lecithotrophy

Lecithotrophy is a mode of animal development in which the embryo relies on yolk stored in the egg for its nutrition during embryogenesis. In lecithotrophic development, nourishment is provided by the yolk rather than by external feeding or direct maternal provisioning after fertilization. This contrasts with planktotrophy, where larvae feed on external food sources, and with matrotrophy or histotrophy, where the mother provides nutrients during or after development.

In practice, lecithotrophy often results in larger eggs that contain substantial energy reserves. Because the embryo typically uses these yolk reserves to reach a more mature, often non-feeding larval stage or direct offspring, lecithotrophic lineages may produce fewer offspring per reproduction event and can have shorter or absent planktonic dispersal. The life-history consequences include potential constraints on dispersal distance and a reliance on stable or predictable environments where yolk-rich eggs can successfully develop without ongoing food intake.

Lecithotrophy is found across diverse taxonomic groups, particularly among marine invertebrates such as mollusks, echinoderms, and crustaceans, as well as in some fishes and other organisms. The strategy can be associated with direct development or with non-feeding lecithotrophic larvae that hatch or are released after yolk depletion. Overall, lecithotrophy represents an energy-rich, yolk-based pathway that shapes reproductive output, development timing, and dispersal potential in the species that employ it.