp., NTUM 12716, holotype, 125.8 mm SL, Solomon Sea, Papua New Guinea, West New Britain Province, off southwestern New Britain. A Lateral view. B Head, dorsal view. Scale 5 mm.

FIGURE 2. Pectoral-fin shapes and nostril shapes of Uranoscopus brunneus n. sp. and U. kishimotoi n. sp. A Left pectoral fin of U. brunneus n. sp.; scale indicates 4 mm. B Nostrils and preorbital spines of U. brunneus n. sp.; scale indicates 3 mm. C Left pectoral fin of U. kishimotoi n. sp.; scale indicates 3 mm. D Nostrils and preorbital spines of U. kishimotoi n. sp.; scale indicates 2 mm. [A anterior nostril; P posterior nostril; PO1 preorbital spine 1; PO2 preorbital spine 2; PO3 preorbital spine 3.]

FIGURE 3. Uranoscopus brunneus n. sp., NTUM 12716, holotype, 125.8 mm SL, Solomon Sea, Papua New Guinea, West New Britain Province, off southwestern New Britain. Lateral view. Colouration immediately after collection. (Photograph: J.- N. Chen).