Cuttlefish are carnivorous predators. They tend to eat small crustaceans including prawns, shrimp, and fish. Cuttlefish grow very quickly, so they have a high energy requirement from the foods they eat. Because cuttlefish breed and thrive in different habitats, their diets are diverse, and they are opportunists, and generalists when it comes to their food selection. Unfortunately, this means that sometimes, when needed, they display cannibalistic tendencies. 

 

It should be noted that diseases can easily spread between members of the same species who cannibalize each other, but if lucky, can promote excellent growth. Between-species cannibalism is not a mechanism for disease spreading, so it would not affect a cuttlefish that eats another member of their cephalopod class that might be disease-ridden. 

 

Although it would seem that between genders, males and females must need to have a different input of metabolic energy and output, however, there are no diet differences between the two. However, differences in diet are seen to be prominent among age groups of cuttlefish. During their primary growth stages, smaller, softer fish are primarily the diet of choice, and as they grow bigger and their hunting skills increase, they take on more challenging prey, such as crustaceans and larger fish. 

 

Not only does relative age and size help determine diet, but prey availability seasonally is another challenge the cuttlefish have to face.