[1] Univ Kiel, Inst Zool, D-24098 Kiel, Germany
[2] Univ Oslo, Dept Biol, CEES, Oslo, Norway
[3] Univ Sheffield, Dept Anim & Plant Sci, Sheffield S10 2TN, S Yorkshire, England
[4] Norwegian Inst Nat Res, N-7004 Trondheim, Norway
[5] Ist Zooprofilatt Sperimentale Reg Lazio & Toscana, Unita Specialist Med Forense Vet Terrestre & Mari, Reiti, Italy
[6] Univ Kaposvar, Fac Anim Sci, Dept Fish & Pet Anim Breeding, Kaposvar, Hungary