Related FAQs: Marine Crabs 1, Marine Crabs 2,  Marine Crabs 3,  Marine Crabs 4, By Species/Group:  Arrow Crabs, Emerald Green Crabs, Decorator Crabs/Sponge Crabs, Fiddler Crabs, Pom Pom Crabs, Sally Lightfoots, & FAQs on: Marine Crab Identification, Crab Identification 1, Crab Identification 2, Crab ID 3, SW Crab ID 4, SW Crab ID 5, SW Crab ID 6, SW Crab ID 7, SW Crab ID 8, SW Crab ID 9, Marine Crab ID 10, Marine Crab ID 11, Marine Crab ID 12, SW Crab ID 13, SW Crab ID 14, SW Crab ID 15, SW Crab ID 16, SW Crab ID 17, SW Crab ID 19, SW Crab ID 20, SW Crab ID 21, SW Crab ID 22, & Crab Behavior, Marine Crab Selection, Marine Crab Compatibility, Marine Crab Compatibility 2, Marine Crab Compatibility 3, Marine Crab Systems, Marine Crab Feeding, Marine Crab Reproduction, Marine Crab Disease, Micro-Crustaceans, Amphipods, Copepods, Mysids, Hermit Crabs, Shrimps, Cleaner Shrimps, Banded Coral Shrimp, Mantis Shrimp, Anemone Eating Shrimp, Arrow Crabs, Emerald Green, Mithrax/Mithraculus Crabs, Crustacean Identification, Crustacean Selection, Crustacean Behavior, Crustacean Compatibility, Crustacean Systems, Crustacean Feeding, Crustacean Disease, Crustacean Reproduction,   Related Articles: Hermit Crabs, Squat Lobsters, Crustaceans, Fiddler Crabs, Arrow Crabs, Algae Control, Nutrient Control and Export,  /A Diversity of Aquatic Life   Crabs For Marine Aquariums? Part 3 To: Part 1, Part 2,

Bob Fenner

Family Mycteridae; Soldier Crabs. Look like Spiders from afar. Walk forward/backward on their stilt-like legs, not sideways as most crabs. Found on Asian and Australian beaches.

Family Ocypodidae; Ghost Crabs, Fiddler Crabs. Common genera: Ocypode, Uca. Former live in moist sand, emerging at night to feed. Ghost crabs have characteristic thickened, elevated eyestalks. Fiddler Crab males sport an oversize claw that they use for signaling. 

Uca crassipes (Adams & White 1848), the Mangrove Fiddler Crab. Tropical Indo-Pacific. Males with one very large claw. The common "Fiddler" used in the freshwater pet trade. Can be kept with fishes, must have a place to get/dry out.  Need clean, consistent high quality water. Temp. 22-30 C. To a little over an inch in diameter.

Family Parthenopidae: Elbow Crabs

Lambrachaeus sp. (poss. L. ramifer); Long-snout elbow crab. Bali 2014

Family Pilumnidae;

Zebrida adamsii White 1847, Zebra Crab. Sea urchin symbiont (obligate). Here in S. Leyte 2013

Family Pinnotheridae; Pea Crabs. Endosymbiotic Crabs that live within Mussels, Giant Clams, Sea Cucumbers and Tunicates/Sea Squirts. Commensals that don't feed on their hosts  (feed on detritus) but use them for protection against predation. 

Family Portunidae; the Swimming Crabs. Able to swim, fifth pair of walking legs modified as paddles.  

Achelous sebae (H. Milne Edwards, 1834), Ocellate Swimming Crab. Reddish brown carapace to 4" width; two eye spots on back corners; dark claw tips. Roatan 2019 pic by LauraH.

Charybdis hawaiiensis Edmonson 1954, the Hawaiian Swimming Crab. The most common large crab in HI. Striped eyes and yellow swimming paddles on last legs are definitive. To about three inches in carapace width. Found in Hawai'i, the Tuamotu and Society Islands. Hawai'i pic.

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Coryrhynchus sidneyi. Shortfinger Neck Crab. Triangular body to three inches. Trop. W. Atlantic. Shorter snout than Podochela spp. Found on gorgonians. Roatan 2019.

Lissocarcinus laevis Miers 1886. Gorgeously marked with white and reddish brown. Found in association with soft corals, anemones. Indo-Mid-Pacific; South Africa to Hawai'i. To 3 cm. Here a giant one inch one on the mud and a tiny individual on an Alcyonacean in N. Sulawesi. Below some other N. Sulawesi shots of the species.

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Lissocarcinus orbicularis Dana 1852. Harlequin Crab. Variably marked, colored. Free-swimming, but usually found in association (in or on) sea cucumbers and anemones. To about half an inch in carapace diameter. Indo-Mid-Pacific; East Africa to Hawai'i. N. Sulawesi pix. at right

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Lissocarcinus species. Here in Hawai'i

Lissocarcinus species. N. Sulawesi. Here on a sea cucumber.

Podochela species. Neck Crab. To three inches. Trop. W. Atlantic. A decorator species that hangs out on gorgonians looking for food in currents. Roatan pic by TiffB 2016

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Portunus sp. Out looking for a meal by night in Fiji.

Family Trapeziidae; the Coral Crabs. Triangular shaped bodies, and multi-colored chelae. Typically found in and about corals of the genera Pocillopora and Acropora. Live well with their own, not other crab species.

Trapezia digitalis Latreille 1823, the Brown Guard Crab.

Trapezia flavopunctata Eydoux & Souleyet 1842, the Yellow-Spotted Guard Crab. Similar marked to its host, Antler Coral (Pocillopora eydouxi). To 1 inch carapace diameter. Indo-Pacific. Hawai'i photo.

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Trapezia tigrina Eydoux & Souleyet 1842, the Yellow-Red-Spotted Guard Crab. Similar marked to its host, Cauliflower Coral (Pocillopora meandrina). To 1/2 inch carapace diameter. Indo-Pacific. Fiji photo.

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Family Xanthidae; Mud, Round Crabs, Boxing and Pom-Pom Crabs (genus Lybia). Have round/oval carapaces, dark tipped claws/chelae. Small, usually less than two inches across. 

Carpilius corallinus, the Batwing Coral Crab. 3-6 in. smooth carapace with white spots on top. Red legs with purple shading. LeenaH pic in Key Largo 2016.

Glyptoxanthus erosus, the Eroded Mud Crab. 1 1/4 to 2 in. Shell has eroded appearance. Tips of walking legs yellow in color. Nocturnal. Picture at night off of Cozumel.

Genus Lybia:

Lybia caestifera Decorator Boxer Crab. Carapace to 4 mm. Bali 2014

Lybia tesselata (Latrelle 1812), the Pom Pom or Boxer Crab. 1-2 cm. Carries anemones of the genus Bunodeopsis on its claws. Indo-West Pacific; Mozambique, Seychelles, Indonesia, PNG, Philippines. Here in N. Sulawesi.

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Platypodiella spectabilis; Gaudy Clown Crab. To 1 inch. Roatan 2016.

Unknown Crabs: Oh yes, there are many  

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Bibliography/Further Reading:

Baensch, Hans & Helmut Debelius. 1994. Marine Atlas, v.1. MERGUS, Germany. 1215pp.

Barnes, Robert. 1987. Invertebrate Zoology. Saunders. 893pp.

Baugh, Thomas M. 1991. Dwellers of the sand (Mole Crabs). FAMA 11/91. 

Bliss, Dorothy. 1982. Shrimps, Lobsters and Crabs. New Century Press. 

Chhapgar, B.F. 1988. Keep a tank in your tank. Crabs and their cousins in the marine aquarium. FAMA 1/88.

Friese, U. Erich. 1985. Crustaceans in the home aquarium. Crabs- hardy and long-lived, they require very little special attention. TFH 1/85.

Headstrom, Richard. 1979. All about lobsters, crabs, shrimps and their relatives. Dover Publ.

Johnson, Don S. 1999. Shrimp, Crabs and Lobsters in the marine aquarium. AFM 8/99.

Kerstitch, Alex. 1992. Crabs in the aquarium. From Fiddlers to Pom-Poms. FAMA 2/92.

Lau, Collin J. 1986. The A-peeling Box Crab. FAMA 8/86.

Shimek, Ronald L. 1998. Crabby comments. Give proper conditions, crabs make happy, enjoyable and entertaining pets. AFM 2/98.

Sticker, Walter T. 1982. Keeping tabs on Crabs, pts. I,II. FAMA 7,8/82.

Tullock, John H. 1999. Crabs and their relatives. AFM 3/99.

Volkart, Bill 1989. Colorful Crustaceans: an introduction to Crabs. TFH 7/89.

Walls, Jerry G. 1995. Crab watch: the Japanese Shore Crab, Hemigrapsus sanguineus. TFH 3/95.

Arrow Crabs:

Giwojna, Pete. 1987. Arrow Crabs. Housebreaking the narrow-snout bristle horn, pts. I, II, III. FAMA 5,6,7/87.

Giwojna, Pete. 1991. The acrobatic sex life of the Arrow Crab. FAMA 9/91.

Fiddler Crabs:

Mancini, Alessandro. 1992. Fiddling with Fiddler Crabs. TFH 10/92.

Wickstein, Mary K. 1977. Fun with Fiddlers. TFH 12/77. 

To: Part 1, Part 2,

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