COMPARATIVE GROWTH PERFORMANCE OF MALE MONOSEX AND MIXED SEX NILE TILAPIA (Oreochromis niloticus L.) REARED IN EARTHEN PONDS

Abstract

Comparative growth performance of male monosex and mixed sex Nile tilapia (Oreochromis niloticus) was conducted in six earthen ponds each measuring 150 m 2 at the Kenya Marine & Fisheries Research Institute (KM-FRI), Kegati Aquaculture Research Station. Male monosex and mixed sex of O. niloticus juveniles at an average weight of 12.2 ± 0.02 g and average length of 7.6 ± 0.02 cm were collected from nursery production ponds. The male monosex juveniles were obtained by feeding newly hatched juveniles with feed dosed with 17--methyltestosterone hormone for a period of one month. Stocking was at 3 juvenile m -2 and feeding was carried out using 28% crude protein diet twice daily for six months at 4% body weight. Selected water quality parameters (dissolved oxygen, temperature, pH, electrical conductivity and total ammonia nitrogen) were measured weekly in situ, while sampling for weight and length measurements was conducted on a monthly basis for a period of six months. Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Condition Factor (CF) and survival rate (%) were measured at the end of six months. Data were subjected to one-way analysis of variance (ANOVA). At the end of six months, the average weight of male monosex and mixed sex fishes was 200.8 ± 0.81 g (mean ± SE) and 123.4 ± 0.76 g, respectively, while the average length of male monosex and mixed sex was 22.4 ± 0.21 cm and 18.6 ± 0.23 cm, respectively. The male monosex O. niloticus achieved significantly increased final weight and length, SGR, FCR and CF than the mixed sex O. niloticus (p < 0.05). However, both male monosex and mixed sex fish recorded similar survival rates (p > 0.05). There were no significant differences in mean water quality parameters in male monosex and mixed sex ponds (p > 0.05). The male monosex fish performed better because most energy was spent on muscle and tissue development while the mixed sex fish spent most energy on reproduction activities at the expense of muscle and tissue development. Further studies should be done in other culture systems such as liner ponds, tanks, cages and raceways. How to Cite

THE INTEGRATION OF FISH AND PLANT PRODUCTION: NILE TILAPIA (Oreochromis niloticus) AND BASIL (Ocimum basilicum) CULTURE IN RECIRCULATING AND AQUAPONIC SYSTEMS

“…There were no significant differences (p>0.05) between the experimental groups in terms of wet weight gain (WWG), relative growth rate (RGR), specific growth rate (SGR) or feed conversion rate (FCR) ( Table 1). Growth rates and feed utilization data recorded for Nile tilapia in the present study were comparable to those of previous reports (Fasakin et al, 1999;Cremer et al, 2002;Rakocy et al, 2004;Rakocy et al, 2006;Ogunji et al, 2008;Yıldırım et al, 2009;Chowdhury, 2011;Antache et al, 2013;Madalla et al, 2013;Mensah et al, 2013;Ferdous et al, 2014;Githukia et al, 2015;Kaya and Bilgüven, 2015;Day et al, 2016 With the incorporation of plant production in the fish culture system, water quality was increased that might have led to an improved growth performance of fish in the AS system compared to the RS, however the differences were not significant (p>0.05) (Figure 5-8 The levels of pH in both experimental setups (RS and AS) were between 5.56 and 7.28, with an average rate of 6.3 and 6.5, respectively. The pH levels in the AS tanks were higher then the RS tanks throughout the study period (Figure 9), but pH in both culture systems were within acceptable limits of 6.5-7.5 as described by Bregnballe (2015).…”

Growth and Body Development of Oreochromis niloticus (Linnaeus, 1758) Fattened in Floating Cages Based on Commercial Feed in Benin

“…The SGR obtained in this study (0.77 ± 0.03 %/day) is lower compared to the values of 1.83 ± Journal of Biology and Life Science ISSN 2157-6076 2020 0.15%/day and 1.47 ± 0.18%/day reported respectively for pond raised O. niloticus monosex male and mixed sex (Githukia et al, 2015). The SGR of this study is also lower than the rates of 2.35; 2.25; 2.17 and 2.02%/day reported by Moniruzzaman et al (2015) in floating cage culture for the monosex male of the same species at the stocking densities of 50; 75; 100 and 125 fish/m 3 respectively.…”

“…The ADWG of O. niloticus monosex in this study after 215 days trial at a stocking density of 48 fish/m 3 is of 1.83 ± 0.08 g. It is greater than the value of 1.05 g reported for juvenile male monosex after 6 months of pond culture (3 fish/m 2 ) using 28% crude protein diet twice daily at 4% body weight (Githukia et al, 2015). On the other hand, an ADWG of 0.62 g was presented by a mixed sex juvenile of the same species, reared in ponds (Githukia et al, 2015).…”

“…The ADWG of O. niloticus monosex in this study after 215 days trial at a stocking density of 48 fish/m 3 is of 1.83 ± 0.08 g. It is greater than the value of 1.05 g reported for juvenile male monosex after 6 months of pond culture (3 fish/m 2 ) using 28% crude protein diet twice daily at 4% body weight (Githukia et al, 2015). On the other hand, an ADWG of 0.62 g was presented by a mixed sex juvenile of the same species, reared in ponds (Githukia et al, 2015). The influence of density is also highlighted because Moniruzzaman et al (2015) under cage-culturing system reported ADWG values of 2.01 g; 1.76; 1.59 and 1.31 g for O. niloticus juvenile male reared at densities of 50 ; 75 ; 100 and 125 fish/m 3 respectively.…”

“…It is also observed that an increase in stocking density results in lower body weight of fish. On the other hand, lower final mean body weight values of 200.08 ± 0.8 and 123.4 ± 0.76 g were also reported respectively for juvenile monosex male and mixed sex populations of the same species after 6 months of pond culture (3 fish/m 2 ) using 28% crude protein diet twice daily at 4% body weight (Githukia et al, 2015). An average weight of 217.90 g has also been reported for O. niloticus grown in floating cages (135 fish/m 3 ) on the Niger Journal of Biology and Life Science ISSN 2157-6076 2020 River after 225 days of rearing, based on a diet containing 31% of proteins, 1/3 of which are of animal origin (Lazard and Legendre, 1994).…”