Distribution, Biology and Ontogeny of Indian River Shad (Tenualosa ilisha)

Abstract

The distribution, biology and ontogenic development of the Indian River Shad (Tenualosa ilisha) compared with some other fishes compile in this review. The distribution in the inland waters of Bangladesh, stock/race, movement and migration pattern, size and sex ratio, age of reproduction, maturity and fecundity and ontogenic development of the mouth, digestive tract and accessory gland of T. ilisha discussed in this article. The life cycle of a fish starts after fertilization, but the mouth and digestive tract development start after hatching. Yolk sac larvae (3.83 ± 0.57 mm SL), pre flexion larvae (8.07 ± 1.83 mm SL), flexion larvae (11.50 ± 1.55 mm SL), post flexion larvae (14.72 ± 1.70 mm SL), and juvenile (18.75 ± 3.02 mm SL) were separated into five groups based on morphological characteristics. At the yolk sac stage, the mouth was closed, however at the pre-flexion stage, the larval mouth gape varied between 177 ± 25 and 367 ± 47 µm. The ranges were 241 ± 31 and 497 ± 59 µm, for the flexion stage, 307 ± 38 and 621 ± 74 µm for the post-flexion stage, and 393 ± 61 and 788 ± 119 µm for the early juvenile stage. Development of the digestive tract is complete at the juvenile stage of this species.