Staying larval helps moray dispersal


American fish biologists have provided evidence to show that moray eels are genetically similar across the entire Indo Pacific ocean thanks to a record time spent in the larval phase.

Most marine fishes have a pelagic larval phase and their offspring are dispersed via ocean currents. For those species with a short larval phase there is limited scope for dispersal, but for those with extended larval phases, such as moray eels, the offspring of a single spawning can be spread over huge areas.

Now a team of scientists from Washington University in Saint Louis has shown that the offspring of the Undulated moray, Gymnothorax undulatus, and the Yellow-edged moray Gymnothorax flavimarginatus, are genetically similar across a huge expanse of the Indo Pacific.

By studying the genetics of the eels at 14-15 locations across the Indo Pacific spanning 22,000 km, they found little or no differentiation supporting the theory that the extended pelagic larval phase of the eels enables ocean-wide continuity of populations.

The study is the first phylogeographic survey of morays and the first to show genetic homogeneity in any fish found across the entire Indo Pacific.

For more information see the paper: Reece JS, Bowen BW, Joshi K, Goz V, Larson A (2010) - Phylogeography of Two Moray Eels Indicates High Dispersal Throughout the Indo-Pacific. J Hered. 2010 Apr 7.