Aspects of the reproductive biology of the bass, Dicentrarchus labrax L. I. An histological and histochemical study of oocyte development

Abstract

Histological and histochemical studies of oocyte development in the bass, Dicentrarchus lubrux L., showed that three types of inclusions are formed during vitellogenesis. Lipid yolk accumulates first as lipid droplets, followed by protein yolk in the form of discrete protein yolk granules. The third type of inclusion are the small cortical alveoli (intravesicular yolk/yolk vesicles, i.e. ' carbohydrate yolk ')which form in the peripheral cytoplasm after both the lipid and protein yolk have started to accumulate. While the protein yolk granules maintain their structural integrity through to maturation, forming a densely packed zone in the mid-outer cortex, the lipid yolk droplets continually coalesce. and migrate centripetally, forming a prominent zone of large lipid droplets in the inner-mid cortex. From the histological study of oocyte development, a number of distinct developmental stages are delineated, while gross examination of the paired ovary revealed that, depending on its stage of development, it can be placed into one of seven maturity stages.

Caracterización histoquímica de ovocitos del pez espada, <i>Xiphias gladius</i>

“…This acellular protein egg envelope contains calcium and is composed of neutral mucopolysaccharides and especially of proteins rich in cysteine and cystine, which suggests that most of the proteinaceous material of this multilamellar layer is determined by the formation of disulphide bonds (Hagenmainer, 1973;Gutiérrez et al, 1985;Sarasquete et al, 1993Sarasquete et al, , 2002Grau et al, 1996;Mayer et al, 1988). In Salmo salar radiata envelopes, Hamor and Garside (1973) detected proteins, mucopolysaccharides, phospholipids, cholesterol, nucleic acids and oxidative enzymes.…”

“…Studies in other fish species (Tesoriero, 1977) have shown that the external layer of the zona radiata was rich in polysaccharides, whereas the inner layer was rich in proteins. In Carassius auratus (Khoo, 1979) and Dicentrarchus labrax (Mayer et al, 1988), polysaccharides adhere to the outer layer which might contribute to the adhesion of the eggs. However, in Siganus rivulatus eggs, the chorion consists exclusively of proteins (Lahnsteiner and Patzner, 1999).…”

“…During the reproductive cycle of fish species, the chemical composition of the fish oocytes (cytoplam, cortical alveoli, yolk, zona radiata, granulosa and theca layers) and the mobilisation of macromolecules and cations between the liver and gonads have been studied by several authors (Wallace, 1978;Khoo, 1979;Gutiérrez et al, 1985, Selman andMayer et al, 1988;González de Canales et al, 1992, Sarasquete et al, 1993Muñoz-Cueto et al, 1996;Grau et al, 1996;Corriero et al, 2004). However, the histochemical localisation of specific metal-bindingproteins (metallothionein/Mt), cations (calcium, iron), thyroid hormones and specific lectin-glycoconjugates during fish oogenesis has received less attention (Sarasquete et al, 2002 a,b;Motta et al, 2005).…”

The Structure and the Embryogenetic Role of Eggs and Egg Membranes of <I>Ancistrus Dolichopterus</I> (Actinopterygii: Siluriformes: Loricariidae)

“…Modern technologies such as scanning electron microscopy (SEM), make it possible to find family-and species-specific variability in the thickness and structure of these layers. These layers undergo structural modification upon activation and fertilization of the egg (Johnson and Werner 1986, Lönning 1972, Mayer et al 1988, Yamamoto and Yamagami 1975. It is also known that the structure and thickness of egg protective membranes results from specific reproductive ecology of given fish species (Stehr and Hawkes 1979).…”

Gross and histological observations of ovarian development in twaite shad, <i>Alosa fallax fallax</i>, from Rivers Mira and Guadiana (Portugal)

“…The presence of two differently stained zones in the cytoplasm of the oocytes in the cortical alveoli stage is related to the development of the Balbiani body, and has been described for a number of species (Bara, 1960;Arruda, 1988;Mayer et al, 1988;Coello and Grimm, 1990). According to Guraya (1986) and Coello (1990), it is composed of two parts, the yolk nucleus and the pallial substance.…”