2.5 Growth performance of catfish The development of a fish can becharacterized as an increased in magnitude, it can also be estimated by theirsize and also the tissue piece.
It speaks to a standout amongst the mostnoteworthy parameters in aquaculture (Silva etal., 2015). Growth isestimated by the units of the length and the weight and is best spoken to asthe important development rate. The main relationship between the weight andthe length can provides an index of the state of well-being of a fish. The conditionfactor ‘K’Fishes can display a ‘determinate’ which is a sort of development inbrief types of hotter areas and an ‘indeterminate’ sort of extensive types ofcolder districts (Dutta, 1994). It could also be measured by using othercriteria such as the glycine uptake by scales, the hepatosomatic index, the RNA:DNAratio and also the protein retention in the tissues. The nutrition whichincludes the quality and quantity of food, will play an important role ingrowth regulation (Siddiqui, 2014). A few number ofenvironmental factors, such as the temperature, the oxygen concentration, the salinityand the photoperiod, can also affect the rate of growth (Tang et al.
, 2008). There are fish that canexhibit a determinate type of growth in short-lived species of warmer regionsand an indeterminate type in long-lived species of colder regions (Dutta,1994). The water temperature is a standout amongst the most critical physicalvariables influencing fish development and creation.
Fish are cold bloodedcreatures which expect around an indistinguishable temperature from theirenvironment (Viadero, 2005).The growth performance of theAfrican catfish can be affected by many factors such as stocking density, feedformulation and water quality. Past studies of Micha (1976) suggest that thegrowth of African catfish to decrease with increasing stocking densities.However, (Van de Nieuwegiessen et al.,2008) had indicated that both the high and low densities had some detrimentaleffects on fish welfare based on juvenile African catfish of 10-100g. Factorssuch as feed can affects the growth of African catfish by the number of proteinlevel contain in the feed. High level of protein is very essential to thegrowth of fish but an optimum level is known to ensure high growth efficiency(Tunde et al.
, 2016). As for Japanese catfish,the growth of the catfish was very fast and it can grew to an average body weight,100g at 80 days after hatching in the natural condition (Akazaki et al., 1991). The Japanese catfish hadcontain less information regarding the nutrients that can help its growth but anotherpast studies of Cong Liu (2012) states that the dietary protein of 43% and dietarylipid of 7% had no significant growth effect on Japanese catfish compared to S. meridionaliswhich had shown better growth performance in the same dietary nutrient.However, the Japanese catfish optimum level of dietary protein is 45% formaximum development (Kim et al.
, 2014).Sex of the Japanese catfish also influences its growth performance as femalegrow much faster than male (Kim et al.,2001). This is due to reaching sexual maturity has reduce its growth rate andreduce its feed efficiency for male.