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Call for proposals: Key Action 5: Sustainable Agriculture, Fisheries and Forestry, and Integrated Development of Rural Areas including Mountain Areas

Project type: Specific Targeted Research Project (STREP)

Funding: European Union

Period: 2002-2006

Coordinator: Dr Geir Lasse Taranger

Abstract

Early male puberty is a significant economic problem in farming of several fish species in Europe. It is therefore necessary to develop strategies to delay puberty. These strategies should meet both, consumer acceptance and the economic interests of aquaculture. However, significant gaps exist in our knowledge as regards the physiological regulation of puberty, which preclude developing strategies to approach the problem. Similarly, although it is known already that differences in the genetic background within a species can result in differences in the timing and/or incidence of early male puberty, there is virtually no information on how genetic differences are reflected in differences in reproductive physiology. The same holds true for the potentially very interesting option of combining suitable genetic traits from identified sibling groups with certain photoperiod treatment regimes. Since photoperiod control appears to be one of the most promising techniques for controlling puberty in farmed fish, this project focuses on

1) improving the understanding of the physiological regulation of puberty

2) the interactions with factors such as the genetic background, nutrition and adiposity

3) notably to clarify how photoperiod affects the BPG axis during puberty. The aim is to further develop photoperiod protocols to be used on Atlantic salmon and sea bass, and also to provide a scientific framework for the future use of such (or similar) protocols in new farmed species such as cod, halibut and turbot.

Objectives

Our overall objective is to develop improved photoperiod protocols for delaying first sexual maturation (puberty) in commercially farmed European fish species by:

-improved knowledge on the mechanisms of activation of the brain-pituitary-gonad (BPG) axis during puberty in fish, including development of new tools to study the BPG axis in salmon, rainbow trout and sea bass

-improved understanding of the importance of differences in light intensity and spectral quality in affecting the BPG axis and the initiation/postponement of puberty, by assessment of pineal melatonin production in vitro and in vivo in salmon and sea bass

-improved understanding of the interactions between photoperiod protocols, genetic background and adiposity in arresting/promoting puberty in salmon and sea bass

Expected results and achievements

The project aims to identify environmental and physiological key factors responsible for initiating puberty in fish along with the development of photoperiod protocols to reliablycontrol puberty in farmed fish. The project will study a broad range of parameters duringnatural puberty, or in response to environmental treatments (photoperiod and nutrition), inthe context of different genetic backgrounds. Significant original information is expectedfrom studies using different photoperiod treatments, diets and sibling groups to developlarge differences in the incidence of early puberty. To combine this means with thethorough analysis of the endocrine processes during treatment-induced advancements ordelays of pubertal development is the major innovative approach that characterises theexperimental model used in this project. Significant progress is expected for both theapplied and fundamental branches of aquaculture research, as well as for aquaculture industries.

Partners

• Dr. Geir Lasse Taranger (coordinator) - Institute of Marine Research - Department of Aquaculture - N-5817 Bergen, Norway
• Dr. Hervé Migaud - University of Stirling - Institute of Aquaculture - Genetics & Reproduction Group - FK9 4LA, Stirling, Scotland, UK
• Dr. Olivier Kah - University of Rennes 1 and Centre National de la Recherche Scientifique - Unité Mixte de Recherche UMR 6026 - 35042 Rennes, France
• Dr Jean-Jacques Lareyre - SCRIBE, INRA, UR1037 - 35042 Rennes Cedex, France
• Prof. Manuel Carrillo and Silvia Zanuy - Spanish Council for Scientific Research (CSIC) - Instituto de Acuicultura de Torre de la Sal (IATS) - Torre de la Sal (Castellon), Spain
• Dr. Rüdiger Schulz - University of Utrecht (UU), Faculty Biology - Research Group Endocrinology - 3508 TB Utrecht, The Netherlands123