The aim of the present study is to investigate the histomorphological changes of the skeletal muscle
during early larval stages of Nile tilapia with special concern to the hyperplasia, occurring in the skeletal
muscles. A total number of 80 Nile tilapia fish Oreochromis niloticus divided into six different agedependent
groups were fixed in neutral buffered formalin and examined by light and scanning electron
microscope(SEM) .It was found that, the myotomal tissues differentiated and divided into epimeric
(epaxial) and hypomeric (hypaxial) part by distinct horizontal septum at 2 days post hatching larvae
.Two types of skeletal muscle appear red muscle fiber and white muscle fiber at 3 days post hatching
larvae .These findings indicated that hyperplastic growth was increased gradually with significant
difference between all stages during early larval stage of Nile tilapia.