This project will consist of a two-level approach towards the Metabolic Theory of Ecology (MTE). At a first stage, we will explore, for the first time, the ontogenetic metabolic scaling (from eggs to adulthood passing through planktonic paralarvae stages) of coastal cephalopods with three distinct life strategies, namely the semi-pelagic European squid Loligo vulgaris, the nektobenthic common cuttlefish Sepia officinalis, and the benthic common octopus Octopus vulgaris.

The main objectives are to: i) test the universality of the 3/4-power law, ii) scrutinize the tentative classification of intraspecific metabolic scaling proposed by Glazier (2005, modified from Bertalanffy, 1957) and iii) investigate how intrinsic (gender, growth, reproduction, locomotion) and extrinsic effects (temperature) may affect metabolic scaling. Closed and flow-through respirometry experiments will able to quantify energy expenditure rates (see Rosa and Seibel 2008, Rosa et al. 2009) and activity levels of metabolic enzymes involved in aerobic and anaerobic pathways of ATP production will also be analyzed (see Rosa et al. 2009). The assessment of eventual growth-related ontogenetic scaling divergences will be evaluated at cellular (hyperplasia and hypertrophy processes) and biochemical levels (muscle protein and nucleic acid levels, see Rosa and Nunes 2005). At a second stage, we will test whether the temperature dependence of individual’s metabolic rates is the mechanism shaping broad-scale species richness gradients in coastal cephalopod fauna, as proposed by the MTE. While many macroecological studies already have tested for a relationship between temperature and diversity (e.g. including our previous ones, Rosa et al. 2008a, 2008b), no studies have fully investigated if the richness patterns in marine systems agree with the precise MTE predictions (c.f. Hawkins et al. 2007). Marine biodiversity research lags behind that on land, with only 10% of overall biodiversity research devoted to marine biodiversity (Hendriks et al. 2006) and exhibits a general neglect of developments in general ecological theory. MTE lacks of comparisons among different kinds of organisms and biomes (Latimer 2007) and, thus, extending it to marine systems is of great relevance