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….

There are currently 32 genera included in the family Pimelodidae (including Pimelodus), making it the second largest and one of the most diverse amongst catfish. However most experts agree that a full systematic revision of the family is needed, as little information about the phylogenetic (evolutionary relatedness) relationships between the various genera exists. Taxonomy information at the species level is also basic at best. It's therefore likely that at least some of the Pimelodids will…

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…

It's debatable as to whether this species should be considered an aquarium subject at all, given its eventual size. All too often, juveniles are sold without adequate information regarding their long term care. These cats can and will attain something close to their maximum size in captivity, and will do so quite quickly. The myth that they will only grow to match the size of the tank they're kept in is just that. It's also worth noting that species such as this can live for well …

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 …

Also known as the painted, saddle or marbled sailfin catfish, it's debatable as to whether this species should be considered an aquarium subject at all given its eventual size. All too often, juveniles are sold without adequate information regarding their long term care. These cats can and will attain something close to their maximum size in captivity, and will do so quite quickly. The myth that they will only grow to match the size of the tank they're kept in is just that. It's a…

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….

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...

This delightful little species can be distinguished from others in the genus by its elongated pectoral spines. It, and others in the genus (and also the closely related genus Erithistes), also go by the common name of moth catfish due to their patterning and shape when viewed from above….

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….