By Prashant Mahajan, CEC, BNHS, Mumbai
With its armoured body, head like a horse, tail like a monkey, eyes like chameleon and a pouch like a kangaroo, the bizarre seahorse (Hippocampus) is unique among fishes. The head is set at right angles to the body, which is completely
enclosed by cruciform, interlocking plates, whose edge often have spines or rounded knobs, quite unlike the scales of other fishes. The seahorse swims upright, propelled by a wavering dorsal fin. The small pectoral fins help to steer the animal as it glides
along. There are no pelvic or tail fins at all. But there is a tail-tapering and prehensile (grasping), able to grip seaweed or twigs as the seahorse watches for food.
The seahorse hunts mainly by sight, sucking tiny water creatures such as baby fishes and shell fishes into its tubular mouth. Its eyes turn independently to view two scenes at once-one eye searching for food, perhaps, while the other checks
out a possible predator. The seahorse can remain still for long periods, secures by its prehensile tail and well camouflaged among weeds or corals. The seahorse grows to 12 or 15 cm long.
The strangest feature of these creatures is that it is the father, which gives birth to the babies and not the mother! As the breeding season approaches the male seahorse’s pouch, the front of his lower abdomen, becomes swollen and ready to
receive eggs. The female lays up to 200 eggs in the pouch, through her long egg-laying tube (ovipositor). About two to six weeks later the young develop inside the pouch and are ejected as tiny replicas of the parents.
Seahorses are common in the costal waters of India and are usually found among marine weeds and submerged rocks where they obtain their food.
Note:
Many seahorses are listed as threatened according to international or national criteria. Seahorse trade is now largely unregulated, but all 32 species were recently provided protections under CITES(Convention on International Trade in Endangered Species). As
of May 2004, trade will be controlled through a system of permits to ensure that it is sustainable and legal.
In 2002, the World Conservation Union (IUCN) Red List of Threatened Species lists one species of seahorse as Endangered, 20 species as Vulnerable and the remaining 11 species as Data Deficient.
( data from WWF )