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Postlarvae

Distribution by Scientific Domains

Earth and Environmental Science	100%

Kinds of Postlarvae

Penaeu monodon postlarvae

monodon postlarvae

Selected Abstracts

Use of Cyclopoid Copepod Apocyclops dengizicus as Live Feed for Penaeus monodon Postlarvae

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2009
Omidvar Farhadian
In this study, the suitability of cyclopoid copepod Apocyclops dengizicus as a live food for black tiger shrimp, Penaeus monodon, postlarvae was investigated. After 14 d, P. monodon postlarvae (PL1) had survival rates of 41.7 ± 2.9% (mean ± SE), 28.7 ± 1.2%, 56.3 ± 3.7%, 4.4 ± 1.9%, and 2.8 ± 1.0% when fed A. dengizicus (CC), Artemia nauplii (AN), mixture of A. dengizicus and Artemia nauplii (CC + AN), artificial shrimp feed (SF), and microalga Tetraselmis tetrathele (TT), respectively. Specific growth rates (SGRs) of P. monodon were maximum (14.2 ± 0.6%/d) in CC + AN, followed by CC (11.0 ± 0.4%/d), AN (9.3 ± 0.7%/d), SF (6.1 ± 0.2%/d), and TT (6.0 ± 0.5%/d). The total n-3 fatty acids of postlarvae increased from 20.6 to 25.8% when fed with CC, 28.8% with AN, and 29.0% with CC + AN. Better survival and SGRs of P. monodon postlarvae could be attributed to docosahexaenoic acid : eicosapentaenoic acid : arachidonic acid ratio of CC (10.2:3.2:1) diet. The results of this study showed that A. dengizicus has a potential to be used as a substitute live feed for P. monodon postlarvae because of better survival, growth, and high polyunsaturated fatty acids. [source]

Effect of Low Salinity on Growth and Survival of Postlarvae and Juvenile Litopenaeus vannamei

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2001
Susan Laramore
The effect of low salinity on survival and growth of the Pacific white shrimp Litopenaeus vannamei was examined in the laboratory due to the interest of raising shrimp inland at low salinities. In three separate experiments, individual L. vannamei postlarvae (, 0.1 g) were cultured at salinities of either 0.5, 1, 1.5, 2, or 3 ppt (N= 5 or 10/treatment) for 18 to 40 d at 30 C in individual 360-mL containers. In each experiment controls of 0 and 30 ppt were run. There was no postlarval survival at salinities < 2 ppt. Survival was significantly different (P < 0.01) at 2 ppt (20%) compared to 30 ppt (80%). Growth was also significantly different (P < 0.01) at 2 and 3 ppt compared to 30 ppt (416%, 475%, and 670%, respectively). A fourth experiment compared juveniles (, 8 g) and postlarvae (, 0.05 and 0.35 g). Shrimp were cultured at salinities of 0, 2, 4, and 30 ppt for 40 d at 25 C, in individual 360-mL and 6-L containers (N= 7/treatment). There was no postlarval survival at < 2 ppt. Postlarval survival at 4 ppt (86%) was not significantly different (P > 0.05) from 30 ppt (100%). Juveniles exhibited better survival at lower salinities (100% at 2 ppt) than 0.05 and 0.35 g postlarvae (29% and 14% respectively, at 2 ppt). The effects of salinity on growth varied with sizdage. Final growth of 0.05 g postlarvae at 2 ppt (693%) was significantly less (P < 0.01) than at 4 ppt (1085%) and 30 ppt (1064%). Growth of 0.35 g postlarvae was significantly less (P < 0.01) for 4 ppt (175%) than for 30 ppt (264%). There was no growth data for juveniles (8 g). It appears from these experiments that the culture of L. vannamei poses risks when performed in salinities less than 2 ppt. [source]

Density and Water Exchange-Dependent Growth and Survival of Litopenaeus setiferus Postlarvae

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2001
Gabriela Palomino
This present study was designed to investigate the effects of stocking density and water exchange on the growth rate, survival and performance index of L. setiferus postlarvae under controlled laboratory conditions. The experiment was done with postlarvae (PL10 to PL40) at densities of 50, 150, 250 and 350 shrimp/m2 and various different water exchanges rate per day (0, 6, 12 and 18%). The maximum growth rate was obtained for shrimp with 12% water exchange per day at all densities. A reduction of the maximum growth rate was observed in relation to density with the highest values in shrimp stocked in a density of 50 and 150 shrimp/m2 (mean value of 0.53 mg/d) and the lowest in shrimp stocked in a density of 350 shrimp/m2 (0.24 mg/d). The multiple regression equation obtained to relate performance index (growth rate* survival : PI), shrimp density (X1) and water exchange (X2) was: PI = 0.31 + (0.001) X1+ 0.039 X2+ 2.28 × 10,6 X12+ (,0.0017) X22+ (0.000026)X1X2,R2= 0.78; P > 0.03. According to this equation the optimum shrimp density-water exchange comhination was between 5 to 12% of water exchange at stocking density of between 50 and 150 shrimp/m2. Salinity, ammonia-N and nitrite-N increased according to the time spent in tanks without water exchange. With no (0%) water exchange, water quality parameters measured were outside the optimum for L. setiferus postlarvae. The use of optimum density and water exchange in a nursery system for L. setiferus with optimum variables established is proposed. [source]

Identification and partial characterization of selected proteolytic enzymes in the digestive system of giant freshwater Prawn Macrobrachium rosenbergii (De Man) Postlarvae

AQUACULTURE RESEARCH, Issue 5 2009
Mohamed Ayaz Hasan Chisty
Abstract Biochemical assays and substrate SDS-PAGE were conducted to partially characterize and identify various types of proteases present in the digestive tract of PL15 giant freshwater prawn (Macrobrachium rosenbergii). Casein hydrolytic assay of the enzyme extracts showed major proteolytic activities at pH 3.0, 6.0 and 9.0, while assay of preincubated enzyme extracts with phenylmethylsulphonyl fluoride (PMSF), a serine protease inhibitor produced a 33.17% reduction in alkaline protease activity. When specific inhibitors tosyl-lysine chloromethyl ketone and tosyl-phenylalanine chloromethyl ketone were used, they resulted in a reduction in activity of proteases in the enzyme extracts by 82.41% and 55.03%, respectively, confirming the presence of trypsin and chymotrypsin, while ethylenediamine tetraacetic acid produced protease activity reduction in 33.92% showing the presence of metalloproteases in the digestive tract of the prawn. Further characterization of the alkaline proteases using SDS-PAGE technique, after incubating the extract in the presence or absence of specific inhibitors, produced six bands corresponding to molecular masses of between 13.48 and 136.1 kDa; two trypsin bands of 13.48 and 36.4 kDa, three chymotrypsin bands in the range of 23.0,73.4 kDa and one for metalloprotease of 136.1 kDa, all of which were identified from a zymogram. This study suggests that protein digestion in M. rosenbergii is initiated by an acid protease followed by a combination of action of alkaline proteases: trypsin, chymotrypsin and metalloproteases. [source]

Cage culture of the Pacific white shrimp Litopenaeus vannamei (Boone, 1931) at different stocking densities in a shallow eutrophic lake

AQUACULTURE RESEARCH, Issue 2 2009
Maria Lourdes A Cuvin-Aralar
Abstract Postlarvae of Litopenaeus vannamei were acclimated and stocked in lake-based cages at the following stocking densities: 10, 20, 30 and 40 shrimp m,2. Another set of shrimp was stocked in concrete tanks as reference samples at 30 shrimp m,2. Significant differences were observed among stocking densities throughout the 95-day culture. The final weight at harvest decreased with increasing stocking density: mean weights of 23.3, 15.8, 13.0, 10.9 and 14.6 g for the 10, 20, 30, 40 shrimp m,2 and reference tanks were observed respectively. There were no significant differences in survival throughout the culture period, ranging between 69% and 77%. Daily growth rates (range: 0.11,0.24 g day,1) and specific growth rates (range: 3.54,4.34%) also differed significantly among stocking densities, both increasing with decreasing stocking density. The feed conversion ratio in the cages did not differ among the stocking densities, ranging from 1.53 to 1.65. The relationship between stocking density and mean individual weight at harvest followed the equation y=81.06x,0.54 (R2=0.938) and that of stocking density and production (in g m,2) is y=58.01x,0.46 (R2=0.834). [source]

The New Zealand common smelt: biology and ecology

JOURNAL OF FISH BIOLOGY, Issue 1 2005
F. J. Ward
The common smelt is one of the most widespread indigenous freshwater fishes in New Zealand. One other member of the family Retropinnidae, Stokellia anisodon(Stokell), is present but is confined to a small region of the South Island. There are many diadromous as well as river and lake resident populations, the latter, sometimes a result of introductions to serve as forage fish for trout. Diadromous smelt spawn during austral autumn,winter on sand bars of lower riverine reaches. Larval stages inhabit coastal marine waters, and the postlarvae to immature stages re-enter rivers and some lowland lakes. Diadromous smelt are distinguished from lowland lake resident forms by high vertebral but low gill raker numbers and larger size and from those present in some isolated waters, by high vertebral numbers alone. Lake or reservoir resident smelt usually spawn in austral spring,summer on sandy shallows at stream mouths or along shorelines. Verified smelt ages (otolith analyses) indicate that in some populations most smelt mature and spawn after c. 1 year. Adult smelt feed on a spectrum of primarily invertebrate animals ranging from small zooplankters to insects and occasionally small fishes. Smelt are a major prey for both brown trout and rainbow trout. Adult smelt are a minor food for the Maori people. As postlarvae they are a component of a few ,whitebait' fisheries. Most smelt populations are increasingly affected by environmental changes induced by human activities. Although many studies have examined problems affecting smelt, further effort is required, along with more basic research. [source]

A multivariate approach to the feeding habits of small fishes in the Guadalquivir Estuary

JOURNAL OF FISH BIOLOGY, Issue 2002
F. Baldoa
In the analysis of the feeding habits of the 11 most abundant fish species in the Guadalquivir Estuary, collected monthly (February 1998 to January 1999) at two different sampling sites, a total of 46 prey taxa were identified. Classifications (based on Bray,Curtis similarities derived from occurrence, number and mass data) of the different fish categories (postlarvae and juvenile,adults of each species) revealed two main trophic guilds, whose preferential prey (SIMPER analysis) were mysids and copepods, respectively. The similarity matrices derived from occurrence, number and mass data were always significantly correlated (RELATE: r>0.636; P<0.01), indicating that a good agreement in feeding patterns emerged from these variables. The seasonal coincidence of maximal fish and key-prey species densities suggests that food availability may be a principal factor influencing the nursery function of the Guadalquivir Estuary. [source]

First description of larvae of Acanthodraco dewitti in the Ross Sea, Antarctica

JOURNAL OF FISH BIOLOGY, Issue 2000
M. La Mesa
Six postlarval and an adult bathydraconid were collected in Terra Nova Bay, Ross Sea, during January-February 1988 and February 1998, respectively. The adult was identified as Acanthodraco dewitti Skóra, 1995 (type locality South Shetland Islands), a species not recorded in the Ross Sea. The postlarvae may be those of A. dewitti. The morphology and pigmentation patterns of the postlarvae are described and compared with those of other bathydraconids. [source]

Ontogenetic Variation in Ammonia Excretion during the Early Life Stages of the Amazon River Prawn, Macrobrachium amazonicum

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2010
Liliam De Arruda Hayd
Dry mass (DM) and total ammonia-N (TAN) excretion were determined in embryos, larvae (ZI,ZIX, Z = zoea ), and postlarvae (PL) at 1, 7, and 14 d after metamorphosis (PL1, PL7, and PL14) of Macrobrachium amazonicum. Animals in postmolt,intermolt (A,C) stages were sorted according to their developmental stages, and placed into incubation chambers (, 30 mL) for 2 h to quantify TAN excretion. After this period, analyses were carried out using Koroleff's method for TAN determination. Individual TAN excretion generally increased throughout ontogenetic development and varied from 0.0090 ± 0.0039 µg TAN/individual/h in embryo to 1.041 ± 0.249 µg TAN/individual/h in PL14. There was no significant difference between embryo,ZIV and ZV,ZIX (P > 0.05), whereas PL1, PL7, and PL14 differed (P < 0.05) from each other. Higher increments in individual ammonia-N excretion were observed between ZIV,ZV, PL1,PL7, and PL7,PL14. Mass-specific excretion rates presented two groups, embryo,ZII (P > 0.05) and ZIII,PL14 (P > 0.05). The lowest value was found in embryo (0.17 ± 0.07 µg TAN/mg DM/h) and the maximum values in ZV and PL1 (0.65 ± 0.25 and 0.64 ± 0.27 µg TAN/mg DM/h, respectively). Results indicate that metabolic rate is proportional to the body mass in M. amazonicum, during early life stages. Variations in ammonia excretion during this phase may be associated mainly with body size. Data obtained in the present study may be useful in developing and optimizing rearing techniques of M. amazonicum, such as the proportions between biofilter and rearing tank size, and stocking density in culture tanks or in transport bags. [source]

Use of Cyclopoid Copepod Apocyclops dengizicus as Live Feed for Penaeus monodon Postlarvae

Effects of Artificial Substrate and Stocking Density on the Nursery Production of Pacific White Shrimp Litopenaeus vannamei

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2004
Komarey R. K. Moss
Nursery production may be enhanced by the addition of artificial substrate to increase the surface area upon which shrimp graze and to serve as refuge. The objective of this study was to assess the effects of the artificial substrate, AquaMatsTM, on the performance of postlarval Pacific white shrimp Litopenaeus vannamei stocked at three densities. Eighteen 230-L tanks were stocked with 10-d postlarvae (mean weight < 0.01 g). Six treatments were evaluated and consisted of shrimp stocked at three densities (778 shrimp/m2, 1,167 shrimp/ m2, and 1,556 shrimp/m2) with and without access to artificial substrate. Shrimp in all treatments received a commercial diet ad libitum. After 6 wk, shrimp were harvested from each nursery tank, counted, and batch weighed. Mean final weight, survival, production, feed conversion ratio, and water quality parameters were analyzed by 2-way ANOVA. There were highly significant (P < 0.001) density and substrate effects on final weight, but there was no significant interaction effect. Final weight was 26.0, 17.4, and 34.5% greater in treatments with substrate than without substrate when stocked at 778, 1,167, and 1,556 shrimp/m2, respectively. There was no significant density, substrate, or interaction effect on survival or water quality. Mean survival was ± 89.1% for all treatments. Increased shrimp growth in the presence of added substrate was likely due to the availability of attached particulate organic matter on the AquaMatsTM that served as an additional food source. Results from this study indicate that artificial substrate can be used to mitigate the potential negative effects of high stocking density on growth of L. vannamei in nursery systems. [source]

Effect of Low Salinity on Growth and Survival of Postlarvae and Juvenile Litopenaeus vannamei

Density and Water Exchange-Dependent Growth and Survival of Litopenaeus setiferus Postlarvae

Effects of Diet and Water Source on the Nursery Production of Pacific White Shrimp Litopenaeus vannamei

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2001
Clete A. Otoshi
Penaeid shrimp reared in eutrophic pond water grow significantly faster than shrimp in clear well water, and this growth enhancement is especially pronounced in postlarval shrimp. The objective of this study was to determine if the nutritional benefits of pond water could supplement a lower protein feed for postlarval Pacific white shrimp Litopenaeus vannamei. Sixteen 230-L tanks were stocked with 10-d postlarvae at a density of 350 shrimp/tank. Four treatments (four replicates/treatment) were tested for 6 wk and consisted of: 1) shrimp grown in well water and fed a commercially available 45%-protein feed (W/45); 2) shrimp grown in pond water and fed the same 45%-protein feed (P/45); 3) shrimp grown in well water and fed a commercially available 52%-protein feed (W/ 52); and 4) shrimp grown in pond water and fed the same 52%-protein feed (P/52). At the end of the experiment. mean weight gain (± SE) for shrimp in pond water (1.85 ± 0.03 g) was significantly greater (P > 0.0001) than shrimp in well water (0.98 ± 0.10 g). Mean weight gain for shrimp fed the 52%-protein feed (1.56 ± 0.13 g) was significantly greater (P > 0.0001) than shrimp fed the 45%-protein feed (1.26 ± 0.20 g). In addition, there was a significant interaction effect between water source and feed (P > 0.0001). Mean weight gain for shrimp in the W/52 treatment (1.23 ± 0.04 g) was 68% greater than shrimp in the W/45 treatment (0.73 ± 0.03 g). However, mean weight gain for shrimp in the P/52 treatment (1.90 ± 0.03 g) was only 5% greater than shrimp in the P/45 treatment (1.80 ± 0.04 g). These results suggest that organically rich pond water provides postlarval shrimp with sufficient nutrients to compensate for nutritional deficiencies associated with a lower protein feed. [source]

Evaluation of indigenous marine periphytic Amphora, Navicula and Cymbella grown on substrate as feed supplement in Penaeus monodon postlarval hatchery system

AQUACULTURE NUTRITION, Issue 2 2009
H. KHATOON
Abstract Three isolated marine diatoms (Amphora, Navicula and Cymbella) grown on substrate were evaluated as feed supplement for Penaeus monodon postlarvae (PL) in hatchery system for a period of 19 days without changing water. Specific growth rate (day,1) (0.27 ± 0.0) and survival (%) (56.3 ± 1.8) of PLs were significantly higher (P < 0.05) in treatment tanks when compared with the control (0.20 ± 0.0; 36.0 ± 1.5, respectively). Shrimp PLs reared in substrate-based tanks had significantly higher (P < 0.05) levels of protein, lipid (521.0 ± 7.0; 304.0 ± 2 g kg,1 dry weight, respectively), ecosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (189.0 ± 2.0; 176.0 ± 2 g kg,1 of total fatty acid, respectively) than the control (435.0 ± 22.0; 258.0 ± 22 g kg,1 dry weight; 172.0 ± 5.0; 152 ± 2 g kg,1 total fatty acid, respectively). The periphytic diatoms contained protein and lipid (430,490; 230,260 g kg,1 dry weight, respectively), EPA (30,150 g kg,1 of total fatty acids), DHA (20,30 g kg,1 of total fatty acids) and nine essential amino acids. The results showed that isolated marine periphytic diatoms grown on substrate could be used as feed supplement in enhancing the growth and survival of P. monodon postlarvae. [source]

Use of Cyclop-eeze as a substitute for Artemia nauplii in larval rearing of giant freshwater prawn Macrobrachium rosenbergii (De Man 1879)

AQUACULTURE NUTRITION, Issue 2 2007
C. MOHANAKUMARAN NAIR
Abstract Four feeding experiments, replacing 25% (T1), 50% (T2), 75% (T3) and 100% (T4), by dry weight, of the live feed Artemia nauplii for Cyclop-eeze, a new larval feed that was claimed to contain the highest known levels of astaxanthin and omega-3 polyunsaturated fatty acids, were compared against a control that was fed with Artemia and egg custard alone, to the larvae of giant freshwater prawn Macrobrachium rosenbergii (De Man 1879). Analysis of different production characteristics of the larvae revealed that the highest survival up to postlarvae (PL) stage was obtained for T2 in which 50% of the Artemia nauplii were replaced by Cyclop-eeze [freeze-dried (FD) deep frozen (DF)], and the highest astaxanthin content of the larval tissue obtained in T4 in which the larvae were fed 100% Cyclop-eeze, although the survival rate was the lowest in this treatment. The costs of different treatments were also compared. The Artemia consumption million,1 larvae was the highest in control (11490 g), followed by T1 (8240 g), T2 (4990 g), T3 (3730 g) and T4, which completely replaced Artemia from stage 5 onwards (1830 g). The highest consumption of Cyclop-eeze million,1 larvae was in T4 (1670 and 10 880 g), followed by T3 (850 and 5560 g), T2 (410 and 2690 g) and T1 (230 and 1490 g) of FD and DF, respectively. The astaxanthin contents of the late-stage larvae fed under the four treatments were 24.90, 27.40, 28.60 and 35.60 ,g g,1 tissue for T1, T2, T3 and T4, respectively, while that of the control was 23.70 ,g g,1. The lowest cost of live feeds million,1 PL was obtained for T2 (US$ 428.60), followed by T1 (US$ 490.46), control (US$ 529.07) and T3 (US$ 583.26), while it was the highest for T4 (US$ 890.93). The results indicated that Cyclop-eeze could economically replace Artemia nauplii at 50% level that could significantly improve the survival and carotenoid composition of the larvae of M. rosenbergii. [source]

Effect of microencapsulated diets supplemented with genetically modified bacteria on the growth and survival of Fenneropenaeus indicus postlarvae

AQUACULTURE NUTRITION, Issue 1 2007
S. SIRVAS-CORNEJO
Abstract Microencapsulated diets were prepared and supplemented with two genetically modified bacteria that produced digestive enzymes. One produced a protease (strain Escherichia coli XL1Bluep635), and the other a lipase and a protease (strain E. coli XL1Bluep7). Fenneropenaeus indicus at the postlarval 1 stage (PL1) were fed these diets for 16 days, and their total length and survival were recorded every 2 days. The results were analyzed by anova and sequential Turkey,Kramer analysis. Shrimp fed on the diet supplemented with strain E. coli XL1Bluep635 (diet 635) exhibited the fastest growth rate of 0.26 mm day,1, followed by shrimp fed on the control commercial unsupplemented diet CD2 , 0.21 mm day,1, and shrimp fed on diet supplemented with strain E. coli XL1Bluep7 (diet 7) , 0.20 mm day,1. The growth rates of shrimp fed on diet supplemented with control strain E. coli XL1BluepUC19 (diet XL1), and those fed on unsupplemented diet prepared in our laboratory (D2), were 0.15 and 0.14 mm day,1, respectively. The survival of shrimp fed on diets CD2 and 635 showed the same level of survival of 83.3%, followed by those fed on diet D2 with 76.6%. Shrimp fed on diet 7, showed 71.6% survival, and those fed on diet XL1, 55%. [source]

Complete and partial replacement of Artemia nauplii by Moina micrura during early postlarval culture of white shrimp (Litopenaeus schmitti)

AQUACULTURE NUTRITION, Issue 2 2006
L. MARTÍN
Abstract Growth rate, soluble protein content, osmotic stress and digestive enzyme activity were studied in early Litopenaeus schmitti postlarvae under different feeding regimens, by partially or completely replacing Artemia nauplii with Moina micrura. Growth was significantly higher in the postlarvae fed with a mixture of M. micrura, Artemia nauplii and algae (0.030 mg dry weight (dw) larva,1 day,1, 17.4 ± 2.1% day,1), together with the postlarvae fed on Artemia nauplii and algae (0.027 mg dw larva,1 day,1, 18.3 ± 1.9% day,1). Complete replacement of Artemia nauplii by M. micrura produced the lowest growth rate (0.018 mg dw larva,1 day,1, 14.3 ± 1.6% day,1) and induced the highest protease and , -amylase activities and lower soluble protein contents. No significant difference among the treatments could be detected in postlarval resistance to osmotic stress. Based on the growth results, soluble protein content, enzymatic activity and osmotic stress resistance, we determined that the partial replacement of Artemia nauplii by M. micrura did not affect the growth, the soluble protein content and the nutritional state in the postlarvae of L. schmitti. To our knowledge, this is the first reported use of M.micrura as feed for early postlarvae of L. schmitti. [source]

Effect of hot water extracts of brown seaweeds Sargassum spp. on growth and resistance to white spot syndrome virus in shrimp Penaeus monodon postlarvae

AQUACULTURE RESEARCH, Issue 10 2010
Grasian Immanuel
Abstract An experiment was conducted to evaluate the effect of a hot water extract of brown seaweeds Sargassum duplicatum and Sargassum wightii on the growth and white spot syndrome virus (WSSV) resistance in shrimp Penaeus monodon postlarvae (PL). Artemia nauplii (instar II) were enriched with both seaweed extracts at various concentrations (250, 500 and 750 mg L,1) and fed to the respective P. monodon (PL15,35) group for 20 days. A control group was also maintained without seaweed extract supplementation. The weight gain of the experimental groups was significantly higher (0.274,0.323 g) than the control group (0.261 g). Similarly, the specific growth rate was also significantly higher (16.27,17.06%) in the experimental groups than in the control group (16.03%). After 20 days of the feeding experiment, the shrimp PL were challenged with WSSV for 21 days. During the challenge test, the control shrimp displayed 100% mortality within 8 days. In contrast, the mortality percentage of the highest concentration (750 mg L,1) of seaweed extract enriched Artemia nauplii fed shrimp was 54,79%. Comparatively, low mortality was observed in S. wightii extract-enriched Artemia nauplii fed shrimp. The polymerase chain reaction analysis indicated the concentration-dependent infection of WSSV in P. monodon PL. [source]

SHORT COMMUNICATION: The effects of inulin on growth factors and survival of the Indian white shrimp larvae and postlarvae (Fenneropenaeus indicus)

AQUACULTURE RESEARCH, Issue 9 2010
Seyed Hossein Hoseinifar
First page of article [source]

Growth and performance of the whiteleg shrimp Penaeus vannamei (Boone) cultured in low-salinity water with different stocking densities and acclimation times

AQUACULTURE RESEARCH, Issue 6 2010
Héctor M Esparza-Leal
Abstract We evaluated the performance of whiteleg shrimp Penaeus vannamei (Boone, 1931) in response to different stocking densities and acclimation periods. Shrimp postlarvae were acclimated from seawater (30 g L,1) to low-salinity well water (<1.0 g L,1) at a constant hourly reduction rate of 40, 60, 80 and 100 h. After acclimation to low-salinity well water, postlarvae from each acclimation time treatment were stocked in three replicate tanks at densities of 50, 100, 150 or 200 shrimps m,2 for 12 weeks of growth. Salinity averaged <1.0 g L,1 for each growth study. The different treatments resulted in significant differences in both the final body weight and the survival rate (SR). Shrimp acclimated for 100 h showed substantially improved survival (83%) relative to shrimp acclimated for shorter periods. Shrimp yields for all cultured periods ranged from 0.32 kg m,2 in tanks stocked at 50 m,2 to 1.14 kg m,2 in tanks stocked at 200 m,2. We conclude that whiteleg shrimp can be successfully grown in low-salinity well water, and that the growth, production output and SRs are significantly higher when shrimp are acclimated for longer periods. [source]

Culture of benthic diatoms and effect of dissolved organic carbon on metamorphosis of the ,white sea urchin Lytechinus pictus (Verrill)'

AQUACULTURE RESEARCH, Issue 4 2010
A Salas-Garza
Abstract The effect of biofilms of the benthic diatom Navicula incerta and of the dissolved organic carbon (DOC) they produce was evaluated on the growth and survival of Lytechinus pictus postlarvae during metamorphosis. In each container, 300 postlarvae were exposed to biofilms beginning on days 1, 3 and 6 of metamorphosis, using three replicates and a blank containing only filtered water. The experiments were run for 15 and 18 days in 500-mL containers with daily water changes. We measured 30 postlarvae from each container and counted all organisms on days 1, 3, 9 and 15; DOC was quantified on days 3, 6 and 9. A second experiment was conducted to evaluate whether the presence of diatoms or the DOC they produced improved postlarval development. Five assays were performed in triplicate: a positive control with biofilms, a negative control with filtered water and three treatments with DOC-enriched water from a N. incerta culture supplied on days 1, 4 and 8. In both experiments, postlarvae attained the largest size and highest survival in the treatments with the biofilm. The results indicate that the increase in postlarval size and survival was due to the DOC produced by the diatoms and not by their presence alone. [source]

The effect of different carbon sources on the nutritional value of bioflocs, a feed for Macrobrachium rosenbergii postlarvae

AQUACULTURE RESEARCH, Issue 4 2010
Roselien Crab
Abstract A 15-day lab-scale experiment was performed to determine the possible use of bioflocs as a feed for Macrobrachium rosenbergii postlarvae. The bioflocs were grown on acetate, glycerol and glucose. A glycerol-fed reactor was initially inoculated with a Bacillus spores mixture. The highest protein content was obtained in the (glycerol+Bacillus) bioflocs, i.e. 58±9% dry weight (DW). The glycerol and acetate bioflocs showed a lower, but similar content (42,43% DW) and glucose bioflocs contained 28±3% DW. Higher total n-6 fatty acid contents were observed in the glycerol and (glycerol+Bacillus) bioflocs. The vitamin C content was variable, up to 54 ,g ascorbic acid g,1 DW in the glycerol bioflocs. Bioflocs were fed to M. rosenbergii postlarvae as the sole feed. High survival levels were obtained in the (glycerol+Bacillus) and glucose groups, i.e. 75±7% and 70±0% respectively. This was significantly higher than the starvation control (0% survival after 15 days). This indicated that the prawns were able to feed on the bioflocs. These results are in accordance with the biofloc's nutritional parameters and suggest that the choice of the carbon source used for growing bioflocs is of prime importance. [source]

Pond-to-pond variability in post-larval shrimp, Litopenaeus vannamei, survival and growth in inland low-salinity waters of west Alabama

AQUACULTURE RESEARCH, Issue 16 2009
Luke A Roy
Abstract Despite the recent success of Alabama shrimp farmers in culturing the Pacific white shrimp, Litopenaeus vannamei, in inland low-salinity waters there is large variability in growth and survival among ponds. Farmers suspect that high mortality occurs during the first weeks of culture following stocking of postlarvae (PL). In order to determine the effect of pond ionic composition on PL growth and survival, three trials were carried out at a shrimp farm. Trials 1 and 2 evaluated PL growth and survival over 21- and 28-day periods, respectively, using static water from different production ponds. Trial 3 evaluated growth and survival over 7, 14, 21 and 28 days using water from one production pond. Results suggest that initial mortality (8,10%) is attributed to the acclimation process and occurs immediately following stocking. Pond-to-pond variations in ionic profiles could be a contributing factor but are not likely the major reason for variable ,survival'. Mortalities after stocking appear to occur quickly as there were no differences in survival from 7 to 28 days post stock. Variable survival is likely due to a combination of reasons including environmental factors, but is largely due to poor handling of PL and stocking errors that produce perceived reductions in survival. [source]

Comparing skeletal development of wild and hatchery-reared Senegalese sole (Solea senegalensis, Kaup 1858): evaluation in larval and postlarval stages

AQUACULTURE RESEARCH, Issue 14 2009
Paulo Jorge Gavaia
Abstract The Senegalese sole is a marine pleuronectiform that naturally occurs in Southern Europe and Mediterranean region where it is being produced in aquaculture, in particular in Portugal and Spain. The aim of this study was to assess the quality of hatchery-reared larvae in comparison with those reared in the wild, and determine to which extension wild growing larvae are also affected by skeletal deformities. The main structures affected included those forming the axial skeleton, the caudal fin complex and both anal and dorsal fins, with the most prevalent anomalies affecting caudal vertebrae and arches. Hatchery-reared fish presented a higher incidence of deformities (79%) compared with the 19% observed in wild specimens. In wild postlarvae collected in Autumn no deformities were observed. This work clearly shows that wild Senegalese sole present less skeletal deformities than those hatchery-reared during larval stages, indicating a selective mortality of wild deformed fish and/or an effect of aquaculture-related rearing conditions in the development of skeletal deformities in sole. [source]

Effect of fishmeal replacement with Artemia biomass as a protein source in practical diets for the giant freshwater prawn Macrobrachium rosenbergii

AQUACULTURE RESEARCH, Issue 6 2009
Nguyen Thi Ngoc Anh
Abstract A 30-day feeding experiment was conducted in 160-L plastic tanks to evaluate the potential use of Artemia biomass as a protein source in practical diets for postlarval Macrobrachium rosenbergii (initial mean weight of 12.12,12.29 mg). Nine isoenergetic and isonitrogenous experimental diets (approximately 40% crude protein) were formulated by replacing levels of the fishmeal (FM) protein difference either with dried or frozen Artemia (0, 25, 50, 75 and 100%). The 0%Artemia treatment, in which Peruvian FM was the only main protein source, was considered to be the control diet. The results showed that prawn postlarvae (PLs) fed the FM control diet had a lower survival (46%) compared with all Artemia diets. Significant differences (P<0.05) were, however, only found at 75% and 100%Artemia protein inclusion levels (survival of 68,77%). A gradual increase in growth performance (live weight gain, specific growth rate and total length) of the prawns was achieved on increasing dietary inclusion of Artemia protein. Additionally, the size distribution exhibited the same response as growth performance. However, prawns fed the frozen Artemia diets showed a better performance than the ones fed the dried Artemia diets. It can be suggested that Artemia biomass may totally replace FM in practical diets for PLs of the freshwater prawn M. rosenbergii. [source]

Survival and growth of hatchery-produced postlarvae and spat of the Caribbean scallops Argopecten nucleus and Nodipecten nodosus

AQUACULTURE RESEARCH, Issue 3 2009
Luz Adriana Velasco
Abstract A study was made of the growth and survival of postlarvae and spat of Argopecten nucleus and Nodipecten nodosus produced in the laboratory and exposed to different conditions of settlement and culture. An evaluation was made of the different types of collection substrates (onion-bags, artificial-grass, fibreglass-plates), two types of settlement inducers (epinephrine, low temperature), and two culture environments (sea, laboratory). The results showed that larger numbers of postlarvae were obtained in artificial-grass collectors than on fibreglass-plates or in the onion-bags. The growth of the A. nucleus postlarvae was not affected by the collector type, while that of N. nodosus was higher on fibreglass-plates, and lesser in the onion-bags. Both thermal and chemical stimulation of the competent larvae resulted in recovery of a greater percentage of postlarvae. The growth of postlarvae of A. nucleus was better in groups exposed to the two methods of settlement induction, while those of N. nodosus remained unaffected by this treatment. The survival of the postlarvae and spat was greater in the laboratory than at sea except in the case of A. nucleus postlarvae attached to collectors, whose survival was similar in both environments. The growth of postlarvae and spat was greater in the sea than in the laboratory. [source]

Environmental sex determination, external sex differentiation and structure of the androgenic gland in the Pacific white shrimp Litopenaeus vannamei (Boone)

AQUACULTURE RESEARCH, Issue 15 2006
Rafael Campos-Ramos
Abstract Environmental effects on sex determination in Litopenaeus vannamei were studied by rearing day 1 postlarvae at three temperatures, under three photoperiods, at high density and by starving. None of the environmental conditions affected sex determination or differential development of gender in this species. From day 50, the development of the endopodite of the first pair of pleopods revealed the first external differentiation, showing a triangular structure with three setae in females, whereas a tubular structure remained in males. Juvenile shrimp sex differentiation took place from days 50,90, independent of size, only if postlarvae reached a development threshold of 150 mg of body weight and 20 mm of body length previously. Histology and scanning electron microscopy of the vas deferens revealed that the androgenic gland (AG) is a single 2-mm cord attached in the subterminal ejaculatory region, just before the distal vas deferens narrows. The AG is composed of large oval cells containing vacuolated cytoplasm, and each cell has a prominent rounded nucleus, similar to all descriptions of the AG in Malacostracans, so we assume that it should have the same function in sex differentiation. [source]

Effects of water exchange and abiotic factors on zooplankton and epibenthic fauna in shrimp ponds

AQUACULTURE RESEARCH, Issue 14 2006
Frank E Coman
Abstract Assemblages of zooplankton and epibenthic invertebrates were collected from a commercial Penaeus monodon (Fabricius) pond at fortnightly intervals over an entire grow-out season. The pond inlet and outlet water were also sampled intensively over three 1-week periods throughout the season. Before stocking the ponds with shrimp postlarvae, copepods dominated the zooplankton. Immediately after the ponds were stocked, there was a rapid decline in zooplankton numbers, particularly the dominant larger copepods, suggesting heavy predation by shrimp postlarvae. For the rest of the season, barnacle nauplii were the dominant zooplankton component in the pond. Pond water exchanges had little detectable influence on the composition or density of the zooplankton assemblage. Instead, the dominance of barnacle nauplii appeared to have been maintained by steady recruitment due to barnacle reproduction in the pond. While changes in the biomass of pond zooplankton were not correlated with physico-chemical characteristics, changes in density were positively correlated with temperature, and negatively correlated with pH, dissolved oxygen and secchi disc readings. Epibenthic faunal density peaked at the end of the season, while the biomass peaked during the middle part of the season. Sergestids (Acetes sibogae Hansen) were the most abundant epibenthic taxa. No correlations were found between physico-chemical parameters and epibenthic fauna biomass or density. Abundances of epibenthic fauna were not related to zooplankton densities, suggesting that trophic interactions between these assemblages is not important. No Acetes were captured in samples of outlet water, and only on a single occasion were large numbers captured in the inlet water; after this, there was a notable increase in the number of Acetes in the pond. This evidence, together with the lack of an increase in the size of Acetes during the season, suggests that water exchange is an important but unpredictable source of recruitment of epibenthic fauna into the pond. The results emphasize the benefits of ensuring that appropriate zooplankton assemblages have been introduced into the ponds, when they are filled, to support the shrimp immediately after stocking. This will depend on the initial inoculum and may be difficult to manipulate with water exchanges once established. Assemblages of epibenthic fauna appear more likely to change with exchanges and may need to be monitored across the season, particularly if their presence reduces production through adverse impacts such as competition with postlarvae, introduction of disease or deteriorated water quality. [source]

Effect of dietary protein level on growth, survival and ammonia efflux rate of Litopenaeus vannamei (Boone) raised in a zero water exchange culture system

AQUACULTURE RESEARCH, Issue 9 2005
Silvia Gómez-Jiménez
Abstract Litopenaeus vannamei postlarvae (1.96±0.07 g) were reared in a zero water exchange system for 25 days at 28°C. They were fed four commercial diets containing 25%, 30%, 35% or 40% crude protein in three replicate aquaria per dietary treatment. Total ammonia, nitrite, nitrate and pH were monitored weekly and total ammonia levels were additionally measured every 3 days using the flow injection analysis method. Total ammonia efflux rates were measured at days 0, 14 and 21, and survival and growth rates were recorded at the end of the experiment. No significant differences between water quality parameters such as temperature, salinity, dissolved oxygen and pH were found. Nitrite concentration remained low in all dietary treatments up to the second week increasing considerably from day 14 onwards suggesting the initiation of the nitrification process. Water total ammonia of all experimental groups exhibited a gradual increase up to day 13; however, following this time ammonia levels of all experimental groups decreased, probably due to either the action of bacterial nitrification or ammonia-N uptake by the animals. High ammonia efflux rates were recorded at day 14, especially after the first hour of immersion in the 25% protein group, but no significant changes occurred in any experimental group after 3 h. No significant differences in weight gain, final weight or survival of shrimp were observed under these experimental conditions. The importance of zero water exchange systems and their effects on the nitrogen metabolism of crustaceans are discussed. [source]