Why amphipods prefer the new available habitat built by C. racemosa? : a field experiment in Mediterranean Sea

Abstract

The spread of invasive species as Caulerpa racemosa affects the habitat structure in vegetated systems and accumulates high amounts of detritus. Those changes in the habitat cause changes that could affect the invertebrate assemblages. It has been demonstrated that amphipods can actively choose the substrata, so the aim of this study was to respond the question: “will amphipods prefer the new available habitat built by C. racemosa or, on the contrary, is the detritus stock the factor responsible of this changes?” To answer this question experiment of habitat selection in field were carried out. Mesh bags were place in field with 4 different habitats: Halopteris scoparia, Caulerpa racemosa, artificial substrata and empty (control bags). The vegetal content was previously defaunated. For each type of habitat 3 treatments were carried out: high content of detritus, low content of detritus and without detritus (7 replicate samples for each habitat and detritus level).