[Abstract] 1. Nowadays, studies focused to test a well-defined set of a priori hypotheses about
spatial and temporal organization of assemblages in marine communities are scarce.
2. This study presents the first fully-developed application of a parsimonious approach
for model selection based on the Kullback-Leibler information theory using multivariate
data to determine the best spatial and temporal models among a set of a priori
alternative models of a soft bottom macroinvertebrate community in the tropical Pacific
continental shelf (from 10 to 90 m deep).
3. Besides of the determination of the most parsimonious model, the Akaike´s
information criterion allows the exploration of the scale-dependent patterns of
community organization and to determine hierarchical relations among the gradients
considered.
4. Depth the most conspicuous spatial gradient affecting macrofaunal assemblages,
and the main discontinuity is located between 40 and 60 m. The degree of exposure is
defined as a secondary gradient and it is only relevant in shallow waters.
5. Seasonal changes in the abundance along the bathymetric gradient of some
portunid crabs and shrimps defined a process of seasonal recomposition, caused by a
vertical shift of the community
