InvertebratesInvertebrates

Invertebrates

Crabs are the most conspicuous and probably the most numerous inhabitants of the forest floor and beach fringe. The little nipper, Geograpsus grayi, is common under the Pisonia forest. The robber crab, Birgus latro, is occasionally observed within the forest but was more abundant prior to harvesting by Cocos-Malays. Three species of hermit crabs are present in large numbers, the red hermit crab, Coenobita perlata, the purple hermit crab, C. brevimana, and the tawny hermit crab, C. rugosa. During the day the hermit crabs take refuge under logs and shrubs, and at night-time venture out to scavenge on the forest floor and beach.

The land crab, Cardisoma carnifex, is abundant, particularly in the saltmarsh and on the fringes of the lagoon. The yellow nipper, Geograpsus crinipes, and the Christmas Island red crab, Gecarcoidea natalis, also occur.

The horn-eyed ghost crab, Ocypode ceratophthalma, is commonly found on the north-western beaches with Grapsus tenuicrustatis common on rocky sections of the coast.

A species of cricket, Ornebius sp., occurs among the leaves of both Cordia and Pisonia, and Nerius lineolatus, a long-legged Dipteran, and the mosquito, Aedes aegypti, are plentiful. Butterflies, ants, cockroaches, beetles and weevils are also present on North Keeling Island.

Spiders, a small wood-louse, centipedes, millipedes, termites, scorpions, various species of ectoparasitic ticks and mites, and a terrestrial mollusc Melampus sp. have been recorded on North Keeling, but as yet no earthworms have been found. Earthworms are abundant on the southern atoll.