Seapen goby

Dorsal spines (total): 7; Dorsal soft rays (total): 8; Anal spines: 1; Anal soft rays: 9. Compressed head and body, and rather small eyes and sculpturing on the angle of the preopercle. Pelvic fins fused to form rounded cup, and frenum folded forming an anteriorly-facing pocket. Head and nape without scales. Eyes set laterally and high on head. Interorbital wide, about twice eye diameter. Mouth anterior and oblique, with several rows of curved pointed teeth. Tongue blunt or bilobed. Gill opening wide, gill membranes free of isthmus and each other until they meet as isthmus at a point below the eye. Unpaired fins low. Pectoral rays 19, branched in adults (Ref. 11432).