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…

Within the genus Boraras this species is most similar to B. naevus, though in the latter the red body colouration does not extend into the head. The two also differ in the following characters: anteriormost lateral blotch of comparable size in both sexes in B. maculatus vs. significantly larger in male than female B. naevus; 9-10 + 9 principal caudal-fin rays vs. 9 + 8; 26-29 lateral scales vs. 24-26; i.6.i. pelvic-fin rays vs. i.5.i.

Known from the Malay Peninsula and Singapore plus Greater Sunda Islands of Sumatra, Borneo and Java in Indonesia with populati0ns from Thailand, Cambodia, Laos and Vietnam formerly considered as conspecific now referred to K. geminus (Ng, 2003).

Type locality is given as ‘Bandjarmassing’ which corresponds to a town now more commonly referred to as ‘Banjarmasin’ in South Kalimantan (Kalimantan Selatan) province, Indonesia (Borneo).

This species is distinguished from its Australian congeners S. jardinii and S. leichardti by possessing a lower number of lateral line scales (21-26 vs 32-36).

It occurs naturally in a number of colour forms of which three were elevated to distinct species status in 2003, but the current majority view is that all represent S. formosus pending a detailed review. Kottelat (2013) mentions that the red form may…

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…

This species is commonly-referred to as ‘T-barb’ in some countries. It’s closely-affiliated with and sometimes traded as the congener B. kuchingensis but that species can be told apart by colour pattern comprising a prominent row of dark spots along the lateral line, plus a short, horizontally-orientated streak extending from the upper part of the operculum. In B. lateristriga the lateral markings usually form a solid stripe and there is no streak extending from the operculum.

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.

Wild swordtails are a fairly basic green colur. However the vast majority of swordtails available in the hobby today are hybrids of X.helleri with X.maculatus or X.variatus. There are a huge number of selectively-bred varieties available, including wagtail, lyretail, tuxedo, albino, neon, red, green and hi-fin.

Swordtails may undergo what appears to be a change in sex. In young fish this may simply be late development. However some adult females develop male characteristics which is thought …

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…

Generally considered to have an enormous natural range extending from Iran to Taiwan and Bali, with records existing from Iran, Iraq, Afghanistan, Pakistan, Nepal, India, Sri Lanka, Bangladesh, Bhutan, China, Myanmar, Thailand, Laos, Cambodia, Vietnam, Malaysia, Indonesia, and Singapore.

However there exists significant evidence to suggest that C. gachua as currently understood represents a complex of similar-looking species, and a taxonomic review of the group is clearly required.