{"id":3230,"date":"2023-10-29T20:19:27","date_gmt":"2023-10-29T20:19:27","guid":{"rendered":"https:\/\/ssni.co.in\/Sustainability\/?page_id=3230"},"modified":"2023-10-29T20:22:09","modified_gmt":"2023-10-29T20:22:09","slug":"villorita-cyprinoides","status":"publish","type":"page","link":"https:\/\/ssni.co.in\/Sustainability\/villorita-cyprinoides\/","title":{"rendered":"VILLORITA CYPRINOIDES"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"3230\" class=\"elementor elementor-3230\" data-elementor-post-type=\"page\">\n\t\t\t\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-17349857 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"17349857\" data-element_type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t\t<div class=\"elementor-background-overlay\"><\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-6e3f71b5\" data-id=\"6e3f71b5\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-14604831 elementor-widget elementor-widget-heading\" data-id=\"14604831\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.16.0 - 20-09-2023 *\/\n.elementor-heading-title{padding:0;margin:0;line-height:1}.elementor-widget-heading .elementor-heading-title[class*=elementor-size-]>a{color:inherit;font-size:inherit;line-height:inherit}.elementor-widget-heading .elementor-heading-title.elementor-size-small{font-size:15px}.elementor-widget-heading .elementor-heading-title.elementor-size-medium{font-size:19px}.elementor-widget-heading .elementor-heading-title.elementor-size-large{font-size:29px}.elementor-widget-heading .elementor-heading-title.elementor-size-xl{font-size:39px}.elementor-widget-heading .elementor-heading-title.elementor-size-xxl{font-size:59px}<\/style><h1 class=\"elementor-heading-title elementor-size-default\">VILLORITA CYPRINOIDES<\/h1>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-230dfd5b elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"230dfd5b\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-44883a5\" data-id=\"44883a5\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-4bc15719 elementor-widget elementor-widget-text-editor\" data-id=\"4bc15719\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.16.0 - 20-09-2023 *\/\n.elementor-widget-text-editor.elementor-drop-cap-view-stacked .elementor-drop-cap{background-color:#69727d;color:#fff}.elementor-widget-text-editor.elementor-drop-cap-view-framed .elementor-drop-cap{color:#69727d;border:3px solid;background-color:transparent}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap{margin-top:8px}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap-letter{width:1em;height:1em}.elementor-widget-text-editor .elementor-drop-cap{float:left;text-align:center;line-height:1;font-size:50px}.elementor-widget-text-editor .elementor-drop-cap-letter{display:inline-block}<\/style>\t\t\t\t<p><strong>Name of Fishery\u00a0<\/strong>Clam Fishery (Black Clam)-(Gear \u2013Hand pick &amp; Dredge)<\/p><p><strong>Target Species\u00a0<\/strong><i>Villorita cyprinoides<\/i>\u00a0<\/p><p><strong>Location<\/strong>\u00a0India-South west coast (Vembanad Lake)<\/p><p><strong>Fishing Area\u00a0<\/strong>FAO 51\u00a0<\/p><p><b>Fishery History<\/b>\u00a0Study reveals that fishery has been in operation for the past 61 years.\u00a0Many fishermen have harvested black clams all their working lives and\u00a0most have harvested for at least 25 years (Suja and Mohamed, 2010).\u00a0During 1991-2000 period the annual black clam production varied from\u00a028,806 t in 1998 to 38,456t in 2000 (Average 33,633t) (Laxmilatha and\u00a0Appukuttan, 2002).\u00a0 During 2008-09, the black clam,\u00a0<i>Villorita cyprinoides\u00a0<\/i>(Family, Corbiculidae) contributes 45,000 t, or about two-thirds of total\u00a0(66,000 t) production in India.\u00a0 (CMFRI Annual Report, 2009).\u00a0Production of black clams fluctuated from 30,178 t to 40,299 t during\u00a02012-2016. (CMFRI, 2017-unpublished)<\/p><p><b>Stock Biology<\/b>\u00a0Biological Informations such as habitat, size at maturity, Age and\u00a0growth, Reproduction, spawning, condition index population density,\u00a0etc. are available.\u00a0 The black clams are located just below the surface of\u00a0the soft bottom sediments. The black shows preference to sediments\u00a0containing 70% sand, 0-6% silt and 0-12 % clay (Kizhakudan and\u00a0Narasimham, 1995). The black clam attains sexual maturity at a length\u00a0of 11 to 15 mm. It spawns twice a year, from May to August, and from\u00a0January to late March (Nair, 1975). Peak spawning period is during May\u00a0\u2013 June (Kizhakudan and Narasimham, 1995). Males are dominant\u00a0throughout the year with a sex ratio of 1: 0.25 (M: F) (Laxmilatha and\u00a0Appukuttan, 2002).\u00a0 A change in salinity is the most important factor\u00a0that triggers spawning. The optimum salinity for spawning is about 10-\u00a012 ppt.\u00a0<\/p><p><b>Data on Target\u00a0<\/b><\/p><p><b>Species population\u00a0<\/b>Landing data of\u00a0past 15 years are available. Data are collected from\u00a0clam societies by CMFRI. The clam fishermen are organized into\u00a0professional societies. The black clam attains a length of 30 mm by the\u00a0end of its first year, and during its second year it grows an additional 11\u00a0mm (Nair, 1975).\u00a0 The estimated von Bertalanffy growth equation\u00a0parameters are: L\u221e = 58mm, K =0.56 (annual basis) and t0\u00a0= 0\u00a0(Kizhakudan and Narasimham, 1995). Rasalam and Sebastian, (1976)\u00a0studied the population density of Veluthully Kayal (4,620 clams\/m2) and\u00a0Vayalar\u00a0(2,860 clams\/m2) of Vembanad Lake.<\/p><p><b>Fishing Activities\u00a0<\/b>Fishing is done by three methods (Narasimham, 2005).\u00a01) Handpicking\u00a0by women and children in shallow waters below 0.5 m depth at low tide\u00a0(Catch\/day = 6-16 kg).\u00a02) In slightly deeper waters of &lt; 1.15 m depth,\u00a0women feel and detect the presence of clams by their feet, remove the\u00a0clay over the buried clams by their feet, accumulate the clams at a\u00a0particular spat and collect them in bamboo basket or aluminium\u00a0containers. About 18-32 kg of clams are collected by women per day. 3)\u00a0\u00a0Fishing is carried mostly by men from a canoe with hand operated\u00a0dredge.\u00a0<b>\u00a0<\/b>\u00a0Harvesting of the black clams continues throughout the year\u00a0(Kripa et al., 2004). Each fisherman harvests black clams about 20 days a\u00a0month. Sundays are an off-day, fishermen cannot harvest in stormy\u00a0days during the June to July monsoon months, and some days are taken\u00a0to rest. The principal harvesting method is by diving under water and\u00a0collecting the clams by hand. Most fishermen own their canoes, while\u00a0others rent them at a rate of about Rs.20. Their harvesting gear also\u00a0consists of a bamboo pole, about 15 ft long, and one of two types of\u00a0cylindrical baskets (\u201ckoodu\u201d). The harvesting sites with abundant clams\u00a0vary somewhat among years according to spat settlement (Laxmilatha\u00a0and Appukuttan, 2002; Ravindran et al., 2006). Fishermen harvest in a\u00a0different site almost every day, and it often takes them about 1.5 hr to\u00a0paddle each way.<\/p><p>In some harvesting location, the fishermen-divers do not use their\u00a0fingers to gather the clams. Instead, they use an iron frame with a net.<\/p><p>Another harvesting method is using a hand rake with a pole\u00a0attached (\u201ckolli\u201d or \u201cvarandi\u201d) while standing in the canoe. Each\u00a0fisherman and his family produce about 14 kg of meat and 130\u2013\u00a0140 kg of shells on his best harvesting days\u00a0<\/p><p>Large scale dredging for the white clam shells is practiced in Vaikom and\u00a0Allappuzha. The subsoil deposit of white clams in the lake is estimated\u00a0at about 4.5 million tons. The shells are taken at a rate of 41,000 to\u00a069,000t\/yr. Dredges are used where waters are about 3 m (8\u20139 ft) deep.\u00a0The white clam shells are also harvested by individual fishermen, who\u00a0use hand rakes from their canoes. Each fisherman collects 250\u2013300 kg\u00a0of white clam shells\/day (Ravindran et al., 2006).<\/p><p><b>Volume caught<\/b><\/p><p><b>Ecosystem Impacts\u00a0<\/b>Kerala has a tropical climate with two rainy seasons, the heavy\u00a0southwest monsoon from June to September and the lighter northeast\u00a0monsoon from October to November. The lake has both brackish and\u00a0nearly freshwater environments. They are separated from each other by\u00a0a man-made bund or barrier, the Thanneermukkom, which runs across\u00a0the middle of the lake. The government keeps it open to allow brackish\u00a0water to flow to the southern part of the lake for six months, but then\u00a0closes it for six months, December to May, each year. Black clams\u00a0cannot reproduce well in low salinity and large areas in this southern\u00a0region, otherwise suitable for the clams, cannot support them now. The\u00a0average size of the black clams has diminished also. In the northern\u00a0region, salinities from 8 to 18 ppt are usual in March to May but the\u00a0water salinity can be as low as 0 ppt during the monsoon. Especially in\u00a0the southern section of the lake, live black clams in some habitats have\u00a0been buried by the sediments. Over the centuries, this annual process\u00a0has led to the accumulation of large deposits of black clam shells.<\/p><p><b>Threats to\u00a0<\/b><b>Sustainability\u00a0<\/b>Catch of under sized clam or juvenile catch in some parts of Vembanad Lake is the major threat to sustainability in long run.<\/p><p><b>Fishers<\/b>\u00a0About 6,500 people are involved in the black clam fishery, 3,658 of\u00a0these are fishermen and the remainders are their wives, children, and\u00a0grandparents (Kripa et al, 2004; Sathiadhas et al., 2004). This fishery is\u00a0their main source of income; some have other part-time jobs.\u00a0Fishermen families are permanent residents of their villages.<\/p><p><b>Management Agencies\u00a0<\/b>The clam fishermen are organized into professional societies. There are\u00a0eight black clam societies distributed around the lake in the Kottayam\u00a0and Alappuzha districts. Fishing rights and licenses for harvesting in the\u00a0lake are issued by the State Department of Mining and Geology. They in\u00a0turn issue licenses for harvesting to their members. The total harvesting\u00a0area leased out to the societies comprises about 4,582 acres (7.2 sq mi)\u00a0(Laxmilatha and Appukuttan, 2002).<\/p><p>The taking of the fossil shell deposits is controlled by the\u00a0government. Dredges are used where waters are about 3 m (8\u20139 ft)\u00a0deep.<\/p><p><b>Processing and marketing\u00a0<\/b>Processing of the clams is usually done in the fishermen\u2019s yards at home\u00a0on the same afternoon. The clams are boiled in Aluminum tub for about\u00a045 minutes with a fire fueled by wood and dry coconut leaves. While\u00a0being cooked, the clam meats become loose from their shells. The\u00a0cooked clams are separated through sieve.\u00a0 The mesh size of the sieve is\u00a0chosen to hold the shells but it allows the meats to fall through to the\u00a0ground. The ratio of meat to shell weight is 1 to 10; the wet meat\u00a0percentage varies from 9 to 14% (Laxmilatha and Appukuttan, 2002).\u00a0Each fisherman and his family produce about 14 kg of meat and\u00a0130\u2013140 kg of shells on his best harvesting days. Fishermen\u2019s wives\u00a0usually sell the meat. Most is sold in the local village door-to-door. The\u00a0black clam shells are in high demand because the occurrence of lime-\u00a0stone is scarce. The shell is used by industries that make cement,\u00a0calcium carbide, and lime (for use on rice farms). The gross and net\u00a0returns from marketing of black clam at Alapuzha were Rs. 82,720\/- and\u00a0Rs. 58,220\/- respectively per family per year (Nikita et al., 2014).<\/p><p><b>Management\u00a0<\/b><b>Regime<\/b>\u00a0CMFRI provide the state level policy details which includes\u00a0 management plan for fisheries as a whole.\u00a0 Recently CMFRI included black clam in Minimum Legal Size (MLS) list and is adopted in KMFR Act.<\/p><p><b>Management\u00a0<\/b><b>Compliance<\/b>\u00a0Yes fishers comply with management regime<\/p><p><b>Community\u00a0<\/b><b>Participation in\u00a0<\/b><b>Management<\/b>\u00a0Yes<b>,\u00a0<\/b>Community is involved in the management of the fishery. No strict enforcement<\/p><p><b>Interest in Certification<\/b>\u00a0Fishery interest in certification will be decided based on stake holder\u00a0meeting shortly<\/p><p><b>Stake holders<\/b>\u00a0Key stakeholders\u00a0are fishers, buyers and processors\/exporters<\/p><p><b>Issues Requiring\u00a0<\/b><b>Special Attention<\/b><\/p><p><b>Additional\u00a0<\/b><b>Comments<\/b><\/p><p><b>Sources<\/b><\/p><p>CMFRI, 2009. Annual Report 2008-09. Central Marine Fisheries Research Institute, Cochin.<\/p><p>CMFRI, 2017 (unpublished). Annual Report 2016-17. Central Marine Fisheries Research Institute,\u00a0Cochin.<\/p><p>Kizhakudan, J.K. and Narasimham, K.A. 1995. Observations on the population characteristics of the\u00a0corbiculid clam\u00a0<i>Villorita cyprinoides<\/i>\u00a0(Gray) in the Citrapuzha portion of the Vembanad Lake.\u00a0CMFRI Spl. Publ., 61:83-87.<\/p><p>Kripa, V., T. S. Velayudhan, J. Shoji, P. S. Alloycious, P. Radhakrishnan, and J. Sharma. 2004. Clam\u00a0fisheries in Vembanad Lake, Kerala, with observations on the socioeconomic conditions of the\u00a0clam fishers. Mar. Fish. Info. Serv. T and E Series No. 178:14 -16.<\/p><p>Laxmilatha, P\u00a0and\u00a0Appukuttan, K K.\u00a02002.\u00a0<a href=\"http:\/\/eprints.cmfri.org.in\/72\/\" target=\"_blank\" rel=\"noopener noreferrer\"><i>A review of the black clam (Villorita cyprinoides) fishery of the\u00a0<\/i><i>Vembanad Lake.<\/i><\/a>\u00a0Indian Journal of Fisheries, 49 (1):85-92.<\/p><p>Nair, G. S. 1975. Studies on the rate of growth of\u00a0<i>Villorita cyprinoides var. cochinensis<\/i>\u00a0(Hanley) from the\u00a0Cochin backwaters. Bull. Dep. Mar. Sci. Univ. Cochin 7(4):919\u2013929.<\/p><p>Narasimham, K.A. (2005). Molluscan fisheries of India. BR Publications, New Delhi, 348p<\/p><p>Rasalam, E. J., and Sebastian M. J. 1976. The lime-shell fisheries of the Vembanad Lake, Kerala. J. Mar.\u00a0Biol. Assn. India 18(2):323-355.<\/p><p>Ravindran, K., Appukuttan, K. K., Sivasankara Pillai, V. N., and Boopendranath, M. R. 2006. Report on the\u00a0committee of experts on ecological and environmental impact of dredging at Vaduthala Kayal\u00a0and Vaikam Kayal. Unpubl. rep. submitted to the Government of Kerala, Thiruvananthapuram.\u00a0Sept., 2006, 45 p.<\/p><p>Sathiadhas, R., F. Hassan, and Y. J. Raj. 2004. Empowerment of women involved in clam fisheries of\u00a0Kerala\u2014a case study. Indian J. Soc. Res. 46(1):39-48.<\/p><p>Suja, N\u00a0and\u00a0Mohamed, K. S.\u00a02010.\u00a0<a href=\"http:\/\/eprints.cmfri.org.in\/7844\/\">The black clam<i>, Villorita cyprinoides,\u00a0<\/i>fishery in the State of Kerala,\u00a0India<i>.<\/i><\/a>\u00a0Marine Fisheries Review, 72 (3): 48-61.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>VILLORITA CYPRINOIDES Name of Fishery\u00a0Clam Fishery (Black Clam)-(Gear \u2013Hand pick &amp; Dredge) Target Species\u00a0Villorita cyprinoides\u00a0 Location\u00a0India-South west coast (Vembanad Lake) Fishing Area\u00a0FAO 51\u00a0 Fishery History\u00a0Study reveals that fishery has been in operation for the past 61 years.\u00a0Many fishermen have harvested black clams all their working lives and\u00a0most have harvested for at least 25 years (Suja &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"https:\/\/ssni.co.in\/Sustainability\/villorita-cyprinoides\/\"> <span class=\"screen-reader-text\">VILLORITA CYPRINOIDES<\/span> Read More \u00bb<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"no-sidebar","site-content-layout":"page-builder","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"disabled","ast-breadcrumbs-content":"","ast-featured-img":"disabled","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","footnotes":""},"class_list":["post-3230","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/ssni.co.in\/Sustainability\/wp-json\/wp\/v2\/pages\/3230","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ssni.co.in\/Sustainability\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/ssni.co.in\/Sustainability\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/ssni.co.in\/Sustainability\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ssni.co.in\/Sustainability\/wp-json\/wp\/v2\/comments?post=3230"}],"version-history":[{"count":7,"href":"https:\/\/ssni.co.in\/Sustainability\/wp-json\/wp\/v2\/pages\/3230\/revisions"}],"predecessor-version":[{"id":3238,"href":"https:\/\/ssni.co.in\/Sustainability\/wp-json\/wp\/v2\/pages\/3230\/revisions\/3238"}],"wp:attachment":[{"href":"https:\/\/ssni.co.in\/Sustainability\/wp-json\/wp\/v2\/media?parent=3230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}