Relationship between weight,size and fecundity in trout (Oncorhynchus mykiss) (Ifrane,Morocco) [Relation entre poids,taille et fécondité chez la truite arc-en-ciel (Oncorhynchus mykiss) de la station de salmoniculture de ras al ma (Azrou-Ifrane)]

The aim of the study is to determine the relationship between some biological parameters (height,weight and fecundity) of a moroccan strain species of rainbow trout showed a good adaptation to moroccan waters,especially in the middle atlas. this species is the result of crossing alien species (oncorhynchus mykiss ) from different sources with other species (salmo kamlopps and salmo clarkii). the results obtained during the period of artificial reproduction (november-february 2012),which takes place in the salmon aquaculture resort of ras al ma covered the national center of hydrobiology and fish breeding (cnhp) show that the relative fecundity (f) average is about 2221 eggs/kg,this fecundity is linked to the total length (lt) and total weight (pt) by the following relations: f = 0.00203 lt3.0889 and f = 1.529 pt1,0442. the relationship between the weight (pt) and length (lt) is of type pt = 0.0138 lt2.9971 showing a growth in favour of the size as all the trout are in a state of sexual maturity.