Phenotypic plasticity has been suggested as the main mechanism for species persistence under a global environmental change scenario (e.g., Charmentier et al. 2008; Deutsch et al. 2008). However, standard models aimed to predict the effect of climatic change on species distribution do not allow for the inclusion of differences in plastic responses among populations. This is mainly because we still lack quantifications of plasticity for several traits in several populations for each species to be modelled. An encouraging pathway that could bring closer our ability to made realistic predictions on species persistence with the pace of current environmental changes, is the identification of general patterns in phenotypic plasticity, which could be easily incorporated into the models (Molina-Montenegro and Naya 2012). In line with this, several studies analyzing latitudinal patterns in phenotypic plasticity have been published in the recent years (Naya et al. 2008; Kellerman et al. 2009; Molina-Montenegro and Naya 2012). However, very few studies have evaluated phenotypic plasticity at the local community level, considering, for example, plastic responses in an entire species assemblage (but see Peacor et al. 2012). In addition, no one of them has addressed the relationship between phenotypic plasticity and basic community structure attributes, such as species trophic habits, body mass and relative abundance. Within this context, here we assessed seasonal flexibility and flexibility during short-term fasting in digestive organs size for an entire fish assemblage, comprising ten species, four trophic levels, and a 37-fold range in body mass. Specifically, we were aimed to test the following hypothesis: (1) Given that species occupying lower trophic levels mainly consume resources that are abundant all year round (e.g., detritus, periphyton), while species occupying higher trophic levels typically predate on resources that markedly change in abundance between seasons f(e.g., insects, fish larvae); we predict a positive relationship between seasonal digestive flexibility and trophic position; (2) Given that food intake rates scale with body mass with an exponent lower than one (typically between 0.66 and 0.75), while organs size scale with body mass isometrically; we predict a negative relationship between digestive flexibility during fasting and body size; (3) Given the potential impact of digestive flexibility on organisms’ fitness, we predict that more flexible species, both in a seasonal and short-term basis, should have greater relative abundances than less flexible species. In agreement with our predictions, we found that: (1) Seasonal flexibility in intestinal length was correlated with species trophic position, as could be expected from seasonal changes in species diet composition and energetic demands; (2) Flexibility during fasting in intestine and liver dry masses were inversely correlated with body size, as expected from scaling relationships; (3) Flexibility in intestinal mass, both seasonal and during fasting, was positively correlated with species relative abundance. In summary, our study identified three interesting trends in digestive flexibility in relation to community structure attributes, which represent an encouraging departure point in the search of general patterns in plasticity at the local community scale. The fact that rare species were the less flexible is, however, worrisome under the current scenario of global environmental change.