Oxyurichthys petersii (Klunzinger, 1871) (Fig. 45)— Red Sea Tentacle-goby

Apocryptes (Gobiichthys) petersii Klunzinger, 1871: 480; type locality: Red Sea, Egypt, Al Quseir .

Size. Attains about 17 cm total length.

Morphology. D VI + I,12–13; A I,12–13; P 22–23. Body elongate, the depth 5.6–6.5 in standard length. Eyes protruding, their upper part well above dorsal profile of head (Fig. 45), each topped by a short fleshy knob. A narrow dermal crest present on nape. Caudal peduncle deep, almost as deep as body. Spines of first dorsal fin elongate, each ending in a short filament. Dorsal and anal fins long-based. Pelvic fins united to form a disc. Caudal fin lanceolate, nearly twice as long as head (Fig. 45). Scales on body ctenoid posteriorly, becoming cycloid anteriorly below middle of first dorsal fin, no scales on cheek, opercle, and prepectoral area (Pezold & Larson 2015). Scales small, at best visible on body as pattern of pale dots.

Live coloration. Yellowish to greenish gray dorsally, abdomen whitish, with a midlateral row 6 slightly elongate, blackish blotches, the first blotch on pectoral-fin base, the last on mid caudal peduncle at caudal-fin base (Fig. 45), sometimes alternating with 5 smaller dark spots. Head with a broad dark bar below eye, indistinctly edged with a pale blue line, followed by a row of dark blotches across operculum. Males with a series of oblique iridescent blue streaks on body, the first below origin of first dorsal fin; membranes of both dorsal fins with yellowish marks, forming longitudinal stripes, separated by short blue stripes.

Similar species. Cryptocentrus steinhardti .

Habitat. Inhabits silty sand or mud substrata of sheltered bays or estuaries, from the shallows to depths of 50 m; takes refuge in a burrow, but is able to dive quickly into mud if threatened when away from shelter.

Geographic distribution. In the native area restricted to the Red Sea (Pezold & Larson 2015). The most common Lessepsian goby migrant in the Mediterranean, where reported from Greece at Kastellorizo Island (Apostolopoulos & Karachle 2016), Israel (Ben-Tuvia 1983; Golani 2021), Lebanon (Bariche & Fricke 2020), Syria (Ali 2018), Tunisia (Golani et al. 2002), and Turkey from Aegean Sea and Mediterranean Sea coasts (Bilecenoğlu et al. 2002; Akyol et al. 2006).