RV Corystes COR1/96
Cruise summary report
|Ship name (ship code)||RV Corystes (74RY)|
|Cruise period||1996-01-03 — 1996-01-12|
|Port of departure||Lowestoft, United Kingdom|
|Port of return||Lowestoft, United Kingdom|
|Objectives||1. Collection of blood, sperm and testis samples from male plaice caught on and off the main spawning areas of the North Sea - to determine the extent to which sperm production and sex steroid levels are affected by the presence of ripe spawning females. This is a continuation of studies which were started on CORYSTES 1/94.
2. Concomitant plankton net collections of fertilised plaice eggs to assess the intensity of spawning in the sampling areas (Bromley).
3. Collection and preservation of plaice ovaries in formalin (for subsequent sizing and counting on the HLAC) and Chan's fixative (for staging the oocytes).
4. Collection of plaice pituitaries for purification of gonadotrophins.
5. Collection of plaice brain hypothalami for possible purification of Gonadotrophin-releasing hormones by Dr Sherwood of the University of Victoria in Canada.
6. Collection of plasma from spawning female flounders for steroid identification by Dr Jan Lambert of the University of Utrecht. No flounders were caught at any of the stations, therefore making this aim impossible to achieve.
7. Experiments in the deck tanks to determine the time course in the drop in sex steroid levels which has been found in captured male plaice (Vermeirssen).
8. In vitro incubations of plaice oocytes to test the effectiveness of '17,20b-P'-like steroids in triggering final oocyte maturation (Scott). Due to bad weather and pressure to achieve some of the other more major aims, no in vitro incubations were carried out.
9. Collection of live male plaice for return to the laboratory.
|Chief scientist||Alexander Pickering Scott (Ministry of Agriculture, Fisheries and Food Lowestoft Fisheries Laboratory)|
|Cruise report||(0.24 MB)|
|Specific||Southern North Sea|
|Biology and fisheries|
|Demersal fish||Quantity: number of specimens = 65|
Description: Plaice for analysis of weight,length,testis,blood hormones