(Lesson, 1827)
1. Distinctive characters of early developmental stages
(a) Eggs
Adult males (showing parental care) with eggs in the brood pouch have net yet been collected from the mangrove waterways.
(b) Post Larvae (Based on 17 mm specimen) (Courtesy: Benjamin de Jesus of the Philippines)
Hippocampus abdominalis 1
Snout does not lie in line with longitudinal body axis. Body rings and tail rings yet to develop fully. Dorsal fin has 29 rays. Dorsal fin origin not yet elevated in this larval stage. Very big dorsal fin occupies around one fourth the total length. (Not so in adults). Anal fin origin below 8th dorsal ray and yet to move posteriorly to reach its original position (between trunk and tail). Caudal and pelvic fins are absent. Tail starts curving at this stage (to act as prehensile organ in the adults). There are no dermal flaps on head, trunk and tail. Lateral trunk ridge and inferior trunk ridge are yet to develop fully in the body and present as undulating lines. Tail ridges yet to become prominent.
2. Salient biological characteristics
Adults exhibit sexual dimorphism. Males show parental care. Males possess brood pouch and incubate the fertilized eggs. The brood pouch opens through an anteriomesial pore present under the tail. Tail is prehensile and without any fin.
3. Salient ecological information
Body is armoured with dermal plates, which form rings. This species is a coastal fish inhabiting brackishwater and mangroves. It is distributed in the Philippines, Thailand, northern part of Australia and New Zealand.
4. Culture fisheries
It could be of use in aquariculture if caught in abundance from natural waters and acclimatized or successfully bred and reared in captivity.