Dragons increase in species numbers.

By Dave Armstrong - 18 Feb 2015 8:10:6 GMT
Dragons increase in species numbers.

The seadragons now number 3 species, but the evolution of these beautiful and highly adapted animals can now be better followed with these three associated with pipefish and the other . There is only one live photograph of the new species: this is a reddish specimen of the closely related weedy seadragon.seadragon image; Credit: © Shutterstock

In a rich display of biodiversity, we try and illustrate many different niches and habitats worldwide. This new species description from the relatively-untouched Australian coasts provides us with more possibilities of fish and other discoveries in this region. Biodiversity is so, in the news,>/q> these days, as we lose more and more of it. As far as tiny plants and animals are concerned, especially in the oceans, there are beautiful and sad discoveries to be made, often just as the species involved are disappearing forever. We love the Australians’ best kept secret - the sea dragons that live around the coasts from Western Australia, to New South Wales and Tasmania. There is a remote group of islands called the Recherche Archipelago, off the SW coast of the continent where a new red species was found at slightly deeper than usual habitat for Phyllopteryx and Phycodurus species.

The scientists responsible for discovering this first new species of seadragon for 150 years are Josefin Stiller, Nerida G. Wilson & Greg W. Rouse, of the University of California, San Diego (Scripps Institution) and the Western Australian Museum in Perth. They produced this aygnathid fish on a biodiversity survey and first diagnosed the pregnant male specimen as the common seadragon, Phyllopteryx taeniolatus. With DNA sequencing however, a search for further specimens revealed 3 more museum individuals from the new species. The camouflage of the commoner species obviously works, hiding the bright red animal with body markings like the leafy seadragon, Phycodurus eques.

The new species has many distinctive features, possibly to adapt it to its 50m deep habitat. The authors describe a complex habitat of mixed reef and sandy bottom, typical of the continental shelf near Perth.2 specimens trawled near Perth were from 72m depths while common seadragons only tend to occur at a maximum of 33m, the prime directive was obvious in the sampling of live specimens, as small tissue clips were taken, rather than the more-destructive fin-clipping often used. Now for the isolation of the relatives DNA for an interesting phylogenetic analysis. The sister group to the seadragons is the spiny pipehorses, in Latin the Solegnathus spp., from New Zealand and Australia. The sister of the S. dewysea is the common seadragon, with the more distant genetics of the leafy seadragon making it more of a kissing cousin

As far as morphology goes, the new species was X-rayed and imaged with its uniform red coloration distinguishing it. No numerous spots like those of the common seadragon were noted while vertical bars did not extend past the lateral trunk ridges, as in the leafy seadragon. The best distinguishing features are probably an inflated pectoral (chest) area and a pair of forward-pointing dorsal spines instead of the backward spines of the other 2 species.

Recreational SCUBA divers would not come across the new species as it lies beneath their normal depth, while its 2 close relatives live inshore, near reefs. The red colour would make it better camouflaged at depth, but general distribution around Australia is basically unknown. Records are 60 years old in some cases, so research would be useful to establish any possible conservation needs. We must remember the 2 other species are near-threatened, so the conclusion has to be that this species is threatened more.

The whole paper is available today in the Royal Society’s Open Science journal as A spectacular new species of seadragon (Syngnathidae)