Growth and development of Metridia pacfizca (Copepoda: Calanoida) in the northern Gulf of Alaska

Juvenile growth and development rates for Metridia pacifca, one of the dominant larger copepods in the subarctic Pacfic, were investigated from March through October of 2001 2004 in the northern Gulf of Alaska. The relationship between prosome length (PL, mu m) and dry weight (D W, jig) was determined: log(10) DW = 3.29 x log(10) PL - 8.75. The stage durations of copepodites ranged from 3 to 52.5 days but were 8-15 days under optimal condition. Seasonally, growth rates increased from March to October and typzcally ranged between 0.004 and 0.285 day(-1), averaging 0.1] 4 0.007 day(-1) (mean +/- SE). After standardization to 5 degrees C (Q(10) of 2.7), growth rates averaged 0.083 +/- 0.005 day(-1) and were signifcantly correlated to chlorophyll a, with saturated growth rates of 0.149 day(-1) for C1-C3, 0.102 day(-1) for C4-C5 and 0. 136 day(-1) for all stages combined. Measured juvenile growth rates were comparable with specific egg production rates in this species. The comparisons of our rates in this study with those predicted by the global models of cipepod growth rates suggested that further refinement of these models is required.