Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-13T01:47:06.857Z Has data issue: false hasContentIssue false

Population structure of thornback rays Raja clavata and their movements in the Bay of Douarnenez

Published online by Cambridge University Press:  11 May 2009

Jean Rousset
Affiliation:
Laboratoire de Biologie Animale, Faculté des Sciences, Avenue Victor Le Gorgeu, 29287 Brest Cedex, France

Abstract

The population structure of the thornback ray, Raja clavata L., expressed in terms of length and sex, seems to be related to hydrological conditions prevailing on the sampling areas. In the exposed area (Cove of Bertheaume), females are more frequently captured than males, and indeed represent the entire catch in the summer. In contrast, in the relatively sheltered area (Bay of Douarnenez) a majority of adult males and immature females are caught.

After winter, only adults and juveniles of Raja clavata migrate into the Bay of Douarnenez. This bay may be a mating area for adults and also a nursery for juveniles particularly for immature females.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Brander, K. & Palmer, D., 1985. Growth rate of Raja clavata in the northeast Irish Sea. Journal du Conseil, 42, 125128.CrossRefGoogle Scholar
Clark, R.S., 1922. Skates and rays (Raiae). No. 1. Egg-capsules and young. Journal of the Marine Biological Association of the United Kingdom, 12, 577643.CrossRefGoogle Scholar
Deniel, C., 1981. Les Poissons Plats (Téléostéens, Pleuronectiformes) en Baie de Douarnenez. Reproduction, Croissance et Migration des Bothidae, Scophthalmidae, Pleuronectidae et Soleidae. Thèse d'Etat, Universitè de Bretagne Occidentale, Brest.Google Scholar
Holden, M.J., 1975. The fecundity of Raja clavata in British waters, journal du Conseil, 36, 110118.CrossRefGoogle Scholar
Nottage, A.S. & Perkins, E.J., 1983. Growth and maturation of roker Raja clavata L. in the Solway Firth. Journal of Fish Biology, 23, 4348.CrossRefGoogle Scholar
Quiniou, L., 1986. Les Peuplements de Poissons Démersaux de la Pointe de Bretagne. Environnement, Ecologie, Structures Démographiques, Relations Trophiques. Thèse d'Etat, Université de Bretagne Occidentale, Brest.Google Scholar
Steven, G.A., 1932. Rays and skates of Devon and Cornwall. 2. A study of the fishery; with notes on the occurrence, migrations and habits of the species. Journal of the Marine Biological Association of the United Kingdom, 18, 133.CrossRefGoogle Scholar
Wheeler, A.C., 1978. Key to the Fishes of Northern Europe. London: Frederick Warne.Google Scholar
Williams, T. & Bedford, B.C., 1974. The use of otoliths for age determination. In Ageing of Fish (ed. T.B., Bagenal), pp. 114123. Old Woking, Surrey: Unwin Brothers.Google Scholar