Giant fish discovered in the AtlanticAugust 22nd, 2008 - 11:14 am ICT by IANS
Washington, Aug 22 (IANS) Researchers have discovered a new species of fish, a grouper that grows to more than six feet and weighs almost 500 kg. These Atlantic goliaths are not the same groupers that swim in Pacific waters, though they look identical.
“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 Matthew Craig of the Hawaii Institute of Marine Biology, co-author of the study in which the discovery was announced.
Because the two populations of grouper are identical, they were both considered part of the same species: Epinephelus itajara.
About three-and-a-half million years ago - before the Caribbean and the Pacific became separated by present-day Panama - they were the same species.
Since that time, the two populations have evolved into genetically distinct populations. While testing the hypothesis that Pacific and West Atlantic grouper were the same species, researchers found significant differences in their DNA.
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 in the Red List of Endangered Species of Fauna and Flora.
“In light of our new findings, the Pacific goliath grouper should be treated with separate management and conservation strategies,” said Rachel Graham, a co-author of the study and convener of the first International Symposium on Goliath grouper.
The finding was published in the journal Endangered Species Research.