|Pattern of oocyte development and batch fecundity in the Mediterranean sardine|
Ganias, K.; Somarakis, S.; Machias, A.; Theodorou, A. (2004). Pattern of oocyte development and batch fecundity in the Mediterranean sardine. Fish. Res. 67(1): 13-23
In: Fisheries Research. Elsevier: Amsterdam. ISSN 0165-7836, more
Fecundity; Oocytes; Oogenesis; Sardina pilchardus (Walbaum, 1792) [WoRMS]; Marine
|Authors|| || Top |
- Ganias, K.
- Somarakis, S.
- Machias, A.
- Theodorou, A.
In the present study, the pattern of oocyte development was investigated in the Mediterranean sardine (Sardina pilchardussardina) in order to examine whether non-hydrated females could be included in batch fecundity measurements. Gonad histologyand frequency distributions of oocyte diameters demonstrated that the Mediterranean sardine exhibits group-synchronoustype of oocyte development. The spawning batch begins to separate in size from the adjacent population of smaller oocytesat the secondary yolk globule stage and a well-developed size-hiatus is established at the tertiary yolk globule stage. Thespawning batch could be clearly identified prior to hydration and batch fecundity-on-fish weight relationships did not differsignificantly between hydrated females and females at the tertiary and migratory nucleus stages. Thus, apart from hydratedfemales, batch fecundity in the Mediterranean sardine may also be measured by the use of females at the tertiary and migratorynucleus stages. Relative fecundity was shown to be independent of body weight and its estimates during the respective peakspawning months for the Aegean Sea and Ionian Sea stocks were 360 eggs/g (December 2000) and 339 eggs/g (February2001).