Cyclic changes in the ovary of the brook stickleback Eucalia inconstans (kirtland)

Abstract

The ovarian cycle of the brook or 5-spined stickleback was studied histologically. Specimens were trapped between July, 1965 andAugust, 1966 in a shallow pond near London, Ontario.Spawning took place from mid-April to mid-July, when the water averaged 10OC. In early August, when the water averaged 20-22°C for prolonged periods, spawning ceased and the ovaries contained only oijgonia, atretic mature oocytes and empty follicles. Oijgonia and immature oiicytes were found throughout the year but only in the spring did the mature stages begin to appear.Oocytes for each year's spawning appear to arise mitotically from a residual stock of lightly basophilic oiigonia. As the oocytes mature, their basophilia increases and they acquire a vitelline membrane and follicular layer. The deeply basophilic cytoplasm of the early oijcyte becomes frothy, as oily droplets of primary yolk are laid down. Finally, i t becomes flled with eosinophilic secondary yolk in the mature Two types of atresia of developing eggs are common, especially during and after the spawning period. The first involves active phagocytosis of yolky material and hypertrophy of the follicular layer, leading to the formation of what could be called a "corpus luteum." In the second type of atresia, neither phagocytosis nor hypertrophy was seen and nothing resembling a corpus luteum was formed.egg.

Seasonal histological and macroscopic changes in the gonads ofCheimerius nufar(Ehrenberg, 1820) (Sparidae: Pisces)

“…Small, intensely hematoxylin stained bodies are found in the central network of the nucleus, which could possibly be chromatin nucleoli (Yamamoto 1956b). The cytoplasm of the later perinuclear oocytes has a slight granular ('frothy') appearance which is in accordance with the findings of other author~ (Abraham, Blanc & Yashouv 1966;Braekevelt & McMillan 1967;Baird 1974;Van der Horst 1976). A thin follicular layer enclosing a zona radiata is also apparent in the late perinuclear oocytes.…”

“…Although most authors agree on the basic characteristics incorporated into such a system, schemes used are often too brief (Kuo, Nash & Shehadeh 1974;Hilge 1975Hilge ,1977, or incomplete (Abraham 1963;Abraham et al 1966), or exhibit too much detail (Yamamoto 1956a;Braekevelt & McMillan 1967;Van der Horst 1976). The classification system implemented in this study is based on the oogenetic and vitellogenetic changes as described by Yamamoto (l956a, b, c, 1957), Braekevelt & McMillan (1967) and Van der Horst (1976). It reflects the nine major phases in oocyte development, each of which can be subdivided (i.e.…”

“…These are briefly outlined: (i) yolk vesicle oocytes are the first to show distinctive yolk formation, and are therefore named primary yolk vesicle oocytes, (ii) Matthews (1938), Braekevelt & McMillan (1967) and Van der Horst (1976) reported on the appearance of acidophilic intravesicular secondary yolk formation between the oil vesicles. Yamamoto (1956a) and Vander Horst (1976) described this stage as primary yolk, but in the system presented here these are renamed early secondary yolk oocytes, (iii) the late secondary yolk oocyte stage follows and is analogous to the secondary yolk stage (stage 6) of Yamamoto (1956a), Braekevelt & McMillan (1967) and Van der Horst (1967), (iv) the tertiary yolk oocyte stage is directly comparable to the tertiary yolk stage of Yamamoto (1956a), Braekevelt & McMillan (1967) and Van der Horst (1967). This stage does not imply a third type of yolk, but rather the coalescence of the secondary yolk which represents a major stage in oocyte development.…”

Morphology of ovarian changes during the reproductive cycle of the fish, <i>Mystus tengara</i> (Ham.)

“…1965Hoar, , 1969Beach, 1959; Dodd, I960: Bowers and Holiday, 1961: IIonma and Tamura, 1962;Franchi, 1962;Perry and Rowlands. 1962: Braekevelt andMcMillan, 1967;Moser. 1967;Anderson, 1964a.h.…”

Aspects of the reproductive biology of the southern mullet,Liza richardsoni, from Algoa Bay, South Africa

“…Ovarian development was assessed using a combination of the classification systems of Yamamoto (1956) and Braekevelt & McMillan (1967), as adopted by Van der Horst (1976) in a study of the groovy mullet L. dumerili. FoHow- ,.…”