Beez Neez now Chy Whella - Caribbean Hermit Crab

Caribbean Hermit Crab

Beez Neez now Chy Whella

Big Bear and Pepe Millard

Wed 25 Mar 2009 23:54

The Caribbean Hermit Crab

The Caribbean hermit crab (Coenobita clypeatus), also known as the tree crab, the tree-climbing crab, the soldier crab, and the purple pincher, is a species of land hermit crab which lives by the Caribbean Sea, southern Florida, Venezuela, and the Bermuda Islands. This species is commonly sold in the United States as a pet. The last of its common names is due to the distinctive purple claw. In captivity they can live to be over thirty years old and over forty years in exceptional cases. Caribbean hermit crabs are omnivorous scavengers who live in colonies of a hundred or more in inland areas. As pets they prefer a relative humidity level between 70% and 78%, and a temperature of 24 degrees centigrade or 75 degrees Fahrenheit. Caribbean Hermit Crabs, like some other species of crabs, are nocturnal, so how made up was I when I saw one sitting on a tree stump during our exploration of Fort Shirley.

The tree lined path where I made my find. Bear had stopped as he had seen a large Zandoli so I have to give credit where it is due. Bear was staring at the floor, I was looking a few feet ahead and there was my chap

Physical description. Coenobita clypeatus is a member of the phylum Arthropoda and the class Malacostraca. The colour varies from a pale red to a dark brown or burgundy. The eyestalks are round and white, with a black or brown stripe on the bottom. The eyes are oval in shape. The abdomen is short and fat. There are four walking legs, four tiny legs to hold the shell in place, a small pincher, a large purple pincher, and four antennae. Although these hermit crabs live on land, they have gills, rather than lungs. The high relative humidity of their native environments, plus water carried in the shell, allows their modified gills to remain wet and thus to function properly in extracting oxygen from the air.

Spermiogenesis. The testes of the species Coenobita clypeatus contains germinal and non-germinative cells. The latter function in the manner of the vertebrate Sertoli cells in apparently providing nourishment, support and possibly hormones during spermiogenesis. Each Sertoli cell surrounds several germinal cells. The mitochondria, rough and smooth endoplastic reticulum and Goldi apparatus show changes in structure when in contact with germinal cells in different stages of spermiogenesis. These changes are suggestive of active synthesis and metabolism of cellular products.

Bear held him up so I could get a shot of his curled up self, I really think he needs to find a bigger shell as way too much is "hanging out". He promptly held a stick for Bear who then put him on the ground for me to video him when he decided danger had past.

Diet. Caribbean hermit crabs are both herbivorous and scavengers. In the wild, land hermit crabs feed off of coconut trees, leftovers from humans, and scavenge dead organisms, such as fish and other crabs. Hermit crabs are able to bury their food in the sand to consume later, but other crabs may find it and consume it themselves. In captivity, land hermit crabs are fed commercial foods which come in many varieties. Hermit crabs are also fed treats that include fruits and vegetables such as coconuts, mangos, papayas, apples, bananas, carrots, or spinach.

Shell usage and shell fights. The land hermit crab uses a shell to protect its delicate body. The shell is sometimes that of a land snail when it is young, but is usually that of a marine snail. When a marine snail dies, the soft parts decompose or are eaten and the empty shell often washes up onto the shore. The hermit crab can then find and occupy the shell. Larger shells are necessary as the crab grows, but that growth is quite slow. Hermit crabs are very particular about their shells. Shell switching is not uncommon as the crab searches for the perfect shell. A desired characteristic of a shell is an opening about the size of the large claw, plus about 2½–3 mm (1/10 in to 1/8 in) all around (more for larger crabs). When threatened, the crab withdraws into the shell and blocks the entrance with the large claw. Fierce shell fights can occur when the shell supply is not adequate. The loser often dies, since many hermit crabs will not release their grip on their shell until they are torn apart. The loss of limbs in shell fights is common, but may not result in death especially since the hermit crab can choose to drop (autotomize) a limb to disengage from the conflict.

As soon as he confidant enough, his legs relaxed, then his eyes came out and lastly his antennae.

Off he went in his shuffling gait. Then as we were looking at a snake this tiny chap about half an inch long, ran up to us, he was way too quick to get him in action.

Shells used by Coenobita clypeatus. When choice of shells is available, hermit crabs seems to prefer intact undamaged shells with circular or oval openings and a smooth mother-of-pearl interior. However in a pinch, they will use whatever they can find that they can fit into, even discarded, man-made items such as plastic glasses, broken bottles or tiny one-person jam jars. Painted shells should not be used for a pet Coenobita clypeatus because it is a potentially dangerous practice that may shorten the crab's life span. The paint will eventually chip off the shell, and the hermit crab may eat the chippings. Some of the snail shells with circular/oval openings available for their use in the wild on the coasts of the tropical Western Atlantic Ocean include : Turban, West Indian Topshell, West Indian Topsnail, (Over fishing of this snail (Bermuda) has been known to negatively effect the Caribbean hermit crab population.) Periwinkle, Tulip, Nutmeg, Rugosa, Tun, Crown Conch and Haitian Tree Snail shells.

Growth and moulting. The Caribbean hermit crab, like all species of hermit crabs, grows through a strenuous and hazardous process called moulting where the exoskeleton of the animal is shed and a new, soft exoskeleton is exposed from beneath. A moult also allows the crab to regrow lost appendages. The smallest Caribbean hermit crabs will moult many times per year, while the largest (about the size of a baseball) may only moult once every 12 to 18 months. Before a moult, the hermit crab will attempt to eat enough to survive the moulting period. It will obtain sea salt from salt water to aid in shedding the old exoskeleton and will store a supply of water. The crab may even seek out a smaller, tighter shell for easier digging or a larger shell for room to shed. Normally the moult is started by digging down into the moist substrate (with its shell) and creating a little cave. There total darkness triggers the secretion of the moulting hormone ecdysone. Over a period of up to three months (larger crabs require the most time),

the buried, moulting crab sheds the old exoskeleton in a process called ecdysis
lost appendages may be regrown (completely or partially),
the new exoskeleton hardens,
the old exoskeleton is eaten, in order to reuse the calcium and other lost nutrients while it's moulting,
the crab regains its strength and returns to the surface.

Sometimes the land hermit crab will moult on the surface where other crabs may eat the shed exoskeleton or even kill the defenceless, moulting crab. Circumstances that may cause a surface moult include illness, or the lack of a substrate in which the crab can bury itself.

Land hermit crab reproduction. Female land hermit crabs release fertilized eggs into the ocean where the salt water causes them to hatch. The hatchlings live in the ocean until their gills mature enough to be able to extract oxygen from air. Once on land, the hermit crab begins to drink fresh water, but still requires sea salt for functions like moulting. After the last developmental moult, the modified gills lose the ability to process water and the crab can drown if trapped under water.

We put him back where we had found him and continued on our way, needless to say I was totally made up, hence the cheesy grin. We returned after getting this shot overlooking Douglas Bay and returned once more to check on my little actor friend, he was quite happy in the leaves.