Microscopic anatomy and ultrastructure of the digestive system of three Antarctic shrimps (Crustacea : Decapoda : Caridea)

Mandibles and stomachs of three Antarctic shrimp species (Nematocarcinus la nceopes, Notocrangon antarcticus, and Chorismus antarcticus) were investiga ted by means of scanning electron microscopy. Transmission electron microsc opy of the midgut glands was applied to find out the nutritional status of the animals, which contained a broad variety of food items in their stomach s. In contrast to the Antarctic krill, the three carideans possess a dual f ilter system; primary filters in the cardia and secondary filters in the py loric chamber. Morphologically, the mandibles and stomachs of the three spe cies vary considerably; however, their food items are similar. We conclude that stomach contents do not really reflect the different modes of life or habitat preferences of the investigated species.