FEEDING STRUCTURES AND THEIR FUNCTIONS IN ADULT AND PREADULT TIGRIOPUS-CALIFORNICUS (COPEPODA, HARPACTICOIDA)

Tigriopus californicus uses several appendages and processes in the co llection and manipulation of food. Their structure and function appear to enable the species to utilize the variety of food materials found in splashpools, including: detritus and organic flocs; superficial mat erial on particles; faecal pellets; protists; diatoms; and small crust aceans. From light and scanning electron microscopy and video, the lab rum and labium appear to be adapted for biting soft and hard food mate rials and holding food for trituration by the mandibles. From energy d ispersive X-ray spectra, the gnathobase of the mandible is suggested t o be sclerotized but not calcified or silicified. It has an array of b ilobate and multilobate teeth, clusters of spinous processes, and a he avy, spine-bearing process to move food into the oesophagus. There is also a flange which articulates in a groove in the labrum which appear s to provide a guide for the gnathobase as it moves vertically.