Muscle growth and swimming in larvae of Clarias gariepinus (Burchell)

This study describes the muscle fibre type distribution and the swimming activity in early stages of Clarias gariepinus (Burchell). It also describes the influence of different diets on muscle fibre numbers and muscle fibre diameters of Clarias larvae. Yolk-sac larvae of Clarias have a superficial monolayer of red muscle fibres that surrounds inner “white” muscle. At about 11 mm length (larvae fed for 3 days on Artemia), an adult­like fibre type distribution begins to appear. One day after hatching, the larvae (about 5 mm total length) show nearly continuous stationary activity interrupted by slow swimming (velocity 2.4 ± 0 .9 body length per second (BL s^-1)). This activity is probably powered by the superficial red fibres. Stimulation of the larvae results in burst-swimming with an initial velocity of at least 17 BL s^-1, which is probably powered by the inner white fibres. After yolk-sac absorption the time spent in stationary activity and swimming decreases. From the start of feeding, a group of larvae was fed with Artemia and another group with dry food. Larvae fed for 3 d on Artemia and larvae fed for 5 d on dry food have similar length, similar white muscle fibre sizes, and similar white muscle fibre numbers. This indicates that muscle develop­ment is related to the length of the larvae, rather than to age.

Article from Marine Science Symposia Vol. 201 - "Mass rearing of juvenile fish". Symposium held in Bergen, 21-23 June 1993. To access the remaining articles please click on the keyword "MSS Vol. 201".