Reproductive Performance of Different Sized Wild and Pond‐reared Penaeus paulensis Females

Abstract

The present study analyzes the reproductive performance of three size classes of wild (average weight of 46.5, 55.0, and 63.2 g) and three size classes of pond‐reared (18.4, 21.3, and 25.1 g) Penaeus paulensis females. Unilaterally eyestalk ablated females were placed for 70 d in 3.6 m diameter tanks at 6 individuals/m2 and a 1.2:1 female‐male ratio. Number of spawns, eggs, nauplii, fertilization and hatching rates were recorded every second day. The length of unfed protozoea I larvae was also recorded. Larger broodstock shrimp tended to suffer higher mortality rates. Smaller, pond‐reared females started spawning at 28.2 ± 4.1 g. The number of eggs and nauplii per spawning event were not significantly different between experimental groups (P > 0.05), but due to their higher spawning frequency, small wild females (46.5 ± 3.7 g) outperformed medium (55.0 ± 1.8 g) and large ones (63.2 ± 7.0 g). No relationship between protozoea length and spawner size was found. Optimum size for the maturation of wild P. paulensis females was estimated to be from 30 to 60 g. It is suggested that the use of this size range can potentially enhance nauplii production of P. paulensis.

The influence of water renewal rates on the reproductive and molting cycles of Penaeus paulensis in captivity

“…The mean number of eggs per spawn was relatively low (16,000-40,000 eggs/spawn) compared with those usually obtained when larger maturation tanks are applied. Although the potential fecundity of P. paulensis reported by Iwai (1978) under field (Southeast Brazilian off-shore areas) was up to 500,000 eggs per spawn, when eyestalk ablated wild females were maintained in captivity for at least 45 days, the mean number of eggs per spawning event ranged from 16,000 to 160,000 (Marchiori and Boff, 1983;Cavalli et al, 1997;Cavalli et al, 1998), while the number of nauplii per spawn ranged from 60,000 to 140,000 (Beltrame and Andreatta, 1991;Marchiori and Cavalli, 1993;Vinatea et al, 1993;Petersen et al, 1996;Reis et al, 1998). In the present study, the number of eggs per spawning event was in agreement with those usually observed for wild broodstock maintained in larger circular tanks, but again a relative decrease was observed in the number of eggs per spawn in this tank shape/size.…”

“…It is, therefore, possible to speculate that the number of eggs per spawn may be reduced in smaller maturation tanks. The reproductive performance traits could be affected by many factors such as different species, broodstock source and size Cavalli et al, 1997;Palacios et al, 1999), nutrition (Harrison, 1990;Sangpradub et al, 1994), genetics (Benzie, 1997;Benzie, 1998) and environmental conditions (Hansford and Marsden, 1995;Crocos and Coman, 1997). Therefore, these findings must be considered to compare reproductive performance reported in different studies.…”

“…Brisson (1986) described in detail the mating behavior of P. paulensis, which is marked by the male turning upside down below the female, rapidly rotating perpendicularly, squeezing the female and then transferring the spermatophore. Although several studies have already dealt with the reproduction of this species under field (Zenger and Agnes, 1977;Iwai, 1978) and laboratory conditions using wild and captive broodstock (Marchiori and Boff, 1983;Beltrame and Andretta, 1991;Marchiori and Cavalli, 1993;Vinatea et al, 1993;Petersen, 1996;Cavalli et al, 1997;Peixoto, 2000), not much information on the…”

Shrimp farming as an alternative to artisanal fishermen communities: the Case of Patos Lagoon, Brazil

“…However, as there is a comprehensive knowledge of the biology and culture of F. paulensis, it is possible to produce large numbers of PL from either wild (Marchiori and Boff, 1983;Marchiori and Cavalli, 1993;Marchiori, 1996) or domesticated broodstock (Cavalli et al, 1997;Peixoto et al, 2003aPeixoto et al, , 2004aPeixoto et al, , 2005. Since production has not yet reached a commercial scale, the laboratory PL provided to the fishermen were still produced at the university's Marine Aquaculture Centre and handed to the fishermen.…”

“…Despite the supposedly advantageous performance of wild broodstock, the unpredictable supply and high capture costs might constrain the sustainable development of F. paulensis farming in the region. In this context, several studies have been carried out to optimize the maturation and reproduction of this species in captivity (Peixoto et al, 2002a(Peixoto et al, , 2002b(Peixoto et al, , 2003b(Peixoto et al, , 2003c(Peixoto et al, , 2004b, especially the evaluation of the domesticated broodstock as an alternative (Cavalli et al, 1997;Peixoto et al, 2003aPeixoto et al, , 2004a. The accelerated search to close the life cycle and improve the reproductive performance of F. paulensis in captivity will certainly contribute to the design of an efficient breeding program.…”