LSU ichthyologist lands major grant to study fish family history

Prosanta Chakrabarty has been curator of ichthyology, or fishes, at the LSU Museum of Natural Sciences for a little more than one year, and he's already landed two major catches: a large grant from the National Science Foundation, or NSF, and the discovery of two new species of fish found in Louisiana.

The two new species were discovered when Chakrabarty and a Taiwanese colleague, Hsuan-ching "Hans" Ho, were looking through jars of batfish collected from the Gulf of Mexico.

"We realized that what was thought to be one widespread variable species was in fact three species," he said. On his first opportunity to do so, Chakrabarty jumped on a research vessel trawling off the coast of Louisiana and managed to collect fresh specimens of the new species he is describing. "Most people in Louisiana probably don't know that there are new species of fish right here in our state," he said.

The grant, titled "Reconstructing Heroini (Teleostei: Cichlidae) - Of Heroes, Convicts, Angels and Red Devils," gives Chakrabarty approximately $520,000 from the NSF and will fund his ambitious and ongoing efforts to untangle and update the complex genetic heritage of heroine cichlid fishes. It also has the potential for supporting the discovery of additional new species.

"Getting a grant this large that focuses on taxonomy is very unusual - it's kind of a dying art," said Chakrabarty. "The funds will help me to do a great deal of taxonomic work, as well as hire post-doctoral students and train workers from some of the areas I collect specimens from."

Cichlids are some of the most popular recreational and aquarium fishes in the world. With more than 2,000 species of cichlids, most carrying unique names like the Jack Dempsey and the Red Devil, they attract a near cult following. They also possess an unusual degree of intelligence. That, paired with the fact that cichlids have the longest period of parental care, keeping watch over offspring until adulthood, makes people feel more attached to these fish than many other families.

"Going back and changing names for fish as popular as these is no easy matter," said Chakrabarty. "Renaming some of these is going to cause me a lot of grief. It's like changing a long-standing tradition to some people - to them, it's just better left alone."

But a better understanding of this fish family could translate to a better understanding of the planet we live on, and perhaps, even of our own human history.

"Cichlids have been around since all the southern hemisphere continents were one," said Chakrabarty. "Understanding their current distribution gives us a better idea of how Earth history has changed over millions of years." For instance, Cuba was once two islands, and the nation of Hispanola was three separate landmasses. "You can still see fossils from the ocean floor on the highest peaks of mountains there."

Geography plays an interesting role in the life of cichlids, which are primarily freshwater fish, though many species of the family appear exotic, more like saltwater species.

"Freshwater is rare in the world. That's hard for most people to comprehend," said Chakrabarty. "If the world's water supply fills a bathtub, a scooped handful would be all the freshwater available. However, out of the 25,000 named species of fish described, around half of them are freshwater, so it produces incredible diversity."

But because geography places insurmountable limitations on freshwater fish - in other words, freshwater species cannot live in saltwater, so they are restricted to the landmass on which their native lake or water supply calls home - it helps researchers identify species.

"We can tell that the species of blind cave fish we discovered in Madagascar are related to the blind cave fish we find in Australia," said Chakrabarty. "They all originated from the same place, and because they're freshwater, we know they didn't simply swim across the ocean. It's basically direct proof that those two landmasses were connected at some point in history."

In addition to supporting this exhaustive taxonomic work, the NSF grant funds student workers, from high schoolers to undergraduates, graduate students and post-doctoral researchers. Chakrabarty plans to identify and train a few Latin American students from areas where he typically collects specimens, as well, in order to train them in the United States and send them back home with the tools necessary for scientific study. Chakrabarty said that local people often recognize species that scientists don't even know about, so by nature they are very good natural historians. Further training, he said, adds to the global scientific collective, as these Latin American countries are awash with biological diversity.

"We want to teach people about their own native fishes. We collect with locals, so we want to bring some students back to learn microscopy, molecular work and other complex skills, to add value to the education they already have," said Chakrabarty. "You can't recognize diversity without being familiar with your own."

Source: Louisiana State University