Lobsters are large marine crustaceans known for their powerful claws and hard exoskeletons. They are omnivorous opportunists, consuming both plant and animal matter. While they have a diverse diet, the role of fish is complex, involving both active hunting and scavenging.
The Primary Diet of Lobsters
A lobster’s diet is highly varied. Their preferred everyday meals consist mainly of slow-moving or sessile invertebrates found on the seafloor. This includes a wide range of prey such as mussels, clams, sea urchins, worms, and various other smaller crustaceans like crabs.
Beyond live prey, lobsters also consume significant amounts of detritus, which is decaying organic matter, and various forms of plant life and algae. This diverse intake ensures they can thrive in different environments, from rocky crevices to sandy bottoms, by utilizing local resources. They are constantly searching for food, primarily moving and hunting under the cover of darkness.
Predation vs. Scavenging
Lobsters do consume fish. They are capable of active predation and will target live fish, though healthy, fast-swimming individuals are generally too quick to be caught. The fish they successfully prey upon are often those that are injured, sluggish, or otherwise compromised, making them easier targets on the ocean floor.
While lobsters will hunt, they are also highly efficient scavengers, readily consuming carrion, including dead fish. A significant portion of a wild lobster’s fish intake comes from opportunistic sources, most notably the salted fish used as bait in lobster traps, such as herring. This readily available, immobile food source effectively supplements their natural diet of invertebrates and detritus. The term “opportunistic feeder” accurately describes their relationship with fish, as they seize the chance to consume it whether they actively capture it or simply find a deceased specimen.
Feeding Mechanisms and Adaptations
The two large claws, known as chelipeds, are functionally distinct and adapted for different tasks. One claw, typically larger and rounder, is the crusher claw, which is used to generate immense force to crack open the tough exoskeletons of crabs and the shells of mollusks. The other claw is the pincer, or cutter claw, which is sharper and more slender, designed for grasping and tearing apart softer material. This claw is used to shred prey, such as fish or worms, into manageable pieces before ingestion.
After the claws process the food, it is passed to the mouthparts, which include the maxillipeds, for the final manipulation before swallowing. The actual grinding of food does not happen in the mouth but rather in a structure inside the stomach called the gastric mill, which contains three hardened, tooth-like plates that pulverize the food.