Examples Of Bioadhesives For Defence And Predation

Bioadhesives are widely used in nature, not only for settlement but also for defence, prey capture, nest construction or mobility. These glues are superbly adapted in terms of chemical composition and biomechanical properties to the requirements of those organisms producing them. More than 100 marine and terrestrial organisms are known to produce adhesives, some of them since 500 million years. However, only little is known about the composition, production, secretion mechanisms and mechanical properties of the vast majority of these glues.Attaching to a substratum, as done by bacteria, plants and animals, surely is the most common function of bioadhesives and has been extensively described in various organisms such as mussels, acorn barnacles, sandcastle worms or slugs.This chapter focuses on animals that use adhesive secretions for defence and predation, as these functions require specialized behaviours and adhesive properties, such as fast curing process in the millisecond range, squirting over distance, protection against own glue, or bonding to various sorts of substrata with varying surface chemistry or texture. The depicted organisms cover a large environmental and phylogenetic diversity. In addition to marine animals such as hagfish and comb jellies, many terrestrial species like centipedes, salamanders, spitting spiders and velvet worms use adhesives for defence or prey capture. With its subterranean lifestyle, the glowworm exhibits a highly specialized adhesive system combined with prey-attracting bioluminescence.Bioadhesion research is challenging but also offers understanding of bioadhesive evolution and mechanisms, and to identify commonalities and functional principles.