MEPS 322:189-197 (2006)  -  doi:10.3354/meps322189

Temperature-dependent development and somatic growth in two allopatric populations of Acartia clausi (Copepoda: Calanoida)

Sérgio Miguel Leandro1,*, Henrique Queiroga1, Laura Rodríguez-Graña2, Peter Tiselius3

1Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
2Departamento de Ecología, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, Uruguay
3Göteborg University, Department of Marine Ecology, Kristineberg Marine Research Station, 450 34 Fiskebäckskil, Sweden

ABSTRACT: This study compares the effect of temperature on the post-embryonic development time and weight-specific growth rate in 2 populations of Acartia clausi from different biogeographic areas (northern and southern Europe). Development was followed from nauplius I to adult at 3 temperatures (10, 15 and 18°C) at saturating food conditions. The relationship between development time and temperature was established by fitting Belehradek’s function. The northern population had a shorter generation time at all temperatures. At 10°C, the development time was estimated to be 33.9 and 36.4 d decreasing to 16.3 and 17.4 d at 18°C for the northern and southern populations, respectively. Prosome length decreased with temperature, and the southern population had longer individuals at all temperatures. ANCOVA revealed a significant (p < 0.001) positive effect of temperature on the growth rates, and nauplii grew faster than copepodites (except at 18°C in the southern population and 20°C in the northern population). Significant differences between populations were noted during larval growth, with nauplii from the north growing faster at high temperatures (18°C). The results indicate that the 2 A. clausi allopatric populations subjected to different temperature regimes have different temperature responses, in particular at high temperatures.

KEY WORDS: Temperature · Development time · Weight-specific growth rate · Acartia clausi · Ria de Aveiro (Portugal) · Gullmarsfjord (Sweden)

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