Yellow rasbora


The yellow rasbora is a species of ray-finned fish in the genus Rasbora from Southeast Asia. It is a primary freshwater fish originally from Java island of Indonesia. It is known as Wader pari fish in Indonesian language. In addition, it is protein source for the local community during the old days.
The taxonomy, phylogeny, and distributional boundary have not been fully studied yet.

Distribution

The species can be found in Indonesia, Thailand, Malaysia, Vietnam, Philippines, Singapore and the United States. The distribution is pretty reliable according to their Genus distribution in which they are native to freshwater habitats in South, Southeast Asia, and southeast China.
However, a journal had stated that R. lateristriata had a west-to-east direction of divergence and migration from Miocene to Plio-Pleistocene. R. lateristriata is often considered to be widely distributed from Sumatra, Java, Bali, across Wallace's Line, to Lombok and Sumbawa Islands of Indonesia.

Habitat and feeding habit

It is a type of riverine fish found in mountainous streams that is in shallow area with relatively fast flowing water and plenty of gravel in river bottom.
The fish is an omnivorous feeder which feeds on phytoplankton, zooplankton, insect larva, leaf cut, and little caterpillar day and night continuously. It is hunted down by snake head and red devil fish in the natural ecosystem.

Spawning site

The requirement for the spawning site is to have clean water flows smoothly, shallow, available enough of sand and gravel, and no garbage around them. Depth of the spawning site is about 30 cm. Artificial induced spawning is unknown.

Morphology

Dorsal spines : 2; Dorsal soft rays : 7; Anal spines: 3; Anal soft rays: 5. Preserved color dark brown dorsally, whitish to yellowish on sides and below; scales margined with minute dark spots; opercle with silvery black spot. 12 scales between nape and dorsal. Mouth strongly oblique with anterior end as high as upper margin of pupil; maxillary extends posteriorly below anterior margin of eye. Lateral line complete, reaching caudal, with 7 rows of scales between lateral lines over middle of caudal peduncle.

Incident

The eruption of Kelud Volcano on February 13, 2014, which released a huge amount of volcanic dust and nearly covered the whole of Java island possibly changed the fish. As a result, the exposure of fish to the volcanic dust which naturally dissolves on the water body, affected and caused change on the histological structure of gills and intestine, but did not have an effect on the histological structure of eyes, liver and gonad of the wader pari fish, respectively.

Current status

R. lateristriata is at vulnerable according to IUCN Red List and the population is declining with numbers from 10,000 to 100,000 mature individuals. The original habitat which used to be moderately abundant is becoming rare which leads to less opportunity for a researcher to do sampling. The declining population trend was probably caused by declining and inconsistent rainfall.