Portal de Periódicos da CAPES

Adaptation of Coenobita scaevola (Forskal) (Crustacea, Anemura) to terrestrial life in desert-bordered shore line

1985; Inter-Research; Volume: 25; Linguagem: Inglês

10.3354/meps025189

1616-1599

Yair Achituv, M Ziskind,

Marine and environmental studies

Coenobita scaevola (Forskal) is a terrestrial hermit crab inhabiting shores of the S ~n a i Peninsula, where animals encounter severe conditions of high temperature, high radiation and low relative humidity.Adaptation of these crabs to such arid conditions was studied.The crabs are nocturnally active, taking refuge during the day in hiding places with milder conditions.Body temperature follows that of their hiding places, which is lower than that of the air.After ca 6 h exposure to direct radiation, the crabs die.Thermoregulatory abil~ty is low.Water loss is lower In shelled crabs, higher in crabs without shell; the shell protects the abdomen from desiccation.Freshly killed crabs evaporate less than live crabs, suggesting that evaporation from live crabs is not a purely passive process.Gill surface area is small in comparison with aquatic crabs.Aquatic oxygen consumption is 1.4 times higher than aerial.Unlike other Coenobita spp.which inhabit sites distant from the sea, and in spite of successful adaptation to terrestrial life, Coenobita scaevola does not penetrate far inland: In desert conditions it depends on the sea for its only water source.