Sicyopus

This species is not in the aquarium trade though is maintained by a few private collectors. It can be distinguished from all other members of the genus by the following combination of characters: first dorsal-fin withfirst dorsal-fin elongate in males; anterior portion of body with loosely-arranged ctenoid scales; head, entire nape to first dorsal-fin base, pectoral base, and belly naked; male colour pattern comprising creamy-yellow anterior portion of body with dark blotch at midbody and bright orange/red in postero...

The fused pelvic fins form a structure normally referred to as the 'pelvic disc', a common feature among gobiids which is used to adhere to rocks and other submerged surfaces. In Sicyopus, as in Stiphodon, this is short-based and attached to the belly only between the fifth pair of fin rays whereas in other sicydiines it's attached between all five rays (Watson, 2005).

Live colouration of this species was not included in the original description but the specimens in our images were identified by Dr. Ronald E. Watson, the principal author, as S. exallisquamulus. It's normally misidentified and traded as the Sri Lankan endemic species Sicyopus jonklaasi. It is diagnosable from congeners by the following combination of characters: 14-15 pectoral-fin rays; both genders exhibit small, widely-spaced scales...

Type locality is given as 'Boleling, northern Bali, Indonesia' which appears to correspond to modern-day Buleleng, but this species is currently understood to have a patchy but wide distribution with a range stretching westwards from the Marquesas Islands (French Polynesia), throughout much of Vanuatu, New Caledonia, the Solomon Islands, Papua New Guinea, Palau, Fiji, Indonesia, the Philippines, Japan, Taiwan, and most recently, southern mainland China...