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Sexual maturity, reproductive behaviour and fertility in the first-generation hybrids of Blicca bjoerkna L. × Abramis brama L.

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NZAU   MATONDO,   B.,   OVIDIO,   M.,   PONCIN,   P   &   PHILIPPART,   J.C..   (2007).   Sexual   maturity,   reproductive  behaviour  and  fertility  in  the  first-­‐generation  hybrids  of  Blicca  bjoerkna  L.  ×   Abramis  brama  L.  8th  International  Symposium  on  Reproductive  Physiology  of  Fish".  3  to   8  June  2007  (Saint-­‐Malo).            

Abstract  

     

Sexual  maturity,  reproductive  behaviour  and  fertility  in  the  artificial  first-­‐generation  hybrids   of  silver  bream,  Blicca  bjoerkna,  and  common  bream,  Abramis  brama,  were  investigated  in   this   study.   The   results   revealed   that   the   females   and   males   of   hybrids   attained   their   first   sexual  maturity  at  the  same  age.  Maturity  in  F1  hybrids  was  observed  at  the  same  moment   as   maturity   in   the   common   bream,   the   latter   being   the   parental   species.   Sizes   of   male   hybrids  at  maturity  were  intermediate  to  their  parents  but  female  hybrids  were  closer  to  the   highest  parental  species,  the  common  bream.  As  for  reproductive  behaviour,  the  numbers  of   spawning   and   mating   behaviours   observed   were   highly   similar.   Female   hybrids   mated   simultaneously   and   successively   with   all   types   of   males,   except  the   common   bream   male,   resulting  in  fertilised  eggs.  Male  hybrids  exhibited  aggressiveness  and  territorial  activities  as   in  parental  species  common  bream.  Successful  survival  was  observed  in  all  post-­‐F1  (F2  and   backcross)  generations  at  each  developmental  stage,  proving  that  these  hybrids  are  fertile.  

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