Size-sorted juvenile swordtails, Xiphophorus helleri Heckel 1848 (Family Poeciliidae), do not show improved growth

acuicultura aquaculture body length body measurements body weight carga ganadera crecimiento croissance cyprinodontiformes fishes gestion growth management mensuration corporelle ornamental fishes peces peces ornamentales peso corporal poeciliidae poids corporel poisson (animal) poisson ornemental stocking density taux de charge