We studied the effects of attached peritrich ciliates on the fitness of natural populations of Acartia hudsonica (Pinhey) in Stony Brook Harbor, Long Island Sound. Ciliate infection occurred during late spring, and ciliate load (No. ind.-‘) was not related to copepod age, stage, or body size. Simulated in situ experiments conducted throughout the period of abundance of A. hudsonica showed that ...
