What makes a good home for hermits? Assessing gastropod shell density and relative strength

Autor(es)

Ragagnin, Marilia Nagata ^[1] ; Sant'Anna, Bruno Sampaio ^[2] ; Gorman, Daniel ^[1] ; De Castro, Claudio Campi ^[3] ; Tschiptschin, Andre Paulo ^[4] ; Turra, Alexander ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Lab Manejo Ecol & Conservacao Marinha, Dept Oceanog Biol, Inst Oceanog, Sao Paulo, SP - Brazil

^[2] Univ Fed Amazonas, Inst Ciencias Exatas & Tecnol, Itacoatiara, AM - Brazil

^[3] Univ Sao Paulo, Serv Imagenol, Univ Hosp, Sao Paulo, SP - Brazil

^[4] Univ Sao Paulo, Dept Engn Met & Mat, Escola Politecn, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MARINE BIOLOGY RESEARCH; v. 12, n. 4, p. 379-388, 2016.
• Citações Web of Science: 2

Resumo

The survival and reproductive success of hermit crabs is intrinsically linked to the quality of their domicile shells. Because damaged or eroded shells can result in greater predation, evaluating shell structure may aid our understanding of population dynamics. We assessed the structural attributes of Cerithium atratum shells through assessments of (a) density using a novel approach involving computed tomography and (b) tolerance to compressive force. Our goal was to investigate factors that may influence decision making in hermit crabs, specifically those that balance the degree of protection afforded by a shell (i.e. density and strength) with the energetic costs of carrying such resources. We compared the density and relative strength (i.e. using compression tests) of shells inhabited by live gastropods, hermit crabs (Pagurus criniticornis) and those found empty in the environment. Results failed to show any relationship between density and shell size, but there was a notable effect of shell density among treatment groups (gastropod/empty/hermit crab). There was also a predictable effect of shell size on maximum compressive force, which was consistent among occupants. Our results suggest that hermit crabs integrate multiple sources of information, selecting homes that while less dense (i.e. reducing the energy costs of carrying these resources), still offer sufficient resistance to compressive forces (e.g. such as those inflicted by shell-breaking predators). Lastly, we show that shell size generally reflects shell strength, thus explaining the motivation of hermit crabs to search for and indeed fight over the larger homes. (AU)

• Processo FAPESP: 10/20550-7 - Comparação entre métodos utilizados para determinar o volume interno de conchas de gastrópodes ocupadas por ermitões
• Beneficiário: Marilia Nagata Ragagnin
• Linha de fomento: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 13/07576-5 - Ecologia populacional de invertebrados bentônicos na baía do Araçá, Litoral Norte do Estado de São Paulo
• Beneficiário: Daniel Gorman
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado