How do mouthparts differ between meat-eating and plant-eating malacostracans?

The mouthparts of malacostracans are highly specialized to reflect their specific feeding habits. While these crustaceans utilize maxillipeds—thoracic limbs modified as accessory mouthparts—to pass food to the head, the structure of the primary chewing mouthparts varies significantly based on diet.1

In flesh-eating species and scavengers, the mandibular incisors are typically large, and the plates and palps of the maxillae and maxillipeds are equipped with strong spines and cutting edges to facilitate the processing of animal tissue. In these carnivores, the molar process is usually small or entirely absent.1

Conversely, in species that consume plants or a broad range of organic material, the mouthparts feature a strong molar with an inner grinding surface, which is necessary for breaking down tougher plant matter. Additionally, filter-feeding malacostracans often possess enlarged plates on the maxillules or maxillae, which are equipped with numerous fine, plumose setae to effectively strain food particles from the water.1