Two seahorses? No - one seahorse.

Sometimes, careful taxonomic research leads to the discovery of new species. Equally importantly, it sometimes leads to a conclusion that two previously recognised species are in fact the same.

In a paper published in Zookeys, taxonomist Graham Short from the California Academy of Sciences and colleagues investigated the seahorses Hippocampus procerus Kuiter, 2001 and H. whitei Bleeker, 1855. The newer species had been distinguished from H. whitei by a number of relatively minor morphological features, including a 'spinier physiognomy'. Careful analysis of both morphology and partial mitochondrial DNA sequence showed that these in fact comprise a single species, which is correctly called Hippocampus whitei.

The holotype of Hippocampus procerus, AMS E2914, adult female, from Hervey Bay, Queensland (photograph Mark Allen).