A study of the major Arthropoda taxa of invertebrates recolonizing Saraca roots occurring on various substrates and under various water velocities was carried out in the upper reaches of the Gombak River. The sites for the recolonization experiments were selected in the fast and slow flowing sections of rocks and boulders, sand and gravel and mud and silt biotopes. The Hydropsychidae and the Nemouridae were the pioneer recolonizers of Saraea roots in the fast flowing sections of the stream whereas the Ptilodactylidae and the Caenidae were the pioneer recolonizers in the slow flowing sections of the stream.
Suatu kajian telah dijalankan bagi menentukan takson utama invertebrata Arthropoda yang mengkoloni semula akar Saraca yang didapati pada pelbagai substrat dan pada kelajuan air yang berbeza di bahagian hulu Sungai Gombak. Tapak-tapak untuk ujikaji pengkolonian-semula telah dipilih pada bahagian laju dan perlahan biotop batuan besar dan sederhana, pasir dan batuan kecil, dan lumpur dan kelodak. Hydropsychidae dan Nemouridae adalah pengkoloni perintis pada akar Saraca di bahagian aliran laju sungai sementara Ptilodactylidae dan Caeflidae adalah pengkoloni perintis di bahagian aliran perlahan sungai itu.
Zooplankton were sampled in Lake Ikeda at a fixed station every month with the aid of a plankton net in order to observe whether cyclomorphism was exhibited by the neonates of Bosmina longirostris. In Lake Ikeda the relative sizes of the antennules and mucrones of B. longrostris neonates decreased in relation to carapace length from 65% in winter to 50% in summer. Mucrone lengths also decreased from 30% in winter to 20% in summer. Both appendages were inversely correlated with surface temperature of the lake. Predation seems to be one of the reasons why neonates of B. longirostris exhibited seasonal cyclomorphism in their antennule and mucrone.
A feeding trial was conducted to investigate the effect of mushroom supplementation as a prebiotic compound in an insect-based diet on the growth performance and feed utilization of red Tilapia (Oreochromis sp.). A total of 120 fingerlings were divided in triplicates for each treatment. Four experimental diets were offered to the fishes within a 56 days treatment period. Out of the four diets, three contained mushroom stalk meal (MSM) supplementation at various levels of inclusion of prebiotic compound (0.5% MSM; 1.0% MSM; 1.5% MSM) and the fourth a control diet without MSM inclusion. During the growth test, fish receiving diet containing prebiotic showed significantly higher (p<0.05) mean individual body weight in comparison with the control diet. The best effect was obtained in fish fed with Diet 2, where the specific growth rate (SGR) was 1.74%, feed conversion ratio (FCR) was 0.58, protein efficiency ratio (PER) was 5.17 and survival was 93.33%. No significant differences (p>0.05) were observed in whole body protein and ash contents among the fish feeding on these diets. All water quality parameters showed no significant difference (p>0.05) in all treatments. The result of this feeding trial indicated that the 10% supplementation level of MSM as a prebiotic for tilapia could be used in the insect-based diet, Zophobas morio.
In this study, juvenile male Sprague-Dawley rats (PND 22) were fed with soya extract, bisphenol A, and 17β-estradiol, respectively by oral gavage to determine the potential effect on the morphology of their reproductive organs and their hormonal levels. After three weeks of treatment (PND 43), all animals were sacrificed and the blood and testes were collected. All the three treatment groups showed histological differences in testes morphology compared to the control. Animals treated with soya extract and bisphenol A showed a decrease in circulating estradiol levels while animals treated with 17β-estradiol showed elevated circulating levels of estradiol. Only the animals treated with soya extract showed elevated levels of circulating testosterone. The results of the present study showed that, soya extract, bisphenol A, and 17β-estradiol can alter the histological structure of the testes and influence circulating steroidal hormone levels.
A 6-weeks feeding experiment was conducted to evaluate the effect of replacement of rice bran with mushroom stalk (Pleurotus florida) an agriculture waste, on growth performance in tilapia fingerlings (Oreochromis niloticus). Three isonitrogenous (32% crude protein) diets were formulated. Rice bran was replaced with 100% (Diet 1), 50% (Diet 2) and 0% (Diet 3, control) mushroom stalk. Each dietary treatment was tested in triplicate group of 12 fingerlings per tank arranged in completely randomized design. The result of this study showed that there was no significant difference (p>0.05) among all diets in terms of growth performance and feed utilization. Diet 1 gave the best results in BWG, SGR, FCR and PER. An economic evaluation indicated that Diet 1 gave the lowest production cost at RM2.03/kg followed by Diet 2 (RM2.18/kg) and Diet 3 (RM2.38/kg). Taking all the factors into consideration, the best diet was Diet 1 with 100% replacement of rice bran with mushroom stalks which is also the cheapest diet. This shows that Pleurotus florida stalks can replace 100% of rice bran in practical tilapia diets.
A dietary study was conducted to assess the use of mushroom stalk (MM), Pleurotus sajor caju, an agriculture waste and
soy bean meal (SBM) as partial and complete replacement of fishmeal (FM) in tilapia fingerling diets. The study was
conducted for 56 days. The diets were processed into sinking pellets. The experimental diets were formulated to replace
fish meal protein at 0, 33, 67 and 100% (diet 4, 3, 2 and 1). In this experiment, Nile tilapia fingerlings weighing about
1.00 g were fed each of four isonitrogenous diet. They were randomly distributed into 12 plastic tanks with each tank
stocking 20 fish. The experiment was conducted in three replicates for each treatment. All the diets were well accepted
by the fish. No physical abnormalities were observed in all treatments. Good growth performance was shown in 33%
replacement (diet 3) of FM diet. However, diet 1 (100% replacement) gave the highest increment in crude protein level
and the best result of feed conversion ratio (FCR) and protein efficiency ratio (PER). Furthermore, the 100% replacement
of FM (diet 1) was the best with a production cost of RM2.61/kg.
The effect of replacement of ricebran by mushroom stalk (Pleurotus florida), an agriculture waste on growth performance of African catfish (Clarias gariepinus) fingerlings was investigated for 42 days. Three isonitrogenous (32% crude protein) experimental diets containing 100% (Diet 1), 50% (Diet 2) and 0% (Diet 3) mushroom meal were formulated. Each diet was randomly allocated to triplicate groups of fingerlings in experimental tanks, with each tank stocking 12 fishes. The fishes were fed twice daily to apparent satiation for 6 weeks. Good survival rates were obtained from fish fed with Diet 1 (94%) and Diet 3 (94%). There was no significant differences in body weight gain (BWG), specific growth rate (SGR) and feed conversion ratio (FCR) among all diets (p>0.05). The fish fed with Diet 1 showed the best BWG, SGR, FCR and PER compared with Diet 2 and Diet 3. An economic evaluation indicated that Diet 1 gave the lowest production cost at RM2.03/kg followed by Diet 2 and Diet 3 at RM2.18/kg and RM2.38/kg, respectively. This study showed that the best diet was Diet 1 with 100% replacement of rice bran with mushroom stalks costing RM2.03/kg, the cheapest among the three diets.