Antifouling adaptations of marine shrimp (Decapoda: Caridea): gill cleaning mechanisms and grooming of brooded embryos

Abstract

Gills in the branchial chambers of caridean shrimps, as well as the brooded embryos in females, are subject to fouling by particulate debris and epizoites. Important mechanisms for cleaning the gills are brushing of the gills by the grooming or cleaning chelipeds in some species, while in others, setae from the bases of the thoracic legs brush up among the gills during movement of the limbs (epipodsetobranch complexes). Setae of cleaning chelipeds and of epipod-setobranch complexes show similar ultrastructural adaptions for scraping gill surfaces. Ablation of the cleaning chelipeds of the shrimp Heptacarpus pictus results in severe fouling of the gills in experimentals, while those of controls remain clean. Embryos brooded by female carideans are often brushed and jostled by the grooming chelipeds. In H. pictus, removal of the cleaning chelae results in heavier microbial and sediment fouling than in controls.