Posts Tagged ‘Freshwater fish’

Environmentalists not in favour of breeding rare fish for export

January 25, 2013

Environment watchers are angered by plans to legalise the breeding of rare fish and the cultivation of rare water plants for export. They say the Ministry of Economic Development, the Department of Wildlife Conservation (DWC) and other government agencies are working together to amend the relevant laws – by Malaka Rodrigo

Malpulutta. Courtesy Galle Wildlife Conservation Society

The export proposal covers eight endemic freshwater fish and 13 endemic water plants. Six of the named fish are “critically endangered” and the other two are “endangered”, according to the 2012 National Red List for Sri Lanka. The Red List is an international classification of the world’s threatened animal and plant species. The water plants include two varieties of “kekatiya” (Aponogeton), seven varieties of “ketala” (Laginandra), and four water plants known as “athi udayan” (Cryptocoryne).

The Wildlife Conservation Society of Galle (WCSG), which has conducted an islandwide survey on freshwater fish, says these fish are too rare to be subjected to a breeding programme. In 2009 and 2012, the society visited areas where, according to previous surveys, the rare fish could be found. A fresh survey noted that most of these rare fish species were not to be found at most of these sites.

Environment lawyer Jagath Gunawardane fears that the export plan could set a risky precedent. Allowing the legal breeding and export of these rare fish could encourage profiteers to hunt for these same fish in the wild.

But the Live Tropical Fish Exporters Association of Sri Lanka says the breeding and export of these rare fish would overall boost lucrative freshwater fish exports from Sri Lanka. At a recent press conference, the association pointed out that Sri Lanka is the loser after restrictions on the breeding of endemic species had led to rare fish being smuggled out of the country and bred elsewhere for profit.

Freshwater fish authority Samantha Gunasekara sees no problem in breeding rare fish, so long as it is done properly and scientifically, and is closely monitored. Mr. Gunasekara, who works for the Customs’ Biodiversity Protection Unit, says that many endemic fish that have completely disappeared from Sri Lanka are being bred in other countries.

The government has appointed a committee to oversee the fish breeding programme. It includes the Department of Wildlife Conservation; the Forest Department; the National Aquatic Research Agency (NARA); the Botanic Gardens Department, and Sri Lanka Customs.Wildlife Conservation Society of Galle president Madura de Silva said fish breeding exercises tended to produce “less colourful” fish than the same species caught in the wild. He feared that exporters would prefer fish caught in the wild.

According to the 2012 National Red List on Conservation Status, one in two species of Sri Lanka’s 91 freshwater fish species risk going extinct in the wild. The most vulnerable freshwater fish are found in streams lying outside the Protected Area Network. These streams are prone to pollution and habitat loss.

Published on SundayTimes on 20.01.2013

‘Bulathhapaya’ and its clan get new scientific Names

August 26, 2012

Research shows exceptional diversity among popular ornamental fish known as ‘puntius’ – Malaka Rodrigo

Pethia nigrofasciata – Bulath Hapaya

Popular freshwater fish that belonged to the genus Puntiushave been re-classified into 5 new genera by Sri Lankan scientists. The results were published last week in a paper in the journal ‘Ichthyological Exploration of Freshwaters’, authored by Rohan Pethiyagoda, now attached to the Australian Museum in Sydney, together with Dr Madhava Meegaskumbura and Dr Kalana Maduwage, both of the University of Peradeniya.

A genus (genera in plural) is a grouping of one or several species that possess common characteristics which also denotes by the first part of binomial scientific names. Based on this new analysis, the South Asian fishes formerly in Puntius have been divided into five genera, namely Puntius, Systomus, Dawkinsia, Pethia and Dravidia. While the first four genera have representatives in Sri Lanka, Dravidia (named for the Dravidian people of South India) is restricted to Kerala, Tamil Nadu and Karnataka.

The filamented-fin barbs have been allocated to a new genus, Dawkinsia, named after the British evolutionary biologist and anti-religion advocate Richard Dawkins, author of the best-seller ‘The selfish gene’. These now include Dawkinsia singhala and Dawkinsia srilankensis. The following four species, meanwhile, have been transferred to the genus Systomus: asoka, martenstyni, pleurotaenia, spilurus (the wet-zone species formerly known as ‘sarana’) and sarana. The bulk of the remaining species have been allocated to a new genus, Pethia, which is also the local Sinhala name for these small fishes. These are Pethia bandula, cumingii, melanomaculata, nigrofasciata and reval. The only Sri Lankan fish that still remain in the genus Puntius are kamalika, vittatus, bimaculatus, thermalis and titteya.

These small freshwater fishes commonly called ‘pethia’ in Sinhala, are also among the most popular inhabitants of tropical aquariums. Many of the 18 species of Sri Lankan Puntius, have for decades been bred by aquarists worldwide and are very popular ornamental fish. These include the ‘bulathhapaya’ (Puntius nigrofasciatus), ‘le titteya’ (Puntius titteya) and Cuming’s Barb (Puntius cumingii). The relationships of such species to Southeast Asian ones such as the Tiger Barb (Puntius tetrazona) have for long been questioned. Could fishes that show such a variety of shapes, sizes and other anatomical characters all belong to a single genus, or have scientists over the years simply been ‘dumping’ new species into Puntius simply for reasons of convenience?

While many have asked the question, few have elected to do a comprehensive study to find answers. The scientists anlysed 31 species of fishes belonging to Puntius from across South Asia using three methods: analysis of DNA, their osteology (a study of their bone structures) and external morphometrics (the proportions of their bodies, the number of scales, etc). The study was by no means easy, they say, and took eight years to complete.

Pethiyagoda explains that there has been a long-felt need to bring the taxonomy of these fishes into line with their evolutionary context. “Attempts to do these using external characters alone over the past several decades have failed. It was time for a multi-pronged approach.” As a result of the species-groups they identified among the Southeast Asian fish formerly in Puntius, it is expected that a cascade of new genera will follow from that region, too.

Being among the most popular ornamental fishes, Sri Lanka Customs’ data show that many of these species are being heavily exported. It is believed that many of them are caught from the wild, which will deplete their wil populations. Loss of quality of riverine habitats suited to them and invasive fish introduced to waterways too, make an impact on their decline. One of the endemic fish that got a new name, Pethia bandula, is confined only to single stream and if this gets contaminated, the entire species could go extinct. So the scientists call for more attention to be paid to the conservation of these fishes.

Published in July.2012