Upper temperature tolerance of North Atlantic and North Pacific geographical isolates ofChondrus species (Rhodophyta)
© Biologische Anstalt Helgoland 1987
The upper survival temperature for most isolates ofChondrus crispus from localities ranging from northern Norway and Iceland to Spain, and for an isolate from Nova Scotia, was 28 °C after 2 weeks of exposure to temperatures of 20–31 °C at intervals of 1 °C. An upper survival limit of 29 °C was exhibited by a few European isolates from the English Channel, the North Sea, and one Irish isolate from the upper intertidal. The warm-temperate Japanese speciesC. nipponicus andC. giganteus formaflabellatus survived 30 °C, whereas 29 °C was the upper survival limit for the coldtemperatureC. pinnulatus formapinnulatus from northern Japan. A possible origin ofC. crispus in the north Pacific is discussed.