Like others in the suborder Anabantoidei this species possesses an accessory breathing organ known as the labyrinth. So-called due to its maze-like structure this organ allows the fish to breathe atmospheric air to a certain extent. Comprising paired suprabranchial organs formed via expansion of the epibranchial (upper) section of the first gill arch and housed in a chamber above the gills, it contains…

B. macrostoma is included in the Betta unimaculata complex of closely-related species within the genus, of which members share the following set of characters: body long and slender with depth at dorsal fin origin 18-25 % SL; head large and blunt with width 19-24 % SL; long maxilla and lower lip with distance from tip of lower jaw to posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.

D. johorensis can be distinguished by the following combination of characters: 5-6 dark, lateral stripes on body in specimens larger than 40 mm; stripes immediately above and below the central stripe (stripes ‘+1’ and ‘-1’, respectively) located on scale rows +2 and -2, not touching dorsal and ventral midlines (except in some small specimens from Peninsular Malaysia); stripes broad, typically between 0.5-1 scale rows deep…

This species is also known by the vernacular ‘jungle perch’ or ‘sidebar barb’ and should not be considered an aquarium subject in all but the most extreme circumstances since it can grow to over 2 feet in length, weigh in excess of 5 kg and is a powerful, pelagic predator. It’s also a popular sport fish with a reputation for striking hard.

P. apogon has formerly been placed within the genera Kryptopterus, Micronema (Rainboth, 1996) and more recently Phalacronotus (Ferraris, 2007) and is an important food fish across much of its native range.

It’s very similar to P. micronema but can be told apart by its longer head (HL fits 4.6± 5.3 times in…

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…

One of four similar-looking, laterally-striped ‘Puntius‘ spp. native to Southeastern Asia alongside ‘P.‘ gemellus, ‘P.‘ johorensis, and ‘P.‘ trifasciatus. Of these ‘P.‘ lineatus is most often confused with ‘P.‘ johorensis by virtue of the fact that these two seem most common in the aquarium trade.

Telling them apart is relatively simple since ‘P.‘ lineatus has 0 – 1 pairs of barbels (vs. 2 pairs in the other three species), juv…

This is one of two species traded under the vernacular name ‘tinfoil barb’, the other being the less well-known congener B. altus. Despite this it appears that B. altus is just as widely available as B. schwanefeldii and in many cases is seen on sale more regularly. Unfortunately both are usually offered at a small size (usually around 50 – 75 mm) with little to no information regarding the eventual size of the fish.

This species isn't especially popular in the aquarium trade but is undoubtedly interesting despite its lack of colour. In addition to its survival ability in the absence of water it's also capable of producing audible sounds though the purpose of these has not been fully-studied. Naturally-occurring xanthic and albino forms have also been recorded.

There is considerable confusion as to the taxonomic status of the two species currently occupying this genus, with ichthyologists widely…