New Zealand Journal of Marine and Freshwater Research abstracts

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Intertidal distribution of six trochids at Portobello, New Zealand

C. P. Mitchell*

Portobello Marine Laboratory, University of Otago, P.O. Box 8, Portobello, New Zealand

Abstract The vertical distribution of the trochid topshells Diloma nigerrima (Gmelin, 1791), D. zelandica (Quoy & Gaimard, 1834). D. subrostrata novazelandiae (Anton, 1839), D. bicana-liculata (Dunker, 1844), D. lugubris (Gmelin, 1791), and D. arida (Finlay, 1927) and of the littorinid Littorina cincta (Quoy & Gaimard, 1833) was studied on rocky shores in Otago Harbour. The upper temperature tolerance while submerged and exposed, weight loss under low and high relative humidities, and survival under constant submergence were determined for each species. Vertical distribution was not directly related to resistance to high temperatures and desiccation but to the conditions likely to be experienced during low tide within the microhabitat occupied by each species. No lethal physical factor was found that would prevent any of the species from occupying subtidal levels. Behavioural responses of each species to high temperatures and desiccation also reflected the environment in the species' micro-habitat at low tide.

Keywords Gastropoda, Intertidal distribution, Trochid topshells, Desiccation, Thermal stress, Behaviour, Portobello.

New Zealand journal of Marine & Freshwater Research, 1980, 14 (1): 47-54
Received 28 March 1978; revision received 6 August 1979 Fisheries Research Division Publication 391

PDF file of entire paper: medium quality (460K); (scanned from paper original: notes about this process)

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