Speleogobius trigloides Zander & Jelinek, 1976

Kovačić, Marcelo, Renoult, Julien P., Pillon, Roberto, Svensen, Rudolf, Bogorodsky, Sergey V., Engin, Semih & Louisy, Patrick, 2022, Identification of Mediterranean marine gobies (Actinopterygii: Gobiidae) of the continental shelf from photographs of in situ individuals, Zootaxa 5144 (1), pp. 1-103 : 85

Speleogobius trigloides Zander & Jelinek, 1976 ( Fig. 12 )—Grotto Goby

Speleogobius trigloides Zander & Jelinek, 1976: 275 , Figs. 4–5 ; type locality: Adriatic Sea , Croatia, Grotto of Banjole, near Rovinj .

Size. Maximum size about 2.8 cm total length.

Morphology. D VI + I,6–7; A I,5–7; P 14–15. Body slender, laterally compressed. Head slightly depressed behind eyes. Snout pointed, shorter than eye diameter. Caudal peduncle slender, lower than body depth. Second dorsal and anal fins with short base and low ray counts (see fin meristics). Dorsal fins of similar height, the first dorsal fin with more or less rounded margin and no elongated spines, except in breeding males that have both dorsal fins higher ( Zander & Jelinek 1976; Miller 1986; Kovačić et al. 2016; Engin et al. 2017). Caudal fin truncate. Scales present on body and on predorsal area, mostly not visible on photographs.

Live coloration. Body primarily red (from rosy to yellow-orange to vermilion) with series of white blotches along dorsal and ventral sides ( Fig. 12 ), 5 irregular whitish dorsal saddles (first below first dorsal-fin origin, second (wider) at interdorsal space, third below rear second dorsal fin, fourth at about middle of caudal peduncle and fifth just before caudal-fin base); a series of 5–6 barely-defined and somewhat coalescing white to yellowish blotches along ventral profile (first on belly below first dorsal fin, last on caudal peduncle). In males, body becoming yellow posteriorly, or at least the caudal fin; white blotches often reduced, sometimes absent, especially the lower ones; dorsal fins yellowish with at least one oblique pink to light purple stripe visible on each ( Fig. 12a ). In females, background body color generally a uniform pinkish red ( Fig. 12b ). Dorsal fins mostly transparent, usually with an oblique whitish stripe on each. While female colors and patterns appear to be quite constant, males may completely lose their white or pale blotches ( Zander & Jelinek 1976; Fesser 1980; Miller 1986; Louisy 2015; Kovačić et al. 2016; Engin et al. 2017).

Similar species. Speleogobius llorisi .

Habitat. Infralittoral to circalittoral species, known from 8–48 m depth, most often on coralligenous beds and concretion, possibly on scree made of boulders, sometimes on deep rocks, on detritic coarse sand or in caves; may swim a few centimeters from the substrate ( Zander & Jelinek 1976; Miller 1986; Le Bris et al. 2015; Louisy 2015; Engin et al. 2017; Bérenger et al. 2019 and pers. com.; Duhau et al. 2020a).

Geographic distribution. Mediterranean. Presently known from southern France ( Duhau et al. 2015; Le Bris et al. 2015; Bérenger et al. 2019 and pers. com.; Iglésias et al. 2020), to the Aegean Sea (Engin et al. 2017), including the northern and southern Tyrrhenian Sea ( Duhau et al., 2020a, 2020b) and the Adriatic Sea ( Zander & Jelinek 1976; Miller 1986; Kovačić 1997).

Figures

FIGURE 4. Live coloration in its natural habitat of Vanderhorstia mertensi. Photo by R. Pillon, Kondyli beach, Peloponnese, Greece.

FIGURE 5. Live coloration in its natural habitat of Thorogobius ephippiatus. Photo by S. Guerrieri, Tuscany, Italy.

FIGURE 12. Live coloration in its natural habitat of Speleogobius trigloides: A) male, B) female. Photos by R. Svensen, Selce, Croatia, Northern Adriatic Sea.