Ecological, behavioral and physiological impacts of bioinvasion on native populations: the case of the invasive swiming crab Charybdis hellerii

Author(s)

Diogo Nunes de Oliveira

• Document type: Doctoral Thesis
• Press: Botucatu. 2016-04-26.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu
• Defense date: 2016-01-26
• Advisor: Rodrigo Egydio Barreto; Ronaldo Adriano Christofoletti

Abstract

Ecological processes, such as predation and competition, have the potential to regulate populations, influencing the functioning of the ecosystem through resources partition and loss of species. The addition of alien species into food webs may change these ecological processes and cause cascading effects. In a pioneering study, the impact of the introduction of a species of Asian crab on the Atlantic west coast was evaluated by a multidisciplinary perspective. For this, population, ecological, physiological, and behavioral aspects were evaluated in natural environment and in laboratory experimentation. The results revealed that the species of invasive crab Charybdis hellerii is established on the coast of São Paulo State. This species is a vigorous competitor, competing for resources with six decapod native species, and an efficient predator with omnivorous habit, which can raise the predatory pressure on four prey groups, three of them considered 'ecosystem engineers'. Behavioral and physiological analysis also showed that invasive species and native Cronius ruber are more active, performing more intra and interspecific behavioral interactions. These species tend to dominate the region of the lower intertidal on rocky shores and both compete directly for the same burrow and food when they are in the same environment. Thus, the population growth of invasive species may increase the competitive pressure on C. ruber, also increasing the risk of competitive exclusion. If this exclusion occurs and environmental selective pressure is high, it may not have enough time for developing behavioral and physiological mechanisms that allow the adaptation of native species to a new habitat. This occurring, this species can get into a local extinction process. Our data support the hypothesis that the introduction of C. hellerii on the São Paulo State coast and the addition in local food webs may raise the predatory and competitive pressure by modifying trophic interactions, community structure and are also potentially harmful to the balance of the ecosystem. (AU)

• FAPESP's process: 11/12824-2 - Ecological, behavioral and physiologic impact of the bioinvasion on native population: the case of the non-indigenous swimming crab Charybdis hellerii
• Grantee: Diogo Nunes de Oliveira
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)