Social interaction as a relevant factor in experimental approaches with the fiddler crab

• Grant number: 20/03369-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): September 01, 2020
• Effective date (End): August 31, 2021
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Tânia Marcia Costa
• Grantee: Carolina Guardino Martins
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

Fiddler crabs are gregarious organisms that inhabit the estuaries' intertidal regions and have been used as a model in several experimental studies, mainly related to sexual selection and their bioturbating capacity. They exhibited a marked sexual dimorphism where the males display a hypertrophied cheliped that can be used in a confrontation with other males, but it is also associated with sexual selection when the males exhibit the cheliped by performing a wave to the female. Also, they are key organisms in the estuarine environment, by promoting bioturbation in the environment and performs its sedimentary activities, contributing to the cycling of nutrients. Social interaction with other individuals of the same species is recurrent in its natural environment, but the main studies involving this animal model were carried out with isolated specimens. The term "social facilitation" has been used to assess whether the behavior of animals can be influenced by the presence of others of the same species. Thus, the objective of this study is to evaluate whether this social interaction is an important factor for carrying out activities related to sexual selection and bioturbation of the fiddler crabs. We tested two hypotheses: 1) Maximum density increases tidal crab activity; 2) Sexual diversity increases the activity of the crab. Field Experiments will be conducted, allowing the use of data from the organism's behavioral model, with the following responses: the number of pins that the animal performs when feeding, the number of waves and the reproduction time. The performances will be compared between the two experimental approaches with the intuition to understand whether the presence of other items should be considered as a relevant variable for carrying out studies with fiddler crabs.