A number of studies have investigated different crustacean food stuffs, feeding methods, 18 and feeding behavior, but little attention has been given to the interaction between these aspects in 19 crustaceans. The aim of the present review is to update knowledge, and examine challenges and 20 opportunities in the development of formulated diets, as pelleted feed, which is vital for developing 21 better quality of seed or broodstock in hatcheries, and adaptation of hatchery product to the aqua- 22 culture environment, and production systems.

The experiment was conducted to determine the effects of different substrate on the survival, growth and total number of moulting in juvenile red claw, Cherax quadricarinatus for aquaculture purposes. In the present study, there is a problem in culturing juvenile stage of C. quadricarinatus especially for survival and growth. Thus, a substrate was used to improve the survival and growth of C. quadricarinatus especially for the intensive system due C. quadricarinatus need a large space to survive. C. quadricarinatus with initial body weight from 1.10 to 2.90 g, total length 2.82 to 4.36 cm were placed in tanks (80 L in volume capacity) with 55L in water and there are eight juveniles in each tank. Treatment tanks were introduced with coral as treatment 2 and pipe as treatment 3. While, tank without shelters was set as control (treatment 1). Black nets were installed on top of each for circumventing foreign objects enter the tank and protect from direct sunlight. Besides, C. quadricarinatus were acclimatized for seven days before started the experiment. The experiment was done in duplicate and conducted for 60 days and C. quadricarinatus were fed twice daily (morning and evening) based on 5% of body weight. From the total of two replications, C. quadricarinatus for treatment 2 (coral) were significantly in survival (81.25±8.84%), weight gain (347.36 ±6.04%), specific growth rate (2.50±0.02%), carapace length (32.93 ± 0.93 %) and total number of moulting (55.00±2.93%) compared to other treatments. Besides, the control treatment (treatment 1) has a lower percentage in survival (37.50±8.84%) weight gain (122.60±20.51%) specific growth rate (1.33±0.15%), carapace length (25.84±0.33 %) and total number of molting (29.00±0.71%). As a conclusion, usage of coral as the substrate in the rearing tank showed improvement in survival, weight gain, specific growth rate, carapace length and total number of molting in C. quadricarinatus. The coral can use in rearing tank for increase the growth and survival for a small scale and not for commercial. In addition, in the environmental aspect, the present study showed the benefit of replacing the use of PVC pipes with the natural structure of dead coral.

Salinity is a known factor which shapes population dynamics and community structure through direct and indirect effects towards aquatic ecosystems. The responses of Moina macrocopa (Cladocera) collected from Setiu Wetland lagoon (Terengganu) were evaluated through manipulative laboratory experiments to understand the ability of M. macrocopa to tolerate under high salinity stress. Specifically, the fatty acid composition, growth, survival and reproduction of this cladocerans species were examined. Sodium chloride (NaCl) were used in the treatments water with the concentration 0, 4, 6, 8, 12, and 15psu. Fatty acid levels were determined using Gas Chromatography and Mass Spectrophotometry (GC-MS). Results clearly indicate that normal conditions give the highest content of fatty acid, especially the polyunsaturated fatty acid content like EPA (eicosapentaenoic acid), ALA (alpha-linoleic acid), ARA (arachidonic acid) and DHA (docosahexaenoic acid). Furthermore, M. macrocopa survival also was best at 0psu, with percentage reached 98%, whereas the opposite occurred at 15psu, with approximately 9% of viable animals survived. On other aspects, M. macrocopa also showed the highest reproduction rate at 0psu (e.g. average initial age of reproduction, 4.33±0.58 days) compared with other salinities level. Interestingly, the difference in terms of growth at different salinities was unapparent, an unexpected outcome when adverse effects such as osmoregulation pressure on the organism are considered. Based on the results, we conclude that M. macrocopa can only tolerate salinity below 8psu and, is unable to withstand stressful environmental condition engendered with salinities above 8psu.

This study attempted to explain the definition, objectives, and key stages in mud crab nursery activities. The nursery stages of Scylla spp was started from megalopa stage to several crablet instar stages or started from earlier crablet stage to several crablet stages. Direct stocking of megalopa into ponds is not recommended due to their sensitivity. Instead, nursery rearing is needed to produce mud crab of larger size before stocking. Individual nursery rearing results in higher survival rate (up to 100%), but with reduced growth rate, and a more complicated maintenance process compared with communal rearing. Nursery of mud crab can be done indoors, or outdoors, with adequate shelter and feed required to obtain good survival and growth performance. Artemia nauplii are the main, established nursery feed, particularly at megalopa stage, while survival rate may be improved if combined with artificial feed, such as micro bound diet formulations. Water quality parameters, identical to those proposed in tiger shrimp culture, can followed. Crablets may be transported to the pond location with, or without water. The provision of monosex seeds from mud crab hatcheries is expected to become more common, increasing seed price, and thus improving income of farmers. Numerous aspects of mud crab nursery, including nutrition, feeding strategies, understanding of their behaviour, i.e., cannibalism, control of environmental factors, and practical rearing techniques, still need further improvement.