Project Abstract

Abstract
Clariid fish species are economically important in Nigeria, particularly in Kano State where they are a common source of protein for the local population. However, there is limited information on the genetic and morphological characteristics of these species in the region. This study aimed to characterize two strains of Clariid fish species found in Kano State using microsatellite markers. Morphological analysis was conducted on a total of 100 individuals from two strains of Clariid fish species collected from different locations in Kano State. Various morphometric measurements were taken, including body length, head length, and fin measurements. Results revealed differences in morphological characteristics between the two strains, indicating potential genetic divergence. Genetic analysis was carried out using microsatellite markers to investigate the genetic variability and relationships between the two strains of Clariid fish species. A total of 10 microsatellite markers were used to genotype the individuals, and genetic diversity parameters such as allele frequency, observed and expected heterozygosity, and genetic differentiation were calculated. The results showed significant genetic variability within and between the two strains, suggesting a degree of genetic differentiation. Overall, the combination of morphological and genetic analyses provided valuable insights into the characteristics of the two strains of Clariid fish species in Kano State. The findings have implications for the management and conservation of these species, as understanding the genetic diversity and relationships can aid in developing effective conservation strategies. Additionally, the results contribute to the existing knowledge of Clariid fish species in Nigeria and provide a foundation for further research on the population structure and evolutionary history of these economically important fish species.

Project Overview

1.1 Animal Variation

Variability is the fundamental and basic characteristics of life. Every level of organization of life displays variation in some parameters, in space or time, within and between cells, tissues, organisms, populations and communities. The existence of variations in natural populations of organisms is a necessary condition for evolution. While variability is both a product and foundation of the evolutionary process, biologists are still confronted with the basic problems of explaining the nature, extent and causes of this web of complexity (Reynaldo and Cesar, 2014). Genetic variation is one key factor in the survival of species. Natural populations are perhaps the best gene banks which are critical resources for genetic variation for current and future application in improvement of farmed species of fish (Dunham, 2004). Morphological differentiation is one of the several approaches which have proved useful in studying variability. Morphological data alone, however, is insufficient to explain variability. Molecular biology, biochemical analysis and other methods coupled with morphology are powerful means in understanding variability and evolutionary relationships among and within populations of organisms (Reynaldo and Cesar, 2014).

Among populations, genetic diversity can also be gained when populations that are not normally in contact with another hybridize that is when isolated population experienced migration, gene flow and genetic drift. This can occur when physical barriers are removed such as when fishes are introduced to an area or escape, or when migration patterns changes due to environmental condition. Populations of many species of organisms may respond differently, both morphologically and genetically, to a changed environment. Individuals tend to express different phenotypes (morphological, physiological or behavioural) when surviving in varied environments (Freeman and Herron, 1998). To this end, genetic studies of fish populations play an important role in the sustenance of genetic diversity (Seeb et al., 2007). Genetic markers can provide valuable information about geographic structuring, gene flow and demographic history of populations that can be highly relevant for conservation and management purposes (Maes and Volckaert, 2007).

Water quality tolerance of catfish is diverse due to environmental changes. The warmer the water, the less the dissolved oxygen likewise, the greater the altitude, the less the dissolves oxygen, causing severe cases and death aquatic organisms including catfish. According to F.A.O., (2003), water quality requirement for catfish are as follows; temperature – 26 to 32oC, dissolved oxygen – 3 to 10 mg/l or > 3ppm, pH – 6 to 8, Alkalinity – 50 to 250 mg/l, Ammonia – 0 to 0.03% and Nitrite – 0 to 0.6mg/l. It also reported that for advanced fry, the requirement are as follows; dissolved oxygen – 3-5ppm, temperature – 30oC, ammonia – 0.1 to 1.0ppm, nitrite – 0.5ppm, nitrate – 100ppm, pH – 6 to 9, carbon dioxide – 6 to 15ppm and salinity – 10 to 16ppt.