There seems to be some controversy and confusion regarding the need for UV-B lighting with hermit crabs. Due to the esoteric nature of our chosen pets, few studies are available to draw from which explicitly study hermit crabs. There is however a considerable volume of research regarding crustaceans, and more specifically decapod biology available to study.Read More →
Those little ‘hairs’ you see all over the body and chelipeds of your hermit crab are not hairs at all. They are an extension of the exoskeleton and are called setae. A seta is an elongate projection with a more or less circular base and a continuous lumen; the lumen has a semicircular arrangement of sheath cells basally. [1] Revising the definition of the crustacean seta and setal classification systems based on examinations of the mouthpart setae of seven species of decapods A. GARM Zoological Journal of the Linnean Society, Volume 142, Issue 2, October 2004, Pages 233–252 What in the function of setae? NotRead More →
There may come a time when you find it necessary to euthanize your hermit crab to end it’s suffering. I’m providing the information that I found to be reliable. Please ensure that you are not confusing a surface molt with death. References https://www.researchgate.net/post/What_is_the_least_drastic_method_to_kill_decapod_crustaceans_for_subsequent_preservation http://kb.rspca.org.au/What-is-the-most-humane-way-to-kill-crustaceans-for-human-consumption_625.htmlRead More →
Fig. 1. (A) Morphology of the branchiostegite and anterior appendages of Birgus latro, lateral view with legs omitted. (B) Lateral view of the branchial chamber of Birgus latro with the branchiostegite on the right-hand side reflected upwards to expose the inner surface of the branchiostegite. Note the distinction between the anterior hairlined portion of the branchiostegite and the posterior respiratory portion. The nephropore (antennal gland opening) faces posteriorly and opens directly into the branchial chamber. (Drawing made from a 500 g animal, approximately 20 cm in length excluding appendages, as shown.) Collapse Published in 1991Adaptations to a Terrestrial Existence by the Robber Crab Birgus Latro: VII.Read More →
When adding newly purchased or adopted hermit crabs to an existing colony, for the long-term health of all, we at CSJ recommend a 30 day quarantine period in an isolation tank. Placing newly purchased or adopted hermit crabs into an existing healthy colony without a quarantine period risks the unnecessary exposure of your healthy hermits to shell disease or parasites. If you are just starting out with hermit crabs and do not have an existing colony or crabitat in place, use of the PPDS Reduction Method will allow you to monitor your new crabs for 30 days and bring them slowly up to ideal environmentalRead More →
In hermit crabs, the fourth and particularly the fifth pereopods are reduced, usually remaining within the confines of the gastropod shell and hence are not used for walking. These appendages do however becoming important when the hermit crab attempts to right itself, providing anchorage within the shell. Further, the fifth pereopod has become specialised as a gill cleaning appendage, often resting within the gill chamber (Bauer 1981). On the abdomen only the left pleopods are retained (Poore 2004).[1] Hermit crabs used specialized setae on the third maixillipedes and fifth pereiopods for most grooming but used the unmodified first, second, and third pereiopods as well. MostRead More →
I am unsure about the set of spots on the legs after the gonopores. Hermit crabs can change gender during a molt so perhaps that is the location of where the male sex tubes would develop after a gender change? Just a theory…. Coenobita rugosus has been found to be intersexual We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please upload your photos to Dropbox here: https://www.dropbox.com/request/ajUgzmoG7co86iH2X0fh Overview of the anatomy of a land hermit crab (Coenobita) References:Read More →
The Cephalic shield [1] or carapace is part of the exoskeleton that covers the cephalothorax. It functions as a protective cover, hence the common name ‘shield‘. We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please upload your photos to Dropbox here: https://www.dropbox.com/request/ajUgzmoG7co86iH2X0fh Overview of the anatomy of a land hermit crab (Coenobita) Photo credits:HUSO Chen Yu-Jung Stacy Griffith References:Read More →
Land hermit crabs have two pairs of antennae. The antennae are vital sensory organs that allow Coenobita to locate the ocean, their food and to explore their surroundings. Coenobita rely on humidity in the air to aid them in smelling and locating various odors. In Coenobita Violascens the antennal acicle is fused with second peduncular segment. To capture odors, crustaceans move their antennules back and forth through the water in a motion called flicking. We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please upload your photos to DropboxRead More →
Chela (organ) A chela /kˈiːlə/, also named claw, nipper or pincer, is a pincer-like organ terminating certain limbs of some arthropods.[1] The name comes from Greek (χηλή) through New Latin (chela). The plural form is chelae.[2] Legs bearing a chela are called chelipeds.[3] Another name is claw because most chelae are curved and have a sharp point like a claw. Also called pincer or pincher. We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please upload your photos to Dropbox here: https://www.dropbox.com/request/ajUgzmoG7co86iH2X0fh Overview of the anatomy of a landRead More →
Coenobita possess compound eyes comprised of faceted lenses which are especially adept at picking up fine movements. The eyes are located on movable stalks and this is one of the primary ways we determine the species of hermit crab we are looking at. We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please upload your photos to Dropbox here: https://www.dropbox.com/request/ajUgzmoG7co86iH2X0fh Overview of the anatomy of a land hermit crab (Coenobita) Photo Credits: The Crab Street Journal has been granted permission by these photographers to use their photo(s) onRead More →
The gills of Coenobita and Birgus are modified for air-breathing but are reduced in number and size and have a comparatively small surface area. The branchiostegal lungs of Coenobita (which live in gastropod shells) are very small but are well vascularized and have a thin blood/gas barrier. Coenobita has developed a third respiratory organ, the abdominal lung, that is formed from highly vascularized patches of very thin and intensely-folded dorsal integument. Oxygenated blood from this respiratory surface is returned to the pericardial sinus via the gills (in parallel to the branchiostegal circulation). Birgus, which does not inhabit a gastropod shell, has developed a highly complexRead More →
The land hermit crab (Coenobita) develops a water sac inside of their shell prior to a molt. As shedding of the old exoskeleton begins, this store of water is used to expand the body to stretch and increase size before the soft exoskeleton begins to harden again We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please upload your photos to Dropbox here: https://www.dropbox.com/request/ajUgzmoG7co86iH2X0fh Overview of the anatomy of a land hermit crab (Coenobita)Read More →
The mandible (from Latin: mandibula or mandĭbŭ-lum, a jaw) [1] of an arthropod is a pair of mouthparts used for either for biting, cutting and holding food. The last three cephalic segments, together with the three most anterior thoracic segments (all of the cephalothorax), house the external mouthparts. From anterior to posterior these are the mandibles, maxillules, maxillae and then the three pairs of thoracic maxillipeds. These are all biramous except for the mandibles and maxillules. [2] Mandibles are often simply referred to as jaws. Maxillipeds are appendages modified to function as mouthparts. Hermit crabs are often seen grooming their eyes with their maxillipeds muchRead More →
grav·id: ˈɡravid/ adjective 1. pregnant; carrying eggs or young. Land hermit crabs carry their brood inside of the shell until they are ready to be released into the ocean. We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please upload your photos to Dropbox here: https://www.dropbox.com/request/ajUgzmoG7co86iH2X0fh Overview of the anatomy of a land hermit crab (Coenobita)Read More →
Hermit crabs in the Coenobita family are Decapods which means they have 10 legs, limbs or appendages. The abdominal appendages of the land hermit crab include the thoracic appendages, pleopods, uropods and telson [1].The thoracic appendages are used for cleaning the gills, gripping the shell, gripping a mate during copulation. The pleopods are used for brooding eggs. At the end of the pleon is the tail fan, comprising a pair of biramous uropods and the telson, which bears the anus. Together, they are used for steering while swimming, and in the caridoid escape reaction. We are building image galleries of specific body parts. If youRead More →
Please note: We’ve updated our language and PPS is now called PPDS – Post Purchase Death Syndrome as this is a more accurate name. written by Sue Latell March 8, 2006 I have belonged to the on-line crabbing community for a little over 3 years now. From day one there was discussion about the number of deaths immediately occurring after purchase. It evolved into a named syndrome: PPDS. Many “unexplainable” deaths that occurred in the time-frame from newly acquired to first post molt death were labeled PPS. Time lines wavered (anywhere from one week-up to one year), and alarmingly glossed over (in my opinion) tooRead More →
written by Vanessa Pike-Russell ‘How old’ is an oft asked question and hard to answer. Lifespan is similar. They both depend on many factors such as diet, exercise, moulting frequency, pecking order, species and availability of seashells. In this article, I will touch on a few of the factors, and finish with some hints on how to get a rough estimate of the size and age of your hermit crab. A big ‘thank you’ to Carol of CrabWorks for her permission to use her wonderful photographs, and for being such an inspiration to us all! How fast a hermit crab grows usually depends on whatRead More →
written by Vanessa Pike- Russell 2000, updated by Stacy Griffith The life cycle of the land hermit crab is unique. It starts by the release of eggs into an ocean tide pool, where the zoea go through a series of moults and developmental stages. A baby hermit crab zoea will be a part of plankton until it grows and starts to resemble hermit crab form. Once they have developed to maturity, hermit crabs leave their watery home, making the long journey to land to find a shell for the protection of the soft abdomen. Once ashore, land hermit crabs go through a metamorphosis, developing modifiedRead More →
This article is in PDF format, please click the link to view it. Read More →
Are hermit crabs looking for light and large shells?: evidence from natural and field induced shell exchanges Shell shopping Photo credit Andrea Skinner Jose- Luis Osorno, LourdesFernandez- Casillas, CristinaRodriguez- JuarezaDepartment of Zoology, University of Florida, 223 Bartram Hall, Fainesville , Fl32611, USADepartamento de Biologia, Facultad de Ciencias, Universidad Nacional Autonoma de Mexico , Mexico D. F., C. P. 04510, MexicoDepartamento de Ecologia Evolutiva , Instituto de Ecologia, Universidad Nacional Autonoma de Mexico A. P.70 275, Mexico D. F., C. P. 04510, MexicoReceived 15 October 1996; received in revised form 9 May 1997; accepted 3 June 1997 Abstract: Terrestrial hermit crabs(Coenobita compressus( H. Milne Edwards)) onRead More →
ectothermic 1. of, or relating to an ectotherm; cold-blooded From Wikipedia: Cold-blooded organisms (called poikilotherms – “of varying temperature”[1]) maintain their body temperatures in ways different from mammals and birds. The term is now outdated in scientific contexts. Cold-blooded creatures were, initially, presumed to be incapable of maintaining their body temperatures at all. Cold-blooded animals are now called ectotherms, a term which signifies that their heat (therm) comes from outside (ecto) of them; the term cold-blooded is misleading. Advances in the study of how creatures maintain their internal temperatures (termed: Thermophysiology) have shown that many of the earlier notions of what the terms “warm-blooded” andRead More →
heterothermic 1. of animals except birds and mammals; having body temperature that varies with the environment From Wikipedia Heterothermic (from Greek: hetero = “other” thermy = “heat.”) is a physiological term referring to a unique case of poikilothermy. Heterothermic creatures are homeothermic for a portion of the day, or year. More often than not, it is usually used as a way to dissociate the fluctuating metabolic rates seen in some small mammals and birds (e.g. bats and hummingbirds), from those of traditional cold blooded animals. In many bat species, body temperature and metabolic rate, are elevated only during activity. When at rest, these animals reduceRead More →
The molting cycle in crustacean is controlled by hormones. Below is a snippet from a study on crustacean molting that explains the role of hormones in the molting cycle. Land hermit crabs continue to molt their entire life unlike some other crustaceans. ERNEST S . CHANGM, ARILYN J. BRUCEA, ND SHERRY L. TAMONEBodega Marine Laboratory, University of California, P.O. Box 247, Bodega Bay, California 94923 SYNOPSISIn order to increase in size, arthropods must first molt (shed) their confining exoskeleton. This molting process is under the immediate control of the steroid molting hormone 20-hydroxyecdysone (20-HE). Read the full article More articles on molting:What is moltingIs myRead More →
Overview of the anatomy of a land hermit crab (Coenobita): We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please contact us via email: crabstreetjournal at gmail dot com Click to be taken to the gallery:Chelipeds or pincersEyesAntenna (antennal flagellum, antennular flagellum, antennule)Mandibles and MaxipellidGills and branchial chamberAbdomen, Uropods, Pleopods, TelsonWater or molt sacEgg clusterGonoporesShieldRead More →
This is a (hopefully) more simplified revision of the original. I have also created a printable calendar for tracking that is free to download. Introduction: The objective of this method is to reduce the impact of physical stress by keeping the hermit crab above ground eating well and exposed to light. Both are vital to the hermit crab’s ability to recover. This is a thirty day method. While this can be accomplished in three weeks, there is no reason to rush. If you are adding new (wild caught) hermit crabs to your existing colony it is important that you do not introduce sick or contagiousRead More →
written by Sue Latel March 8, 2006 Little Billy has had 3 hermit crabs since his 12 birthday. He has a 20 gallon tank housing his 3 small PP crabs. One day when he is at the store picking up some ocean salt water for his crabs, he spots a tank containing 2 poor little Ruggies that have no water except for a damp sponge, huge pellets of food that he doubts they have even attempted to eat, and no ground cover to protect them from the 100 watt heat lamp that is shining directly on them from an open tank top. Billy has been aRead More →
Exact text of the original paper by Herbst: The name Coenobita Clypeatus (usually pronounced seen-oh-bit-a cly-pe-ait-us) may be translated as “shield-bearing monk or cloister brother,” which conjures up a truer image of this often gregarious and variously cloistered resident of tropical East American shores than does “hermit crab.” But, like most common names, “hermit crab” or “soldier crab” in native parlance, will certainly endure. The animal so called belongs to a small family of terrestrial decapod crustaceans quite distinct from the marine hermit crabs. The family Coenobitidas is composed of two genera: Birgus and Coenobita. Birgus is represented by a single species, Birgus latro (Linnaeus,Read More →
written by Jennifer Borgesen The fungi: how they grow and their effects on human health. (includes related article on documentation of fungal exposure and disease relationship) Date: 07-01-1997; Publication: Heating, Piping, Air Conditioning; Author: Burge, Harriet A. Shape and structure of fungi “The fungal cell is similar to that. of plants and animals, containing all of the same organelles (nucleus, mitochondria, ribosomes, membrane systems, etc.). Like plants, the fungal cell is bounded by a rigid cell wall. However, while plant cell walls contain cellulose as the basic structural material, fungal cell walls contain a material that is similar to that in insect exoskeletons (chitin). MostRead More →
Originally written by Vanessa Pike-Russell, updated 2018 by Stacy Griffith If you have heard it, you would think that it sounds like something between a frog croak’s, a chicken’s clucking and something else thrown in for good measure. “The land hermit crab sometimes communicates by a whirring-chirping sound, though not too often. These noises usually have been heard during aggressive encounters in the crabs’ natural environment and are seldom heard in captivity. The only behavior observed that may resemble aggression has been when one crab shakes or rocks another to drive him from a shell the aggressor wants. Even in this act neither crab isRead More →
Originally written by Vanessa Pike-Russell and Lisa Loseke updated by Stacy Griffith Arthropods (e.g., insects and crustaceans) must molt their exoskeletons periodically in order to grow; in this process the inner layers of the old cuticle are digested by a molting fluid secreted by the epidermal cells, the animal emerges from the old covering, and the new cuticle hardens. The molting process is a central, and nearly continuous, part of a crab’s life. A hermit crab may spend 90% of its time getting ready to molt, molting, or recovering from a molt. There are many dangers to molting including predation, difficulty in movement as musclesRead More →