Gobies & Sleepers

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...

Butis spp. are largely nocturnal ambush predators with cryptic patterning to help them blend in with their surroundings. They can also lighten and darken their body colouration to an extent, have a habit of aligning themselves with solid surfaces whether horizontal, vertical, or inverted, and often swim in an upside-down position. The genus is usually included in the family Eleotridae of which members are often referred to...

Occurs in northern and eastern Australia and southern New Guinea. In the former its range extends from the Pilbara and Kimberley regions of Western Australia state around the northern and eastern coastlines of the continent as far as the Towamba river system in New South Wales state.

Until recently the genus Stigmatogobius contained 18 species, but most have now been reclassified, leaving just 7 species currently assigned to it. S. sadanundio is by far the most common of these in the hobby. It makes an attractive addition to the brackish or hardwater community with medium-sized tankmates....

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...

This species probably hasn't been seen in the trade yet but should make an interesting aquarium fish if it ever becomes available. Within the genus it's most similar to S. surrufus and S. mele from which it differs only in terms of meristics. In description it's distinguished from the former only by possession of more teeth in the upper jaw although images of live specimens depict S. surrufus as a more intensely-coloured, reddish fi...

This species was referred to as S. sp. 'orange fin' or S. sp. 'ST01' prior to being offically named and is one of the more commonly-traded members of the genus, though often in batches containing only one gender, a mixture of species, or misidentified under an incorrect name such as S. zebrinus. It can be told apart from congeners by the following combination of characters: usually 9 soft second dorsal-fin rays; 15 soft pectoral-fin rays; first dorsal-fin in male poin...

This species is traded as S. sp. 'rainbow', S. sp. 'gold fin', or S. sp. 'gold cheek' and is among the more widely-available members of the genus although its identity was unclear prior to 2013. The most commonly-traded fish certainly appears to...

This species seems not to have appeared in the trade and is similar to several congeners in appearance, most notably S. weberi which is native to the Maluku archipelago and other islands around the coast of Papua (formerly Irian Jaya). The two are said to be most easily-distinguished by examination of the belly which is fully-scaled in S. pelewensis but lacks scalation in S. weberi. The Gobiidae is the most speciose vertebrate family and notoriously problematic in terms of identifying fishes down to sp...

This species is rare in the aquarium trade and normally expensive when available. It's one of the most easily-identifiable in the genus by the combination of usually 14 pectoral-fin rays, 10 segmented second dorsal-fin rays, relatively small adult size, unique colouration in males and the shape of the first dorsal-fin in males in which the fourth and fifth spines are...

This species is not traded commercially at present and the specimen pictured above was brought back from northern Papua New Guinea by private collectors in 2008. It's diagnosable from other members in the genus by possession of 10 segmented rays in the second dorsal fin, males with filamentous spines in the firstandusually with 14 rays. Colour patterning in males is also distinctive (see 'Sexual Dimorphism'). The Gobiidae is the most speciose vert...

This species has been traded for a number of years, though not always under the correct name. We've seen it on sale as S. elegans or S. atropurpureus on numerous occasions, for example, and other trade names include 'Sumatran blue neon goby', 'cobalt blue goby' and 'freshwater neon goby'. Further confusion has arisen because other species are sometimes sold as S. semoni meaning identification has not always been easy and there ...

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.

Due to its highly amphibious nature this must be one of the most interesting, endearing species that can be kept in aquaria. Some specimens rarely enter deep water, preferring to sit in the shallows with the body submerged and eyes protruding above the surface. Others seem to favour resting completely exposed on rocks, sand or bogwood, returning to the water periodically to wet themselves. Subdominant individuals (those that are unable to secure a favourable territory) tend to attach themselves ...

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.

This species is among the more frequently-traded members of the genus, although confusion regarding its identification and natural distribution is commonplace and it's often misidentified as B. nunus or B. xanthozonus. It can be diagnosed as follows: <30 lateral scales; one black band on head, three on body; first black band on body overlapping first dorsal fin to the extent that almost all fin, except a narrow margin, is black, and beginning opposite centre of opercle...

Apparently restricted to slow-moving or standing freshwater habitats such as marshes, temporal swamps and floodplains where aquatic vegetation and submerged grasses proliferate. One locality consisted of undisturbed marshland with lightly tannin-stained water and dense growth of Vallisneria spp.

B. sabanus is very similar to B. doriae and these two are easily confused. However in B. doriae most of the first-dorsal-fin and two-thirds of the pectoral-fin are black while in B. sabanus the last one or two rays of the first dorsal-fin are colourless and less than half of the pectoral-fin is black. In addition there are usually smaller dark 'saddles' betw...

Type locality is '55 miles north of Singapore, freshwater ditches, Mawai District, Johore, Malaysia', and this species has been recorded throughout much of Peninsular Malaysia and southern Thailand. Records from Borneo and Singapore appear to be in error although it may have been extirpated from the latter but as with most members of the genus a degree of confusion surrounds its identity (see 'Notes').

Lake Eyre is a vast endorheic basin within which lies the lowest point in Australia at some 15 m BMSL. It only fills with water occasionally and when it does so forms the country's largest salt lake. C. eremius does not occur in the lake itself since no fishes are able to survive there, rather it inhabits isolated freshwater springs, flowing artesian bores (wells), and ephemeral waterholes where it tends to be associated with rocks and other submerged cover.

This fish is also commonly sold as the dragon or Peruvian goby, or dragon fish, and its bizarre appearance has made it popular in the trade. This is unfortunate, as not only does it grow very large, but it has specialised feeding requirements and does not survive for very long in freshwater. When provided with the correct conditions, however, it makes a unique and fascinating captive subject. There is a smaller species in the genus, G. peruanus, that does survive in freshwater, being a riverine ...

This species is considered endangered across its native range, but has recently begun to appear in the hobby a little more often as a result of commercial farming. It's still by no means common though. Superficially it looks very similar to the much commoner Northern purple spotted gudgeon (Mogurnda mogurnda), but can be distinguished by the presence of only 30-36 scales along its lateral line, (as opposed to 37-48 in M. mogurnda), and a higher degree of red spotting in the second dorsal fi...

A good species of gudgeon for the beginner, being tolerant of a wide range of water conditions, hardy and easily bred. We've even seen them spawning in dealer's tanks on more than one occasion. It's easily confused with the similar looking, but rarer Southern purple spotted gudgeon, Mogurnda adspersa, a fish which is now being farmed for the trade despite being endangered in nature....

One of the largest goby species in the world, O. marmoratus is unsuitable for the vast majority of aquaria, but is an interesting oddball for the true enthusiast with the facilities to house it properly. It is a nocturnal ambush predator and generally remains motionless during daylight hours unless striking at food. It is a popular food fish in some of its native countries, where it is known as soon hock....

This species is normally imported alongside a smaller-growing, near-identical congener currently listed as R. cf. nantaiensis with both traded as R. candidianus. They can be separated by snout length, which is noticeably longer in R. candidianus, and adult size with R. cf. nantaiensis reaching just 50-55 mm. R. candidianus can be distinguished from other congeners by a combination of cha...

This species has been exported for the ornamental trade but often labelled as the congener R. mekongianus. Although the two do appear relatively similar R. chiengmaiensis can be identified by a combination of external characters including: presence of 5 irregular dark markings on the body (vs. 7-8 i...

Very few details exist but the type locality is given as 'Yangso, Li Kiang, Kwangsi Province, southern China', which should correspond to an unspecified location within the Li River (Li Jiang) system in Guangxi Zhuang Autonomous Region, southern China. The specimens in our images were collected i...

In addition, there appear to exist two colour forms based on male dorsal-fin morphology and patterning; one in which the 4th ray of the first dorsal-fin is longest with a square bluish-black blotch on the anterior ⅔ of the fin, and a second in which the 2nd and 3rd rays of the first dorsal-fin are longest with the fin itself paler and lacking dark markings.

This species was previously considered to be a subspecies of R. nagoyae but has generally been accepted as distinct since 2008. It can be told apart from other Rhinogobius spp. from Taiwan by presence of irregular, wavy, reddish brown lines on the cheek and opercle.

As is typical for the genus eggs are deposited on the ceiling of a cave or crevice and guarded by the male until hatching. Several potential sites should be offered in the form of rocks (flat slate tends to be easiest to handle, see below), terracotta pipes, plant pots, etc. A nuptial male will select a site and defend it agai...

This species appears to exist in a number of different forms which exhibit differences in colour pattern, morphology, or both, and it's currently unclear whether all of them are truly conspecific or not although to avoid confusion we list all together here.

Presumably inhabits small rivers, tributaries and streams with substrates of gravel, rocks, boulders, and exposed bedrock which undergo seasonal variations in water flow rate, depth and turbidity. Lanyu Island is volcanic, measures just 45 km² and has no major rivers or large settlements with a permanent human population of around 4000, although there is a large nuclear waste storage facility at its southern end.

This species appears to exist in a number of different forms which exhibit differences in colour pattern, morphology, or both, and it's currently unclear whether all of them are truly conspecific or not although those in the aquarium trade all appear similar to one another. We've been unable to obtain a copy of the original description so it's not currently possible to provide a detailed diagnosis either, with most recent studi...

It's unlikely that this species has been in the aquarium hobby given its natural range and the lack of commercial fishing for the ornamental trade in that area. Among congeners it's most similar to R. davidi but can be told apart by presence of 8 (vs. always 9 in R. davidi) soft dorsal-fin rays, 10 (vs. 11-12) transverse scale rows, and 6-7 (vs. 8-10) scales between the first dorsal-fin origin and upper pectoral-fin base.

This species may not yet have appeared in the ornamental trade but it has been collected by a few individuals. It can be told apart from related species from Taiwan by possessing 30-32 longitudinal (lateral) scales vs. 32-39 in other species, and 6-8 scale rows between the origin of the first dorsal-fin and upper pectoral-fin base vs. 9-15 in other species.

Known from various parts of the middle and upper Mekong river basins with record existing from the Nam Tha, Nam Ou, Nam Khan, Nam Lik, Nam Ngum and Nam Mang tributary systems in Laos, the Nam Noeua (a tributary of Nam Ou) in Vietnam, and the Mae Nam Kok in Thailand. Occurrences in the Chao Phraya drainage in central Thailand most likely refer to the congener R. chiengmaiensis.

This fish is normally imported alongside the congener R. candidianus and is actually the commoner of the two in the aquarium trade. It looks very similar to R. candidianus but does not grow as large and possesses a more rounded snout. Most specimens also have spot-like markings on the sides of the head which has led to them being identified as R. nantaiensis, but the fish do no...

This species occurs in a couple of colour forms with fish from northern and central Taiwan possessing a greyish base body colour and those from the Linbian river, southern Taiwan having a dark marking in the anterior portion of the first dorsal fin and larger, more intense red spots on the body. The latter form is also smaller in size, lays smaller eggs, does not exhibit extreme sexual dimorphism and has been refe...

This species' name has appeared quite regularly on ornamental fish trade lists since the mid-00's but it's unclear whether the species itself has ever been exported since fish labelled as such do not appear to fully match the most recent key (see below). That said, its natural habitats lie in the same region as the loach Yaoshania pachychilus so it's reasonable to assume that some specimens may have been collected, and the fish in our images were ca...

This species has been in the aquarium trade since 2010 and is sold under several names including 'Chinese vermilion goby', 'Zhou's scarlet goby', 'scarlet goby', and 'flame goby'. It can be told apart from congeners by the following combination of characters: second dorsal-fin rays I, 8-9; anal-fin rays I, 7-8; pectoral-fin rays 16-18; longitudinal scale series 29-31; predorsal scales 10-12; vertebral count 10+16=26.

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...

This species is available occasionally, though not always under the correct name. We've seen it on sale as S. elegans on numerous occasions, for example, and other trade names include 'Sumatran blue neon goby' (it's not found on Sumatra), 'cobalt blue goby' and 'freshwater neon goby'. Further...

This beautiful little fish is not actually a goby, it's a member of the Eleotridae family, commonly known as sleepers or gudgeon. Members of this family lack the fused pectoral fins of true gobies. This species is one of the smallest and most attractive in the family, and makes an ideal resident of the planted community tank....

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...

It can be diagnosed as follows: <30 lateral scales; two black body bands reaching ventral midline posterior to anal-fin; band above anal-fin also reaching ventral midline no black band on head, though the first band may touch the posterior margin of the eye; band above anal-fin not reaching ventral midline; 6 branched anal-fin rays; 7-8 predorsal scales. Brachygobius currently contains 9 described species but is likely to prove more diverse should a review be carried out. Alt...

Type locality is the 'river below Calcutta' which corresponds to the western side of the Ganges River delta south of Kolkata, West Bengal state, with reports as to its wider distribution varying significantly. It's sometimes said to be present throughout India plus both mainland and maritime southeast Asia, but is more likely restricted to India, Bangladesh, Sri Lanka, and possibly Myanmar.

Not often seen for sale, but if you can find it, it makes a peaceful addition to the brackish or hardwater community of medium-sized fish. It was previously considered a member of the now defunct genus Batanga. The fish in our picture is a young specimen. Adults develop a pleasing pattern of reds and blues and are most attractive....

Due to its highly amphibious nature this must be one of the most interesting, endearing species that can be kept in aquaria. Some specimens rarely enter deep water, preferring to sit in the shallows with the body submerged and eyes protruding above the surface. Others seem to favour resting completely exposed on rocks, sand or bogwood, returning to the water periodically to wet themselves. Subdominant individuals (those that are unable to secure a favourable territory) tend to attach themselves ...

Something for the true oddball enthusiast, this bizarre looking goby has been imported at least once over the last few years. It's a mud-burrowing species that digs networks of sloping tunnels in the substrate in nature. Apparently each series of burrows has several openings, one of which has a mound outside. According to Itani and Uchino (2003), this mound suggests that the fish "actively process sediment". Even more odd is its appearance (see picture). It has greatly reduced eye...

B. xanthozonus can be considered something of an enigma since its name has been widely misapplied in aquarium literature for decades, when in reality it's probably never been exported for the ornamental trade. The majority of fish seen labelled as such are either B. doriae or B. sabanus, themselves often misidentified.

There are a number of unidentified species within the grouping of which several are referred to using a two-letter code based on their respective colour pattern for ease of reference, with 'CB' shorthand for 'cross band', for example. R. sp. 'CB' is the commonest member of the grouping in Japan but has not yet entered the international aquarium trade as far as we know.

Some wild populations have evolved a complex amphidromous breeding strategy in which adults live and spawn in freshwater or brackish streams and the pelagic post-hatch larvae are washed downstream to the sea where the post-larval fry spend the first part of their life developing in estuarine nursery zones under brackish to full marine conditions. Once they reach a certain stage of development they begin to migrate upstream with some mov...