Marine Animal Encyclopedia
Caribbean Spiny Lobster Panulirus argus
Species ID: P.PA
Description: A large lobster lacking the familiar claws of its Atlantic relative. This species has small spines all over its body and two long, thick spiny antennae. The head and legs are bluish while the body and tail are range to brown with large white spots. Sexes appear similar and juveniles resemble adults with a more purple hue
Maximum Size: 45 cm (1.5 ft)
Longevity: Approximately 20 years
Status: Not currently on the IUCN endangered species list, but recognized as an animal that could become endangered in the near future
Caribbean Spiny Lobster & People: Caribbean spiny lobsters are highly sought after as food both commercially and recreationally. If high fishing pressures persist without proper management, lobster populations will become at risk of decline in the near future
Geographical Range: The Caribbean spiny lobster is found on coral reefs throughout the Caribbean. Its range extends north to the Carolinas and south to Brazil
Coral Reef Zone: Back reef, fore reef and dropoff zones
Favourite Habitats: Caribbean spiny lobsters are found in reef areas with caves, crevices and other substantial cover. Juveniles often prefer seagrass beds, which offer protection and camouflage
Depth Range: 0–90 m (0–295 ft)
A Day in The Life
Dawn: Feeding declines and spiny lobsters seek shelter
Day: Most spiny lobsters hide in crevices, but during breeding season mating may occur in the open
Dusk: Lobsters emerge from hiding places to forage
Night: Lobsters actively forage around the reef for food
Who Eats Who
The Caribbean spiny lobster feeds on small invertebrate prey such as snails, clams, chitons, and crabs. Lobsters are also detritivores, feeding on dead and decaying organisms. Despite its spines, the Caribbean spiny lobster is a favourite meal of many predators including sharks, rays, groupers, triggerfish, moray eels, sea turtles, octopus, and humans!
Scuba Diver & Snorkeler Best Practices
Participate in environmental initiatives : Participate in underwater cleanup projects and public education efforts whenever possible. These initiatives make a huge difference to the coral reef, and help spread word of eco-diving best practices.
During the day, lobsters often huddle inside protective caves and crevices, where they are easy to approach. During a night dive, lobsters can be found roaming the reef. Approach slowly and be aware of their long spiny antennae, which they will wave in defence.
Caribbean spiny lobsters are omnivores and detritivores. They prefer to eat slow-moving prey like snails, clams, crabs, urchins and other invertebrates, but they have also been recorded occasionally feeding on vegetation. Lobsters creep about the reef at night and use their front legs to bring prey near the mouth where strong, plate-like mandibles allow them to crush hard shells and reach the meat inside.
Observe, record & share:
O P.PA-101 – Foraging: Spiny lobsters forage around the reef looking for invertebrate prey
O P.PA-102 – Scavenging: Spiny lobsters pick at carcasses on the seabed
Attack & Defense Behaviour
Caribbean spiny lobsters must defend themselves against a wide variety of reef predators. The spiny lobster’s primary defence, aside from its spiny armour, is to hide in caves and crevices which are easily defended. If predators approach, the spiny lobster waves its antennae in defence. By rubbing their antennae against a plate at the base of each eye, in the same way as a violin bow rubs against the strings, lobsters can also produce a variety of sounds that can frighten predators away. In open areas, threatened lobsters may snap their tail rapidly forward, in a motion known as a “tail-flip”, which allows them to rocket backwards at great speed.
Observe, record & share:
O P.PA-201 – Antennae waving: Lobsters wave their long, spiny antennae in a threatening display
O P.PA-202 – Hiding in caves: During the day, and in threatening situations at night, lobsters seek shelter under ledges or in caves, sometimes in groups
O P.PA-203 – Tail-flip escape: When lobsters feel threatened in an open area, they may use a “tail-flip” to escape
O P.PA-204 – Sound production: If a potential threat does not respond to an antennae display, spiny lobsters can produce an intimidating rasping or grinding sound
Caribbean spiny lobsters reproduce sexually and do not change sex during reproductive development. During breeding season, males leave their hiding spots in broad aylight to look for females, which remain hidden. Once a male has found a female, he uses his front legs to grasp her gently and pull her out of her cave headfirst. The male slides his body under hers so that the lobsters rest belly-to-belly, and he then transfers a small sac containing sperm to the female’s tail before she returns to her shelter. When the female’s eggs are ready to fertilize, she breaks the sac open to liberate the sperm. The fertilized eggs are held under her tail for roughly four weeks until they hatch. Females with eggs are known as “gravid” or “berried” females. The breeding season of this lobster spans late spring through summer, with mating occurring during the day.
Observe, record & share:
O P.PA-301 – Daytime exploration: Lobsters wandering the reef during the day are likely male lobsters looking for females to mate with
O P.PA-302 – Gravid female: A female lobster holding eggs beneath her tail
O P.PA-303 – Coaxing the female: Males use their front legs to gently pull the female from her shelter.
O P.PA-304 – Sliding under the female: The male slides under the female in order to transfer his sperm
O P.PA-305 – Spawn transfer: While beneath the female, the male shudders as he transfers his sperm sac to the female, who escapes to shelter immediately afterwards
Moulting: Moulting is a rarely witnessed, nocturnal behaviour that is a dangerous, yet unavoidable part of life for the Caribbean spiny lobster. Because the lobster’s hard shell does not grow as the soft body beneath gets larger, they must periodically shed the old, cramped shell in exchange for a new, larger one. When a lobster is ready for moulting, the old shell splits at the base of the tail. The body carapace and tail move apart and the soft bodied lobster emerges. The newly moulted lobster often sits by its shell while recovering from the effort of moulting before moving away to shelter. The new shell is secreted rapidly over the next few days, and is larger than the old. During this time the lobster is highly vulnerable to predation, and usually stays hidden. Divers and snorkelers may find old disused lobster shells lying around the reef.
Did You Know?
• Like sea turtles, sharks and rays, Caribbean spiny lobsters are also able to detect and follow magnetic fields which they use to navigate.
• Spiny lobsters undergo seasonal mass migrations as sea surface temperatures drop during the fall, often after the first strong storm. Spiny lobsters exit their caves and undertake migrations,in amazing single-file formations, sometimes consisting of around 50 individuals, towards deeper water where temperatures are more stable.
• As for many sea creatures, size determines fertility in Caribbean spiny lobsters. For example, an 8 cm female may carry up to 230,000 eggs, while a 40 cm female may carry up to 2.6 million.
What to do?
Share your observations today!: Discover your species of interest, observe its behaviour, and share your pictures and videos with friends and coral reef enthusiasts around the world! Upload media to the web, tagged with species common name (ex.: trumpetfish) and species ID code (ex.: A.AM) or species behaviour code (ex.: A.AM-101)