Development of mud crab breeding technology for conservation and communal livelihoods in the Setiu Wetlands, Terengganu, Malaysia (original) (raw)
Related papers
2017
Population biology is regarded as one of the important domain for nature resource management particularly when any species of economic and social importance is involved. In this study, the population structure of tropical orange mud crab, Scylla olivacea (Herbst 1796) was investigated in a tropical mangrove forest in Setiu Wetlands, Terengganu, Malaysia. This study specifically address some aspects of population biology of this species particularly of sex ratio, carapace width-weight and growth pattern. Mud crabs were sampled during pre and post monsoon season i.e. during October 2014 and January 2015, respectively. Mud crabs were collected using crab-baited collapsible traps in the identified areas. A total of 30 crabs were captured, of which 18 were male (60.0%) and 12 were female (40.0%). The overall sex ratio, male to female for pre monsoon and post monsoon were ( and 3:1, respectively. Male’s mud crab were bigger and heavier than females. Positive correlation was observed betwe...
Culture of Soft Shell Mangrove Crab, Scylla Spp. Production in the Southwest Region of Bangladesh
International Journal of Oceanography & Aquaculture, 2019
The experiment was conducted for a rearing for a period of 150 days from mid-September to mid-February 2017 in three earthen ponds with an installing of 9880 cages per hectare with an average depth of 1.0 meter. The experiment was designed at the ponds of Kaligonj Chingri Farm as a treatment T1, Allarchar chingri farm as a treatment T2 and Shamnagar private crab farm as a treatment T3. Before stocking crabs were categorized at five size groups. At stocking, all crabs were with an initial mean carapace width and weight of individual was recorded in three treatments. The average final weight of crab was recorded to be 180.56±4.08, 175.80±7.11 and 178.62±6.42 g in treatment T1, T2 and T3, respectively. The increase in weight of mud crab was the highest in T1 followed by T3 and T2. About five group of different crab weight was stocked in the cages of three treatments. Best SGR (1.67±0.01) and FCR (2.00±0.08) were recorded in treatment T1. The highest survival rate was also observed in T1 and the lowest survival rate was in T2. There was a significant variation (P<0.05) in the survival rate of crabs among three treatments. The net production of crab was at 5082.51, 4689.63 and 4923.48 kg/ha in treatment T1, T2 and T3, respectively. Highest production of soft shell crab was recorded in treatment T1. But no significant (P<0.05) different was recorded in treatment T1 and T3. But a significant (P>0.05) different was found between treatment T2 and treatment T1 and T3. Majority of the crabs about 60-70% molted during night than day time. As the crabs were increased in size, molt duration became longer from 17.0 to 26 days. Overall, highest growth, survival, production and net benefit of soft shell crab recorded at treatment T1. Therefore, treatment T1 and treatment T3 appeared to be most suitable for soft shell crab culture for availability of saline water and trash fish in this area.
The populations in coastal areas in east Africa have increased dramatically in the last decades, resulting in increased pressure on coastal resources. The examples are declining fish catches, deteriorating conditions of coral reefs and reduction of mangroves forests. The objective of the study was to asses the potential of grow-out Aquaculture of mud crabs Scylla serrata, as an alternative livelihood for resource-poor coastal communities. Growth rate and survival of mud crabs (S. serrata) cultured in individual drive-in cages (30 x 30 x 30 cm) located in the mangrove forests dominated by Rhizophora mucronata were evaluated. The effect of feed (Terebralia pallustris -gastropod meat, fish offal and mixture of the 2) was determined in a completely randomised design. Feeding was done at 10% body weight at incoming tide throughout the experimental period of 120 days. Monthly sampling was employed and total weight (g), cheliped length (cm), carapace length (cm) and width (cm) were measured. The study aimed at establishing the growth rate, moulting and mortality of crabs fed using locally available feeds. A total of 180 drive-in cages were used for the experiment giving 60 replicates for each treatment. Drive-in cages were built with "fitos" and grouped in sets of 10 for easy management. Crab seed stock of 50 -380 g for the experiment were bought from artisanal fishermen. Application of ANOVA and post-hoc test revealed that crabs fed with mixed feed had significantly higher % growth (47.9%) compared to fish offal (33.4%) but were similar to gastropod meat (43.2%) p < 0.05. Growth rate was significantly affected by feed type, where higher values were recorded in mixed feed diets (gastropod meat and fish offal, 1.29 g/day) compared to the individual feeds (0.96 and 0.97 g/day for fish offal and gastropods meat respectively. There was no significant difference in growth of monosex crabs female (0.996 -1.55 g/day) and males (0.893 -1.01 g/day) p = 0.373.
A Review of the Nursery Culture of Mud Crabs, Genus Scylla: Current Progress and Future Directions
Animals
The nursery stages of mud crab, genus Scylla, proceed from the megalopa stage to crablet instar stages. We review the definition and several of the key stages in mud crab nursery activities. The practice of the direct stocking of megalopa into ponds is not recommended due to their sensitivity. Instead, nursery rearing is needed to grow-out mud crabs of a larger size before pond stocking. Individual nursery rearing results in a higher survival rate at the expense of growth and a more complicated maintenance process compared with communal rearing. The nursery of mud crabs can be done both indoors or outdoors with adequate shelter and feed required to obtain a good survival percentage and growth performance. Artemia nauplii are still irreplaceable as nursery feed, particularly at the megalopa stage, while the survival rate may be improved if live feed is combined with artificial feed such as microbound diet formulations. Water quality parameters, identical to those proposed in tiger sh...
The Bay of Piru is one of potential fisheries resources of Western Seram District. Extensive mangrove, sea grass bed and coral reefs ecosystem were found in this area, contributing a lot on it productivity. Among many fish resources found there, the mud crab of Scylla serrata was one of the resources extensively exploited by local fisher of Pelita Jaya and its vicinity area. High demand on mud crab, high price, and high economy dependence of local fisher has influence the fisher to exploit the resources in unsustainable ways for over than 20 years that lead to resources degradation. The study was aimed to investigate the status of mud crab fishery and the effect attributed to the status then gives some recommendations for the management. The result shows that majority of mud crab captured was small to medium carapace width, of female mud crab harvested, 95% were in their reproductive status, the sex ratio was very between month but in average was almost equal (p< 0.05). The Pelita Jaya people were mainly elementary school graduated with relatively low level of environmental knowledge on sustainable natural resources management. Institutional aspect on natural resources management was also poor. Management on size captured, reproductive status, pot mesh size, and sanctuary side agreement should be implemented soon.
2015
This pioneer study on the captive broodstock breeding of the mud crab (Scylla paramamosain) consisted with a series of experiments. The larvae rearing trial was fed with Artemia umbrella, enriched rotifer and rotifer from Z1 to Z2 stages followed by Artemia nauplii, enriched Artemia nauplii and commercial diet, respectively from Z3 to megalopa. Highest larval stage index (LSI), significantly higher (p<0.05) megalopa and crablet survival was achieved from enriched rotifer followed by enriched Artemia feeding schemes that had the eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), n-6 to n-3 and EPA to DHA ratios of 17.32%, 3.82%, 0.20 and 0.22, respectively in megalopa for subsequent metamorphosis to crablet. Growth of mud crab displayed the sigmoid pattern for both sexes with significantly higher (p<0.05) weight gain in males. The female mud crab grew faster (p<0.05) in outdoor tanks, but survival and the proportion of intact crabs were higher (p<0.05) under indoor ...
Reproduction Performances of Mud Crab (Scylla olivacea) Broodstocks with Different Feeds
2015
Broodstock maturation diets is important research in order to increase the reproduction performance of spawning females. This research was conducted to determine the appropriate feed for mud crab broodstock spawned and as information in support of efforts to provide quality stem in a controlled manner. The study was conducted at the Installation Research Marana Institute For Coastal Aquaculture (RICA). The test animals that used were 15 ind. mud crab broodstock having of size 200±15 g, carapace length 6±0,5cm, carapace width 12±0,5 cm with gonadal maturity level (TKG I) obtained from crab fishing locations. Research using completely randomized design which consists of 3 treatments and 5 replications. The treatments tested were: A (trash fish), B (squid) and C (golden apple snail). Variable measured were the rate of gonadal maturity, egg diameter, the degree of spawning, embryo incubation period, the number of larvae, hatching rate, larval amino acid and proximate analyze content and...