(Valenciennes)
1. Distinctive characters of early developmental stages
(a) Eggs
Setipinna taty egg
Spherical eggs with diameter ranging from 1.1 to 1.5 mm; about 10 to 20 oil globules are present in different salinity range (with more number in mixo-oligohaline condition and less number in mixo-euhaline condition). Some of the oil globules are big and others small. Perivitelline space is narrow with 0.03 mm thickness. Size of oil globules range from 0.05 to 0.09 mm in diameter. Yolk is segmented.
(b) Prolarvae
(Yet to be recorded from mangrove waters) (After Delsman, 1932a)
Setipinna taty 1
Prolarva of 3 mm size bas 30-31 pre-anal myomeres and 18- 20 post-anal myomeres. The respective myomere counts reduce to 29 and 16 during metamorphosis. Oil globules are located in hinder part of yolk and as the larva grows, smaller oil globules are located immediately after the yolk and the larger ones lining towards posterior side up to anal pore.
(c) Postlarvae (After Delsman, 1932a)
Setipinna taty 2
Specimen measuring 10 to 14 mm possess 27 to 29 pre-anal myomeres and 18 to 20 post-anal myomeres. In this size range, pre-anal myomere count decreases and he corresponding post-anal myomere count increases due to the forward shifting of the anus. Anal fin has 50 to 56 rays. Caudal fin bifurcated. Dorsal fin origin nearer to caudal fin base than to snout in larval form, but moves towards snout as the specimen grows. Filamentous 1st pectoral fin ray not yet developed in larval form.
2. Distinguishing characters of postlarval forms in similar species occurring in the area
(a) Setipinna phasa
With more anal fin rays (72-75).
(b) Setipinna melanochir
With less anal fin rays (44-50). Pre-anal and post anal myomeres are 38 and 14 respectively.
(c) Setipinna godavari and S. breviceps
Adults easily distinguishable. No report available about the larval development of these species.
3. Salient biological characteristics
(a) Maximum size
Up to 200 mm in marine environment; up to 80 mm in shallow mangrove waterways.
(b) Age and growth
This species attains total length of 95-110 mm in first year, 125-130 mm in second year and over 150 mm during third year in gangetic estuarine system.
4. Salient ecological information
(a) Habitat
Post larvae and juveniles up to 80 mm total length occur in mangrove waterways. Adults occur in estuaries and coastal waters. Though it is occurring in brackish waters, it seems not to migrate up to fresh water. (Setipinna phasa is equipped well to occur even in fresh water).
(b) Geographic distribution
Throughout Indo-Pacific, except Australian waters.