Preliminary assessment of a microbound diet as an Artemia replacement for mud crab, Scylla serrata, megalopa (original) (raw)
Related papers
Use of microbound diets for larval culture of the mud crab, Scylla serrata
Aquaculture, 2006
Routine commercial production of mud crab seed is currently restricted by our limited understanding of the nutritional requirements of Scylla spp. as well as problems commonly associated with the live foods used in mud crab hatcheries. This study investigated the use of microbound diet (MBD) particles as a food source for megalopa and zoea III stage larvae of Scylla serrata. In the first experiment, the nutritional value of four MBD containing dried rotifers, Artemia meal, fish meal or squid meal were evaluated for megalopa reared individually in 250-ml aquaria. Survival of MBD-fed megalopa to the first crab stage ranged from 46.7% to 60.0% with those fed MBD containing fish meal or squid meal showing higher survival than those fed MBD containing Artemia meal or dried rotifers. Larvae fed live Artemia showed the highest survival (80%), while unfed megalopa did not survive to the first crab stage. There were no significant differences (P > 0.05) in the average time required for megalopa to reach the first crab stage when fed any of the four MBD. However, shortest development time was recorded for larvae fed live Artemia. In a second experiment, zoea III larvae were cultured communally at a density of 25 larvae l − 1 and were fed either 100% live Artemia nauplii, 100% MBD or a 50%:50% combination of MBD and Artemia. Highest survival (66%) and development rate to the zoea IV stage were recorded for larvae fed the 50%:50% combination of MBD and Artemia. Some successful molts were also found among larvae fed MBD exclusively, while total mortality was observed in unfed (control) replicates. The results indicate that the experimental MBD may contain certain beneficial nutrients lacking in Artemia and that co-feeding the MBD with Artemia may enhance larval survival and development. However, they also show that total replacement of live food with the experimental MBD will result in poor survival of zoea III larvae of S. serrata. The results indicate great potential for the use of MBD particles as dietary components for both zoea and megalopa stages of S. serrata. These findings have important implications for the eventual development of cost-effective and reliable hatchery techniques for mud crabs.
Fisheries …, 2002
Two experiments were conducted to determine a suitable feeding schedule and the optimal density of Artemia nauplii on the survival and development of mud crab Scylla serrata larvae. The first experiment consisted of 10 treatments, where rotifers were shifted to Artemia nauplii at the zoea (Z) 1, 2, 3, 4 and 5 stages. Five other treatments were similar to these first five; however, rotifers were continuously added together with Artemia nauplii. The second experiment consisted of five treatments that were carried out to determine the optimal Artemia nauplii density. Four treatments fed different Artemia densities (0.5, 1, 1.5, 4 individuals (ind.)/mL) and in the fifth treatment the density of Artemia nauplii was increased with the developing zoeal stage. The survival rate until the Z5 stage was higher when Artemia were supplied from the Z3 stage (P < 0.05). Mortality caused by cannibalism was observed either when Artemia feeding was delayed or when fed at a low density (0.5 ind./mL). In contrast, feeding Artemia from the early zoeal stage or at a high prey density (4 ind./mL) accelerated metamorphosis and caused the acceleration of morphological characteristics, such as a greater chela length, carapace length and setae bearing pleopods at the Z5 stage. The chela length at the Z5 stage decreased proportionally with the delay of Artemia feeding or a decreasing prey density. The chela to carapace length ratio (ChL/CL ratio,%) could be used as an indicator to predict the success of survival to megalops. A ChL/CL ratio over 45% produced a high percentage of megalopal molting failure. Therefore, to avoid cannibalism or excessive feeding in the larval mud crab, Artemia should be given from the Z3 stage at an optimal level of 1.5 ind./mL or increasing density according to the zoeal stage.
Aquaculture Reports, 2019
This study aims to compare the rearing of purple mub crab, Scylla tranquebarica larvae with different feeding regimes. This study consisted of two treatments, namely Treatment A (rearing of mud crab larvae without artificial feed) and Treatment B (rearing of mub crab larvae with artificial feed starting at Zoea 3 to the crablet stage) each with three replications. The rearing tanks used from Zoea 1 to Megalopa (M) stages were cylindrical fiberglass tanks with 0.65 m in the diameter and 200-250 liter volume. Each tank was stocked with newly hatched larvae at a density of 50 larvae L −1. The results showed that Treatment A had better survival rate (from Zoea 1 to crablet) and crablet production namely 0.51% and 138 respectively compared with Treatment B namely 0.27% and 121 respectively but there was no significant difference (P > 0.05). Although the survival rate on Treatment B was lower but the percentage of megalopa stage appearance and the Larval Stage Index value on 18-20 days after hatching of Treatment B were higher than Treatment A. Based on the results of this present study, rearing of Zoea 3 to Zoea 5 and M is still sufficient by using only enriched Artemia nauplii (with High Unsaturated Fatty Acid (HUFA) as much as 80 ppm). For the rearing of larval Zoea 5 and M to crablet, besides fed with Artemia nauplii can also be fed with additional feed in the form of fresh feed (shredded shrimp meat) or artificial feed that used in shrimp post larval rearing.
Aquaculture, 2009
This article presents an overview of recent progress on the nutrition of Scylla serrata larva and its implications in feed formulation. Recently published results of dietary trials with S. serrata larvae have helped build a basic framework of knowledge concerning the dietary requirements of this species, and these advances will undoubtedly upgrade hatchery production which traditionally has depended heavily on live food such as rotifers and Artemia nauplii. However, many aspects of larvae mud crab nutrition is still not fully understood and further studies are required in order to develop an optimized diet. The purpose of this review is to summarize the information that has been published to date, and to highlight areas where more research is needed. Key subjects are assessed under the following major headings; problems associated with use of live food in larval culture; development of a formulated diet for hatchery production of S. serrata larvae; and nutritional requirements for protein, lipid and carbohydrates.
Aquaculture, 2004
This paper reports on experiments to determine particle size preference and optimal ration for the various larval stages of the mud crab, Scylla serrata, fed microbound diets (MBD). All experiments used 14 C-labelled rotifers as components of MBD, and ingestion was determined by assessing the 14 C content of S. serrata larvae after feeding on the MBD. Five size ranges of MBD ( < 150, 150 -250, 250 -400, 400 -600 and 600 -800 Am) were used to assess ingestion by Zoea I, Zoea III, Zoea V and Megalopa. All were fed a ration equivalent to twice the equivalent dry weight of live foods provided to each larval stage under standard rearing conditions (standard ration). MBD particle size preference increased with increasing larval development. Highest ingestion rates by Zoea I, Zoea III, Zoea V and Megalopa were found for particle size ranges of < 150, 150 -250, 250 -400 and 400 -600 Am, respectively. MBD within these particle size ranges were used in subsequent experiments to assessed optimum rations for each of the four larval stages. Larvae were fed rations based on multiples or fractions of the standard ration (100%): 12.5%, 25%, 50%, 100%, 200% and 300%. There were no significant increases in ingestion, for any of the four larval stages, when ration was increased above 100%. For Zoea I, Zoea III and Zoea V larvae, there was no significant difference in the rate of MBD ingestion when ration was reduced to 50%; however, a 25% ration brought about a significant decrease in ingestion. There was no significant decrease in the rate of ingestion by Megalopa when ration was reduced from 100% to either 50%, 25% or 12.5%. The results suggest that rations currently used for larval rearing of S. serrata may be excessive. Little is currently known of the feeding behaviour and nutritional requirements of S. serrata larvae, and the results of this study are a significant development in this field. D
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 ...
Improved techniques for rearing mud crab Scylla paramamosain (Estampador 1949) larvae
Aquaculture Research, 2007
A series of rearing trials in small 1 L cones and large tanks of 30–100 L were carried out to develop optimal rearing techniques for mud crab (Scylla paramamosain) larvae. Using water exchange (discontinuous partial water renewal or continuous treatment through biofiltration) and micro-algae (Chlorella or Chaetoceros) supplementation (daily supplementation at 0.1–0.2 million cells mL−1 or maintenance at 1–2 millions cells mL−1), six different types of rearing systems were tried. The combination of a green-water batch system for early stages and a recirculating system with micro-algae supplementation for later stages resulted in the best overall performance of the crab larvae. No clear effects of crab stocking density (50–200 larvae L−1) and rotifer (30–60 rotifers mL−1) and Artemia density (10–20 L−1) were observed. A stocking density of 100–150 zoea 1 (Z1) L−1, combined with rotifer of 30–45 mL−1 for early stages and Artemia feeding at 10–15 nauplii mL−1 for Z3–Z5 seemed to produce the best performance of S. paramamosain larvae. Optimal rations for crab larvae should, however, be adjusted depending on the species, larval stage, larval status, prey size, rearing system and techniques. A practical feeding schedule could be to increase live food density from 30 to 45 rotifers mL−1 from Z1 to Z2 and increase the number of Artemia nauplii mL−1 from 10 to 15 from Z3 to Z5. Bacterial disease remains one of the key factors underlying the high mortality in the zoea stages. Further research to develop safe prophylactic treatments is therefore warranted. Combined with proper live food enrichment techniques, application of these findings has sustained a survival rate from Z1 to crab 1–2 stages in large rearing tanks of 10–15% (maximum 30%).
Deleted Journal, 2024
Blue swimming crab (Portunus pelagicus) is one of the most important commodities of softshell industry. Besides mud crab its demand as feed is increasing day by day. As a coastal dominant country, Bangladesh has a great feasibility of this species in culture, production, use and export. However, the production contribution from Bangladesh is still from natural sources and far behind in terms of farming, culture and production. Optimization of larval rearing techniques is therefore important to develop intensive hatchery rearing technique for this species. So, this study is aimed to develop larvae production technique of Portunus pelagicus with a better survival rate. Newly hatched first zoeal of Portunus pelagicus were reared using three different diets till second zoeal stage: (Treatment 1= Artemia franciscana umbrella + Rotifer (Brachionus rotundiformis); Treatment 2= Rotifer (B. rotundiformis) and Treatment 3= Artemia franciscana umbrella). Then, Artemia franciscana nauplii were used for all three treatments till they metamorphosed to crab instar. Regularly, water quality parameters were monitored and maintained and the survival and molting to next stages was observed. The result showed that, all the hatched zoea of P. pelagicus could successfully turns into crab instar stage under all the treatment applied, but the highest survival rate 6.08% was found in case of treatment 2 followed by 0.58%, 0.91%, respectively in treatment 1 and 3. In terms of metamorphosis, it took more than 15 and 14 days respectively from zoea 1 to metamorphose into megalopa for treatments 1 and 3, whereas metamorphosis from zoea 1 to megalopa in treatment 2 finished at the 12 th day with a higher Larval Stage Index (LSI) value which was 4.9. Finally, at the 15 th day larvae were metamorphosed into crablet for treatment 2 and 18 and 16 days required for metamorphosis into crablets for treatment 1 and 3, respectively. However, the larval feed showed a significant effect on growth and survival of P. pelagicus larvae, whereas the earlier larval stage of P. pelagicus rearing with Rotifer (B. rotundiformis) is found as the most suitable diet.
Aquaculture, 2008
Introduction of formulated diet particles for larval culture will simplify hatchery protocols and promote consistent survival, while decreasing total operating costs. The blue swimmer crab, Portunus pelagicus, is a commercially important species with substantial aquaculture potentials in the Indo-Pacific region. Feeding trials aimed at investigating protein nutrition of P. pelagicus larvae were undertaken with the megalopae instar. Microbound diets (MBD) with four different dietary protein sources (fish meal, squid meal, krill meal and soybean meal) were formulated and fed to newly molted megalopae until they metamorphosed to the first crab stage. Thirty megalopae were reared individually for each dietary treatment, with the addition of two control treatments of megalopae fed live Artemia nauplii and an unfed treatment.Survival was high for all fed treatments (73.3–93.3%), while total mortality was recorded for the unfed control. Megalopae fed the fish meal based MBD demonstrated higher survival than that of megalopea fed live Artemia, suggesting that MBD have the potential to completely replace live food for the culture of P. pelagicus megalopae without adversely affecting their survival. These results also suggest that P. pelagicus megalopae are able to adapt to a range of dietary protein sources. For megalopae fed live Artemia nauplii, mean development time was significantly shorter (4.0 ± 0.4 days) and the mean carapace width and dry weight of newly settled first stage crabs were significantly greater, (3.1 ± 0.0 mm, 1.3 ± 0.1 mg, respectively) than megalopae in all other fed treatments. Among MBD treatments, no significant difference in mean development time was detected, however, the mean carapace width of crabs that metamorphosed from megalopae fed fish meal based MBD (2.8 ± 0.0 mm) was larger than those fed squid meal based MBD (2.6 ±0.0 mm) and the mean dry weight of individuals fed fish meal based MBD (0.87 ± 0.04 mg) was also significantly heavier than those fed soybean meal based MBD (0.72 ± 0.04 mg). The outcome of this research provides valuable information regarding protein requirements of P. pelagicus megalopae and will aid in optimising formulated diet particles for potential use in commercial hatcheries.
Ingestion of Brachionus plicatilis and Artemia salina nauplii by mud crab Scylla serrata larvae
Aquaculture Research, 2004
Two feeding experiments were conducted to determine if Brachionus plicatilis and Artemia salina nauplii were ingested by mud crab Scylla serrata larvae. In the ¢rst experiment, larvae were fed with increasing densities of Artemia nauplii with or without Brachionus to determine consumption with increasing densities of Artemia and with increasing zoeal stage. This experiment also aimed to determine if the presence of Brachionus as an alternative prey in£uenced the intake of Artemia by the crab larvae. There was generally an increase in intake with increasing densities of Artemia and increased consumption of Artemia as the larvae grew. Consumption of Brachionus was consistently high in all zoeal stages. There was a signi¢cant reduction in the intake of Brachionus with increasing consumption of Artemia in the early zoeal stages (Z1, Z2, Z3), but at later stages (Z4, Z5) the intake of Artemia was no longer a¡ected by the presence of Brachionus. In the second experiment, daily ingestion within instar of zoeal stages and megalopa were compared. There was an increased consumption of Artemia nauplii on the day before molting and increased ingestion of Brachionus on the dayafter larvae had molted, except at Z3. Megalopae exhibited a decline in Artemia nauplii intake on the days before metamorphosis to crablet. Aquaculture Research, 2004, 35, 62^70 Live food intake by mud crab larvae J C Baylon et al.