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

• Published in: Journal of Plankton Research
• Main Authors: Liu, Hui, Hopcroft, Russell R.
• Format: Text
• Language: English
• Published: Oxford University Press 2006
• Subjects: ORIGINAL ARTICLES; Gulf of Alaska; Pacific; Subarctic; Alaska; Copepods
• Online Access: http://plankt.oxfordjournals.org/cgi/content/short/28/8/769; https://doi.org/10.1093/plankt/fbl009

Juvenile growth and development rates for Metridia pacifica, one of the dominant larger copepods in the subarctic Pacific, were investigated from March through October of 2001–2004 in the northern Gulf of Alaska. The relationship between prosome length (PL, µm) and dry weight (DW, µg) was determined: log 10 DW = 3.29 × 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 typically ranged between 0.004 and 0.285 day−1, averaging 0.114 ± 0.007 day−1 (mean ± SE). After standardization to 5°C (Q 10 of 2.7), growth rates averaged 0.083 ± 0.005 day−1 and were significantly 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 copepod growth rates suggested that further refinement of these models is required.