Bradbury’s Triangular Batfish

description

Description. Morphometric and meristic data are provided in Table 1. Values are given for the holotype, followed by the range and / or mean values of all types in parentheses. Body depressed, disk markedly triangular in dorsal view, head elevated above rest of disk; tail base broad; caudal peduncle thick and broad, semi-cylindrical, flattened ventrally and tapering posteriorly; rostrum thick and pointed, directed forward horizontally (Figs. 2 A – B), with a broad base, distinctly overhanging illicial cavity and mouth; rostrum moderately long, 6.2 % SL (6.2 – 9.4 % SL, mean 7.7 % SL), shorter than orbital diameter; orbit small, 13.5 % SL (11.1 – 13.5 % SL, mean 12.4 % SL), eyes directed dorsolaterally; no pupillary operculum; interorbital space wide 8.1 % SL (7.6 – 9.8 % SL, mean 8.5 % SL), forming a deep groove (Fig. 2 A); frontal ridges strongly convex, elevated above the rostral base (Fig. 2 B). Illicial cavity large, triangular, higher than wide; esca a single bulb, bearing 2 small cirri on dorsal margin; mouth small, terminal; small villiform teeth on jaws forming narrow bands, those on fifth ceratobranchial forming 2 large, elongated patches close together; teeth on vomer and

Two new species of the batfish genus Malthopsis (Lophiiformes: Ogcocephalidae) from the Western Indian Ocean

diagnosis

Diagnosis. A species of Malthopsis distinguished by the following combination of characters: body covered by blunt, smooth bucklers and numerous prickles; rostrum moderately long (mean 7.7 % SL) and stout, with a broad base, directed forward horizontally; three irregular rows of bucklers on top of head; ventral surface of disk densely covered by prickles and scattered small bucklers, with some slightly larger bucklers on breast; subopercular buckler blunt, without enlarged spines; orbit small (mean 12.4 % SL); interorbital space broad (mean 8.5 % SL), forming a deep groove; OD / RL = 1.3 – 2.2; OD / IO = 1.3 – 1.7; and anal fin reaches or nearly to the caudal-fin base when fully depressed.

Two new species of the batfish genus Malthopsis (Lophiiformes: Ogcocephalidae) from the Western Indian Ocean

discussion

Remarks. Malthopsis bradburyae n. sp. belongs to a species group with the ventral surface densely covered by minute prickles (e. g., M. kobayashii, M. tiarella, M. asperata and M. gnoma). It differs from M. tiarella by having 5 – 6 dorsal-fin rays (modally 5, vs. 6 – 7 in M. tiarella), bucklers on body surface blunt and smooth (vs. pointed and rough), and lacking brown bands on the caudal peduncle (vs. bands present on peduncle); from M. kobayashii in its rostral spine directed forward horizontally (vs. directed forward and upward), in having a relatively wide interorbital space (7.6 – 9.8 % SL vs. 6.0 – 7.5 % SL), and bucklers on body surface blunt and smooth (vs. relatively pointed and rough); from M. asperata in having all bucklers blunt (vs. pyramid-like bucklers with spinelets); and from the western Atlantic species, M. gnoma, in lacking gill filaments on the fourth gill arch (vs. filaments on the fourth gill arch); and in the rostral spine directed forward horizontally (vs. upward and forward). It is also similar to M. annulifera from the western Pacific in having the rostral spine directed forward horizontally and principal bucklers on the body are relatively flat and smooth

Two new species of the batfish genus Malthopsis (Lophiiformes: Ogcocephalidae) from the Western Indian Ocean

distribution

Distribution. Known only from the type series taken off Tanzania at a depth 100 m.

Two new species of the batfish genus Malthopsis (Lophiiformes: Ogcocephalidae) from the Western Indian Ocean