30438 Abobi et al./ Elixir Appl. Zoology 79 (2015) 30438-30443 Available online at www.elixirpublishers.com (Elixir International Journal) Applied Zoology Elixir Appl. Zoology 79 (2015) 30438-30443 Analysis of the Fecundity and Gonadal stages of African carp, Labeo senegalensis (Valenciennes, 1842) from the White Volta, Ghana Abobi S.M*, Alhassan E.H and Asare I.O Department of Fisheries and Aquatic Resources Management, University for Development Studies. P.O. Box TL 1882 Tamale, Ghana. ARTICLE INFO ABSTRACT Article history: One hundred and fifty specimen of Labeo senegalensis caught by gill nets from the Received: 14 December 2014; White Volta at Yapei, Ghana were examined for the stages of gonad maturity, eggs, Received in revised form: length-weight relationship (LWR) and condition factor during the dry season of 2013. 20 January 2015; Out of the 150 specimen, 89 were females and 61 were males. The sex ratio of males to Accepted: 12 February 2015; females was thus 1: 1.5. Eleven out of the 89 females were found to contain gonads. The stages of gonad maturity ranged from immature stage to maturity stage. The total eggs Keywords found in the eleven female was 2,385 with a mean value of 217 eggs per gravid female White Volta, Condition factor, of the species. The Gonado- Somatic Index ranged from 1.29 to 3.28 with a mean of 2.0 Length weight relationship ± 0.57. The total length of Labeo senegalensis ranged from 9.5 cm- 24.6 cm with a Gonad, mean of 16.0 cm ± 2.86 cm. The body weight of Labeo senegalensis ranged from 20 Gonado-somatic index grams - 212 grams with a mean of 121.34 grams ± 93.89 grams. The LWR of species 2 Labeo senegalensis was highly significant (P<0.001) with r of 0.907. The LWR of the was W = 0.180 x TL 2.66 with a slope b of 2.6 which indicated a negative allometric growth pattern ( b<3) of the species. The Condition factor ranged from 0.93 to 2.90 and with a mean of 1.926 ± 0.61. The general wellbeing of the Labeo senegalensis was suitable during the study period. © 2015 Elixir All rights reserved. Introduction Penny (1988), fish is quicker to cook and is more easily digested In Ghana, fisheries constitute an important sector in the than meat of other animals. People in Yapei depend on the national economic development and are estimated to contribute fisheries for their livelihood. The demand for fish and fishery 4.5 percent of the total Gross Domestic Product (GDP) and 5 product has put tremendous pressure on our oceans and fresh percent of the Gross Domestic Product (GDP) in agriculture in water bodies which are in many instances already strained to the the year 2009. The fisheries (both marine and freshwater) sector limit. According to FAO (1991), fish production had risen employs an estimate of (2) two million people. The sector almost five folds over the past 40 years from 20 million tones produces a total of 420,000tons of the 880,000 tons needed toover 100 million tonsin 2010. annually. Deficit of 460,000 tons is made up through fish import There has been no appreciable increase in annual fish 2008-2009 (Kwadjosse , 2009).According to FAO statistics, production over the years. In 2003, Ghana produced only 51.7 inland capture fisheries contributed 27 percent of total Ghanaian percent of its requirements from its domestic sources and in fish production in 2009 (FAO, FishStat Plus). It is estimated that 2004, achieved 68.1 percent of its fish requirement through the Volta River provides 90 percent of national freshwater fish domestic production and imports. Tilapia is the major species production (Abban, 1999). farmed and constitutes over 80 percent of aquaculture The landings of freshwater fish in Ghana were officially production. The catfishes; ( Clarias sp ., Heterobranchus sp . and estimated to be 75,000 tons in 2006 and formed 20 percent of Heterotis niloticus ) account for the remaining 20 per cent the total fish landings from the country. The estimated landings (FAO., 2005). for Lake Volta are probably greatly underestimated. The In Ghana, there are four (4) major inland water bodies estimated catch is between 150, 000 and 200, 000 tones/year namely, the Volta river (including Black, White, Red Densu, Oti (De Graaf and Ofori-Danson, 1997). Other unpublished catch and Pra river), Keta lagoon (330km 2), lake Bosomtwi (49km 2) estimates based on reservoir-wide catch-assessment surveys and and the Volta lake (844 km 2) plus more than fifty (50) brackish frame surveys proposed that the reservoir produced 217,000– water bodies dotting the coastline, most of which are RAMSAR 251,000 tones in 2000 (Braimah, 2000, 2001, 2003). Abobi et designated sites (Ewer, 1966).The Volta River Basin occupies al. (2014) reported Labeo senegalensis as one of the top 10 most 417,382 km 2 in six countries .The basin drains 70 percent of abundant species out of 52 freshwater species the authors Ghana. Basin elevation range from sea level to 920 m above sea encountered at the Yapei stretch of the White Volta. level, with a mean elevation of 257m and correspondingly low Freshwater fish is an essential irreplaceable source of highly channel grades. The lower Volta River is fed by three major quality cheap animal protein crucial to balanced diet in marginal tributaries. To the west, the Black Volta River or Nakambe foods. Fish contain important nutrients such as essential fatty River drains 147 000 km 2, mostly of western Burkina Faso with acids, calcium, iron and vitamins (Paul and Southgate, 1978). small areas of Mali and Cote d’Ivoire (Evans and Vanderpuye, Cyprinidae are highly important food fish and they make the 1973).The White Volta River or Nazinon River drains 10, 000 largest part of biomass in most water bodies except for fast km 2 including much of northern and central Ghana and Burkina flowing rivers (Turan et al ., 2013). According to Mayhew and Tele: E-mail addresses: [email protected] © 2015 Elixir All rights reserved 30439 Abobi et al./ Elixir Appl. Zoology 79 (2015) 30438-30443 Faso. To the east, the Oti River drains 72 000 km 2 of The study of fecundity and gonads contribute in no mean by northwestern Benin and Togo. The three tributaries join in providing a base line data for the development, planning and northern Ghana to form Lake Volta. The basin is primarily direct fish exploitation which will increase domestic food supply underlain by a Voltarian formation consisting of sandstone, and consequently improve the livelihood of the fisher folks in shale’s and mudstones. Another formation is Precambrian Yapei and its neighboring communities. classified into Birimain, Buem and Tarkwaian rocks (Dickson Materials and Methods and Benneh, 1977). Currently, one hundred and twenty one Study area (121) species have been identified in the Volta reservoir The study was conducted at Yapeiportion of the White (Dankwa et al ., 1999). It is also known that 32 fish species are Volta River in the Central Gonja District of the Northern region present that were not recorded during the early stages of of Ghana. Yapei is about 43 km south-west of the regional reservoir filling (Denyoh, 1969). capital, Tamale.Yapei lies within latitude 9 0 110’’N and1 010 1 Cyprinidae are large family of freshwater fishes that 0”W (Figure 1). The White Volta river drains an area of about comprise of the carp, the true minnows and their relatives 92,000km 2 (Ewer, 1966). It passes through Yapei in a north- commonly called the carp family or minnows (Holden and southward direction. The river is a perennial water body with an Reed, 1972). Its members are known as cyprinids. It is the average width of about 150 m and headstream of the great Volta largest fish family and the largest family of vertebrate animal in River in West Africa, which has maximum depth of 75 m, an general. The family belongs to the order cypriniformes. The average depth of 18.8 m and elevation of 85 m above sea level. family is derived from the ancient Greek kyprinos (carp). Labeo The climate of the Central Gonja district lies within the tropical senegalensis locally called Gbingbinifufu in the west Gonja continental zone. The annual rainfall is unevenly distributed and District are extremely fecund by nature (Holden and Reed, limited to six months from May to October. The mean annual 1972) and display a worldwide distribution in fresh waters with rainfall ranges between 1000-1500 mm with its peak in a maximum length 65.0cm and a maximum weight of close to September. The relative humidity is between 70-90 percent 4Kg and maximum age of six (6) years (Lagler, 1971). Labeo during the long dry season. Temperatures are generally high and senegalensis is a stomach less fish with a toothless jaw. It has a exhibit seasonal variation. The mean annual temperature of 35% snout with tubercles slightly apparent, center of scales pinkish with maximum temperature of about 40% is usually recorded in and surrounding zones lined with melanophores which form March to April. undulating longitudinal lines. Labeo senegalensis tolerate best in a temperature range of 22 -26 0C (Encyclopedia Britannica, 2006).Its distribution is known from Chad, Niger, Gambia and Volta as well as some coastal basins (Dankwa et al ., 1999). According to Agyen-Tweneboah (2007) cyprinid dominated by Labeo senegalensis was abundant in the Yapei stretch with a relative abundance of 16.3%.The fecundity of Labeo senegalensis is particularly significant because of their vulnerability to overfishing.