Functional Morphology of the Feeding and Associated Appendages of the Detritivore-Collector Atyid Shrimps, Caridina Cantonensis and Caridina Trifasciata — a Scanning Electron Microscopy Study

The present study used Scanning Electron Microscopy (SEM) to examine the functional morphology of the feeding and associated appendages of the detritivore-collector atyid shrimps Caridina cantonensis Yu, 1938 and C. trifasciata Yam & Cai, 2003. The third maxillipedes of both species are equipped with serrate setae ending in a terminal pore, which setae may thus serve both as mechano- and chemo-receptors. Pereiopods 1 and 2 have dense, long, simple setae and single-rowed serrate setae for effective brushing fine-particulate organic matter and scraping periphyton from the substratum. Pereiopods 3 and 4 are heavily armed with large cuspidate setae and with simple type setae, which can be used for food collection or providing strong anchorage. The dactylus of pereiopod 5 is oval, flattened, and equipped with serrate setae on the ventral margin. In contrast to the suspension-feeding Atya innocuous (Herbst, 1792), Caridina spp. show a lower setal diversity, while all setal types on the pereiopods are mechano-receptors, being specialized for collecting food.