New research suggests that marine scientists may have been underestimating the biodivesity of the Caribbean sea:
Things are not always what they seem when it comes to fish — something scientists at the Smithsonian Institution and the Ocean Science Foundation are finding out. Using modern genetic analysis, combined with traditional examination of morphology, the scientists discovered that what were once thought to be three species of blenny in the genus Starksia are actually 10 distinct species. The team’s findings are published in the scientific journal ZooKeys, Feb. 3.
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“DNA analysis has offered science a great new resource to examine old questions,” said Carole Baldwin, a zoologist at Smithsonian’s National Museum of Natural History and lead author of the paper. “This discovery is a perfect example of how DNA barcoding is illuminating species that we’ve missed before, particularly small cryptic reef fishes like Starksia blennies. We don’t know where we stand in terms of understanding species diversity, and our work suggests that current concepts may be surprisingly incomplete.”
But DNA analysis cannot stand on its own — Baldwin and her team only recognize genetic lineages as species if they are supported by morphology. So traditional morphological analysis, such as comparing patterns of pigmentation and numbers of fin rays, is conducted to solidify their findings.
One interesting aspect of the research is that Starksia species that were thought to be broadly distributed throughout the Caribbean — as most Caribbean reef fish species are — break up into multiple species with geographically restricted ranges. One species in the study, for example, was divided into three — a species in the east (Bahamas/Turks and Caicos), one in the south (Curacao, Netherlands Antilles) and another in the west (Belize, Central America). Baldwin predicts that other widespread species in the genus may also represent species complexes that break into multiple, geographically distinct species after further study. Furthermore, the team’s DNA data suggest that other types of Caribbean fish (e.g., some gobies) may similarly represent species complexes comprising numerous new species, and traditional concepts of speciation in the Caribbean may need to be re-evaluated.
Read more in the complete article from ScienceBlog.com.
[Photo: Kevin King]
