I asked Bruce this same question. Since then, we have learned that diatoms are not the best food, so you would want to use something else. We ve also learned a lot about other aspects of the biochemistry of copepods and their food sources, so there are other issues about the types of fatty acids etc. In this study, Bruce was mesuring egg production rate to look at food limitation, but there are other ways you might do this. In the strictest sense, food limitation occurs when ingestion rate is not at its maximum, so the best measurement would be those examining in-situ ingestion rate.
Copepods have a complicated life history.
A Nauplius looks very little like an adult copepod, while the copepodite stages look like smaller versions of the adult and function similarly. Calanus and Pseudocalanus can take a few weeks to months reach adult stage, which then can last for several weeks. Once they are an adult, the females of most copepod species continue to reproduce for as long as there is sufficient food to produce eggs. Most likely yes, although there have not been as many studies about this. Additionally, the males have most of the burden of chasing down the females, essentially capturing them, in order to mate.