Some aspects of the fishery of the threatened Yellow Catfish Horabagrus brachysoma from Vembanad lake with a note on their landings at Vaikom, Kerala, India

Abstract

The landings of the endangered bagrid catfish Horabagrus brachysoma from three selected markets along Vembanad Lake, Kerala was quantified at 6744kg during October 2003 September 2004, with the greatest share (51%) from Koluthumkadavu market of Vaikom. A considerable portion of the exploited stock consisted of individuals in the size ranges of 180-280mm TL in the case of males and 160-300mm TL in the case of females. Seasonal variations in landings have been discussed and an appraisal of the fishing techniques for H. brachysoma in the lake ecosystem has been presented. KEYWORDSFishing techniques, fishery, Horabagrus brachysoma, landings, Vembanad lake, Yellow CatfishThe Yellow Catfish Horabagrus brachysoma (Gunther) is one of the most important inland food fish, highly appreciated for its taste and having very high consumer demand in the central districts of Kerala, southern India, especially in the regions surrounding the Vembanad lake. In addition, fingerlings of this bright yellow coloured catfish has now become the choice among ornamental fish hobbyists and traders both in India and abroad and there exists an increasing demand for them in the international aquarium markets. As early as the last decade, Kurup et al. (1993) had observed that this species, along with other catfishes of the Vembanad lake were facing serious population declines and that they required immediate protection and artificial propagation. Due to the rapid decrease in populations of this species in the wild, the fish has been listed as Endangered in the Conservation Assessment and Management Plan workshop for assessing the status of freshwater fishes of India (Molur & Walker, 1998). The commercial significance of H. brachysoma as a much relished food fish and an ornamental species has made it an excellent candidate for commercial aquaculture (Prasad et al., 2005), and preliminary studies on the growth of this species has been studied by Hakim and Prasad (2006). Excepting two general studies, one by Kurup et al. (1995) and the other by CICFRI (2001), no attempts have been made till date to quantify the landings of H. brachysoma from the regions around the Vembanad lake, even though the species has been listed as threatened. Our study was a preliminary attempt to quantify the landings of H. brachysoma from the regions in and around Vaikom, a major fish landing centre located along the Vembanad lake. Observations were also made with regard to sex and size composition of the specimens as well as seasonal variations in the landings. The fishing techniques for H. brachysoma in the Vembanad lake have also been discussed. METHODOLOGYData on the landings of H. brachysoma from the Vaikom region of Vembanad lake during October 2003-September 2004 were quantified based on the catches registered at three major markets -Koluthumkadavu, Ullala and Kothavara using the data supplied by fish vendors, traders as well as fisherman cooperatives operating in the region. Total landings for each week were compiled by visiting the respondents and gathe...

Fishery, growth, and mortality of threatened Asian Sunfish, Horabagrus brachysoma (Gu¨nther 1864) in five rivers of Western Ghats hotspot, India

“…The current level of exploitation was found in between 62% and 87% of the maximum exploitation (E max ) from the ve river systems. Horabagrus brachysoma is an important food sh exploited from Western Ghats rivers by traditional shers using various shing methods such as gill nets, cast nets, drag nets, stake-nets, and hook-andlines (Bindu 2006;Sreeraj et al 2007;Renjithkumar et al 2011Renjithkumar et al , 2016. The unregulated and unmanaged nature of the shery is seen as a signi cant threat to the species (Raghavan and Ali 2013).…”

“…. The landing of the species from Kerala state rivers ranges from 3.67 t to 17.1 t(Renjithkumar et al 2011(Renjithkumar et al , 2016 whereas annual landings in Vembanad Lake ranged between 2 and 439 t(Bindu 2006;Sreeraj et al 2007;Kurup et al 1995). Overall, the shery for H. brachysoma appears to be unsustainable in many rivers of the Western Ghats due to overexploitation of stock and habitat destruction(Raghavan et al 2016), and the IUCN has classed the species as 'Vulnerable' due to an overall population drop (Raghavan and Ali 2013).…”

Molecular Identification and Ecology of a Newly Discovered Population of Sun Catfish Horabagrus brachysoma from Northern Western Ghats of India

“…[19,20]. In the Kerala state H. brachysoma has been found to be reported from Chalakudy, Periyar, Meenachil, Manimala, Pampa, Moovatupuzha, Achenkavil rivers as well as from Vembanad Lake, Shastham Lake and Kale wetland [16][17][18][19]. At the northern most proximity of Western Ghats H. brachysoma have been recorded from Nethravati, Kali and Aghanashini rivers of Karnataka [20].…”

“…Horabagrus brachysoma commonly called as sun catfish, yellow catfish or Günther's catfish is characterized by anterior depressed large head; obtusely rounded snout; sub terminal transverse mouth; eyes large inferiorly visible from ventral surface of head; dorsal and pectoral fin having serrated spine with 5-7 and 8-9 branched rays, respectively; adipose dorsal fin short and well separated from caudal base; ventral fin with i6 rays; long anal fin with iii23-iii28 rays and a distinct coloration with brownish back dorsal side, pale yellow on sides, white belly, a thick black shoulder spot and semilunar thick black ring at caudal base [12,15]. The species is heavily targeted by artisanal fishermen in inland waters of southern Western Ghats because of which it has now become vulnerable to overexploitation [16][17][18]. Multiple stress factors like overexploitation of wild stock for commercial fishery and international aquarium pet trade, habitat alteration, pollution, and minimum population doubling time have resulted in population decline of H. brachysoma in its native occurrence ranges and as a result of which this species has been listed as Vulnerable in IUCN Redlist [19].…”

Spawning and early development of the endemic and threatened Yellow Catfish Horabagrus brachysoma (Günther, 1864) (Teleostei: Bagridae)

“…The RARS is engaged in a program for mass production of seeds of H. brachysoma with the goal of promoting larval rearing and aquaculture (Bindu 2006;Padmakumar et al 2011) and the seeds produced as part of the Indian Council of Agricultural Research (ICAR) Mega Seed Project were utilized for stocking the Sasthamcotta Lake by the Kerala State Fisheries Department (Padmakumar et al 2011). Previous research on H. brachysoma focused on its biology (Sreeraj et al 2006;Padmakumar et al 2010; Journal of Threatened Taxa | www.threatenedtaxa.org | 26 January 2014 | 6(1): 5368-5374 5369 Bindu et al 2012), fishery (Sreeraj et al 2007), breeding (Padmakumar et al 2011), population genetics (Muneer et al 2009, 2012 and aquaculture (Sahoo et al 2010;Giri et al 2011). However, there is only limited information on the embryonic development of this species under captive conditions (Padmakumar et al 2004).…”