EAST COAST ROCK LOBSTER

Panulirus homarus

Distribution

East coast rock lobsters found in the Indo-West Pacific region, from East Africa along the coast of the Indian Ocean, as far as the Malay Archipelago, and then along the coasts of the Pacific Ocean to Japan in the north and Australia, New Caledonia and probably the Marquesas Islands in the south.

The East coast rock lobster has an exoskeleton that is brown to brick red with orange spines and blue-green markings on the head. They have two pairs of antennae and five pairs of legs which are attached to the thorax. The head and thorax are fused into a single unit called the carapace. Warm-water lobsters do not have claws.

East coast rock lobsters prefer shallow, warm water. They inhabit rocky reefs in the surf zone at depths of 1-36 meters.

This lobster is a carnivore (meat eater). East coast rock lobsters feed predominantly on mussels. In regions where there are insufficient mussels, rock lobsters have been known to feed on sea urchins, starfish, abalone (perlemoen), crustaceans and bristleworms. They use their front appendages to pull food toward their mouths, crushing the shells of mollusks and snails with their mandibles.

The East coast rock lobster is solitary until they reach the juvenile stage, when they begin to congregate around protective habitat in nearshore areas. As they begin to mature, these lobsters migrate from the nursery areas to offshore reefs. They also share their coral reef homes with one another.

East coast rock lobster males are polygynous (males have more than one female as a mate at one time) and females are monogamous (since they form exclusive bonds every mating season). When the time is approaching for the females to shed their shells, they initiate pairing by repeatedly going to where the male lobster lives.

The pair lives together for a couple days and when the females are about to molt they jab the male they are living with. The male then approaches the soft females, and turn them over onto their backs to place a packet of sperm on their underbelly. When the female is ready to lay eggs, she scratches open the packet to fertilise her eggs and then places it under her tail. The eggs are tended there until they hatch. In a day or two the female lobsters move to a different shelter to finish hardening their shells. No sooner do the females leave the males’ shelter, does another female move in to go through the same process she just completed. This goes on until all the females in that male’s area have their eggs fertilized.

Females bear their orange eggs on tiny hairs beneath the tail, and are said to be ‘in berry’. The eggs hatch after 80-90 days. East Coast rock lobsters have a long and complex life-cycle moulting 11 times during the larvae stage and grow slowly, reaching sexual maturity after approximately 3 years. They can live up to 50 years or more.

Their main predators are fish, octopus, and seals.

Over-exploitation by fisheries is likely to be a localised threat to this species.

Did you know?

• They will warn one another of impending danger by rubbing their antennae on the bases of their eyes to sound an alarm
• East coast rock lobsters taste with their legs and chew with their stomachs
• Research suggests that they keep growing forever