Genetic differentiation and inheritance of random amplified polymorphic DNA (RAPD) markers in pectoral spine phenotypic sub-groups of Clarias gariepinus

Information on genetic relationship of phenotypically divergent sub-groups would be useful for better identification, utilization and management of species. Recent study revealed phenotypic divergence in a reservoir population of Clarias gariepinus. Genetic variability of polymerase chain reaction (PCR) products of the phenotypic divergent sub-groups was investigated in this study. Polymorphism and genetic variability were investigated in electrophoresed random amplified polymorphic DNA (RAPD)-PCR products of blood samples of twenty (20) C. gariepinus individuals. The population comprised of five (5) individuals of the non-peses phenotypic sub-group- individuals that did not possess anteriorly serrated pectoral spines denoted by S and fifteen (15) individuals of peses sub-groups that possessed anteriorly serrated pectoral spines denoted as C. Standard protocols were followed in analyzing six screened RAPD primers per individuals DNA fragment. Produced bands of pheno-grams were scored and analyzed to establish polymorphism as well as within and between sub-populations allelic variability using unweighted paired group method of algorithms (UPGMA) and dendrograms cluster analysis. Genotype data of individuals in the groups were tested for canonically significant discriminant grouping using discriminant function analysis (DFA). Results reveal that the primers were polymorphic: 746 bands were obtained from 63 detected loci which gave 80.95% polymorphism. Polymorphic information content (PIC) ranged between 0.18 and 0.49. Percentage polymorphic band were 78.00 and 69.84% for peses and non peses sub-groups, respectively. Dendrogram separated the population to two groups. All peses individuals were in one cluster while all the non-peses individuals were on the second cluster. Within group variations were also observed: DFA revealed that 100% of original phenotypically grouped cases were correctly classified. It was concluded that RAPD primers are suitable genetic markers for establishing variability in C. gariepinus sub-populations; the pectoral spine phenotypic groups are genetic variants and are potential varieties for the species. The results would have wide application in identification, utilization and management of genetic resources of C. gariepinus.Keywords: Random amplified polymorphic DNA (RAPD) marker, morphologic and genetic variability, Clarias gariepinus.African Journal of Biotechnology Vol. 12(37), pp. 5567-557

Access to Land and Food Security: Analysis of ‘Priority Crops’ Production in Ogun State, Nigeria

Using Ogun State located in south-western Nigeria, this chapter draws attention to the increase in output productivity of priority crops in the State from 2003 to 2015 due to the acquisitions of over 47,334 hectares of agricultural land across 28 communities in different Local Government Areas (LGAs). From Ogun State Agriculture Data, eight priority crops are analyzed: cassava, maize, rice, melon, yam, cocoyam, potato and cowpea. Statistics reveal that the cultivation of cassava gives the highest average output of 4,515,620 metric tonnes and yield per hectare of 16.41 relative to other produce which affirms that Ogun State has the most comparative advantage in the cultivation of cassava followed by maize. The chapter further explores other pro-poor programmes directed at ensuring food security in the State

Growth performance of blue mussel (mytilus edulis) in Ofiki River, Oyo State, Nigeria.

An assessment of growth performance of Mytilus edulis in Ofiki River in Oyo state, Nigeria was carried out to collect baseline information about its stock, enhance understanding on its biology and broaden knowledge about its culture in Nigeria. Shell length, tissue growth, biomass, body condition and somatic production of blue mussel (Mytilus edulis) collected from net bags were assessed for 12 months (June 2004 – July 2005) fromsamples collected along the river course at four different sites.Growth and production performances was determined using Von Bertalanffy growth function following length class grouping of the Mytilus edulis collections. Highest mean level of Ash Free Dry weight (AFDW) of 1.80g at a mean density of 0.75 (NM-2) was obtained in length size class38.50mm-41.00mm (longer size group) of Mytilus edulis in Ofiki river. Lowest mean level of Ash Free Dry weight (AFDW) was obtained in shorter length size class 17.50mm-20.00mm (0.12g at 1.67NM-2 density). Overall growth performance (Ø) recorded was 3.27, mean abundant(3.71±0.60NM2), somatic production (2.636±0.084 gm-2year-1) and productivity (0.77). Body condition index of Mytilus edulis in Ofiki River was high with peak at dry season. It was concluded from this study that there exists good culture potential for blue mussel (Mytilus edulis) in ofiki river, Oyo State as spats of various growth stages were obtainable and growth rate of Mytilus edulis obtained was high

Cytogenetic study and serum protein characterization of Clarias gariepinus (BURCHELL, 1822) and Heterobranchus bidorsalis (Geoffroy Saint-Hillaire, 1809) in South western Nigeria

Specimens of Clarias gariepinus and Heterobranchus bidorsalis were cytologically analysed while their serum protein was employed to characterize the two species. The diploid chromosome numbers for C. gariepinus and H. bidorsalis were 2n=56 and 2n=52 respectively. The nombre fondamental (NF) of C. gariepinus, and H. bidorsalis, were 51 and 49 respectively. The electrophoretic banding pattern of the two species produced five common bands while the relative mobility of the bands studied showed that there are few slow moving bands, more fast moving bands but no intermediate bands. The occurrence of chromosome number around the modal value which occurs generally among the clariid fish may suggest an ongoing speciation while the presence of five common bands may also be used as a diagnostic marker for biochemical differentiation of the two fish species.Keywords: Clarias gariepinus, Heterobranchus bidorsalis, diploid chromosome number, cytogenetics, genetic variation, electrophoresis

Effect of crowding stress on growth performance and carcass quality of Juvenile African catfish (clarias gariepinus) fed varying crude protein levels.

The evaluation of the effect of crowding stress on growth performance of juvenile Clarias gariepinus fed varying crude protein levels might be useful in determining the optimal stocking density in relation to optimal dietary crude protein level and consequently better growth performance. The effect of crowding stress on growth performance and carcass quality in C.gariepinus was investigated. A twelve week feeding trial was conducted to ascertain the effect of two dietary crude protein levels (40 and 45 CP%) and stocking densities (10,15and 20 fish/m3) on growth performance, feed and nutrient utilization, and carcass quality of C. gariepinus juvenile. Fish were reared in plastic tanks (50x30x27 cm) containing dechlorinated water supplemented with aeration. The results showed that growth performance of the test fish reduced significantly (

Cold Shocking at 5oC AND 7oC in Triploid Production: Effects on Embryonic Development, Hatchability and Fry Performance in Clarias Gariepinus

Production of genetically improved fast growing triploid Clarias gariepinus was carried out through cold shock application of fertilized eggs at 5oc and 7oc.The effects of the shock application on embryo survival, hatching time, hatchability and fry performance (fry survival and weight at critical growth stages) of Clarias gariepinus were investigated for commercial production purpose. Results revealed that the treatment reduced foetal survival from the 12th to 24th hour of incubation (p<0.05) and fragmentation of ovarian follicle under 5oc cold-shocked treatment. Hatching time was also reduced (p>0.05).Hatchability was significantly reduced (p<0.05) with 5oc cold shocked (T1) having the least value. Fry performance-Mean survival at completion of yolk sac and swim up stages and weight gain at 21 and 28days after hatching were significantly improved by the treatment (p<0.05).Cold shocked treatments performed better than the un-shocked while the 5oc cold shock gave the best performance. Weight after 28days of rearing were 0.179±0.02g, 0.087±0.12g and0.049±0.02g for T1 (5oC), T2 (7oC) and T3 (control) respectively. It was concluded that triploid produced by cold shock application especially of 5oc cold shock would enhance fry performance. However, intending commercial triploid breeders would need to compensate for high foetal mortality, delayed embryological processes and low hatchability