(Bloch and Schneider, 1801)
1. Distinctive Characters Of Early Developmental Stages
(a) Embryonic stages
Adults with embryonic stages net yet recorded from the mangroves.
(b) Early juveniles (Based on 80 mm disc length specimen)
Dasyatis imbricatus 1
Spiracles less than half the size of the eye (as large as an eye in adults); rough plates not yet developed over interorbital, cranium and middle of back; disc width equals the length; ostrum mildly pointed at front dorsal surface brownish with no yellow spot (adults reddish brown with yellow spot); tail whip-like, slightly longer than disc length, with venomous spine and gland and without dorsal or ventral cutaneous fold (tail scarcely as long as disc in adults); dorsal and caudal fins absent.
2. Distinguishing characters of early juveniles/juveniles of similar species occurring in the mangroves
(a) Himantura uarnak
Tail much longer than disc and tail with 30-35 blackish blue bands; small dark spots of mesh work on back.
(b) Dasyatis sephen (Pastinachus sephen )
Tail with central cutaneous fold.
3. Distinguishing characters of juveniles of similar species occurring in the adjacent seas
(a) Amphotistius zugei
Tail with dorsal and ventral cutaneous folds; ventral cutaneous fold larger than dorsal.
4. Salient biological characteristics
Viviparous; young ones feed on crabs and gastropods in the mangrove waterways (Jeyaseelan, 1981). Grows to a maximum size of 1400 mm disc length in the sea.
5. Salient ecological information
Early juveniles and juveniles (80 mm to 302 mm disc length) occur sporadically in the mangroves of South Asia.
6. Other information if any
A venomous fish, at times causing trouble to traditional tribal fishermen, who used to hand pick fishes and shell fishes from the mangrove waterways.