Pregnant thorny seahorse in Negros, Philippines - April's featured observation

This month's iSeahorse featured observation is from Negros in the Philippines. Nudisusie managed to capture this excellent shot of a very pregnant thorny seahorse, Hippocampus histrix . It looks as though he’s just about to give birth to a whole bunch of tiny seahorses.

Seahorses are well-known for male pregnancy. But among fishes they are also quite unique in that they are ovoviviparous, meaning that they give birth to live young. Most other fishes undergo ‘broadcast spawning’, where both males and females release gametes into the water column with the hopes they’ll meet in the currents. Many other species lay eggs and guard them, but seahorses are among the only fish that see the pregnancy through full term. This unique trait makes seahorses especially interesting to biologists studying reproductive biology. Recent research has even shown that the seahorse brood pouch works very similarly to the mammalian (and human) placenta.

Like many seahorse species, the thorny seahorse is listed on the IUCN Red List as Vulnerable as a result of being caught as bycatch and habitat loss. Gaining insight into our own reproductive biology is just one of the many reasons to conserve seahorses. Thanks again to nudisusie for posting!

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Posted on May 24, 2016 04:50 PM by projectseahorse