Behavioural plasticity as a key factor in the survival and evolution of the macrofauna on exposed sandy beaches

Brown, ALEXANDER

Behavioural plasticity as a key factor in the survival and evolution of the macrofauna on exposed sandy beaches

Journal Article

1996

Journal Title

Revista Chilena de Historia Natural (Valparaiso, Chile)

Link to Journal

https://dx.doi.org/10.7196/sajs.718

Department

Department of Biological Sciences

Faculty

Faculty of Science

Abstract

Behavioural patterns evident in members of the sandy-beach macrofauna, including tidal rhythms and orientational responses, are not inflexible but become modified according to physical circumstances. Both long-term and short-term t1exibility in behaviour is apparent. The former often results in behavioural differences between populations and is relatively easy to study compared with short-term modifications, which are generally encountered by accident and are thus poorly documented.As survival on exposed sandy shores is only possible for animals that can react appropriately to changes in conditions, and particularly to dramatic. unpredictable perturbations such as beach erosion during storms, it is suggested that behavioural t1exibility is a key factor which has been rigorously selected for in the evolution of the sandy beach macrofauna. The question is also raised as to whether synchrony of behaviour is a further genetically-facilitated attribute which has played a role in this evolution. Key words: sandy beaches. behaviour, plasticity. RESUMEN Patrones conductuales evidentes en miembros de la macrofauna de playas arenosas, incluyendo ritmos mareales y respuestas de orientación no son int1exibles si no que se modifican según !as circunstancias. Cambios de largo y corto plazo son aparentes. Los primeros (rcsultando en difercncias conductualcs entre poblaciones) son relativamente faciles de estudiar, pero Ios segun-dos se encuentran stlo por accidente y por lo tanto son pobremente documentados. Como la sobrevivencia en playas arenosas expuestas es sólo posible para animales que pueden reaccionar apropiadamente a Ios cambios en !as condiciones, y particu-larmente a pe11urhacioncs dramáticas c irnpredecibles. tales como erosión de la playa durante temporales, se sugiere que la flexibilidad conductual es un atributo clave, el cual ha sido rigurosamente seleccionado durante la evoluci6n de la macrofauna de playas arenosas expuestas. Se plantea tambien si la sincronización de la conducta es un atributo determinado geneticamente que ha jugado un rol en esa evolución. Palabras claves: playas arenosas, conducta. plasticidad.