Ontogeny of maternal behavior and brood pheromone in crayfish

Summary

Third stage crayfish were maze tested to determine their preference for paired stimulus solutions of females in various breeding stages and of males. Formerly unattractive female crayfish begin to produce a brooding attractant when they deposit eggs (Fig. 1). The attractant become maximally effective when the eggs hatch (Fig. 2). Behavioral changes occur as larvae develop into the fourth stage and result in both a reduced larval attraction to any mother's stimulus (Figs. 3, 4) and a tendency to become solitary. At the same time the mother's attractant becomes less potent (Fig. 5). The mother receives feedback from her developing brood which maintains her behavior and attractive stimulus (Fig. 8). In the absence of this feedback, the mother's behavior changes to include larval predation in some species (Fig. 4, 6, 7) and her stimulus is no longer attractive (Figs. 8, 9).