6 Foot, 1000 Pound Fish Evolve in Opposite Oceans

August 22nd, 2008

IF you plan to put your golf bags away and don scuba gear the next time you go into the Pacific Ocean deep you may find yourself face to face with a monster. A fish that has measured over 6 feet in length and weighs over 1,000 pounds.

Interestingly enough, this fish had been discovered before in the Atlantic Ocean, but the ones in the Pacific were misclassified as the exact same ones.

“For more than a century, ichthyologists have thought that Pacific and Atlantic goliath grouper were the same species, and the argument was settled before the widespread use of genetic techniques. The genetic data were the key to our finding: two species, one on each side of the isthmus.,” said Dr. Matthew Craig of the Hawaii Institute of Marine Biology, lead author of the study.

About three-and-a-half million years ago, before the Caribbean and the Pacific became separated by present-day Panama, the two were the same species, but they have evolved in their different habitats.

The two have evolved into completely different species. While testing that the Pacific and West Atlantic grouper were the same species, researchers found significant differences in the DNA from both populations. The differences indicate that the two populations have effectively evolved into two separate species after being separated from one another by Central America. The new Pacific species is now classified as Epinephelus quinquefasciatus. E. itajara is currently listed as critically endangered to extinction in the World Conservation Union’s Red List of Endangered Species of Fauna and Flora. Due to its scarcity, E. quinquefasciatus may also be considered critically endangered.

“In light of our new findings, the Pacific goliath grouper should be treated with separate management and conservation strategies,” said WCS researcher Dr. Rachel Graham, a co-author on the study and convener of the first International Symposium on Goliath grouper which provided the impetus for this highly collaborative study.