Ovarian maturation of wild Farfantepenaeus paulensis in relation to histological and visual changes

Abstract

The present study describes the ovarian development stages of wild Farfantepenaeus paulensis (Pe¤ rez-Farfante) through the combined observation of histological and visual characteristics. Twenty-¢ve females (61.872.4 g) were captured in 35^40-m deep waters o¡ southern Brazil (271S). The females were grouped according to the size and shape of their ovary and then killed. The colour of the fresh ovary was compared with a chromatic scale catalogue. Analysis of the histological sections of each ovary determined the morphological characteristics, size and frequency of the di¡erent oocyte types. Based on these characteristics, four distinct stages of ovarian maturation are proposed: stage I (immature), characterized by the presence of small basophilic oocytes (52.1719.9 mm) and ovary colour ranging from translucent to creamy; stage II (developing), with yolky oocytes (YOs) (144.2726.1 mm) and a light green colour; stage III (mature), presenting largeYOs but with cortical rods (235.0730.2 mm) and an olivebrown colour; and stage IV (spent), with atretic oocytes and the same ovary colour pattern as stage I. The gonadosomatic index ranged from 1.6 (stage IV) to 13.7% (stage III) and was closely related to the different ovarian maturation stages. The observation of visual features coupled with histological characteristics was found to represent a reliable procedure to evaluate the ovarian maturation of F. paulensis.

Stages of gonadal development and mean length at first maturity of wild females of white shrimp (Litopenaeus schmitti - DECAPODA, PENAEIDAE) in southern Brazil

“…(Vogt et al, 1989;Castille & Lawrence, 1991;Tan-Fermin, 1991;Medina et al, 1996;Quintero & Garcia, 1998;Palacios et al, 1999). Recently, the investigations intending to classify the ovaries for fishery management purposes have suggested the simplification of the development stages, reducing it to only 4, named immature, developing, ripe and spent (Peixoto et al, 2003;Dumont et al, 2007). It does happen due to high similarity between developing and incipient maturity stages, which show similar stage of cell development, but slightly different organization.…”

“…At least 15 ovaries, from each development stage, were sampled. A sample of ovarian tissue was collected from anterior part of gonad for histological sectioning since homogeneous development along the ovary has been reported for a similar species (Peixoto et al, 2003). Shape and color (Pantone, 1999) of ovaries were digitally recorded under the approximated same quantity of light, to establish a macroscopic classification validated by subsequent histological sections.…”

“…This technique has been proved to be useful in many penaeid species, such as F. paulensis and F. brasiliensis (Peixoto et al, 2003;Dumont et al, 2007), A. longinaris, (Dumont & D´Incao, 2004, Penaeus indicus (Castille & Lawrence, 1991;Quinitio & Millamena, 1992), Penaeus kerathurus (Medina et al, 1996;Vogt et al, 1989) and Penaeus monodon (Palacios et al, 1999).…”

Reproductive cycle and size at first sexual maturity of the white shrimp Penaeus schmitti (Burkenroad, 1936) in northeastern Brazil

“…Our results also indicated that females present a significantly higher relative frequency in larger size classes, which have been previously reported for P. schmitti populations (Santos et al, 2005(Santos et al, , 2008. Penaeid females are larger than males due to the body space needed for gonadal development (Hartnoll, 1982;Dall et al, 1990) and thus more abundant in larger size classes (García & Le Reste, 1986) Studies of ovarian development in penaeids have been used as a tool for the establishment of guidelines for fishery management (Quintero & Gracia, 1998), as well as the improvement of breeding technology for aquaculture operations (Peixoto et al, 2003;Dumont et al, 2007;Gonçalves et al, 2009;Machado et al, 2009). Histological analyses of the ovaries are considered to be one of the most accurate procedures for the determination of the maturational stage of female crustaceans (Ohtomi et al, 2003;Carbonell et al, 2006).…”

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

“…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.…”