Spiny Lobster
Scientific Name: Panulirus versicolor
During the winter storms, which bring about quick currents and dangerous waves in shallow waters, juvenile spiny lobsters leave and travel over 30 miles (19 km) to the deeper reef habitats where they will live for their adult life. When migrating or moving to another area, they will line up, touching their antennae to the tail of the lobster in front of them. As many as 100,000 lobsters will get in this line, which is thought to look like one long eel or snake. If a brave animal dares to attack, the lobsters gather in a circle with their tail pointing inward, displaying all of their spines outward.
Region: Philippines
Appearance
Like the name says, the spiny lobster has spines covering most of its antennae and its upper body. Painted like a colorful rock with many legs, the spiny lobster uses disruptive coloration or a form of camouflage that breaks up the shape of the animal making it harder to be seen. Stripes, squiggles and spots on its hard shell blend this lobster into the colors and textures of the coral reef. The spiny lobster doesn’t have pincers or claws like most other lobsters. They use legs called walking legs to move about. The second to the last of their legs has a large spine on it, which is used for protection. One pair of the long, thin antennae is white and can reach lengths over 2 feet (60 cm) long. Spiny lobsters may grow to about 20 inches (50 cm) in total length.
The spiny lobster, like other crustaceans, has an exoskeleton or a hard external skeleton that encases, protects and supports their soft body. While the lobster grows, it periodically molts or sheds its exoskeleton and produces a new larger one. Just before molting, the lobster produces a new soft exoskeleton under its outer one. When the lobster starts to burst out of its shell, the old exoskeleton splits where the body and the tail come together. The crab crawls out of the old exoskeleton and leaves it on the reef. In order to fit into the new larger exoskeleton, the lobster pumps its body cells full of water. During the period after it molts, the lobster must be extra careful and take shelter inside a deep reef crevice. The new exoskeleton is soft, making it easy for predators to eat it. Once the new exoskeleton is hard, the body cells pump out the extra water and the body is ready to grow into its new shell.
Habitat
This critter spends the day hiding in caves and crevices or under coral heads or reef tables. It roams the reef by night, creeping sideways or backwards while finding its way around. The spiny lobster remains in shallow areas that are dense in corals and other creatures. It will stay in sheltered clear water areas with slower currents at depths of 10 to 67 feet (3 to 20 m).
Spiny lobsters may sometimes live together in groups of about 20 to 25 individuals, often living under the same tabletop coral.
Range
Spiny lobsters live in the warm parts of the Pacific Ocean, Indian Ocean, and Red Sea.
Diet
Feeding only at night, spiny lobsters will pick worms, clams, oysters, and other slow moving invertebrates or animals without backbones out of the sand. They can also be considered scavengers or animals that eat whatever is available to them because they will pick up dead fish they are laying around the reef.
Reproduction
A male deposits a spermatophore or packet of sperm onto the female’s chest area where all the legs attach. This is often called the ‘tar spot’ because the spermatophore is a dark black color. After the female produces her eggs, she will break open the spermatophore to release the sperm, which fertilizes her eggs. Female lobsters carrying eggs beneath the abdomen are known as ‘berried’. They stick the bright orange eggs to the stomach area under the tail with special appendages called swimmerets. The swimmerets not only secure the eggs, but also rotate the eggs, bringing them oxygen rich water that helps in their growth. Female spiny lobsters can produce eggs up to four times a year and there can be up to a half a million eggs each time. The eggs remain under the female for about four weeks and eventually turn brown. When they hatch, the females fans her tail, releasing her young into the open ocean as planktonic larvae or larvae that live in the upper layer of the ocean, and float there until they reach a certain size. This spreads out the larvae over a wide range of areas. In spiny lobsters, this phase of their life can last as long as 6 months and the tiny lobsters can be carried thousands of miles.
A species or group of organisms that is in danger of extinction or disappearing
from the face of the earth in the near future if its situation is not improved.
A species that can be found throughout its natural range but is declining in number and may become
endangered in the absence of special protection efforts.
A species that is not declining in number but is of special concern because it is sensitive to pressure by
particular human activities or natural events.
A species that is not declining in number and is not sensitive to pressures by human activities or natural
events.
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Threats and Management
Like most lobsters, the spiny lobster is sought after for its tastiness. Many fishers rely on this lobster for income. The spiny lobster is abundant throughout its range, making for a valuable commodity. This fishing industry has been on the increase since 1958 and continues to grow. However, the spiny lobster’s population remains stable because of strict fishing laws and regulations. In order to give the lobsters time to reproduce and replenish the population, spiny lobsters can only be caught during certain times of the year, often called lobster season. Even during lobster season, which only lasts for about three months, only lobsters of a certain size can be caught. As well, females that are berried cannot be captured. Spearfishers are not allowed to catch spiny lobsters. With the spear in hand, it is impossible to accurately measure the lobster with a lobster stick or stick that shows the minimum length of a lobster that can be caught.
Did You Know?
Lobsters can cast off a leg if it is bitten by a predator. This strategy helps to keep the lobster from getting an infection in an open wound where the animals would have bit it. By casting off the limb, the lobster can seal off the place where the leg attached. Eventually, the lobster will regrow or regenerate the leg.
Spiny lobsters produce noises to warn other lobsters to stay out of their territory. They rub the hard area at the bottom of their antennae against ridges on their head. It makes a grating noise that warns others to stay away.
Like a house fly, the spiny lobster has compound eyes. The eye is made of thousands of tiny cylinders that each has their own lens and light receptor. Each cylinder can see part of the image before them, creating a mosaic out of what the animal is seeing. The eyes of the tiny lobster are high on stalks and protected by a clear casing that is part of the lobster’s hard outer shell. Having eyes up high gives the lobster a complete view in front and to the sides.
Scientists are modeling a new telescope after the lobster’s eye. It will give the widest available view of the sky of any telescope. Mounting this type of telescope to a satellite will do years of space surveying work in just weeks.
To quickly escape from predators, the spiny lobster pumps the strong muscles in its tail to shoot off backwards.
References
Print Publications:
Allen, G. R. & Stene, R. 1996. Indo-Pacific Coral Reef Field Guide. El Cajon, California: Odyssey Publishing Company. 378p. ISBN# 981-00-5687-7.
Allen, G. R. 1997. Tropical Marine Life. North Claredon, Vermont: Periplus Editions Ltd. 64p. ISBN# 962-593-157-0.
Banister, K. & Campbell, A. 1988. Encylopedia of Aquatic Life. New York, New York: Equinox (Oxford) Ltd. 349p. ISBN# 0-8160-1257-101-X.
Colin, P. L. & Arneson, C. 1995. Tropical Pacific Invertebrates. Beverly Hills, California: Coral Reef Press. 296p. ISBN# 0-9645625-0-2.
Coleman, N. 1999. Dangerous Sea Creatures Aquatic Survival Guide. Australia: Neville Coleman’s Underwater Geographic Pty Ltd. 95p. ISBN# 0-947325-24-7.
Hoover, J.P. 1993. Hawaii’s Fishes. A Guide for Snorkelers, Divers and Aquarists. Honolulu, Hawaii: Mutual Publishing. 183p. ISBN# 1-56647-001-3.
Perrine, D. 1997. Mysteries of the Sea. Lincolnwood, Illinois: Publications International, Ltd. 312p. ISBN# 0-7853-2430-5.
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Vocabulary Words
Berried – When a female lobster sticks her bright red eggs to her abdomen.
Disruptive coloration – A form of camouflage that breaks up the shape of the animal to make it harder to be seen.
Exoskeleton – A hard external skeleton that encases, protects and supports the soft body of animals like crustaceans.
Extinction – An organism that has not been present on the face of the earth for over 50 years.
Invertebrate – An animal without a backbone.
Lobster stick – A plastic wand or stick that is used to measure from the lobster’s eye to the end of the upper body to determine if it is large enough to be legally taken. This prevents all the juveniles from being caught. They are left to replenish the population for next year.
Molt – The periodic process of shedding an exoskeleton as crustaceans grow.
Organism – A living thing.
Planktonic larvae – Newly born animals that live in the upper layer of the ocean and float there until they reach a certain size. This spreads out the larvae over a wide range of areas.
Scavengers – Animals that eat whatever is available to them.
Species – A group of organisms capable of breeding and producing fertile offspring; organisms that share the same gene pool.
Spermatophore – A packet of sperm that is deposited onto a female’s body. The spermatophore will be used when the female has fully developed eggs that are ready to be fertilized.
Swimmerets – Specialized appendages on a female lobster that are on the abdomen underneath the tail that hold a mass of eggs. They are also used to circulate oxygen rich water around the eggs.
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