Limiting factors in the distribution of intertidal crabs (Crustacea: Decapoda) in the avon-heathcote estuary, christchurch

Abstract

The distributions of the brachyuran crabs Helice crassa Dana, 1851, Hemigrapsus crenulatus (Milne Edwards, 1837), Cyclograpsus lavauxi Milne Edwards, 1853, Macrophthalmus hirtipes (Jacquinot, 1853), and Halicarcinus whitei (Miers, 1876) (Crustacea: Decapoda), and of the common half crab, Petrolisthes elongatus (Milne Edwards, 1837) (Decapoda: Anomura), were recorded in the Avon‐Heathcote Estuary, Christchurch. Experiments on the effects of salinity and substrate showed that H. crenulatus is euryhaline and has a wide tolerance of differing substrates, whereas P. elongatus is stenohaline and requires a rocky substrate. Low salinity and particle size of the substrate may limit the distributions of other crabs in the estuary. © 1976 Taylor & Francis Group, LLC.