a1 Alfred-Wegener-Institut für Polar-und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
a2 National Oceanography Centre, Southampton, School of Ocean and Earth Science, University of Southampton, European Way, SO14 3ZH Southampton, United Kingdom
a3 Biologische Anstalt Helgoland, Stiftung Alfred-Wegener-Institut für Polar- und Meeresforschung, 27498 Helgoland, Germany
The influence of temperature on larval survival and development was studied in the edible crab, Cancer pagurus, from a population off the island of Helgoland, North Sea. In rearing experiments conducted at six different temperatures (6°, 10°, 14°, 15°, 18° and 24°C), zoeal development was only completed at 14° and 15°C. Instar duration of the Zoea I was negatively correlated with temperature. A model relating larval body mass to temperature and developmental time suggests that successful larval development is possible within a narrow temperature range (14° ± 3°C) only. This temperature optimum coincides with the highest citrate synthase activity found at 14°C. A comparison for intraspecific variability among freshly hatched zoeae from different females (CW 13–17 cm, N = 8) revealed that both body mass and elemental composition varied significantly. Initial larval dry weight ranged from 12.1 to 17.9 μg/individual, the carbon content from 4.6 to 5.8 μg/individual, nitrogen from 1.1 to 1.3 μg/individual, and the C:N ratio from 4.1 to 4.4. A narrow larval temperature tolerance range of C. pagurus as well as the indication of intraspecific variability in female energy allocation into eggs may indicate a potential vulnerability of this species to climate change. Large-scale studies on the ecological and physiological resilience potential of this commercially fished predator are needed.
(Received May 29 2008)
(Accepted October 22 2008)
(Online publication January 20 2009)
c1 Correspondence should be addressed to: S. Thatje, National Oceanography Centre, Southampton, School of Ocean and Earth Science, University of Southampton, European Way, SO14 3ZH Southampton, United Kingdom email: [email protected]