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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

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Ragagnin, Marilia Nagata [1] ; Sant'Anna, Bruno Sampaio [2] ; Gorman, Daniel [1] ; De Castro, Claudio Campi [3] ; Tschiptschin, Andre Paulo [4] ; Turra, Alexander [1]
Total Authors: 6
[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
Total Affiliations: 4
Document type: Journal article
Source: MARINE BIOLOGY RESEARCH; v. 12, n. 4, p. 379-388, 2016.
Web of Science Citations: 2

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)

FAPESP's process: 10/20550-7 - Comparison between methods for the determination of the internal volume of gastropod shells used by hermit crabs
Grantee:Marilia Nagata Ragagnin
Support type: Scholarships in Brazil - Scientific Initiation