Can fiddler crabs detect underwater predators? A laboratory test with Leptuca thayeri

Author(s)

De Grande, Fernando Rafael ^[1] ; Cannicci, Stefano ^{[2, 3, 4]} ; Costa, Tania Marcia ^{[1, 5]}

Affiliation

^[1] Sao Paulo State Univ UNESP, Botucatu Biosci Inst, Postgrad Program Biol Sci Zool, BR-18618000 Botucatu, SP - Brazil

^[2] Univ Hong Kong, Swire Inst Marine Sci, Pokfulam Rd, Hong Kong, Hong Kong - Peoples R China

^[3] Univ Hong Kong, Sch Biol Sci, Pokfulam Rd, Hong Kong, Hong Kong - Peoples R China

^[4] Univ Florence, Dept Biol, Via Madonna Piano 6, I-50019 Florence - Italy

^[5] Sao Paulo State Univ UNESP, Biosci Inst, Lab Ecol & Anim Behav, Coastal Campus, BR-11330900 Sao Vicente, SP - Brazil

• Document type: Journal article
• Source: ETHOLOGY ECOLOGY & EVOLUTION; v. 31, n. 1, p. 86-97, JAN 2 2019.
• Web of Science Citations: 0

Abstract

Fiddler crabs are intertidal organisms well known to be highly adapted to low tide activity, thus a number of researches have studied their physiological, behavioral and sensory adaptations to such a tidal phase. However, recent evidences showed that some fiddler crabs are the main food item of fish, suggesting that they could also be active underwater. Based on these preliminary observations, we designed laboratory trials aimed to investigate the ability to detect underwater predators in Leptuca thayeri, across sexes and life stages. We tested a combination of chemical and visual cues, using the predator fish Sphoeroides greeleyi, and, as a control, the non-predator fish Mugil curema. Leptuca thayeri detected the presence of chemical cues coming from the predator fish, although significant differences between adults and juveniles were observed. Adults of L. thayeri remained within their burrows and avoided predator exposition, while juveniles were bold and even increased their activity on the sediment surface. We suggest that juvenile crabs' boldness could be explained by a predator inspection behavior, which allows them to gather information about the possible risk of different predatory species, while experienced adults reduce predation risk recognizing the predator itself. (AU)

• FAPESP's process: 13/06472-1 - Effects of predatory pressure on the fiddler crabs' activity rhythms Uca thayeri (Brachyura, Ocypodidae)
• Grantee: Fernando Rafael de Grande
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 16/08687-3 - Hosting of visiting researcher in the area of ecology and phisiology of intertidal organisms - Dr. Stefano Cannicci
• Grantee: Tânia Marcia Costa
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• FAPESP's process: 10/09763-9 - Behavioural ecology of Ocypodoidea crabs
• Grantee: Tânia Marcia Costa
• Support Opportunities: Regular Research Grants