Hippocampus casscsio Zhang, Qin, Wang & Lin 2016

This species is distinguished from other seahorse species by the following set set of characters: high number of tail rings (34-37); pectoral-fin rays 15; dorsal-fin rays 16, with dorsal fins covering 2 trunk rings and 2 tail rings; a rounded nuchal plate without a raised coronet; snout length approximately 30% in HL; an eye spine; 2 cheek spines; tail length approximately 60% in SL; body colour plain dark brown; males with fully enclosed brood pouch with a small opening for the incubation of eggs (Ref. 116585).

Dorsal soft rays (total): 16

Hippocampus casscsio, the Beibu Bay seahorse, is a species of marine fish of the family Syngnathidae. It is found off the coast of Hainan, China, and from sites around Beibu Bay/the Gulf of Tonkin. It inhabits shallow coastal waters to depths of 15 metres (49 ft). It is expected to consume small benthic and planktonic crustaceans such as copepods, shrimps, and mysids, similar to other seahorses. This species is ovoviviparous, with males brooding eggs in a brood pouch before giving birth to live young. It grows to a length of 13.3 centimetres (5.2 in).