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Host associated probiotics (HAPs) provide health benefits to the host when administered as dietary supplement. However, a short-term probiotics application strategy has yet to be optimized. A 90-days study was conducted to evaluate the response of Malaysian mahseer, Tor tambroides post larvae fed with basal diet enriched HAPs for 30- days, and its response following another 60-days feeding with only basal diet. Three experimental diets (Enterococcus faecalis strain 2674 (T1), Aeromonas sp. strain A8-29 (T2) and E. faecalis strain FC11682 (T3)) were prepared by spray-coating each HAPs on a basal diet at 1 x 108 CFU/g feed. Differences in growth performances, whole-body proximate and fatty acid composition, muscle morphometry, and gut morphology were evaluated. Results showed that after 30 days, T3 fish produced highest growth. All HAP treatment groups showed better muscle distribution profile, improved fatty acid composition, and higher villus length, width and area, than control group. After 90 days, the growth of T3 fish was still the highest. Muscle distribution profile and villus growth were higher in HAP treatments, although only total n-6 PUFA, total MUFA, linoleic acids, and linolenic acids in HAP treated fish remained high after probiotics withdrawal. No difference in whole-body proximate composition was observed in both 30 and 90 days. Collective findings demonstrated that short-term application of HAPs at an early stage could be used to boost T. tambroides growth, with E. faecalis strain FC11682 showing the best efficacy. [ABSTRACT FROM AUTHOR]

This study describes the fatty acids, total carotenoids, and cell diameter characteristics of the female ovary and hepatopancreas of the mud crab, Scylla olivacea , with comparisons at different ovarian maturation stages. Seventy-one S. olivacea individuals at all stages of ovarian maturation were sampled from the Setiu wetlands, Terengganu, Malaysia. The ovary and hepatopancreas of each crab were used for morphological studies, histological and biochemical analyses (fatty acid composition and total carotenoids). Morphological observations indicated there was an increase in ovarian gonado-somatic index (GSI), with color changes from translucent to dark red; however, a relatively consistent hepato-somatic index (HSI) in the hepatopancreas, with the color ranging from yellow to yellowish-brown. Histological analysis indicated that oocyte diameter was positively correlated with GSI. Hepatopancreatic tubules had a relatively constant diameter from Stage 2 to 4, with increased proportions of R- and B-cells. Biochemical analysis indicated there was a significant increase in total carotenoids in the ovary during maturation. The hepatopancreas, however, had relatively consistent total carotenoid concentrations that were greater than those of the ovary. Overall, the lipid analysis results indicated there were lesser concentrations of fatty acids in the hepatopancreas, while in the ovary there were increasing concentrations during maturation. The lesser concentrations of fatty acids in the hepatopancreas than ovary suggested that energy was transferred to the ovary for future embryonic and larval development. The relationship between the hepatopancreas and the ovary in nutrient content is an important finding in providing a baseline to formulate an optimal diet for improved mud crab hatchery practices. [ABSTRACT FROM AUTHOR]

This study focused on the effect of common natural diets, scadfish and squid on the growth performance, morphology, histology and fatty acids of ovary and hepatopancreas of female orange mud crabs, Scylla olivacea. Twenty individuals of newly mature crabs (body weight = 69.21 ± 2.19 g, carapace width = 7.18 ± 0.07 cm) with 10 individuals per treatment were cultured for 60 days with ambient water parameters. Twenty individuals of control crabs were also collected from the wild. The highest body weight gain (BWG), carapace width gain (CWG), gonadosomatic index (GSI) as well as oocyte and tubule diameter were recorded during the captivity, with the mud crabs fed with scadfish leading (BWG = 36.58%, CWG = 14.90%, GSI = 0.47%, oocyte diameter = 47.19 μm, tubule diameter = 167.82 μm). Likewise, high concentrations of ∑PUFA, ∑EPA, ∑DHA and ∑n3 were reported in scadfish‐fed crabs compared to both squid‐fed and wild‐caught crabs (p < 0.05). In contrast, lower fatty acids were noted in the hepatopancreas of crabs from all treatments, suggesting an occurrence of nutrient transfer from the hepatopancreas to the ovaries. Overall results concluded that scadfish is preferred as the main diet for crabs in captivity. [ABSTRACT FROM AUTHOR]

The main focus of the study was to assess the effect of lipid levels on the reproduction of the female orange mud crab, Scylla olivacea. Four isonitrogenous feed (~420 g/kg) were formulated with different lipid percentages: T 1 = 60 g / kg , T 2 = 80 g / kg , T 3 = 100 g / kg , and T 4 = 120 g / kg. A feeding trial was carried out on 120 matured female mud crabs for 90 days with 30 replicates in each treatment. Based on the morphological, histological, and hormonal analysis of each crab, the performances of each experimental diet were tested. The results of the experiment disclosed positive body weight gain (BWG) and specific growth rate (SGR), with the highest value recorded in crabs that were fed T4 (BWG: 14.43 ± 1.14 g ; SGR: 0.10 ± 0.01 % da y − 1 ). The highest gonado-somatic index (GSI) and hepato-somatic index (HSI) were noted in mud crabs that were fed T4, each with a value of 14.51 ± 1.13 % and 5.23 ± 0.55 % , respectively (P < 0.05). The histological assessment revealed that the highest oocyte diameter was recorded in mud crabs fed T4 (192.80 ± 21.93 μm), where the oocyte diameter was correlated with the progesterone (Pg) concentrations in the ovary with r = 0.73. Evidence also indicated that Pg and estradiol (E2) are important in the ovarian development in S. olivacea and their concentrations were affected by the lipid levels. An overall analysis revealed that 120 g/kg of lipid in the diet contributes to optimal reproductive performance in Scylla olivacea. Yet, a further experiment is expected to be carried out in the future to determine the nutrient-dose response as 120 g/kg lipid may not be the optimum lipid level for reproductive and growth performance in S. olivacea. Moreover, the extrapolation of data from this study can be used as guidelines in feed formulation for developments in future research in adult crustaceans. [ABSTRACT FROM AUTHOR]

This experiment aimed to evaluate the efficiency of formulated feeds with different lipid levels (T1 = 60 g/kg, T2 = 80 g/kg, T3 = 100 g/kg and T4 = 120 g/kg) in the biochemical composition of female orange mud crab, Scylla olivacea, during the fattening period. Experiments were conducted on 120 crabs with BW and CW of 186.42 ± 37.90 g and 10.24 ± 0.66 cm, respectively, for 90 days. The crabs were reared in tanks, and dissections were performed in 10 individuals per treatment every 30 days. Overall assessments disclosed that mud crabs fed the T4 showed the highest BWG (1.80 ± 0.78 g, 13.78 ± 1.81 g and 14.51 ± 3.81 g), SGR (0.03 ± 0.02%day−1, 0.19 ± 0.01%day−1 and 0.28 ± 0.02%day−1), GSI (9.90 ± 1.05%, 11.31 ± 1.68% and 17.30 ± 2.13%) and HSI (4.17 ± 0.52%, 5.22 ± 0.40% and 5.06 ± 0.45%) during fattening periods. Meanwhile, EPA and DHA were the most important fatty acids required for maturing ovaries in mud crabs. During 60‐ and 90‐day culture period, higher EPA and DHA were noted in the ovary of mud crabs fed with T4 (EPA: 4.79 mg/g and 6.69 mg/g; DHA: 4.55 mg/g and 6.85 mg/g) compared with hepatopancreas (EPA: 1.84mg/g and 2.47 mg/g; DHA: 3.28 mg/g and 3.71 mg/g) (p <.05). The low fatty acid composition in the hepatopancreas indicates a nutrient transfer from the hepatopancreas to the ovaries for maturation. Two‐way ANOVA suggested that 120 g/kg of feed with 60–90 days of duration would be the best for crab rearing. [ABSTRACT FROM AUTHOR]

The present study examined the physical characteristics of semi-moist formulated feeds to the reproductive maturation of female orange mud crab, Scylla olivacea. In this study, two experiments were conducted. The first experiment compared four types of natural diets; fish offal (discarded organ), mangrove clams (Polymesoda erosa), black devil snail (Faunus ater), and commercial shrimp feeds (control), to select the basal diet for the formulation of feeds. Proximate compositions of the different diets revealed that the mangrove clam, P. erosa (protein = 81.63 % and lipid = 13.54 %) is the most suitable ingredients for the mud crabs' diet. Fatty acid analysis also showed that mangrove clams had the highest concentration of ARA, EPA, and DHA at 0.56 %, 1.62 %, and 2.68 % respectively. In the second experiment, four isonitrogenous feed (~42 %) with different lipid percentages; T1: 6 %, T2: 8 %, T3: 10 %, and T4: 12 % were formulated to investigate the effects of the lipid inclusion on maturation of mud crabs. The effects of different levels of lipid on palatability, feed water stability, nutrient leaching, buoyancy, and total solids were studied prior to feeding experimentation. The palatability tests showed high attractability of the crabs towards the feeds. Meanwhile, high water stability (dry matter retention) were recorded in all experimental feeds after long immersion hours, with low nutrient leaching, and low solids disintegration. Later, feeding trial on 120 matured female mud crabs (carapace width: 10.24 ± 0.66 cm and body weight: 186.42 ± 37.90 g) revealed that the semi-moist formulated feeds are readily accepted by the crabs. The crabs from all treatments recorded positive body weight gain (BWG) and specific growth rate (SGR) with crabs fed T4 dominating (BWG = 11.43 g, 14.65 g, and 12.13 g; SGR = 0.35 %day-1, 0.13 %day-1, and 0.08 %day-1 during 30-, 60-, and 90-day of feeding trials respectively) (p < 0.05). Similarly, morphological results showed that high GSI was noted in S. olivacea fed with T4, increasing at subsequent feeding trials (10.44 %, 11.03 %, and 14.51 %) (p < 0.05), which were inversely proportional with the HSI (8.92 %, 5.11 %, and 4.76 %) (p < 0.05) compared to other treatments, probably contributed by the high percentage of lipid inclusion. These findings demonstrate that diets contained 12 % lipid and 42 % protein (T4) is ideal for somatic and reproductive growth of S. olivacea. Yet, a nutrient dose-response study is expected to be carried out in the future to estimate the optimum lipid level required for reproductive and growth performance in S. olivacea. • The developments of high quality formulated feed for mud crab broodstock are important in aquaculture to reduce feed wastage. • Preliminary study suggested mangrove clams, Polymesoda erosa as main ingredients in diet formulation of mud crabs. • Results suggest that the mud crab readily accepts semi-moist feed with 12 % lipid and 42 % protein levels. [ABSTRACT FROM AUTHOR]

Simple Summary: Information on the diet composition, food types, and feeding behavior of decapods is important for developing well-formulated diets in aquaculture, since feed constitutes the largest operational cost in crustacean hatcheries. The use of formulated feed for decapods at a commercial scale is still in the early stages. This is probably because of the unique feeding behavior that decapods possess: being robust, slow feeders and bottom dwellers, their feeding preferences change during the transition from pelagic larvae to benthic juveniles as their digestive systems develop and become more complex. This article presents an overview of recent progress on the nutrition and feed formulation of commercially farmed decapods during the juvenile stages. In this review, we attempt to update the information on the topic from the last 25 years and examine challenges and opportunities in the development of formulated diets, considering diet composition and decapod feeding behavior during the juvenile stages, which is vital for developing a better quality of feed formulation in hatcheries. The increasing market demand for decapods has led to a considerable interest in cultivating decapod species at a larger scale. Following the development of hatchery technologies, most research has focused on the development of formulated feeds for commercially farmed decapods once they enter the juvenile stages. The use of formulated feed for decapods at a commercial scale is still in the early stages. This is probably because of the unique feeding behavior that decapods possess: being robust, slow feeders and bottom dwellers, their feeding preferences change during the transition from pelagic larvae to benthic juveniles as their digestive systems develop and become more complex. The current practice of decapod aquaculture involves the provision of juveniles with food such as natural diet, live feed, and formulated feed. Knowledge of nutrient requirements enables diets to be better formulated. By manipulating the levels of proteins and lipids, a formulated feed can be expected to lead to optimal growth in decapods. At the same time, the pellet's physical characteristics are important factors to be considered upon formulating commercially farmed decapod feeds, considering the unique feeding behavior of the decapod. However, most published studies on decapod nutrition lack data on the physical characteristics of the feed types. Thus, it is difficult to establish a standard feed formulation that focuses on the physical pellet properties. Moreover, careful consideration must be given to the feeding behavior of species, as decapods are known as bottom feeders and are robust in terms of handling feed. Information on the pellet forms, diet composition, and unique feeding behaviors in commercially farmed decapods is gathered to suggest potential better formulated diets that can optimize growth and reproduction. Thus, the purpose of this review is to summarize the information that has been published to date and to come up with suggestions on ways to improve the feed formulation in decapods that comply with their feeding behavior and nutrient requirements. Further research is needed to explore the potential of the pelleted feed at the adult stage so the decapod can take full advantage of the nutrients present in the pellets. [ABSTRACT FROM AUTHOR]