Degeneration of postovulatory follicles in the Iberian sardine Sardina pilchardus: structural changes and factors affecting resorption

Ganias , Konstantinas and Nunes, Cristina and Stratoudakis, Yorgos (2007) Degeneration of postovulatory follicles in the Iberian sardine Sardina pilchardus: structural changes and factors affecting resorption. Fishery Bulletin, 105(1), pp. 131-139.

[img]
Preview
PDF (The document's language is English .) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (1350Kb) | Preview
Official URL: http://fishbull.noaa.gov/1051/ganias.pdf

Abstract

Inaccuracy in the aging of postovulatory follicles (POFs) and in estimating the effect of temperature on the resorption rate of POFs may introduce bias in the determination of the daily spawning age classes with the daily egg production method (DEPM). To explore the above two bias problems with f ield-collected European pilchard (Sardina pilchardus, known regionally as the Iberian sardine), a method was developed in which the time elapsed from spawning (POF age) was estimated from the size of POFs (i.e., from the cross-sectional area in histological sections). The potential effect of the preservative type and embedding material on POF size and the effect of ambient water temperature on POF resorption rate are taken into account with this method. A highly significant loglinear relationship was found between POF area and age; POF area shrank by approximately 50% per day. POFs were also shown to shrink faster at higher temperatures (approximately 3% per degree), but this temperature effect is unlikely to be an important source of bias in the assignment of females to daily spawning classes. The embedding material was also shown to influence the size of POFs, the latter being significantly larger in resin than in paraffin sections. In conclusion, the size of POFs provides an indirect, reliable estimation of the time elapsed from spawning and may thus be used to test both the validity of POF staging criteria for identifying daily classes of spawners and the effect of other factors (such as temperature and laboratory processing) in applications of the DEPM to S. pilchardus and other fish species.

Item Type: Article
Title: Degeneration of postovulatory follicles in the Iberian sardine Sardina pilchardus: structural changes and factors affecting resorption
Personal Creator/Author:
CreatorsEmail
Ganias , Konstantinas
Nunes, Cristina
Stratoudakis, Yorgos
Refereed: Yes
Journal or Publication Title: Fishery Bulletin
Volume: 105
Number: 1
Page Range: pp. 131-139
Date: 2007
ISSN: 0090-0656
Issuing Agency: United States National Marine Fisheries Service
Subjects: Biology
Ecology
Fisheries
Item ID: 8938
Depositing User: Patti M. Marraro
Date Deposited: 27 Jun 2012 16:55
Last Modified: 27 Jun 2012 16:55
URI: http://aquaticcommons.org/id/eprint/8938

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...