It can be told apart from similar-looking congeners such as P. crescentus and P. muzaffarpurensis by the following combination of characters: barbels absent; lateral line incomplete with up to 5 pored scales; 20-22 lateral line scales; 8 predorsal scales; dorsal-fin with a vertically-orientated black streak and a black tip with orange markings; a dark spot at the base of the caudal peduncle.

P. chola was retained in Puntius sensu stricto, of which members are defined by the following combination of characters: adult size usually less than 120 mm SL; maxillary barbels absent or present; rostral barbels absent; 3-4 unbranched and 8 branched dorsal-fin rays; 3 unbranched and 5 branched anal-fin rays; last unbranched dorsal-fin ray weak or strong and unserrated; lateral line complete with 22-28 pored body scales…

This species continues to be mislabelled as O. melastigma, a name currently considered invalid by the majority of recent workers, or O. javanicus, a valid but distinct taxon. Roberts (1998) demonstrated that MClelland’s description of Aplocheilus melastigmus, later renamed O. melastigma, does not correspond with any known Oryzias species from the Indian subcontinent or Myanmar since it’s said to have a dark spot in the dorsal-fin and an excessively slim body, among other anomalies.

This species is diagnosable from other members of the genus primarily by its unique colour pattern which consists of 7-11 dark blue, irregularly-shaped, parallel vertical bars on the anterior portion of each flank plus a short horizontal stripe on the caudal peduncle which extends into the central caudal fin rays. Phylogenetic analyses suggest it’s most closely-related to Indian Devario spp. plus D. xyrops from the western slope of the Rakhine Yoma mountains in Myanmar (Fang et al., 2009; Fang and Kullander, 2009).

This species is available sporadically and makes an excellent choice for those new to keeping loaches. It’s distinguishable from congeners by a combination of characters including: truncate/rounded caudal-fin; no scales on top of head; dark, squarish spots o…

These are still regarded as valid by some authorities although it’s widely accepted that they represent variants of R. vaterifloris due to a lack of type material hindering conclusive study. Rasboroides nigromarginata (Meinken, 1956) has also been used to refer to a reddish form in which males differ from other populations in possessing dark fin margins, but the name is currently considered synonymous with R. vaterifloris by most sources despite the fish being rediscovered in 2010.

For many years this species was considered to occur in two colour forms with yellow or red dorsal, anal, and pelvic fins, respectively, but the red-finned variant has now been elevated to full species status as P. reval (Meegaskumbura et al. 2008). The latter is a smaller fish with a maximum SL of 33.6 mm recorded to date.

As well as the obvious differences in body size and fin colour P. cumingii can be told apart from P. reval by the following…

X. cancila is often seen referred to as ‘freshwater garfish’, and although it does superficially resemble the true gars of the family Lepisosteidae, it’s actually a member of the Belonidae, or needlefishes, the majority of which are marine or estuarine in existence.

There are currently just two species in the genus although the probable existence of a third member has been noted by Roberts (1989) among oth…

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…

Generally very peaceful making it an ideal resident of the well-researched community tank. As it places no special demands in terms of water chemistry it can be combined with many of the most popular fish in the hobby including other small cyprinids as well as tetras, livebearers, rainbowfishes, anabantoids, catfishes and loaches.

It’s a schooling species by nature, and at least 6-10 specimens should be purchased. Maintaining it in such…