Archive for May 23rd, 2009

May 23, 2009

More and More and More Pygmy Seahorses

Hippocampus pontohi via (c) H. Menke

How did I miss this news?! In 2008 three new species of seahorse were described! The smallest of the three: Hippocampus satomiae, from scattered areas within Indonesian reefs near Derawan, the Lembah Strait (of northern Sulawesi), and northern Borneo.

Florida boasts H. zosterae, known as the dwarf seahorse, clocking in at the size of a nickel or a quarter. (I’ve kept them in aquariums before, but not with tremendous long term success.) Unlike many of the syngnathids (or seahorses and pipfishes) you might see in public aquaria that take frozen mysis and non-live food sources H. zosterae are notoriously difficult to convert over to frozen foods. H. satomiae is puny in comparison and makes the dwarfs look like relative giants, this newest species is roughly the size of a pea!

Lourie and Kuiter’s paper in Zootaxa late last year announced two other pygmies: Hippocampus pontohi and Hippocampus severnsi. H. satomiae might be the smallest, but these two others are not much bigger at just 1.7 cm! All three new pygmies share a lifestyle spent primarily hanging on to bryozoans, gorgonians, sea fans, and even hanging out within macroalgae like Halimeda in relatively shallow water areas of reef systems.

Like H. zosterae, it appears that H. satomiae, H. pontohi, and H. severnsi all carry relatively few young for each round of brooding in the pouch. Collected specimens of all three new pygmies had just 8 – 11 fry in the pouch. Compare that to adult H. erectus – the lined seahorse, also found in Florida waters – that may give birth to a hundred or even two hundred fry at a round. H. zosterae, the dwarf, routinely gives birth to 8 – 15. (Although fifteen really is extreme! The males look like they’ve swallowed marbles!)

The fry from these three new pygmies are also benthic, like most other pygmy seahorse species and the zosterae dwarf. Once the little ones are out of the pounch they settle into the habitat and get on with the buisness of life and growing up. Several other seahorse species actually have pelagic fry instead and the young go through a stage where they are apart of the general plankton swept along in the currents.

Now if we could just convince Monterey Bay to nab a few of these miniature beauties to include in their new Secret Lives of Seahorses exhibit!

A good question to ask, after contemplating all of this: how many seahorse species exist? Well, we just don’t know. Currently all the seahorse species known are grouped beneath the Hippocampus genus boasting 52 members. A full nineteen of those have been described in just the last eight years since 2001! In fact, two new seahorse members were published this year – both pygmies – H. debelius and H. waleananus! I doubt these new five species are the end of the road. There are likely more syngnathids lurking out there in the tropical reef-associated shallows! (Or better yet, perhaps larger members are hidden within the deep water coral reef systems we’re just beginning to truly explore.)