That's a moray

A nice video to catch your eye...



...and call your attention to this story on moray eel genetic diversity and distribution across the Pacific Basin. Joshua Reece, a graduate student at Washington University in St. Louis, has just completed a survey of the Family Muraenidae in which he collected two species of morays, the undulated and the yellow-edged, at locations spread across the Pacific. The goal was to identify genetic differences among populations that would indicate a disruption of gene flow. Reece's results, published in The Journal of Heredity, showed exactly the opposite - both species showed virtually no genetic differences across the wide Pacific. How come?

Reece, who collected a total of 289 eels over the course of the study, believes that the answer to the genetic homogeneity of morays across wide-flung reef communities lies in the dispersal of their larval stages. While adult morays are hunker-down type fish, often spending most of their lives on just a few square meters of reef, their pelagic larvae are extremely long-lived and can cover hundreds, perhaps thousands of miles. Most larval reef fish have a month or so in which to disperse; the leptocephalus larva of the moray may persist for many months, or even years.

Another question arises, however. If morays are such efficient dispersers, able to spread their genes across the Pacific, how do we explain their speciation into more than 150 different species, most of which occupy very similar niches. That may be Joshua's next project.