Plasticity in reproductive traits of an intertidal rocky shore chiton (Polyplacophora: Chitonida) under pre-ENSO and ENSO events

Abstract

Chitons (Polyplacophora) are marine molluscs that mostly inhabit intertidal rocky shores. As ectothermic organisms living at the land–ocean interface, they are strongly influenced by temperature and live at their upper thermal limits (Helmuth et al., 2006; Vinagre et al., 2019). As life-history traits (i.e. size at birth, growth, reproduction and size at death) are vulnerable to temperature changes in ectothermic organisms, they reflect the phenotypic expression of the interaction between genotypic and environmental influences (Cole, 1954; Stearns, 1992; Begg, 2005). It is therefore likely that changes in growth and reproduction help to maximize fitness under given constraints. This might be interpreted as nonadaptive plasticity (morphological, physiological or behavioural) with the capacity to produce different phenotypes (i.e. the range of potential phenotypes that a single genotype could generate if exposed to a specified range of environmental conditions; see Stearns & Koella, 1986...