MEPS prepress abstract  -  DOI: https://doi.org/10.3354/meps13027

Multiple niche-based analyses reveal the dual life of an intertidal reef predator

Ryan Andrades*, Juliana M. Andrade, Pedro S. Jesus-Junior, Raphael M. Macieira, Angelo F. Bernardino, Tommaso Giarrizzo, Jean-Christophe Joyeux

*Email: ryanandrades@gmail.com

ABSTRACT: Intraspecific niche shift occurs in nature and can be measured from different ecological aspects such as distributional, dietary and behavioral aspects. While the ecological niche concept is widely known and adopted, it has been applied to widely different approaches in ecological investigations. In this study, we addressed four niche-based analyses (spatial, dietary, isotopic and functional) to investigate whether the ecological niche of the intertidal predatory fish Labrisomus nuchipinnis varies ontogenetically between juvenile and adult stages. L. nuchipinnis inhabited more complex intertidal tidepools dominated by calcareous algae, rocky rubbles and macroalgae, whereas juveniles occurred in pools with a predominantly sandy substrate. Also, dietary and isotopic niches indicated a trophic niche partitioning between juveniles and adults, with the latter foraging in more diverse (8 vs. 2 dominant prey types) and large-sized food resources (e.g., grapsid crabs). The ecological functional niche based on 10 morphological traits corroborated that juveniles and adults did not overlap their niches in functional space, which may facilitate juvenile survival and adult growth in a semi-confined intertidal ecosystem. Our study revealed that L. nuchipinnis exhibits a marked niche change during its life cycle acting as distinct ecological species along its ontogenetic development. This evidence suggests niche variations within coastal marine ecosystems may be a strategy to increase fitness in a highly competitive environment.