In this review and synthesis, new data from held and laboratory experi
ments on red drum, Sciaenops ocellatus, larvae as prey to larger fishe
s are presented to illustrate two approaches to the study of developme
ntal effects on predation. Various sizes and species of predatory fish
es imposed very different levels of mortality on experimental populati
ons of red drum larvae. Differences in predator size explained little
of the overall variation in mortality rates. In the laboratory, respon
siveness of red drum to a single size and species of predatory fish wa
s relatively low through much of the developmental period but increase
d steadily. Response effectiveness improved and the predator's capture
success decreased once the prey exceeded 20 mm in length. General ont
ogenetic trends in the behavioural interaction of various larvae and t
heir piscine predators are described by combining 22 data sets on a sc
ale of roughly comparable ontogenetic state. This scale, together with
absolute and relative measures of predator and prey size, are used to
assess the roles of ontogeny and scaling in the predation interaction
. Ontogeny is shown to be a significant contributor to changes in resp
onsiveness, response effectiveness, and capture success. The influence
of scaling always took the form of an interaction with ontogeny and n
ot a main effect.