Habitat use of the Caprellidea (Crustacea: Amphipoda) from Ceuta, North Africa

Although the caprellid amphipods are very important in marine ecosystems, knowledge of their ecology is scarce. During a sampling programme in North Africa (1998-2000) a total of 22 caprellid species belonging to 5 genera were collected. The habitat use was investigated for all of them. The composition of the caprellidean communities was clearly different between exposed and sheltered areas. Caprella, danilevskii, C. fretensis, C. grandimana, C. liparotensis and C penantis were found in exposed areas, while C dilatata, C hirsuta, C takeuchii and Pedoculina garciagomezi preferred sheltered areas. The species of the former group were morphologically characterised by large size, elongate body somites, a short basis of gnathopod 2 and short pereopods, This morphology enables the caprellids to develop a "parallel" posture attaching strongly to the substrate in areas subject to heavy wave action or strong currents. The smaller species, such as C. cavediniae, C. ceutae, C. erethizon, C. monai, C. santosrosai and C. tuberculata were restricted to deeper coraligen areas, living on hydroids instead of algae. Caprella acanthifera, Phtisica marina and Pseudoprotella phasma were habitat and substrate cosmopolitan. An up-to-date record of caprellid-invertebrate associations is also given.