How does shape affect predator- prey interactions in fish? Implications for marine food web structure and dynamics

Each species pertains to a given functional niche, depending on its relationships with others species and its interactions with the abiotic environment. Understanding inter-specific interactions is critical to know and predict ecosystems' structure, functioning and dynamics, but also their response to anthropogenic impacts. Predator-prey relationship is one of the main biotic interactions as it both determines the survival of the prey and the predator and is the keystone of food webs. Unraveling the determinants of predator-prey relationships or, in other terms, the reason why a given predator catches a given prey is therefore of primary importance. Fishes are characterized by a remarkable diversity of shapes which can be associated by their feeding and predation abilities. Body morphology may affect their movements (swimming) and their predation strategy (benthic search, active hunting, ambush…). This study aims at assessing whether, besides the simple size ratio, a predator fish's morphological shape is related to its diet composition, based on four different fish species from the Eastern English Channel.