Reef Pest or Ecosystem Destroyer? The Diet of an Invasive Species in the Caribbean, The Lionfish Pterois Volitans

Undergraduate #70
Discipline: Biological Sciences
Subcategory: Ecology

Maya Munstermann - University of Connecticut
Co-Author(s): Luiz Rocha and Claudia Rocha, California Academy of Sciences

Pterois volitans, the lionfish, is a scorpaenid native to the Indo-Pacific Ocean. In Caribbean reefs, it has become an invasive species with a depth range from 1 to 1,000 feet. P. volitans is a threat due to their immense numbers and prodigious consumption of prey at all depths of the Caribbean reefs. In the Caribbean, P. volitans are opportunistic feeders with a wide range of food preference, feeding on almost any prey organism smaller than they are. Past studies have investigated the impact of P. volitans’ dietary preferences on shallow reef ecosystems and the threat posed there is well known. In contrast, we wanted to explore lionfish predation patterns in the much more poorly understood mesophotic (“twilight zone”) reef ecosystems in two localities. Mesophotic reefs are low light coral ecosystems between 200 and 500 feet that support diverse fish populations. It is crucial to understand anthropogenic impacts on these under-studied, deeper ecosystems in order to better frame questions about their preservation, yet the extent of the threat P. volitans represents to mesophotic reefs is unknown. Twenty-seven specimens of P. volitans were sampled from mesophotic reefs (200-400 feet) near Curaçao and 21 from the mesophotic reefs near Bermuda. The entire contents of each specimens’ stomach were removed, DNA extracted and the DNA sequenced for each sample. From the DNA matches provided by GenBank, we identified 7 orders, 26 families, and 30 species of fish and crustaceans (see fish below). The dietary analysis of P. volitans from shallow water differed from that of the species in mesophotic depths. In shallow reefs, Labridae was the most consumed family of fish (27%). In mesophotic reefs, the Serranidae (67%) was the most strongly represented fish family in the stomach content analysis. Paranthias furcifer made up 94% of serranid sequences, revealing a high consumption rate of this species by P. volitans. All P. furcifer specimen sequences were from the Bermuda locality. Based solely on the “sampling” represented by the opportunistic feeding behavior of P. volitans, it would appear that P. furcifer presently occurs in large numbers in mesophotic reefs. Despite this abundance, it is now suspected that P. furcifer populations face endangerment due to the high levels of P. volitans predation. This threat is greatly enhanced by the fact that Bermuda is an isolated reef ecosystem with high endemism and limited recruitment potential from dispersal.

Funder Acknowledgement(s): National Science Foundation; California Academy of Sciences

Faculty Advisor: Rich Mooi, rmooi@calacademy.org

Role: The samples from mesophotic reefs collected prior to my arrival by my mentor for the REU internship. Once I obtained the samples, I was given training in the Center of Comparative Genomics Lab. From there, I completed the rest of the data analysis by myself. The research I individually completed included processing the samples, analyzing the results, and constructing the abstract and final presentation.