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There is intense international interest in the development of spiny lobster aquaculture and of particular interest is the development of artificial diets for spiny lobsters. However, there is little information on the feeding behaviour of spiny lobsters and their ability to handle and consume artificial feeds of different dimensions. Observations of the feeding behaviour of juveniles of the spiny lobster Jasus edwardsii in culture found that they waste significant amounts of food through externally fragmenting the feed pellets before sweeping particles into the mouth. The consumption efficiency of different sized pellets was found to change markedly with increasing size of the juvenile lobsters. Up to 50% of artificial food was wasted by the inefficient feeding behaviour of the lobsters. However, consumption of the feed could be reduced by as much as 19% by altering pellet size. These results indicate that the size of feed pellets, and their consistency and fragmentation characteristics, will be critical aspects of cost‐effective feeding of cultured spiny lobsters. 相似文献
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Comparison of diets for the tropical spiny lobster Panulirus ornatus: astaxanthin-supplemented feeds and mussel flesh 总被引：1，自引：0，他引：1
The fast‐growing tropical lobster Panulirus ornatus is a good aquaculture candidate generating increased research to develop potential feeds. We conducted a 12‐week experiment, assessing growth, survival and tissue carotenoid levels of juvenile P. ornatus. Lobsters were fed either pelleted feeds supplemented with astaxanthin and containing 30, 60, 90 or 120 mg total carotenoid kg?1; or one of two fresh mussel reference feeds – blue Mytilus edulis and green‐lipped Perna canaliculus. There was no clear dose response, in terms of growth rate, to increasing dietary astaxanthin content; mussel‐fed lobsters had inferior growth rates. Twelve‐week survival was unaffected by treatment. Whole lobster carotenoid (4.7, 16.7, 27.8 and 32.8 mg kg?1, dry matter basis) increased with increasing dietary astaxanthin; pre‐treatment carotenoid was 22.2 mg kg?1. Apparent total carotenoid content of the mussel‐fed lobsters was unexpectedly high because of interference by other pigments. High‐performance liquid chromatographic analysis of free astaxanthin levels varied from a pre‐treatment value of 7.3 mg kg?1 to 2.0, 7.6, 12.5 and 23.6 mg kg?1 with increasing dietary astaxanthin, and 3.5 (green‐lip) and 5.9 (blue) mg kg?1 for the mussel‐fed lobsters. Although dietary astaxanthin, over the investigated range, did not affect growth rate or survival, there was a dose–response increase in tissue carotenoid content and darkening of the exoskeleton pigmentation, which may have important implications for immunocompetency and marketing. These implications are discussed in the context of pelleted feed development for this species. 相似文献
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This paper presents bioeconomic data on lobster farming in Vietnam, and perceived constraints to the development of the industry. The farms were found to be profitable, with an average benefit cost ratio of 1.44 and an average net revenue of 262 million VND year?1 (or just under US$15 000 year?1). Investment in the enterprise is high compared with other enterprises in the region. However, disease has the potential to devastate lobster crops and there is little information available to lobster farmers about disease prevention and management. Hence, the lobster enterprise is a high‐risk high‐return industry. The predominant perceived constraints to the development of lobster operations include water quality and temperature issues, insufficient access to credit, good‐quality affordable feed and accurate information about technology improvements in lobster farming. It seems that improving the livelihood of lobster farmers in Vietnam is dependent on reducing their dependence on wild stocks for seed and feed, improving access to credit and improving technical and market information flows. Such improvements are likely to lead to higher profitability, given high export demand and hence sustained high prices for their lobster product. 相似文献
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Assessment of the production and dispersal of faecal waste from the sea‐cage aquaculture of spiny lobsters 
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下载免费PDF全文 Despite the rapid expansion of spiny lobster aquaculture, very little is known about its potential environmental impacts. In an effort to understand the potential impacts of sea‐cage culture of spiny lobsters, the faecal output and settling velocity of faeces of spiny lobster were quantified. These data were then used in hydrodynamic modelling to assess the dispersal pattern of faecal material from two sizes of hypothetical spiny lobster farms, so that inferences about likely benthic impacts could be made by modelling different scenarios of farm stocking density and food conversion efficiency. The overall mean settling velocity of lobster faecal strands was 0.9 ± 0.05 cm s?1. There was a positive correlation between both the weight and density of faecal strands and their settling velocity. Conversely, neither the length nor the surface area of faecal strands was correlated with the settling velocity. Hydrodynamic modelling showed that faecal material deposition mainly occurred directly beneath the sea‐cages. The density of faecal material deposition increased proportionately with higher stocking density and FCR values. Overall, the results indicate that the deposition of faecal waste from sea‐cage lobster aquaculture is unlikely to cause widespread benthic impacts when operating to the current highest commercial stocking and feeding levels. 相似文献
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David G. Bourne Lone Hj Nicole S. Webster Jennie Swan Michael R. Hall 《Aquaculture (Amsterdam, Netherlands)》2006,260(1-4):27-38
The role of bacterial biofilms in disease processes is becoming increasingly recognised in both clinical and environmental settings. Biofilm development within a rearing tank of the tropical rock lobster Panulirus ornatus was studied to evaluate if the biofilm is a reservoir for potentially pathogenic bacteria that cause mass larval mortalities. Within a 5000 L larval rearing tank, fiberglass microscope slides were systematically distributed during a standard rearing attempt to assess biofilm development. Culture-based counts for two media types, TCBS and Marine Agar (MA), demonstrated increased bacterial densities until days 11 and 13 respectively. For both media types, a drop in the plate counts was followed by a subsequent increase towards the end of the experiment. Scanning electron microscopy (SEM) confirmed that cell densities decreased between days 13 and 17, most likely due to sloughing of the biofilm into the water column. SEM images revealed distinct changes in dominant morphologies reflecting a succession of bacterial populations. A dynamic succession of microbial species during biofilm development was also demonstrated using denaturing gradient gel electrophoresis (DGGE) profiling of bacterial 16S rRNA genes in combination with statistical ordination analysis. Prominent changes in the DGGE profiles coincided with the decrease in bacterial numbers observed by SEM and plating on MA between days 13 and 17. Fluorescence in situ hybridization (FISH) identified -Proteobacteria as being numerically abundant in the biofilm. This was supported by results from DGGE analysis, which retrieved only sequences affiliated with - and γ-Proteobacteria. DGGE bands affiliated with Vibrio became dominant towards the end of the larval run (days 21 to 24). A Vibrio harveyi strain isolated from the biofilm late in the larval rearing trial (day 24) demonstrated increased larval mortality in small scale phyllosoma survival studies. The detection of Vibrionaceae at the end of the larval trial coincided with mass phyllosoma mortality and show that the biofilm is a reservoir for potentially pathogenic bacteria. 相似文献
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In an 8‐week growth experiment, juvenile spiny lobsters (Panulirus ornatus) grew best on a feed containing at least 610 g kg?1 crude protein on a dry matter basis (DM) and a digestible protein to digestible energy ratio of 29.8 mg kJ?1. The study entailed a six treatment by four replicate randomized block experiment with 222 wild‐caught P. ornatus of mean initial weight (±SD) of 2.5 ± 0.19 g. The lobsters were fed one of five isolipidic feeds (approximately 130 g kg?1 DM) in which the crude protein was serially incremented between 330 and 610 g kg?1 DM, or a reference diet comprising the flesh of frozen green‐lip mussels. Lobsters fed the pelleted feeds had high survival (79 ± 4.5%) and responded to increasing dietary crude protein content with progressively higher growth rates, with the daily growth coefficient improving from 0.72% day?1 with 330 g kg?1 crude protein to 1.38% day?1 with 610 g kg?1 crude protein. Both growth rate and survival were low with the mussel diet (0.80% day?1and 41 ± 4.5%, respectively). These results demonstrate that tropical spiny lobsters grow well when fed high‐protein, high lipid, pelleted feeds, but feeding on a sole diet of freshly thawed green‐lip mussels was unsatisfactory. 相似文献
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The suitability of VIE tags to assess stock enhancement success in juvenile European lobsters (Homarus gammarus) 下载免费PDF全文
下载免费PDF全文 Sarah T V Neenan David J Hodgson Tom Tregenza Dominic Boothroyd Charlie D Ellis 《Aquaculture Research》2015,46(12):2913-2923
Assessments of stock enhancement programmes for European lobsters (Homarus gammarus) require mark‐recapture analysis of stocked individuals. However, established tag technology is deemed unsuitable for extensive use by many current lobster hatcheries, particularly upon the early juvenile stages. We tested the suitability of fluorescent Visible Implant Elastomer (VIE) tags for use in 5‐month‐old juvenile lobsters. Three treatment groups comprising 348 cultured lobsters in total were used to examine survival, growth and tag retention, and to assess mobility, shelter use and moulting behaviours. Tagging had no significant effect on lobster survival, growth, mobility, shelter use or moult frequency. Survival over 7 weeks was 75% among lobsters tagged with two elastomers, 76% in those with one elastomer and 74% among untagged controls. Mortality during moulting did not increase in tagged (6%) compared to untagged lobsters (9%). We found no evidence that VIE tags cause any negative effects that would be expected to inhibit survival upon wild release, but tag loss had reached 12% in both tagged treatments after 7 weeks and showed no sign of abating. Our study suggests that VIEs effectiveness in discerning cultured lobsters long after wild release may be limited when used in smaller juveniles. 相似文献
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《Journal Of Applied Aquaculture》2013,25(3):43-57
Abstract The growth, survival, and biochemical composition of juvenile southern rock lobster, Jasus edwardsii, were examined in response to a variety of diets, consisting of a natural food organism (blue mussel, Mytilus edulis) and/or commercial shrimp pellets. Blue mussel supported significantly better (a minimum of 25% higher) growth than a range of shrimp diets. Diet intake (0.83-1.26% wet body weight/day) and feed conversion ratio (1.34-2.48) with the formulated diets were generally similar to that with blue mussel (1.03% wet body weight/day; 1.55 feed conversion ratio). Changes in the chemical composition of southern rock lobsters due to treatments were more clearly observed in the digestive gland than in the whole body. Carapace color and tissue carotenoid level varied significantly with carotenoid content of the diets. A caro-tenoid level of 115 mg/kg is required in formulated diets to produce southern rock lobsters of similar color to wild-caught juveniles. In a separate experiment, a blue mussel diet was compared to mixed diets comprised of blue mussel and a shrimp, Penaeus monodon, diet. In the mixed diets, blue mussel was replaced with the formulated diet for either ×days/week or 6 days/week. Growth and survival did not differ significantly among treatments. The use of formulated diets in the culture of southern rock lobster appears feasible but will require increased knowledge of the nutritional requirements. Until specific diets are developed, this study has shown that similar growth can be obtained from a mixed diet, consisting primarily of a cheap formulated diet supplemented with blue mussel once per week. Such a scenario offers real possibilities for significantly reducing the cost of southern rock lobster production. 相似文献
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Claw size and dominance in cultivated versus wild European lobsters Homarus gammarus were compared. Normally, lobsters develop a short, high and wide crusher and a slender scissor claw. In culture, both claws often develop into scissor claws. With growth, cultivated males developed one significantly elongated scissor claw (major claw), and one normal scissor claw, compared to wild males (minor claw). The differences increased with size. The wild males had higher claw index than cultured ones, due to the crusher claw. Wild lobsters with higher claw index were dominant. Cultivated males with claw indices at least 200 mm2 higher than the opponent, won. Only scissor claws were broken in the encounters. Even if cultivated lobsters in time develop claws equal to wild lobsters, they might still be less robust. In the light of these findings, we suggest that lobsters cultivated for restocking purposes should be given access to an appropriate substrate allowing them to develop one claw into a crusher during the early benthic stage. 相似文献
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Danielle Johnston Roy Melville-Smith Blair Hendriks 《Aquaculture (Amsterdam, Netherlands)》2007,273(1):108-117
Two trials were conducted to compare the growth and survival of western rock lobster Panulirus cygnus post-pueruli and year 1 juveniles fed different diets. Trial 1 compared lobsters fed a formulated pelletised feed developed for Panulirus ornatus supplemented with fresh mussels (Mytilus edulis) two days per week, with lobsters fed a daily diet of pellets. Trial 2 compared lobsters fed the pellet-mussel supplement diet with those fed a daily diet of fresh mussels.In the first trial, diet treatment did not significantly affect survival, although it was higher in tanks supplemented with mussels. Growth of post-pueruli and year 1 juveniles fed the pellet diet (0.03 g/day; 0.14 g/day, respectively) was significantly lower than growth of post-pueruli and year 1 juveniles fed pellet-mussel supplement diets (0.07 g/day; 0.2 g/day, respectively). Year 1 lobsters fed the pellet-mussel supplement diet consumed considerably less pellet (0.27 vs 0.40 g pellet dry matter/day (DM/day)) than those fed pellets indicating that they will preferentially favour mussel over pellet diets. Feed conversion ratio (FCR) was significantly better for lobsters fed the pellet-mussel supplement diet as a result of the poor growth of pellet-fed lobsters.In the second trial, survival was significantly higher for lobsters fed mussels only. Growth of post-pueruli fed a mussel diet (0.14 g/day) was significantly higher than those fed pellet-mussel diets (0.11 g/day), but there was no significant difference in growth for year 1 juveniles (0.33 g/day). Feed intake of mussel on a dry matter basis was higher than pellet intake for both size classes, with mussel intake being more than double pellet intake for post-pueruli (0.20 vs 0.49 g DM/day).Poor growth of P. cygnus on a pellet only diet indicates that the current formulation for P. ornatus may be inadequate for P. cygnus. However, as pellet intake declined dramatically for year 1 lobsters offered a mussel supplement, and pellet consumption was significantly lower than mussel consumption, it is more likely that poor growth may be attributed to inadequate palatability and intake. The similarly good survival of lobsters fed pellet and pellet-mussel diets indicates that the pellet diet is an acceptable maintenance diet for P. cygnus, but is not suitable for maximising growth for this species. Further research is needed to improve palatability, intake and potentially nutritional composition of this pellet diet before its suitability for P. cygnus is assured. 相似文献
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Juvenile (1–10 g) southern rock lobsters, Jasus edwardsii, were subjected to five photoperiods [0L(light):24D(dark); 6L:18D; 12L:12D; 18L:6D; 24L:0D] during a 112‐day trial, and growth, survival, colour, food consumption and activity were examined. Lobsters grown under the 6L:18D and 24L:0D photoperiods had significantly lower (P < 0.05) final mean weight and specific growth rate than any other treatments. Photoperiod had no effect on survival or colour of lobsters. Food consumption differed significantly during the first week of the trial; after 5 weeks, food consumption was similar in all treatments. Major peaks in activity occurred during dark periods for lobsters exposed to photoperiods that had a light:dark regime. Activity of lobsters exposed to continuous light or dark regimes remained constant and at low levels during the 24‐h period. Food consumption or activity does not appear to determine the rate of growth of lobsters in the different photoregimes. One over‐riding outcome of this and other studies on photoperiod is that the growth and survival response of juvenile J. edwardsii was not significantly better than those of the standard 12L:12D cycle. 相似文献
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A decrease in somatic growth rate, and hence productivity, of the South African west coast rock lobster population which occurred in the late 1980s has had important ramifications for subsequent TACs set for this resource. These are critically dependent on monitoring growth rates and determining whether an increase back towards earlier higher levels is underway. The available data are not well balanced by season and location, and a GLMM approach is used to take account of season–location interactions by treating these as random effects. This results in much less precise estimates of annual somatic growth rate than had been suggested by an earlier fixed effects GLM approach, and has necessitated a change in the philosophy underlying management of the resource. 相似文献
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《Journal Of Aquatic Food Product Technology》2013,22(3):63-78
Abstract The present study was undertaken to determine potential sources of Listeria monocytogenes contamination through statistical analysis of L. monocytogenes results from lobster and snow crab samples and Listeria spp. results from environmental swabs. The objectives were (1) to compare crustacean analysis records for relationships between presence/absence of L. monocytogenes and crustacean species, year, total aerobes, staphylococci and fecal coli-form; and (2) to identify sites prone to Listeria spp. contamination. There were no significant differences in L. monocytogenes incidence between lobster and snow crab nor between five consecutive years of survey. Total aerobes and staphylococci counts were significantly associated with incidence of L. monocytogenes; fecal coliform counts were not. On surfaces in contact with the processed product, Listeria spp. were mostly found within crab crushers, drum meat separators, shucking machines, on aprons, gloves, work tables and knives. Higher incidence of Listeria spp. were found on surfaces not in direct contact with the processed product such as truck boxes, foot stools, floors, drains and employee boots and pants. 相似文献
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Movement influences the annual distribution patterns of a species and is an important determinant of stock structure. In situations where monitoring programs have quantified movement or distribution patterns by sampling during particular times of the year, seasonal changes in abundance as well as the degree of connectivity among adjacent stocks can be underestimated. Here, a summer abundance trawl survey was combined with a 1-year mark-recapture tagging study to infer seasonal changes in distribution within and among American lobster (Homarus americanus) stocks. Within the study area, lobsters were concentrated in central Northumberland Strait (Canada) during August, yet their observed dispersal behaviour implied that density declined in the central portion and increased in the northern portion of Northumberland Strait during winter. Stock mixing among management zones was not observed and individual tendencies to move were predicted to decline precipitously in early December. These movement patterns are consistent with the hypothesis of seasonal limitation by hard-substrate habitat availability causing population redistribution. Such information can ultimately be useful when assessing changes in abundance or exploitation rates, and for guiding management efforts. 相似文献
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Duangjai Pisuttharachai Motoshige Yasuike Hideaki Aono Keisuke Murakami Hidehiro Kondo Takashi Aoki Ikuo Hirono 《Fisheries Science》2009,75(1):195-206
Two complementary DNA (cDNA) libraries were constructed from phyllosomas and hemocytes of adult Japanese spiny lobster Panulirus japonicus and a total of 2,673 expressed sequence tags (ESTs) were obtained. After assembly and clustering, 450 and 458 unique sequences
were found from the phyllosoma and hemocyte cDNA libraries, respectively. Of these, 114 and 220 ESTs showed significant homologies
with known genes in the National Centre for Biotechnology Information (NCBI) database. The remaining sequences were of unknown
function. Immune-related genes found in this study include lectin, proteinase inhibitor, prophenoloxidase, heat-shock protein,
antimicrobial peptide, and a few putative defense-related proteins. 相似文献