This Will Supprise U.
Fish is one of the cheapest and important sources of protein, it contains lipid, mineral and vitamins. In Africa, especially in Nigeria, the species mostly cultured are Clarias gariepinus, Heterobanchus species and their hybrid. The reason for their culture is base on their fast growth rate.
Clarias gariepinus is a catfish (family Clariidae). It is a carnivorous fish and feeds mainly on animal food (Nawaz et al., 1994). The genus is commercially important in inland waters of West Africa and in river Benue at Makurdi and other fast growing rivers and in rapids (Anonymous 2004). Clarias geriepinus may be found 420 North and 280 South’s and 170 West to 1360 East (Anonymous, 2004). And it is one of the fish that can be seen in fish market throughout the year.
The cat fish can be defined as displaying an eel shape having elongated cylindrical body with dorsal and anal fin being extremely long nearly reaching the caudal fin both fin containing only soft fin rays. The outer pectoral ray in the form of a spine and the pelvic fin normally has six (6) soft rays. The head is fluttered, highly ossified, the bones above and on the sides forming a casqued and the body is covered with smooth scale less skin. The skin is generally dark pigment on the dorsal and lateral part of the body. The coloured is uniform marbled and changes from greyish olive to blackish according to the substrate. On exposure to light, skin colour generally becomes light. they have four parts of unbranched barbles, one nasal, one maxilla longest and most mobile on the vomer are of two (2)mandibles, that is inner and outer on the jaw tooth plates are present on the jaw as well as the vomer. The major function of the barble is for prey detection. The surpra branchial or accessory respiratory organ composed of a paired pear shaped air chamber containing two arborescent structure is generally present.
It is vitally important to obtained detailed knowledge on the population structure in commercially exploited Clarias geriepinus and to apply such knowledge in the management of fisheries (Tengels, 1986).
Clarias gariepinus is widely tolerant to extreme environmental condition. A remarkable feature of this fish is the presence of an accessory breathing organ that enables this species to breathe air when very active or under dry condition. it Remains in the muddy substrates of pond and occasionally gulp air through the mouth. it can leave the water at night using its strong pectoral fin and spine in search of land based food or can move over short distances on land into breeding areas through very shallow pathway (Seegers, 1991). It possesses a wide variety of food sources which it can thrive upon. A bottom feeder which occasionally feeds at the surface forages at night on a wide variety of prey. It’s a voracious predatory fish known to swallow any kind of animal live or dead that can fit its mouth. They are able to relatively catch larger prey whole, and feeds on insects, plankton, invertebrates, birds, fish rotten flesh and plants. It can also adapt to filter feeding and feeds on zooplankton from the water (Anonymous, 2006). The cat fish can survive during the dry season due to the presence of the accessory air breathing organs (Brutum and Clay 1979). It is also able to craw on dry ground to escape drying pools, and can survive shallow mud for a long period of time between rainy seasons. It migrates to the rivers and temporary stream to spawn, thus catfish is also grown in ponds in local areas. Growth is efficient and fast, they grow to a body weight of rarely a kilogram in half of a year in which they consume 0.9Kg dry fish weight grain. Growth is maximum at maximum feed intake; optimum temperature for growth however should best be 250C. A special aspect however, is the requirement of a rather undisturbed environment
Clarias gariepinus which is widely considered to be the most important catfish species in aqua-culture has almost pan Africa distribution, form the Nile to the West Africa and fro Algeria to Southern. They also occur in minor Asia, in most West Africa basins and in the Nile generally. Clarias gariepinus live in most River basins sympatrically with Clarias angullaris . They inhabit Tropical Rivers and lakes of Southern Africa (Asia meske 1985), African catfish is a widely recommended food in Africa. Marketed fresh and frozen, eaten boiled, fried and baked. This has given rise to development of culturing techniques. During intraspecific aggressive interactions, this species was noted to generate electric organ discharges that were menophasic head positive and lasting from 5-260 minutes (Seeger, 1991).
Length and weight are usually measures of great importance, since weight is used to determine the amount of food given to the fish during culture. The relationship between body length and weight of fishes represents a great importance in fisheries biology and population dynamics where many stock assessment model require the use of length-weight parameters.
Mouth gape and length-weight relationships of fishes are used broadly for different purposes, to know the length value, to convert growth equations in length into equivalent ones in weight, to compare interspecific and intra-populations, morphometry, to determine the position and size of the mouth in relation to the location and size of food items and the relative size of the mouth can b used to determine the size of the food particles ingested and to determine the index of wellbeing of individual fish. Mouth gape and length-weight and other hard structures are used determine the age of the fish.
AIM AND OBJECTIVES
This study is aimed at monitoring the growth pattern of this species using mouth gape and weight-length relationship.
To enlighten fish farmers and intending fish farmers on the importance of the knowledge of parameters such as mouth gape, weight and length in aquaculture.
To determine the condition factor of the fish using mouth gape length-weight relationship (to know the wellbeing of the fish in the water body in River Benue.)
To estimate the mean weight of fish based on known length.
SCOPE AND LIMITATION OF STUDY
This study will be looking at the mouth gape and length-weight relationship of Clarias geriepinus. it will also relate body length to other body parameters such as dorsal fin length, anal fin length, head length, length of maxillary and mandible barbles, numbers of rays in both anal and dorsal fins. This study will be covering fish collection from River Benue.
There were setbacks I intended to encounter in the course of the study, much to mention but a few
Finance: Money to carryout feasibility study and the cost of buying the specimen for data collection and in the transportation during market survey
Reduction: reduction In the sizes and length of morphometric parameters of the fishes which will affect the metric strategies of the fish due to muscular tension among are fish and its relation after death.
Shrinkage of fish due to preservation including freezing
Operation skills and consistency
HYPOTHESIS: there is no significant relationship in the mouth gape and the length weight relationship. There is a significant relationship in the mouth gape and the length-weight relationship in Clarias geriepinus.
Fish as an important and popular source of animal protein has never met the demand in and Nigeria as regards to supply. It contains mineral salt and polyunsaturated fatty acids.
Taxonomic hierarchy of species
BIOLOGICAL FEATURES OF CLARIAS GARIEPINUS
Body elongated, head large, depressed and bony with small eyes, narrow and angular occipital process, gill openings wide air breathing labyrinthic organ arising from gill arches, first gill arch with 24-110 gill rackers, cleithrum pointer, narrow with longitudinal ridges and with sharpness, mouth terminal large, and four pairs of barbels present. Long dorsal and anal fins without dorsal fin spine and adipose fin, anterior edge of pectoral spine serrated. Caudal fin rounded, colour varies from sandy-yellow through gray to olive with dark greenish-brown markings, belly white.
HABITAT AND BIOLOGY
North African catfish (generally referred to as African catfish) have almost pan-African distribution (but are naturally absent from the maghred upper and lower Guinea and Cape provinces). They are equally present in Jordan Lebanon, Israel and turkey. Clarias gariepinus has also been introduced into most other countries in Africa as well as several in Europe, Asia and South America. Similarly to other species, China has adopted it within its rice field and it is currently among the main producing countries even though this species does not appear separately in its production statistics. This species is found in lakes, streams, rivers, swamps and floods plains many of which are subject to seasonal drying. The most common habitats are floodplains, swamps and pools where they can survive during the dry seasons due to their accessory air breathing organs.
Clarias gariepinus undertake lateral migrations from the larger water bodies which they feed and mature at about the age of 12 months to temporarily flood marginal areas in order to breed. These reproductive migrations typically take place shortly after the onset of the rainy season(s). The final gonadal maturation is associated with rising water levels. Under stable environmental conditions, adult C. gariepinus has mature gonads year-round under ideal conditions, a ripe female may lay about 60,000 eggs/kg prior to mating, males compete aggressively for females with which they mate in single pairs the females swishing her tail vigorously to mix the eggs and sperm and distribute the fertilized eggs. The adhesive eggs stick to submerged vegetation and hatch in 20-60 hours depending on temperature. The yolk sac is absorbed within 3-4 days and stomach is fully functional within 5-6 days after onset exogenous feeding. Sexual differentiation begins between 10 and 15 days after hatching larvae ,feed and grow rapidly in the warm (usually >240c) nutrient rich flood plains, reaching 3-7g within 30 days. As flooded marginal areas dry up with the end of the rains, juveniles and adults make their way back to deeper water. In areas with two rainy seasons, there are usually two reproductive peaks during the year, corresponding to intensity to the magnitude of the rains. Stomach contents of Clarias species typically include insects (adult and larvae), worms, gastropods, crustaceans, small fish, aquatic plants and debris, but terrestrial seeds and berries, and even birds and small mammals have also been observed. Larvae are almost exclusively dependent on zooplankton for the first week of exogenous feeding large C. gariepinus, because of their high number of gill rackers, also target zooplankton as a primary source of food. Although generally omnivorous C. geriepinus relatively better digests high protein diets than carbohydrates most species of Clarias are slow foraging predators with very small eyes, using their four pair of barbels to feel their way around in the dark and good detected by the array sensitive taste buds covering the barbells and head.
Approximately 70 percent of feeding activity takes place at night research in South Africa showed that removal of the barbells reduced feeding efficiency in C. gariepinus by 23 percent.
In general, capture their prey by gulping them with a rapid opening of the mouth Clarias catfishes and then retaining them either on gill rackers or fine recurved teeth arranged on dentary pre-maxillary, vomerine and pharyngeal bands. C. gariepinus exhibit a variety of feeding strategies including sucking the surface for terrestrial insects and plants fragments of small cichlids. Growth is relatively rapid, approaching maximum size within a couple of years. First year growth is nearly linear resulting in the large initial jump in size. C. gariepinus has an average adult length of 1-1.5m (3ft 3 in 4ft 11 in) it reaches a maximum of 1.7m (5ft 7in) total length and can weigh up to 60kg/130lb.