Boraras

Appears to be endemic to southwestern Borneo though occurence records are scant. Type locality is 'Bandjarmasin', a port town in the Indonesian province of Kalimantan Selatan (South Kalimantan), and following Kottelat (1991) it's range extends westwards as far as the Jelai Bila river basin, near the town of Sukamara, where it's said to occur sympatrically with the congener B. merah. Boraras was erected in 1993 in order to separa...

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.

Appears endemic to southern Borneo. The type specimens were collected from the Jelai Bila river basin at Nataik Sedawak, presumably a settlement of some kind, near the town of Sukamara in the Indonesian province of Kalimantan Tengah (Central Kalimantan). Its range extends westwards from the Jelai Bila watershed whereas that of the congener B. brigittae, with which it may occur sympatrically there (see 'Notes'), extends east.

Bung Khong Long is a lake and confirmed locality in Nong Khai province, Thailand. Aquatic plant species in the lake and surrounding floodplain include Hydrilla verticillata, Ceratophyllum dermersum, Chara zeylanica and Blyxa echinosperma. Salvinia cucullata is found floating on the surface and emergent plants comprise Eleocharis dulcis, Nelumbo nucifera, Lepironia articulata and Nymphaea lotus.

Known only from southern (peninsular) Thailand with the type series originating from a swamp some 83 km north of Surat Thani city, Surat Thani province. It's been recorded at additional locations, all within the lower Tapi river drainage on the Gulf of Thailand slope of the Malay Peninsula. In the description Conway and Kottelat (2011) report the occurence of a similar-looking, possibly conspecific fish on the Andaman Sea side of the Peninsula, close to Trang province.

The anatomical structure of miniaturised cyprinids can vary greatly, and there are two principle 'groupings' with some species possessing intermediate features to some degree. The first contains those fishes which though small are essentially proportionally dwarfed versions of their larger relatives, e.g., Barboides, Microdevario, Microrasbora, Horadandia, Boraras, Sawbwa, Sundadanio, Danio, Laubuca and Rasbora. The other includes those in which anatom...