New Species Of Sea Bass Identified Based On Larval, Adult Specimen

Brett Smith for – Your Universe Online

Thanks to a lot of hard work and a little luck – two scientists from the National Museum of Natural History at the Smithsonian Institution have identified a mysterious larval fish and the same fish in its adult stage as a new species of sea bass.

Most fish that live in the ocean have a pelagic larval stage that floats inside the surface or near-surface currents, an ecosystem very distinct from the one they occupy as adults. Two distinct environments often call for two distinct physiques and appearances to maximize the odds of survival, leading to larvae that appear very different from the adults of the same species.

The newly identified fish, described in a new report published on Tuesday in the journal PLOS ONE, first came to the attention of researchers via a photograph in a previous study. It was identified as a member of the sea bass family Serranidae, but its seven very elongated dorsal-fin spines made it a very unique looking specimen.

“This feature isn’t known in any Atlantic sea bass larvae, but it is similar to one species of Indo-Pacific sea bass,” said study author David Johnson, a zoologist at the Smithsonian museum. “We initially thought the larva must have been caught in the Indo-Pacific Ocean, but we were wrong.”

However, the fish larva in the photo was identified as being captured in the Florida Straits — the body of water located between Florida and Cuba.

To properly identify the fish, the study team obtained the mysterious larva for further review. They found that the DNA from the specimen did not match up with any recognized fish in their database. Only then did the researchers begin considering the larva as a new species in spite of not having an adult specimen.

Meanwhile, Smithsonian scientists investigating deep-reef fish off Curacao inside the southern Caribbean gathered several “golden bass,” which the team recognized as Liopropoma aberrans. However, genetic analyses revealed more than one species had been collected. Incorporating this new genetic data with available DNA barcoding information for all known western Atlantic sea bass produced an unforeseen discovery: The larva from the Florida Straits is the same novel species of Liopropoma. The sea bass was ultimately named Liopropoma olneyi, after a deceased colleague, John E. Olney.

“This was one of those cases where all the stars were properly aligned,” said study author Carole Baldwin, a zoologist at Smithsonian’s National Museum of Natural History. “We discover a new species of sea bass on Curacao deep reefs that just happens to be the missing adult stage of a larval fish from Florida, which we only knew existed because it was included as ‘decoration’ in a scientific publication. What a great little fish story!”

She added that the reefs where the adult fish live are remote and underexplored ecosystems.

“You can’t access them using traditional SCUBA gear, and if you’re paying a lot of money for a deep-diving submersible that goes to Titanic depths, you’re not stopping at 300 or 800 feet to look for fishes,” Baldwin said. “Science has largely missed the deep-reef zone, and it appears to be home to a lot of life that we didn’t know about.”

Image 2 (below): An adult of the new species of sea bass, Liopropoma olneyi, recently discovered in the deep reefs of Curacao. Once discovered, it simultaneously solved the identification mystery of a fish larva found in the Florida Straits. Credit: Barry Brown, Substation Curacao