by Nakayama, Cintia Labussière

Abstract (Summary)
Under laboratory conditions, broodstock of penaeid shrimp are usually maintained in hard-bottom tanks (concrete or fiberglass). This practice, however, may affect the reproductive performance of Farfantepenaeus paulensis as this species has a strong burrowing behavior. With this in mind, wild-caught broodstock maintained for 50 days either in hard-bottom maturation tanks or in tanks provided with a sand substrate were evaluated in terms of reproductive performance, physical condition, and biochemical composition of tissues (hepatopancreas and ovary), hemolymph and eggs. After a seven day acclimation period, shrimp were stocked in 10m² tanks at a density of 7 individuals per m² (male to female ratio of 1: 1.3). Females were then unilaterally eyestalk ablated. No differences in reproductive performance were observed, but females from the hard-bottom tank presented a higher number of spawns and consequently more eggs were produced. This trend, however, was not observed in terms of total nauplii produced as these females spawned fertilized only in the first two weeks of the experiment, while those in the tank provided with sand substrate produced fertilized spawns throughout the experimental period. This indicates a possible relationship between tank bottom type and mating success in this species. Regardless of treatment, the physical condition of males improved at the end of the experiment. On the other hand, physical condition of females maintained in hard-bottom tanks deteriorated, while those from the tank with substrate presented no significant changes. Survival of females from the tank with substrate was also comparatively higher. Biochemical analysis of tissues, hemolymph and eggs presented no significant differences between treatments. Although having no significant effect on broodstock performance and biochemical composition, the use of sand substrate in maturation tanks improved the survival and physical condition of females, and resulted in a higher mating success. Therefore, results from the present study recommend the use of sand substrates in maturation tanks of F. paulensis, though this may make it more difficult to select ready-to-spawn females and to clean tanks.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Ronaldo Olivera Cavalli; Wilson Francisco Britto Wasielesky Junior; Silvio Ricardo Maurano Peixoto; Wagner Cotroni Valenti

School:Fundação Universidade Federal do Rio Grande

School Location:Brazil

Source Type:Master's Thesis

Keywords:Shrimp mating biochemistry compositon broodstock reproductive performance body conditons


Date of Publication:08/21/2006

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