Analysis of habitat utilization by the fish-hunting cone snail, Conus catus
Authors:Jason Preble, Joseph Schulz
Mentor:Joseph Schulz, Associate Professor of Biology, Occidental College
Cone snails (genus Conus) are a large group of venomous, predatory, marine gastropods. Fish-hunting cones (such as C. catus) are especially popular for research due to the highly specific, neurotoxic action of their venom peptides on vertebrate systems. This makes them prime candidates for pharmaceuticals and reagents. However, fish-hunters are generally more rare than other cones and are understudied in their natural habitats. C. catus is a shallow-water species that preys on gobies that cohabitate intertidal benches. The purpose of this study was to assess habitat utilization by C. catus and other species using geographic information systems and multi-year mark/recapture data collected from a bench site on Kaua’i. The site was amenable to this approach because of an abundance of C. catus and because the shallow water (<1 meter) allowed for the use of a GPS. Although more time-consuming, this method catches details in distribution that can be easily missed using standard transect or quadrat approaches. Our results show clumping of C. catus and other species in areas of rock/sand substrate especially on the northern end of the bench. This is likely due to nocturnal snails seeking daytime refuge and higher prey abundance in these areas. Egg capsules showed that the boulders also provide breeding sites. Distribution patterns were consistent over years and seasons (winter and spring), but nocturnal distributions should be assessed, as they may be different. Relative abundance of C. catus was remarkably high (40.94%), demonstrating the highest abundance of fish-hunting cones known for any site in the world. A lack of juvenile sizes and low recapture rates of C. catus could suggest migration and an underestimation of the total population. This study illustrates that this method, though novel among similar studies, is an alternative to transect and quadrat approaches that provides detailed spatial information in intertidal environments.