Pond-reared Broodstock Research Articles

Comparison of reproductive performance and offspring quality of giant freshwater prawn ( Macrobrachium rosenbergii) broodstock from different regions

An experiment was conducted to compare the reproductive performance and offspring quality of Macrobrachium rosenbergii broodstock from four different sources: (1) Vietnam wild; (2) Vietnam pond-cultured; (3) Hawaii pond-cultured and (4) China pond-cultured M. rosenbergii females were individually followed for 180 days in three 1200-l fresh water recirculation systems and fed a commercial diet. Ovarian development, moulting and spawning events were checked daily. In addition a number of egg and larval quality parameters were determined. The breeding frequency, fecundity, egg laying success rate, egg dimensions and egg hatchability were not significantly different between animals from the four different sources. However, there were significant differences in terms of offspring quality between the different broodstock sources. Individual dry weight, larval development rate, time to reach the postlarval stage, postlarval survival and tolerance to ammonia toxicity were all better in the offspring originating from China pond-reared and Vietnam pond-reared broodstock sources compared to those originating from Vietnam wild and Hawaii pond-reared sources. Moreover, offspring quality from Chinese and Vietnamese pond-reared broodstock proved more stable in terms of ammonia tolerance over three consecutive reproduction cycles. In general, the pond-reared broodstock from China and from Vietnam resulted in better offspring quality than the Hawaii pond-reared and Vietnam wild broodstock. These results indicate that broodstock sourcing deserves proper attention in hatchery operations of M. rosenbergii. It furthermore proves that domesticated (pond-reared) animals are not necessarily inferior as breeders compared to wild-sourced animals. The results may also point out the potential to selectively breed stocks with improved characteristics adapted to the local culture environment.

Variation in Reproductive Performance and Egg Quality Between Wild and Pond-Reared Indian White Shrimp, Fenneropenaeus indicus, Broodstock

ABSTRACT The shrimp hatchery industry worldwide has placed immense interest on the production of closed-life cycle broodstock from farm stock. Unfortunately, majority of the studies have proven that pond-reared broodstock are inferior to their wild counterparts in terms of reproductive performance, spawn quality and post-hatching performance. In the present study, reproductive performance, egg, and nauplii quality of wild and pond-reared Indian white shrimp, Fenneropenaeus indicus, broodstock were analyzed. Biochemical analyses were done with egg and nauplii from both the sources, in an attempt to explain the difference in their performance. Results indicated better reproductive performance by wild females compared to pond-reared ones. The wild eggs contained higher total lipid, and vital HUFAs namely EPA (Eicosapentaenoic acid), DHA (Docosahexaenoic acid) and ARA (Arachidonic acid). However, one of the dominant PUFA, 18:2 (n-6) was high in pond broodstock eggs. Biochemical analysis also indicated that glucose, carotenoids, and triacylglycerol content were significantly higher (P < 0.001) in wild eggs. But, egg protein and triacylglycerol content did not record significant difference between the egg samples. The percentage viable nauplii, nauplii length and triacylglycerol content were all significantly higher (P < 0.05) with wild nauplii. This study proves the better nutritional profile of wild eggs and nauplii in terms of analyzed biochemical components. But, as our knowledge on specific nutrient requirement for successful reproductive performance and offspring quality is limited, the better performance of wild eggs could not be attributed to any single nutrient. Meanwhile, it could be presumed that all the deficient nutrients collectively contributed to the poor reproductive performance and spawn quality.

Domestication, growth and reproductive performance of wild, pond and tank-reared brown tiger shrimp Penaeus esculentus

This study demonstrated the development of techniques for closed life cycle production of the brown tiger shrimp Penaeus esculentus and the capacity for the production of multiple generations of domesticated stock. Laboratory and on-farm closed cycle production of P. esculentus for three generations was achieved, growing the shrimp from eggs to reproductive adults wholly in both tank and pond systems. Pond-reared broodstock were ultimately larger than those grown from egg to adult in tanks. Growth of the tank-reared stocks in early juvenile stages was lower and likely slowed by the lack of a supplementary natural-biota food source. Reproductive performance from captive broodstock was assessed and found to be at a level comparable to broodstock captured from the wild fishery even when adjusted for differences in age and size. Maturation rates of wild caught broodstock were higher than those for pond and tank-reared broodstock. However spawning rates for pond-grown broodstock and hatch rates were the same without adjusting results for size or age. Due to the larger size, and therefore fecundity, of the wild spawners, the slightly higher number of eggs per spawning, combined with identical hatching rates, resulted in a slightly higher, but non-significant, production of nauplii for the wild spawners. Even so, the pond-reared spawners demonstrated a level of reproductive output sufficient for hatchery production at a commercial scale. The spawners grown entirely in tanks from egg to adult-broodstock size had significantly lower spawning rates and numbers of eggs per spawning compared to the wild and pond-grown broodstock and these spawners were unlikely to be suitable for commercial-scale hatchery production. Further improvements to the tank growout protocols, particularly with early-stage nutrition, may improve the ultimate reproductive performance of broodstock reared in this manner. Having established the feasibility of farm-scale closed cycle production for P. esculentus, there is now the potential for selection of the faster growing shrimp at harvest, to produce a potentially faster-growing next generation. Importantly, it is possible to produce reproductively capable pond-grown broodstock within the 12-month commercial production cycle.

Growth, Survival and Reproductive Performance of Domesticated Australian Stocks of the Giant Tiger Prawn, Penaeus monodon, Reared in Tanks and Raceways

The growth, survival and reproductive performance of domesticated Australian stocks of the giant tiger shrimp Penaeus monodon were evaluated in trials conducted in 1997 and 2003. The 1997 trials assessed the performance of first generation progeny of wild broodstock from the northeast coast of Australia and fourth generation progeny of pond-reared broodstock, which also originated from northeast coast wild stocks. In these trials, growth and survival of the shrimp were assessed when reared for 17 mo in tanks. Reproductive performance of the shrimp was assessed at 14.5 mo and 17 mo. The 2003 trials assessed the performance of first generation progeny of wild broodstock from the Gulf of Carpentaria (north coast of Australia). In these trials, growth and survival of shrimp were assessed when reared for 14 mo in tanks and raceways. Reproductive performance of the shrimp was assessed at 11 mo, 12 mo, and 15 mo. Growth and reproductive performance of the stocks varied between trials, families, ages and rearing systems. The most pronounced differences in growth and reproductive performance were between the 1997 and 2003 trials. At 11 mo of age, the average wet weight of the shrimp in the 2003 trials (females 117.1 ± 5.8 g; males 87.9 ± 7.6 g) was 200% greater than the average wet weight of shrimp in the 1997 trials (females 55.2 ± 6.8 g; males 41.2 ± 3.4 g). The reproductive performance of the shrimp was also higher in the 2003 trials in terms of the percentage of spawnings hatching (52.0% in 1997; 77.1% in 2003) and mean hatch rate (21.5% in 1997; 31.6% in 2003). Differences in the growth and reproductive performance of the tank-reared stocks between years were indicative of significant improvements in the rearing environment, diet and husbandry techniques. Variation in the reproductive performance between families was consistent across rearing environments and at different ages and suggests the potential to improve reproductive performance through genetic selection. Notably, this study identified hatch rates of nauplii from the spawned eggs as a key area for future improvement of domesticated stocks reared in tanks and raceways. Future efforts to improve the growth and reproductive performance of domesticated P. monodon could benefit from integrating incremental improvements to husbandry with genetic selection.

Observations on growth, sexual maturity and spawning performance of pond-rearedPenaeus merguiensis

This 12-month preliminary study investigated the development of sexual characters, primary sexual maturity, ovarian maturity and spawning performance of pond-reared Penaeus merguiensis in relation to culture conditions in south-east Queensland, Australia. Post-larvae of P. merguiensis were produced and cultured in two 60-m3 tanks during the first 14 weeks. Before winter, they were harvested and stocked in three different overwintering facilities: a 200-m2 covered pond, two 60-m3 outdoor tanks and a 15-m3 indoor, recirculated tank at a stocking density of 10 individuals m−2. The development of sexual characters was found to be similar to that reported previously in wild P. merguiensis. Males matured at younger ages and smaller sizes than females. Overall, the average size at primary sexual maturity of pond-reared P. merguiensis was 23.1 mm carapace length for males (possessed spermatophores) and 29.3 mm for females (being impregnated). Water temperature and the availability of natural food strongly influenced prawn growth, maturity rate and their subsequent spawning performance. Growth, maturity rate and spawning performance of prawns in the covered pond were significantly higher than in the other overwintering facilities. Prawns started mating at 6–7 months, reached full ovarian maturation and spawned as early as about 8 (peaked at 9–11) months from hatching, producing high fecundity and viable larvae. There was a strong relationship (P < 0.001) between prawn size and fecundity. The results of this study suggest a potential for using pond-reared broodstock P. merguiensis for hatchery production and for domestication or selective breeding programmes.

Improved reproductive readiness of pond-reared broodstock Penaeus merguiensis by environmental manipulation

Abstract Two environmental manipulation protocols were tested against a current maturation technique (CONTROL) in an 81-day experiment. PROTOCOL 1 mimicked changes in the natural environment from winter to spring when ovarian maturation and spawning in Penaeus merguiensis starts. PROTOCOL 2 evaluated whether a clear improvement of temperature from a fluctuation period to a stable one could help trigger ovarian maturation. In phase A (first 30 days) of the experiment, temperature and day length were gradually increased from 22 to 27 °C and from 10 to 14 h, respectively, while light intensity was stepwise reduced from 360 to 240, 120 and 5 lx for PROTOCOL 1. For PROTOCOL 2, light intensity and day length were manipulated as for PROTOCOL 1, but temperature was cycled from 22 to 27 °C every 3 days. In phase B (the following 30 days) temperature, light intensity and day length were stably maintained at optimal levels (27 °C, 5 lx and 14 h light, respectively). During phase B, the proportion of female prawns reaching stages III and IV was significantly (P

Comparison of ovary histology between different-sized wild and pond-reared shrimp Litopenaeus vannamei (=Penaeus vannamei)

Summary Ovarian maturation of pond-reared and wild Litopenaeus vannamei (= Penaeus vannamei) broodstock was compared by analyzing morpho-histological characteristics. The number of spawns by each female was also considered to determine if successive rematurations can affect ovarian development. Individually tagged 42 wild and 47 pond-reared females were sampled at the end of a production period in a commercial hatchery. Morphological variables were recorded and ovaries were histologically evaluated for oocyte type and diameter. Although wild shrimp were bigger than pond-reared, no differences were seen in gonadosomatic indexes, either considered as a group or within stages of maturation. Differences between pond-reared and wild shrimp were observed in previtellogenic and early-vitellogenic oocyte distribution in vitellogenic and cortical stages. However, no differences were obtained in relation to the proportion of late vitellogenic oocytes and mature oocytes with cortical rods, or oocyte diameter in each maturation stage. Occurrence of atresia was negatively correlated to the number of spawns of each female, whereas gonadosomatic index and postovulatory follicles had a positive correlation with the number of spawns. Pond-reared broodstock appeared to have a normal maturation compared to wild Litopenaeus vannamei (= Penaeus vannamei) in our conditions. Successive spawnings did not seem to produce substantial alterations in the rematuration capacities of individual spawners in terms of the variables measured and the conditions of this experiment.

Gonadal maturation and reproductive performance of giant tiger prawn ( Penaeus monodon Fabricius) from the Andaman Sea and pond-reared sources in Thailand

Broodstock trials were conducted with Penaeus monodon to compare the gonadal maturation and reproductive performance of four combinations of broodstock: wild-caught, pond-reared, and two groups of cross-matings between wild-caught and pond-reared. Wild-caught broodstock were captured from an off-shore area of the Andaman Sea. The average weight of wild-caught females was almost double that of pond-reared females. Wild-caught broodstock produced significantly greater numbers of eggs than pond-reared broodstock, despite comparable egg quality. Cross-matings between broodstock from the two sources did not improve gonadal maturation or reproductive performance.