Diving with Crabs, Lobster & Shrimp

Lanta Marine Life | Decapoda

Crabs, lobster & shrimp are Decapod crustaceans, ten-footed (five pairs of legs) scavenging marine animals which include many familiar groups, such as crabs, hermit crabs, lobsters, and shrimp. They are found everywhere when diving Koh Lanta.

Even though decapods are ten-footed animals, they can actually have as many as 38 appendages, arranged in one pair per body segment, though only 10 are considered 'legs'.

The macrurous (shrimplike) species, which can be as small as 1 cm, have elongated bodies with long abdomens, well-developed fan tails, and often long, slender legs.

The brachyurous (crablike) types, which in the case of spider crabs can have spans of almost 4 metres between their outstretched claws, have bodies that are flattened and laterally expanded, frequently with stout, short legs and reduced tail fans.

Porcelain Crabs

Porcelain Anemone Crab (Neopetrolisthes maculatus)

Porcelain crabs are small decapod crustaceans which resemble true crabs, but are in fact closer to squat lobsters in their structure. Reaching a maximum 15 - 20 mm across, their compact and flattened bodies allow them to live and hide in rock crevices for protection.

Hairy Red Hermit Crab (Dardanus lagopodes)

The family Diogenidae comprises the 'left-handed hermit crabs' as the left claw is enlarged, rather than the right claw which is the case for the majority of hermit crabs.

Painted Spiny Lobster (Panulirus versicolor)

Achelata contains the spiny lobsters (Palinuridae), the slipper lobsters (Scyllaridae) and the furry lobsters (Synaxidae), and whilst similar in appearance to true lobsters, are not in fact true lobsters.

Peacock Mantis Shrimp (Odontodactylus scyllarus)

Sporting a thick shell that covers the back of the head and the first four segments of the main body, mantis shrimp are among the most efficient crustacean predators.

Tiger Mantis Shrimp (Lysiosquillina maculata)

Unlike the smashing mantis shrimp, spearing mantis shrimp have barbed ‘spring-loaded’ front limbs used to stab and capture soft-bodied prey, such as fish and worms.

Peacock-Tail Anemone Shrimp (Periclimenes brevicarpalis)

Palaemonid Shrimp are small to moderate-sized shrimps, rarely reaching more than 5 cm. This family of shrimp have a long toothed beak and the front two legs have claws. The second pair of legs are larger and longer than the first pair.

Durban Dancing Shrimp (Rhynchocinetes durbanensis)

Hinge-beak Shrimps, also known as Dancing Shrimps due to the way they move, are a family of small red, orange and white coloured shrimp with large greenish-bluish eyes. These shrimp are defined by their beak which is hinged and can open upward.

The Anemone Shrimp, also called Broken-back Shrimp, are a large family of over 330 species, including several species of cleaner shrimp. A small number of these species can be found at the dive sites around Koh Lanta.

This family are shrimp-like, but are not actually shrimp, but rather they are more closely related to the crawling decapods such as lobsters and crabs.

Scuba Diving & Snorkel Trips

If you'd love a chance to spot Crabs, Lobster & Shrimp on one of our daily high season diving trips from Koh Lanta then send us an email to info@diveandrelax.com.

Join our high season speedboat dive trips to some of Thailand's best dive sites and enjoy small groups, short journey times, with a focus on great personal service, safety and fun.

Not yet a certified diver? Learn to Scuba Dive on Koh Lanta with the 3 day SSI Open Water Diver course.

Book online to save 10% on dive trips and scuba courses on Koh Lanta.

Find Out More

Indo-Pacific Marine Life Guides

Allen, G., Steene, R., Humann, P., DeLoach, N. (2003) Reef Fish Identification, Tropical Pacific. Jacksonville, FL., USA: New World Publications, Inc., ISBN 1-878348-36-1.
Humann, P., DeLoach, N., (2010) Reef Creature Identification, Tropical Pacific. Jacksonville, FL., USA: New World Publications Inc., ISBN 978-1-878348-44-9
Debelius, H. (2013) Indian Ocean Reef Guide. Frankfurt, Germany: IKAN - Unterwasserarchiv, ISBN 978-3-939767-52-7.
Debelius, H. (2004) Nudibranchs and Sea Snails, Indo-Pacific Field Guide. Frankfurt, Germany: IKAN - Unterwasserarchiv, ISBN 3-925919-51-1
Erhardt, H., Knop, D. (2015) Corals Indo-Pacific Field Guide. Frankfurt, Germany: IKAN - Unterwasserarchiv, ISBN 3-925919-69-4.
Veron J.E.N., Stafford-Smith M.G., Turak E. and DeVantier L.M. (2016). Corals of the World

More Marine Life References and Further Information

Diving with Crabs, Lobster & Shrimp

Lanta Marine Life | Decapoda

Porcelain Crabs

Hermit Crabs

Spiny Lobsters

Smashing Mantis Shrimp

Spearing Mantis Shrimp

Palaemonid Shrimp

Hinge-beak Shrimp

Anemone Shrimp

Stenopods