The question of what a baby lobster is called does not have a single, simple answer because these crustaceans undergo one of the most dramatic transformations in the ocean. Unlike many animals that are simply smaller versions of their parents, a lobster’s journey from egg to adult involves a complete physical metamorphosis, changing its appearance, habitat, and behavior multiple times. This complex life cycle requires different names to accurately describe the organism at its various, distinct phases. The terminology reflects the drastic physical changes a young lobster experiences as it transitions from a tiny creature floating in the open ocean to a miniature adult settled on the seabed.
Why There Are Multiple Names
The primary names for young lobsters refer to four distinct developmental stages: the larva, the post-larva, the puerulus, and the juvenile. The earliest stage is generally called a larva, but the specific name depends on the lobster species. For instance, the American lobster goes through several zoea stages, while the spiny lobster’s larva is called a phyllosoma. These early stages are tiny, translucent, and bear little resemblance to the familiar adult form. The puerulus is the next stage, often referred to as a post-larva, and represents the transitional phase between floating life and bottom-dwelling life. This form is characterized by its transparent, miniature adult-like appearance, though it lacks a hardened shell. Once this transitional form settles onto the seabed and completes its final metamorphosis, it is called a juvenile. This four-stage terminology helps differentiate between the vastly different forms a lobster takes before it reaches maturity.
The Planktonic Beginning
The lobster’s life begins as a microscopic, free-floating organism in the upper water column, a habitat known as the plankton. Larval forms, such as the spiny lobster’s phyllosoma, are often flattened, leaf-shaped, and transparent, making them nearly invisible as they drift in ocean currents. American lobster larvae, or zoea, are smaller and more insect-like but must remain buoyant near the surface. This early stage is characterized by rapid growth and multiple molts as the lobster sheds its rigid exoskeleton. The American lobster larva typically spends only a few weeks in this vulnerable, floating phase before settling. Spiny lobster phyllosoma stages can last significantly longer, sometimes drifting for nine to twelve months or even up to two years, relying on ocean currents for dispersal across vast distances.
Transition to the Seabed
The planktonic phase ends with the metamorphosis into the puerulus stage, marking the shift to a benthic, or bottom-dwelling, lifestyle. The puerulus is a non-feeding, highly energetic transitional form that actively swims toward the shore and is often glass-clear, making it difficult to detect. This stage is dedicated to a downward migration, as the young lobster must locate a suitable, sheltered environment on the seabed to survive.
Upon finding a safe place, such as a bed of seagrass or a rocky crevice, the puerulus undergoes one final molt to become a juvenile. The young lobster now looks like a miniature version of the adult, complete with fully developed claws (in the American lobster) and a hardened exoskeleton. Juvenile lobsters are solitary and spend their time hiding in complex shelter during the day, emerging at night to forage on small invertebrates, worms, and mollusks. They will continue to molt and grow within these sheltered areas for several years until they are large enough to move into deeper water.
Protecting the Young
Conservation efforts focus on protecting lobsters at the immature stage to ensure future populations, primarily through management tools that regulate harvest size. Fishery regulations establish a minimum legal size, determined by measuring the length of the carapace, or the main body shell, from the eye socket to the rear edge. This minimum size ensures that most lobsters have the opportunity to reproduce at least once before they can be legally harvested.
Another management tool is the practice of V-notching, which protects proven breeding females regardless of their size. If a fisherman catches a female lobster carrying eggs, they are required to gently cut a small, V-shaped notch into one of her tail flippers before releasing her. This mark identifies the female as a protected breeder who must be immediately returned to the sea, even if she is later caught without eggs, ensuring she can contribute multiple times to the next generation.