Though this species appears on ornamental trade lists quite often the name appears to be routinely misapplied to other species, particularly B. doriae.

It can be diagnosed as follows: <30 lateral scales; two black body bands reaching ventral midline posterior to anal-fin; band above anal-fin als...

This species is not traded for aquaria but is occasionally exported as bycatch among shipments of other species. It differs from congeners in that the outermost row of teeth are not enlarged plus the interorbital space and cheek below eye are not scaled.

Butis spp. are largely nocturnal ambush predators with cryptic…

Type locality is given as ‘Stream at end of long narrow bay, Waigeo Island, Irian Jaya, Indonesia’, with the species also known from rivers draining the northern slope of New Guinea as well as Halmahera Island (Indonesia), the Admiralty Islands (Papua New Guinea), the Bismarck Archipelago (Papua New Guinea), D’Entrecasteaux Islands (Papua New Guinea), Louisiade Archipelago (Papua New Guinea), Bougainville (Papua New Guinea), Vanuatu, and…

As with all members of the genus sexual dimorphism is pronounced. Males are brightly-coloured, with a reddish-orange stripe extending posteriorly from the pectoral-fin, with the posterior portion of the body entirely suffused with red. A darkish band extends from behind the eye to the edge of the opercle, and the basal third of the caudal-fin is reddish-orange.

Known only from the Ryukyu Islands, Japan, and thus far recorded from just 4 streams on Okinawa island and two on Iriomote island. The type series derived from both islands with Okinawa given as type locality.

It may be more widely-distributed than this however, and was possibly transported to the Ryukyu Islands via the Kuroshio Current, an ocean current similar to the Gulf Stream transporting warm, tropical water northward from an area east of Taiwan past Japan towards the polar region.

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).

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…

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…

Inhabits freshwater swamps and associated streams, typically shaded from the sun by dense riparian vegetation. The water is normally clear or lightly stained with tannins, and the fish found in water less than a metre deep alongside related species including Betta edithae, B. miniopinna, and B. fusca. PH has been measured to range between 4.9-5.5.

Known only from a handful of localities in Bangkok, Samut Sakhon, Samut Songkhram and Samut Prakan provinces in central Thailand, all of which lie on the coast of the Gulf of Thailand.

Most habitats are in close proximity to Bangkok, which continues to expand rapidly, are considered under extreme threat, and recent surveys have failed to confirm that the fish is still present in Samut Songkhram and Samut Prakan.