"According to density, samples were split into subsamples (1/2 - 1/32) using a Folsom splitter. Rare taxa and developmental stages were counted from the entire sample. With 10 exceptions, calanoid and harpacticoid copepods were identified to species level, and the sex and developmental stage was also determined. Cyclopoid specimens were only identified to genus level. In the calanoid genera Paraeuchaeta, Scaphocalanus and Lucicutia and the harpactidoid Drescheriella, copepodite stages were not further identified to species level but combined. Mean abundance is given as geometric mean. The mean population stage was calculated according to Marin (1987), and the weighted mean depth after Bollens and Frost (1989). Female copepods of C. acutus and M. gerlachei were sorted from preserved samples, and four different gonad developmental stages were determined according to Runge (1985): immature (stage 1), medium ripe (stage 2), semi-ripe (stage 3) and ripe (stage 4)." (http://dx.doi.org/10.1016/j.dsr2.2007.12.013)
References:
Bollens, S.M. and B.W. Frost, 1989. Predator-induced diel vertical migration in a planktonic copepod, Journal of Plankton Research 11 (5) (1989), pp. 1047 - 1065.
Marin,V. 1987. The oceanographic structure of the eastern Scotia Sea IV. Distribution of copepod species in relation to hydrography in 1981, Deep-Sea Research I 34 (1) (1987), pp. 105 - 121.
Runge,J.A., 1985. Relationship of egg production of Calanus pacificus to seasonal changes in phytoplankton availability in Puget Sound, Washington, Limnology and Oceanography 30 (2) (1985), pp. 382 - 396.