Manipulation chromosome through heat shock treatment is safe method and can be applied to mass production in order to fulfil demand in animal food industry. The aim of the study was to evaluate how heat shock affected fertilized eggs after 4 minutes (triploid) and 40 minutes (tetraploid) of fertilization. After heat treatment of Clarias gariepinus fish eggs, the rate of abnormality of fertilized eggs were also determined. Heat shock treatments were 39°C, 40°C, and 41°C for 4 minutes, with times of 4 minutes after fertilization and 40 minutes after fertilization, with three repetitions of each treatment. The results showed that heat shock after 4 minutes of fertilization significantly affected the rate of slow embryonic development starting from the cleavage stage of 8 cell up to hatching compared to treatment 40 minutes after fertilization. The treatment with a shocking temperature of 41°C after 4 minutes of fertilization resulted in the highest percentage rate of abnormalities, 45.67%. Thus, this study revealed that tetraploid development was superior to triploid development due to higher egg abnormalities in triploid. Tetraploids are preferable as broodstocks to produce sterile triploids and can enlarge rapidly.

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Recent studies have shown that extracted soil has the potential to enhance microalgae growth. An experiment was conducted, and a kinetic model was developed to understand and predict the growth rate of Dunaliella primolecta with consideration of soil extract effects. Dunaliella primolecta was cultured and mixed with extracted soil from the Raja Musa Forest Reserve, Malaysia. At present, no model of microalgal growth associated with the soil extract effect has been developed to predict cell density and growth rate. A mathematical model was derived to describe the growth rate and cell density production of microalgae with soil extract in the cultured microplate. The prediction model of microalgae concentration agrees with the experimental data, with R2 ranging from 0.94 to 0.98. Culturing microalgae with 1% of soil extract concentration yielded a significant increment of growth rate. However, the growth rate remained constant at a higher concentration, suggesting the percentage as an optimal value. Thus, the soil extract acts as a growth enhancer that doubles the growth rate of cultured microalgae. A parametric study was conducted to characterize the light intensity and temperature effect on the growth model concerning soil extract effect.

In Malaysia, the development of aquaculture industry faces general feed cost problems. Feed cost is about 70% to 80% of total production. One of the reason is the usage of corn meal which is expensive. Thus, the alternative way is by using plant waste. This idea develop interest towards the aquaculture industry. Hence, this study investigated the replacement of corn meal with coconut waste in different percentages and assess the growth development of the African catfish, Clarias gariepinus. The study design used 5 feed treatments with 3 replications treatments each. The percentage replacement of corn meal to coconut waste become the variables and labelled the treatments by P1 (10% replacement), P2 (20% replacement), P3 (30% replacement) P4 (40% replacement) and control treatment (0% replacement). The suitability of coconut waste feed product had been determine by using the growth performance based on the survival rate of the fish, absolute body weight gains, feed conversion rate and specific growth rate of the fish. Proximate analysis of the formulated feeds was also conducted. Result shows that formulated feed using 30% of coconut waste could possibly replace the corn meal and increase the growth of juvenile African catfish.

Partial interaction between two different materials of composite beam is consequent from longitudinal slip and transverse uplift effects at interfacial surface. The behaviour has yielded higher order differential equation as compared to beam that interacts fully. In this paper, a meshless approach for the analysis of composite beam with partial interaction by Element Free Galerkin (EFG) method is formulated and investigated. Discretized solely by nodes, the Moving Least Square (MLS) method is adopted for the EFG shape functions formulation and the variational approach is chosen in developing its Galerkin weak form. The weak form essential boundary conditions are enforced by Lagrange multiplier, where comparable results are obtained between developed EFG code and established analytical solutions. In addition, influence of various weight functions on shape function smoothness of EFG code is explored.