Bryaninops spongicolus, Suzuki, Toshiyuki, Bogorodsky, Sergey V. & Randall, John E., 2012

Suzuki, Toshiyuki, Bogorodsky, Sergey V. & Randall, John E., 2012, Gobiid fishes of the genus Bryaninops from the Red Sea, with description of two new species and two new records, Zootaxa 3170, pp. 1-17 : 6-9

Bryaninops spongicolus , n. sp.

Figures 4–7 ; Table 1

Holotype: BPBM 41004, male, 24.5 mm SL, Red Sea, Sudan, Wingate Reef, wreck of Umbria , about 4 miles east of Port Sudan, 37°19'N, 19°38'E, on a line hanging from the wreck and partly covered with red sponge, 23 m, S.V. Bogorodsky, 14 October 2009.

Diagnosis. Dorsal-fin rays I,8; anal-fin rays I,8; pectoral-fin rays 15; scales on body reaching to above base of pectoral fins, the longitudinal scale series 52; transverse scale rows 11; body elongate, the depth at anus 15% SL; head width slightly greater than head depth; snout long and depressed, 41% head length, and depressed; eye 28% head length; lower jaw slightly protruding; gill opening extending forward to below center of eye; two pairs of recurved canine teeth on side of lower jaw; caudal fin rounded; pelvic disc broadly oblong and flat, not reaching genital papilla; each pelvic spine flattened to a lobe and joined to frenum, without a pocket beneath; body translucent in life, dusky yellow over abdomen; snout mainly yellow with a lateral blackish stripe from eye to front of jaws; scattered melanophores on head posterior to eye.

Description. Dorsal-fin rays VI + I,8; anal-fin rays I,8; pectoral-fin rays 15, upper three rays unbranched; longitudinal scale series 52; transverse scale rows 11; segmented caudal rays 9+8; branched caudal rays 6+5; gill rakers 3 + 9.

Body elongate and moderately compressed; body depth at anus 15% SL; head length 27% SL; head width slightly greater than head depth; head depth 51% head length; eye large, placed laterally and extending slightly above dorsal profile, 28% head length; snout long and depressed, 41% head length and roughly rectangular in dorsal view.

Mouth slightly oblique; gape reaching posteriorly to a point below nasal pores; jaws reaching posteriorly below eye to a point between anterior edge of orbit and anterior edge of pupil; lower jaw slightly protruding; dorsal margin of upper jaw slightly convex; teeth in both jaws conical, inwardly curved; upper jaw with four to five rows of teeth anteriorly, narrowing to two rows posteriorly; outer row of teeth with two medium-sized teeth preceding eight large teeth, and followed by medium-sized teeth; teeth of inner rows small; lower jaw with seven rows of teeth, small except innermost row of medium size, two large teeth on each side at front of jaw, and two large teeth near middle of side of jaw. Tongue trilobed. Gill opening wide, extending forward to below center of eye.

Cephalic sensory systems shown in Fig. 4 ; anterior oculoscapular-canal with pores B', C, D (single), E, F, and G'; three preopercular-canal pores, M', N and O'.

Scales ctenoid; scales dorsally on body reaching forward to below origin of first dorsal fin, and laterally to above base of pectoral fin; head, breast, base and axil of pectoral fin, and anterior and midventral abdomen naked. First dorsal fin triangular, the first spine longest; second dorsal fin equal in height to first dorsal fin anteriorly, lower posteriorly; anal fin lower than second dorsal fin; pectoral fins not reaching past end of pelvic fins; pelvic fins moderately long, 20% SL, the disc broadly oblong and flat, not reaching anus; each pelvic spine flattened to a lobe and joined to frenum, without a pocket beneath; caudal fin rounded.

Color of holotype in preservative ( Fig. 5 ): head and body white; snout with a lateral blackish stripe consisting of many black dots from eye to front of jaws; abdomen and ventral side of caudal peduncle with many brown dots; a blackish line at base of anal fin.

Color of holotype in life ( Fig. 6 ): body transparent dorsally, crossed by seven faint pale red bars, two below first dorsal fin, two below second dorsal fin, and three, less distinct, on caudal peduncle; ventral part of body mainly red, except abdomen golden yellow, densely dotted with dark brown and crossed by oblique red bands; snout mainly yellow with a lateral blackish stripe; scattered melanophores on occipital region; a white line dorsally on vertebral column interrupted by red bars, thus appearing as a series of six white dashes; all fins hyaline.

Figure 7 is an underwater photograph of what we believe to be Bryaninops spongicolus . It was taken by Jean Louis Rose on red sponge in 12 m at a site known as Middle Garden, near Naama Bay, southeast coast of the Sinai Peninsula, hence about 1,000 km north of the type locality in Sudan. There are some color differences, such as less yellow on the snout of the Rose photograph and the lips more green. However, comparison is difficult due to one photograph being a lateral view and the other dorsolateral. Positive identification should wait the collection of a specimen.

Distribution. Presently known from the holotype from off Sudan, with a possible range extension to the Gulf of Aqaba.

Etymology. Named B. spongicolus in reference to its being found as a commensal on sponge.

Remarks. We first identified this species as Bryaninops dianneae Larson , described from two specimens from Fiji collected from a green sponge in 7.5 m. Larson (1987) reported two additional lots totaling 14 specimens, 9–25 mm SL, from the green finger-like sponge Haliclona sp. in 6– 15 m. The third author and colleagues collected seven specimens (BPBM 38983, 14– 24 mm SL) from a green tubular sponge in 8 m at Viti Levu, Fiji. Randall (2005: 521) published an underwater color photo of B. dianneae taken in Fiji on green sponge.

The pelvic disc of both B. dianneae and B. spongicolus is oblong and very flat, instead of rounded and cup-like as in most other species of the genus, but the disc is much shorter in B. spongicolus . Other differences are the rounded caudal fin, compared to truncate in B. dianneae , and the smaller eye. In addition, there are differences in life color. The snout and lower jaw of B. spongicolus is mainly bright yellow, and the blackish stripe on the side of the snout less distinct. The side of the abdomen is dusky yellow with small red blotches, compared to a broad elliptical whitish area in B. dianneae .

The holotype was one of four individuals of this goby observed on the same piece of line about 3 m in length hanging U-shaped from the wreck of the Umbria , and partly covered with red sponge. Two of the fish were notably larger, and only one of the two large ones was collected.

Figure 6 shows that this species, as in others of the genus, uses its pectoral fins, as well as the pelvics, to adhere to the substratum, in this case sponge. The same is true of the underwater photo of Figure 7 that we believe to be Bryaninops spongicolus , despite the color differences.

We note also the difference in the host sponge of Bryaninops dianneae , consistently reported from finger-like green sponge of the genus Haliclona , whereas B. spongicolus has been found only on encrusting red sponge.

Comparative material. Bryaninops dianneae , BPBM 38983, 7: 14–24 mm SL, Fiji, 15 March 2002.

Figures

FIGURE 4. Head of holotype of Bryaninops spongicolus sp. nov. showing cephalic sensory pores and papillae. Top: dorsal view; middle: lateral view; bottom: ventral view. Letters indicate sensory canal pores, and prime marks the terminal pores; (S) means a single pore; AN: anterior nasal pore; PN: posterior nasal pore. Dots represent the sensory papillae. Arrow shows position where gill membranes are attached to isthmus. Drawing by T. Suzuki.

FIGURE 5. Holotype of Bryaninops spongicolus sp. nov., BPBM 41004, 24.5 mm, wreck of Umbria, Sudan. Photo by T. Suzuki.

FIGURE 6. Holotype of Bryaninops spongicolus sp. nov. at wreck of Umbria, Wingate Reef, Sudan. Photo by S. V. Bogorodsky.

FIGURE 7. Bryaninops spongicolus sp. nov., Middle Garden, southeast Sinai Peninsula. Photo by J. L. Rose.