The larvae of the spiny eel, Mastacembelus pancalus were reared and examined the development of larvae.
Larvae survive up to 390 hrs of hatching and improved survival rate showed in rain water than pond and
supplied tap water. The larval development progress were categorized into nine distinguish stages. In the
first stage, larvae carried yolk sac on their body. In later stage, yolk sac was convex interiorly and become
tubular. Yolk sac was completely disappeared in the third stage within 80-90 hrs of hatching and started to
exogenous feeding. Eyes were fully pigmented at the fourth stage. In fifth stage, intestine and kidney were
developed. Well-developed jaws were visualized in the sixth stage. In later stages, gut and airbladder were
visualized. In the eight stage, distinct anal and dorsal fin were observed. At the last stage, spiky notochord
was shown within 370-390 hrs of hatching but yet to complete larval stages