Trophic Niches and Trophic Adaptations of Prey-Specialized Spiders from the Neotropics: A Guide

Abstract

Spiders are the most diversified group of terrestrial predators. They employ a wide variety of feeding strategies, and exploit several prey types, from invertebrates up to small vertebrates. Many studies on the trophic ecology of spiders have focused on generalist and euryphagous species. Thus, our knowledge of prey specialist (and stenophagous) species is very limited despite the high number of endemic species occurring in the Neotropics, many of which are most probably specialized. In this chapter, we provide a guide on how to study the trophic niches of spiders in order to encourage other researchers to investigate prey-specialized species. At the beginning, we define the term trophic niche and identify its dimensions (prey type, size, and availability). We critically outline methodological approaches on how to study it. A narrow trophic niche is paralleled by the evolution of specific cognitive, behavioural, metabolic, morphological, and venomic adaptations used in prey capture. We provide an overview of these adaptations and focus on approaches to reveal them. On the basis of an extensive bibliographic review, we summarize the current state-of-the-art with respect to knowledge on the trophic ecology of Neotropical spiders, with particular emphasis on specialists. Finally, we provide recommendations for future research.