Abstract
Feeding activity was investigated for the artificially raised juvenile fish of olive flounder Paralichthys olivaceus and ocellate puffer Takifugu rubripes which incurred hunger trials for varioustime spans. They were fed brine shrimp Artemia salina nauplii programatically every 6 hours, and the time interval between two sequential gulps (GI) was monitored for abouthalf an hour. Their statistics demonstrated that the flounder's gulping pitch wassusceptible to hunger: it varied the fickle attack in the early trials to the periodic one in the late trials with the acceleration ofthe pitch. On the contrary, the puffer demonstrated a shift in mean GI that didn't correlateto the hunger persistence and stable pitch of any trials, which may mean that the puffer was under the control of someother factor than the stimulus of hunger.
The stochastic estimates on the gulping number per mean GI for each trial typified those of either binomial, Poisson's or negative binomial distribution type. The flounder indicatedthe succession from negative binomial type (via Poisson's) to binomial. The puffer, on the other hand, nearly conveys Poisson's with one exception. These lend support to the explanation between hunger persistence and the gulping mode, which isthe focus of our research.
