Venom variation during prey capture by the cone snail, Conus textile.

Cecilia A Prator,Joseph R Schulz,Kellee M Murayama,Frederique Lisacek

doi:10.1371/journal.pone.0098991

Abstract

Observations of the mollusc-hunting cone snail Conus textile during feeding reveal that prey are often stung multiple times in succession. While studies on the venom peptides injected by fish-hunting cone snails have become common, these approaches have not been widely applied to the analysis of the injected venoms from mollusc-hunters. We have successfully obtained multiple injected venom samples from C. textile individuals, allowing us to investigate venom compositional variation during prey capture. Our studies indicate that C. textile individuals alter the composition of prey-injected venom peptides during single feeding events. The qualitative results obtained by MALDI-ToF mass spectrometry are mirrored by quantitative changes in venom composition observed by reverse-phase high performance liquid chromatography. While it is unclear why mollusc-hunting cone snails inject prey multiple times prior to engulfment, our study establishes for the first time a link between this behavior and compositional changes of the venom during prey capture. Changes in venom composition during hunting may represent a multi-step strategy utilized by these venomous animals to slow and incapacitate prey prior to engulfment.

Highlights

During the last 50 million years, cone snails have evolved into hundreds of species with prey preferences that generally fall within three categories: fish-hunters, worm-hunters, and mollusc-hunters [1]
The results obtained by MALDI-ToF MS are mirrored by quantitative differences in venom composition profiles obtained by reverse-phase HPLC column (RP-HPLC) of single injected venom samples (Figure 1B)
Qualitative as well as quantitative changes in venom peptide composition during prey capture are, a consistent feature of the envenomation process in C. textile and are not dependent on geographic distribution or the volume of venom injected. We have identified both qualitative and quantitative changes in venom peptide composition during single feeding events of the mollusc-hunting cone snail, C. textile

Summary

Introduction

During the last 50 million years, cone snails (genus Conus) have evolved into hundreds of species with prey preferences that generally fall within three categories: fish-hunters, worm-hunters, and mollusc-hunters [1]. Interspecies venom variation is well established and recent studies have demonstrated that intraspecific variation exists in the composition of prey-injected venom peptides from several fish-hunting species [3,4,5,6]. These instances of variation might be explained by stochastic, genetic as well as individual differences in age, size, or geographic location. Other venomous animals such as snakes and scorpions have been shown to exhibit variation due to diet or hunting strategy [7,8,9,10]. Studies on the fish-hunter, Conus striatus, indicate that venom analyzed from the dissected duct is more complex than the injected venom from the same animal, revealing that mechanisms for venom peptide sorting, packaging, and/or selective delivery into prey must exist [5,12]

Methods

Results

Conclusion