ANTIPREDATOR BEHAVIOR IN PARADISE FISH (MACROPODUS-OPERCULARIS) LARVAE - THE ROLE OF GENETIC-FACTORS AND PATERNAL INFLUENCE

The paradise fish, a small insectivore, coinhabits marshes of Southeas t Asia with several predator fish species. Its ability to recognize an d avoid harmful fish may depend upon both genetic factors and experien ce. Here we demonstrate genetic variability between the 20-day-old lar vae of two inbred strains of paradise fish (P and S) in predator explo ration and avoidance, using predator models. We show that, in comparis on to S larvae, P larvae exhibited an elevated frequency of leaping an d backing and an increased approach latency when faced with a predator model with eyespots. Analysis of a classical cross system between the two strains revealed significant departure from an additive-dominance genetic model and suggested the involvement of both epistatic effects of several genes and paternal effects. The effect of the paternal inf luence during the 5-day postspawning period was found to be strain dep endent: later predator avoidance behaviors were influenced by the pres ence of the father in P larvae but not in S larvae. On the basis of th ese and previous results, we speculate that the 5 postspawning days ma y represent a developmentally sensitive period during which specific e nvironmental stimulation, e.g., stimuli associated with the father, is critical for later development of appropriate antipredatory responses . We conclude that developmental aspects of antipredatory behavior in paradise fish are influenced by a complex interplay between genetic an d environmental factors.