Gonad development in females of fiddler crab Uca rapax (Crustacea, Brachyura, Ocypodidae) using macro and microscopic techniques

Abstract

ABSTRACT. The morphology of the ovaries in Uca rapax (Smith, 1870) was described based on macroscopic and microscopic analysis. Females were collected in Itamambuca mangrove, Ubatuba, state of São Paulo, Brazil. In the laboratory, 18 females had their ovaries removed and prepared for histology. Each gonad developmental stage was previously determined based on external and macroscopic morphology and afterwards each stage was microscopically described. The ovaries of U. rapax showed a pronounced macroscopic differentiation in size and coloration with the maturation of the gonad, with six ovarian developmental stages: immature, rudimentary, developing, developed, advanced and spent. During the vitellogenesis, the amount of oocytes in secondary stage increases in the ovary, resulting in a change in coloration of the gonad. Oogonias, primary oocytes, secondary oocytes and follicular cells were histologically described and measured. In female's ovaries of U. rapax the modifications observed in the oocytes during the process of gonad maturation are similar to descriptions of gonads of other females of brachyuran crustaceans. The similarities are specially found in the morphological changes in the reproductive cells, and also in the presence and arrange of follicle cells during the process of ovary maturation. When external morphological characteristics of the gonads were compared to histological descriptions, it was possible to observe modifications that characterize the process in different developmental stages throughout the ovarian cycle and, consequently, the macroscopic classification of gonad stages agree with the modifications of the reproductive cells. KEYWORDS.Macroscopic analysis, histological analysis, oogonias, primary and secundary oocytes, Uca rapax. RESUMO. Desenvolvimento da gônada em fêmeas do caranguejo-violinistaUca rapax (Crustacea, Brachyura, Ocypodidae) utilizando técnicas macro e microscópicas. A morfologia dos ovários de Uca rapax foi descrita baseada nas análises macroscópica e microscópica. As fêmeas foram coletadas no manguezal de Itamambuca, Ubatuba, Estado de São Paulo, Brasil. No laboratório, os ovários de 18 fêmeas foram retirados e preparados para histologia. Os estágios gonadais foram caracterizados previamente por meio de análises da morfologia externa e macroscopia e posteriormente cada estágio foi descrito microscopicamente. Os ovários das fêmeas de U. rapax apresentaram uma diferenciação macroscópica pronunciada no tamanho e coloração durante o processo de maturação, sendo caracterizados seis estágios de desenvolvimento ovariano: imaturo, rudimentar, em desenvolvimento, desenvolvido, avançado e esgotado. Microscopicamente, estes estágios diferiram quanto ao tamanho, cor e proporção de oogônias e oócitos presentes. Na análise histológica, oogônias, oócitos primários e secundários e células foliculares foram descritos e mensurados. As modificações observadas nos oócitos durante o processo de maturação dos ovários das fêmeas de U. rapax são similares às descrições de gônadas de outras ...

Histological Description of Gonadal Development of Females and Males ofCallinectes sapidusRathbun, 1896 (Decapoda: Portunidae)

“…The macroscopic characteristics of the reproductive system of males and females observed in this study were similar to those reported in other brachyurans; in females, this acquires a singular form of H (Castiglioni et al, 2007). The first part of the gonad of the male is the testicular region and the storage of gametes occurs in the posterior region (Goldstein and Dupré, 2011).…”

Morphology and ultrastructure of the adult ovarian cycle in Mithracidae (Crustacea, Decapoda, Brachyura, Majoidea)

“…The oocytes during development are enclosed by follicular cells, being this process similar to other Majoidea [16], Raninidae [33], Portunidae [7], Ocypodidae [34] and to Penaeidae [35] and Palaemonidae [36] shrimps. The central germinal zone facilitates the displacement of the oocytes to the ovarian margin during the development [37], which is apparently a pattern for Majoidea [14][15][16] and other Brachyura such Uca rapax (Smith, 1870), Callinectes ornatus Ordway, 1863 and C. danae [7,34,38]. According to the histochemical tests, oogonia and oocytes have basophilic cytoplasm composed of protein, neutral polysaccharides (glycogen) and the absence of acid polysaccharides in all phases of development as observed in Chionoecetes opilio and Hyas coarctatus [14].…”

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“…Otsu (1963) proposed four stages for oocyte development in the freshwater crab Potamon dehaani based on changes in the cytoplasmic granulation of oocytes. In Uca rapax and in G. cruentata, the classification of germ cells was based on degree of vitellogenesis (Castiglioni et al, 2007;Desouza and Silva, 2009). In decapods, the germ cells are classified according to a range of criteria such as cell diameter, nuclear appearance (Mota and Tomé, 1965) and degree of vitellogenesis (Kulkarni et al, 1991).…”