New isopod species that feeds on fish

Researchers have discovered a new species of marine cryptofauna in the Florida Keys in the US. The majority of the biodiversity in the ocean is made up of microscopic, hidden species known as cryptofauna.

There are 15 species of Gnathia in the region, including the nearly three-millimetre-long isopod.

Gnathia jimmybuffetti, a newly found species of crustacean belonging to the gnathiid isopod family, was caught using shallow water light traps and identified using photomicrographs and genetic sequencing.

“Upon examination, it was determined to be a species that was previously unknown to science,” said senior investigator Paul Sikkel, a research professor in the Department of Marine Biology and Ecology at the Rosenstiel School. “It’s the first new Florida gnathiid to be discovered in 100 years.”

These tiny animals, which are found throughout the world’s oceans lead a very curious life. The juveniles are most active at night and feed on the blood of fish like a mosquito or ticks. The adults do not feed and live hidden in rubble on the ocean floor. Given their lifestyle, they are grouped as parasites, organisms that require a living host for survival.

The current severe marine heat wave events in Florida and other regions of the world that host coral reefs are a big concern for species like Gnathia Jimmybuffetti, which cannot simply swim to cooler water. Work by Sikkel’s team on other gnathiid species has shown that at above-average seawater temperatures, mortality rates increase, and the abundance of gnathiids on reefs decreases significantly. To the extent these effects are likely to be similar for the myriad of other small invertebrates that live in or near the benthos (bottom), this can have major impacts on coral reef food webs.

Since the species was discovered in the Florida Keys and Sikkel and his team are long-time fans of Jimmy Buffett’s music—which is synonymous with the Florida Keys—they named the new species: Gnathia jimmybuffetti after the music legend.

“By naming a species after an artist, we want to promote the integration of the arts and sciences,” said Sikkel, whose research team named a similar species from the Caribbean after Bob Marley (Gnathia Marley).

“All species in an ecosystem play an important role and all species have something to teach us,” said Sikkel. “As we discover new species, we are reminded of how many undiscovered species there still are.”