''Acentronura gracilissima'', the bastard seahorse, is a species of pygmy pipehorse from the coastal waters of Japan and Vietnam, it is expected to occur elsewhere but reports in other areas need to be confirmed. It occurs on rock and algae reefs downto depths of where it feeds on

mysids Mysida is an order of small, shrimp-like crustaceans in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch or "marsupium" in females. The fact that the larvae are reared in this ...

, small crabs, fish larvae and probably also on

harpacticoid Harpacticoida is an order of copepods, in the subphylum Crustacea. This order comprises 463 genera and about 3,000 species; its members are benthic copepods found throughout the world in the marine environment (most families) and in fresh ...

copepods Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ocean floor), a number of species have p ...

and

gammarid Gammaridae is a family of amphipods. In North America they are included among the folk taxonomic category of " scuds", and otherwise gammarids is usually used as a common name. They have a wide distribution, centered on Eurasia, and are euryha ...

shrimps as recorded in other species in the family

Syngnathidae The Syngnathidae is a family of fish which includes seahorses, pipefishes, and seadragons (''Phycodurus'' and ''Phyllopteryx''). The name is derived from grc, σύν (), meaning "together", and (), meaning "jaw". The fused jaw is one of the tra ...

. The bastard seahorse is ovoviviparous; the males incubate the eggs in a brood pouch located under the tail.

References

gracilissima Fish of the Pacific Ocean Fish described in 1850 Taxa named by Hermann Schlegel Taxa named by Coenraad Jacob Temminck {{Syngnathiformes-stub