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New native freshwater fish found in Suriyakanda stream
A Sri Lankan researcher has revealed a new species of loach, a freshwater fish, found in a stream in Suriyakanda.
Banded Mountain loach
Loaches are bottom-dwelling freshwater fish that live in natural streams as well as rivers, the researcher notes.
During a fish survey in Suriyakanda two years back, researcher Hiranya Sudasinghe found a fish that looked different from other known loaches. He has proved it is a fish species new to science. The findings were published this week in the acclaimed scientific journal ZooTaxa, officially recognising the fish as a new species endemic to Sri Lanka.
It has been classified as Schistura madhavai in honor of Prof Madhava Meegaskumbura, a senior researcher who has discovered a number of new species. Mr. Sudasinghe who graduated from the University of Peradeniya also recalls Prof Meegaskumbura’s guidance. Mr. Sudasinghe’s previous research led to recognising two new catfish species endemic to Sri Lanka.
The new fish was recorded from a small stream about two metres wide in Suriyakanda. The stream flows through a tea plantation. Suriyakanda is about 1,000 metres above sea level, so the new fish has been tagged as a hill-stream loach. In his research papers, Mr. Sudasinghe says, loaches have small barbels which act as sensory organs that helps them to find food on murky bottoms of freshwater streams. Most loaches have either three pairs or four pairs of barbels and the new member has three pairs of barbels, the researchers explains.
The researcher says little is known about the biology of these species in Sri Lanka though there are four other loaches commonly called as ‘Ahirawa’ in Sinhala. Revealing an interesting fact, Mr. Sudasinghe says in his research paper that the native freshwater fish recorded from the highest elevation in Sri Lanka could be a loach. It is the endemic Sri Lanka banded mountain loach (Schistura notostigma) found above 1,200 metres in hill country.
He says in his paper that the spiny loach (Lepidocephalichthys thermalis) is the most common of all the loaches in Sri Lanka found in a variety of habitats including streams, tanks, rivers and ponds in both dry and wet zones. It has a high tolerance towards environmental and physical parameters and sometimes found in harsh conditions as well, he says in the published research.
Common loach
Even its name “thermalis”, is derived because it was first discovered and described from the hot springs in Kinniya, Trincomalee, Mr. Sudasinghe says in the paper. However, it is not endemic and found in India as well.
Tiger loach (Paracanthocobitis urophthalma) is another endemic fish in this group found in streams and rivers in the lowland wet zone. The bands in the body of Tiger loach is similar to that of a tiger, the researcher says in the paper.
The endemic fish known as Sri Lanka Jonklaas’s loach (Lepidocephalichthys jonklaasi) is found only in well-shaded small streams in lowland rain forests and is known only from few scattered localities making it critically endangered, just few steps from extinction, Mr. Sudasinghe’s research paper says.
Mr. Sudasinghe says the new loach, too, had been found only from one stream in Suriyakanda and not anywhere else. This is a risk to the fish’s survival.
However, there is possibility that the new loach be found in other streams in the area. With the new discovery, the number of Sri Lanka’s freshwater fish increased to 88 and 55 of them are endemic to the country.