By Severus A on Sunday, January 31, 2016 at 6:21pm
Greetings, hermie peeps. Whether you intentionally bought a marine hermit to enter your family, one accidentally was brought home via shell collecting excursions, or one came home with you by accidental purchase due to pet store carelessness in confusing these lovable critters with their terrestrial cousins, this caresheet provides you with the setup instruction and care details for these lovable yet misunderstood creatures people often balk or are scared of keeping because of the myth of an expensive "hard-to-maintain" setup. Marine hermits DO NOT require a full reef setup to be happy and healthy. In fact, many MHC's are as active and feisty as their land cousins making them poor candidates for an reef setup. What they need is a saltwater aquarium aka marine hermit crabitat. Below is what you will need to set up and maintain a Marine crabitat. The ingredients are readily available at most petstores- enjoy. Marine hermit crabs, contrary to popular belief, are rather inexpensive and easy to maintain. The following is a list of products you will need: in total, the cost should be no more than $125.00. To trim down the cost, you can purchase the aquarium, water conditioner, light, and filter as one discounted package by buying an aquarium kit from a LFS or petstore. I myself use an Aqueon Aquarium from such a kit. Read this below for your marine hermit needs. If you have any questions, feel free to message me here.
Marine Salt Mixes (I use Instant Ocean and Kent Marine Salt brands, with Instant Ocean brand- the ratio to create the proper salinity gravity for hermits is one half cup per gallon of water)
Bottled Spring Water (Use the spring water to fill the entire aquarium, NEVER use tap water because tap water, even after being treated with water conditioner to remove chlorine could still contain trace elements of copper which is fatal to hermits and their invertebrate companions; equally, never use distilled water or water treated by reverse osmosis because such water is too purified of natural elements thereby sickening your crabbies)
How deep should the water be- The Enclosure is to be filled to its entireity as one would with an aquarium for fish with spring bottled water that has been salinated by Marine Salt Mixes *i.e. Instant Ocean, etc* to the full safe saltwater gravity specifications for marine creatures as outlined by the brand's instructions; there is no need for a land area for these species.
Live sand for substrate- I use CaribSea brand Livesand though there are other brand's available. Be sure to read the product's description that it is safe for invertebrates and bottom dwelling creatures to burrow in. This sand is ESSENTIAL both for the crabs to feel safe and to provide a biological colony of bacteria which in general, keeps the water pristine clear/clean for the hermits to live and breathe in. I recommend 2-4 inches of sand. Crabs of this variety do not need to burrow as deep as their Land hermit cousins because they have no need to hide in deep moistened burrows for molting due to the fact their entire habitat is submerged. NEVER use gravel especially coloured gravel because the crabs CAN NOT burrow in it, the rocks will hurt the crabs' legs, and the paint will melt in marine water thereby poisoning them.
Uncured Live Rock for climbing and to add to the crabitat's mini-ecosystem (Do not use cured live rock because cured live rock because it is devoid of organisms which negates purpose of introducing it into the enclosure)
Live seaweed from the environment your species live in the wild for them to forage in, hide in, and eat for snacks *i.e. kelp, malcroalgae, etc*
Extra shells for changing as they grow
Minimum tank size: 3-4 gallons for diminutive species like Clibanarius Tricolor *blue-legged hermits smaller than a dime*, 10 gallons for usual sized species like genus Dardanus *sea anemone carrying hermits and the classic red legged white spotted hermit*
How many per tank- 3-4 small Dardanus hermits can be homed in a 10 gallon aquarium provided there is sufficient seaweed, rocks, and coral skeletons for them to climb/hide/play etc; depending on the species, an upgrade into a 30 gallon for 3-4 large hermits (10 gallons of seawater per every jumbo sized Dardanus Megistos and Dardanus Penduculatus) may be required in 2 years from time of purchase as they get closer and closer to the jumbo size (5 inches wide and beyond) depending on their growth rate and maximum attainable size
Filter that generates sufficient oxygen- It is essential to have an aerated system because these crabs are fully aquatic and strictly breathe water. Even if you decide on constructing areas where the crabs can climb unto land, you will still need a filter because these hermits breathe strictly water in their natural habitats and will not seek land to obtain oxygen if the oxygen is depleted in the water.
Marine "water conditioner/stress coat"- this product removes any harmful substances like chlorine in the water. Even though the appropriate aquarist uses bottled spring water, it is still prudent to add the full dose of this to aid crabs in calming and healing following their initial arrival from the petstore *or in the case of hermie hitchhiker accidents ze beach* and for established hermits to recover faster from molts
Heater- For those of you whose hermits were bought at a petstore or accidentally acquired in shell collecting excursions on tropical beaches, you will need a submersible aquarium heater set on the range between 72F-80F. I keep my range close to 77F for my Dardanus and Clibanarius genus hermits. (Hermits found in colder waters like the upper Atlantic British hermit Pagurus Bernhardus WILL NOT require a heater; the same goes for hermits found in the Northwest Coastal beachlines ranging from the US to Canada)
Aquarium Lighting- to simulate day and night cycles, though is not necessary unless you are going full reef setup.
Lid- the Lid *aquarium cover* is essential for tropical species, which most in the hobby are, to reduce evaporation from the heated water.
Calcium and Iodine supplements- these are optional though encouraged to be added according to brand outlines to ensure healthy molts. I use Kent Brand to meet this need.
Diet-
Marine hermits of all species will subsist on a solid diet of algae wafers, aquatic crab sinking pellets, and shrimp pellets. They will also eat seaweed hence I listed it as an item to furnish their home with. I feed mines once per evening. In this feeding, I leave extra foods for them to eat through the night into the morning. Feed no more than what the crab can consume in half a day.
How to identify if your crab is marine-
Marine hermits often have brightly coloured eyes *i.e. green*, have unusual coloration *i.e. striped legs*, and are more hairy than their terrestrial counterparts. The most important identifier is the antenna. The terrestrial hermit antenna are segmented, like an insect's for it is adapted to smell and perceive the atmosphere of land while their marine counterparts have smoother ones for scanning the water. Should you have a marine hermit whether by accident or intentionally and happen to be new to this trade, follow my guidelines here to the road to a path of much hermie happiness.
Submersible thermometers and hydrometers are a must too. They permit you to monitor the parameters of the environment and provide perching spots for shrimps.