Daily activity of four tropical intertidal hermit crabs from Southeastern Brazil

Abstract

This study describes the daily activity in a simulated high tide situation of four species of hermit crabs (Pagurus criniticornis, Clibanarius antillensis, C. sclopetarius, and C. vittatus) that coexist in an intertidal flat in southeastern Brazil. Observations were done in two-hour intervals during two subsequent days (48 h) in three replicate pools with thirty crabs each. Among species (between and within genera) there was an evident variation in activity patterns, of which three could be distinguished. The circadian activity patterns of C. antillensis and C. vittatus could be characterized as evening and nocturnal, with resting peaks during the morning and afternoon. The circadian activity pattern of C. sclopetarius was characterized by two marked peaks of inactivity, corresponding to dawn and evening, which could represent an intrinsic association with the semi-lunar tidal cycles of the study area. Pagurus criniticornis showed high activity not influenced by day/night conditions during the entire observed period. These activity pattern variations of the studied hermit crabs should be taken into account in designing further experiments. More precise and accurate interspecific behavioral comparisons among species could be achieved in nocturnal experiments, the high activity period of all species.

Behavioral repertory of Trichodactylus panoplus (Crustacea: Trichodactylidae) under laboratory conditions

“…Red light bulbs were used for nocturnal observations, as they are widely used in experiments with crustaceans (TURRA & DENADAI 2003).…”

Subjective resource value and shell abandoning behavior in hermit crabs

“…Although hermit crabs must upgrade their shell periodically for growth (Childres, 1972), the 'naked' inter-period is characteristically brief (Billock and Dunbar, 2009;Laidre, 2012) because without it, crabs have no protection for their soft abdominal exoskeleton and risk desiccation (for intertidal and terrestrial species), physical injury, and predation (Arnott and Elwood, 2007). Hermit crabs inhabit dynamic coastal environments that are regularly affected by storms, king tides and floods and have thus evolved a suite of behavioral responses to deal with these harsh conditions, e.g., the ability to extricate themselves, and their shell from the sediment if buried (Barnes, 2002;Rebach, 1974;Taylor, 1981;Turra and Denadai, 2003) or the capacity to adopt a sessile lifestyle if trapped (Gherardi, 1996;Hazlett, 1981;Manjon-Cabeza and Raso, 1995;Rodrigues et al, 2000;2002). The circumstances under which individuals will fully abandon shells, however, tend to be restricted to those that pose a real and immediate risk of injury or death (Gorman et al, in review;Hinchey et al, 2006).…”

Reproductive behavior of intertidal hermit crabs (Decapoda, Anomura) in southeastern Brazil

“…Behavioral studies on Brazilian hermit crabs are recent (TURRA & LEITE 2000a, TURRA & DENADAI 2002, 2003. The little information on the reproductive behavior of species that occur along the Brazilian coast was described in the studies of HAZLETT (1966HAZLETT ( , 1972HAZLETT ( , 1996a on populations located in the Caribbean and southern USA.…”