Saltwater crabs for aquariums are beautiful and attractive creatures that bring color and vibrancy to marine environments. I have been keeping these crabs for a long time, and their strange behaviors and characteristics fascinate me.
They are peaceful and can easily coexist with other marine animals, making them ideal companions in a marine aquarium. Learning about saltwater crabs and how to properly care for them has helped me become a successful aquarium keeper.
Below are some of the saltwater crabs that are easy to keep and help enhance the beauty of the tank, based on my experience in our aquariums.
1. Porcelain Crab
Porcelain-Crab
Species Overview
- Scientific name: Petrolisthes spp.
- Family: Decapoda
- Size: Usually 2 to 3 cm long
- Behavior: Porcelain crabs are generally docile and easily injured, as their shells are not strong.
- Color: Their bodies can be different colors, like white, gray, or pink.
- Body structure: Their legs are relatively long, and like other species of crabs, they have ten legs. The front two legs are very large and strong, which they use for defense and gathering food.
- Shell Changes: If their shells are broken or damaged, they grow new ones.
- Origin: Originating primarily in marine environments, the species has lived on rocky seabeds, algae, and coral reefs since ancient times.
- Lifespan: Generally 3 to 5 years
Residence
A 5- to 8-gallon tank will suffice if only 1–2 porcelain crabs are kept. If you want to keep multiple crabs or other marine animals, a 25-gallon or larger tank is ideal. Create hiding places with rocks in the tank, as they like to hide.
Porcelain Crab Care
Water conditions and parameters: Water temperature 22°C to 26°C (72°F to 79°F), pH 7.8 to 8.5, and salinity 30 to 35 ppt (parts per thousand) are ideal.
Diet: Porcelain crabs survive by eating microscopic food, such as plankton and detritus. With the help of their two large front claws, they strain food from the water.
Breeding
Female crabs lay eggs, and their larvae float on the surface of the water when they hatch. The hatchlings gradually mature into adult crabs.
Suitable Partner
Choosing the right mates for porcelain crabs is very important, as the behavior and size of mates can affect their health. Suitable companions include clownfish, ghost shrimp, Amano shrimp, stone crabs, etc.
2. Sally Lightfoot Crab
Sally-Lightfoot-Crab
Species Overview
- Scientific name: Grapsus grapsus
- Family: Grapsidae
- Size: Can be about 8-12 cm (3-5 inches) wide. Keeping the feet wide can make their overall size bigger.
- Behavior: They can move very quickly, especially when a predator or danger approaches. They like to hide in rock crevices or small holes.
- Color: Their backs are usually bright red or orange. The legs and claws are a mixture of red, blue, and black, with touches of red being more common. The abdomen is white or light blue. The eyes are black and usually stand out from the rest of the body.
- Origin: Galapagos Islands and the coast of western America
- Lifespan: Generally 2 to 4 years.
Residence
Sally Lightfoot crabs naturally like to hide in rocks, so the presence of rocks in the aquarium is important. Place large rocks or live rocks in the aquarium to provide adequate shelter for the crabs to hide and relax. Arrange the rocks to create hiding places and place the stones firmly so they don’t topple over when the crab moves.
Care of the Sally Lightfoot Crab
Water conditions and parameters: A tank of at least 30 gallons or more is suitable for them. A water temperature of 22°C to 26°C (72°F to 78°F), salinity of 1.023 to 1.025 specific gravity, and a pH of 8.1 to 8.4 are ideal. 20-30% of the water should be changed weekly to maintain good water quality.
Diet: Sally Lightfoot crabs are omnivores, so they need a variety of food. They like to eat algae growing on stones or rocks. If there is no algae, you can provide algae-based food. Feed seafood such as small pieces of fish or plankton. You can also offer boiled vegetables, such as spinach or zucchini.
Breeding
Breeding Sally Lightfoot crabs in aquariums is quite challenging as their breeding process in the natural environment is complex and dependent on specific conditions. The Sally Lightfoot crab lays its eggs far from the ocean water, and it takes time for the eggs to hatch. The young stay in the ocean water for a while as larvae before they grow into full-fledged crabs and return to the seabed.
Suitable Partner
Because Sally Lightfoot crabs are very skittish and can sometimes exhibit defensive behavior, their tank mates should be selected with care. Clownfish, damselfish, gobyfish, firefish, etc., are suitable companions for them.
3. Halloween Hermit Crab
Halloween-Hermit-Crab
Species Overview
- Scientific name: Ciliopagurus strigatus
- Family: Paguridae
- Size: Usually 2 to 3 inches long.
- Behavior: These crabs are generally social and like to live with other hermit crabs. They communicate with each other and may share hiding places.
- Color: Halloween hermit crabs usually have a combination of bright orange, black, and white, which is a characteristic they are known for.
- Origin: Southeast coast of the United States, Caribbean islands, and parts of Mexico and Central America.
- Lifespan: With proper care, they can live for about 10 years or more.
Halloween Hermit Crab Care
Water conditions and parameters: Minimum tank size is 20 gallons. The ideal water temperature is 70°F to 80°F (21°C to 27°C); ideal pH is 8.1 to 8.4. Twenty to twenty-five percent of the water should be changed every week to keep the tank water clean.
Diet: They mainly eat plants and shellfish, so their diet should include algae, fruits, vegetables, and commercial crab food.
Breeding
The Halloween Hermit Crab breeding process is somewhat complicated and dependent on the right environment. Normally, male and female hermit crabs mate with each other during the breeding season. After mating, the female crab usually lays 20,000 to 50,000 eggs. After about 2 to 4 weeks, the eggs hatch, and the larvae emerge. Caring for larvae can be somewhat challenging, as they are usually free-floating.
Suitable Partner
Halloween hermit crabs usually mate with other hermit crabs. However, they can be kept with some other marine animals such as Gulffish, nakoli, or small marine fish (which are small and calm).
4. Dwarf Yellow Tip Hermit Crab
Dwarf-Yellow-Tip-Hermit-Crab
Species Overview
- Scientific Name: Calcinus elegant
- Family: Paguridae
- Size: They are usually about 1-2 inches in size as adults.
- Habits: Dwarf Yellow Tip Hermit Crabs are generally social creatures, so keeping multiple crabs can help them get along well.
- Color: Their body color is usually yellow, and the surface has a white or yellow tip.
- Origin: Western and Eastern Indo-Pacific regions.
- Lifespan: Generally 5 to 10 years.
Residence
A 10-gallon tank is initially sufficient to house 2-3 dwarf hermit crabs. However, if you want to keep other marine animals with them, it is recommended to use a minimum 20-gallon tank. There should be enough rocks, corals, and shells in the tank so that the hermit crabs can take shelter and exhibit their normal behavior.
Dwarf Yellow Tip Hermit Crab Care
Water Conditions and Parameters: Water temperature should be 22°C to 26°C (72°F to 79°F), salinity: 1.023 to 1.025 SG, and pH level: 8.0 to 8.4. Ammonia and nitrite should be zero (0 ppm), as these are toxic.
Diet: They usually feed on vegetables, shells, and other remains of marine organisms. In the aquarium, they can be fed vegetables, tablets, and special crab feed.
Breeding
Dwarf yellow-tip hermit Crabs are commonly found on the sea floor, and their reproduction process occurs naturally in the marine environment. However, breeding them successfully in an aquarium is quite challenging, and the success rate is very low, so breeding in an aquarium is not recommended.
Suitable Partners
It is important to select suitable mates for Dwarf yellow-tip hermit Crabs so that they can live well in the aquarium. Clownfish, Gobies, Blennies, etc., can be suitable companions for them.
5. Crown Hermit Crab
Crown-Hermit-Crab
Species Overview
Scientific name: Clibanarius coronatus
Family: Diogenidae
Size: They are usually 2-4 cm in size, but some species can be larger.
Body Structure: Hermit crabs use snail shells to protect their soft bodies. Crown hermit crabs have crown-like spots on their heads, which is the reason for their name.
Nature: Hermit crabs are peaceful; they help clean the aquarium by eating waste.
Color: Their body color can usually be black, red, brown, or orange. The edges of their legs have white or bright spots.
Origin: Found in the coastal areas of the Indian Ocean and Pacific Ocean.
Lifespan: They can usually live for 10 to 15 years.
Residence
1-3 hermit crabs require at least an 8-gallon tank, and 4-6 hermit crabs require a 15-20-gallon tank. Additionally, the tank should be provided with stones, corals, and snail shells so that the crabs can move easily and nestle in the shells for protection.
Crown Hermit Crab Care
Water Conditions and Parameters: A water temperature of 24°C to 28°C (75°F to 82°F), a pH level of 8.1 to 8.4, and a salinity of 1.023-1.025 are ideal parameters for them. Ammonia and nitrite should be kept at 0 ppm, as these are toxic chemicals. Moreover, 15-20% of the water should be changed every week.
Food Habits: They are omnivorous, meaning they eat both plant and animal food. In aquariums, they prefer to eat algae, detritus, and fish food. They also act as scavengers, eating dead fish, old food, and other organic matter.
Breeding
Breeding crown hermit crabs in aquariums is quite complicated and rarely occurs naturally. Their breeding is more common in natural marine environments.
Suitable Partners
They are generally peaceful in nature and can coexist well with other marine animals in the aquarium. Nassarius snails and turbo snails can be suitable companions. Crown hermit crabs can coexist well with peaceful fish like clownfish, blennies, and gobies.
6. Zebra Hermit Crab
Zebra-Hermit-Crab
Species Overview
- Scientific name: Calcinus laevimanus
- Family: Paguridae
- Size: Zebra hermit crabs are about 1 to 2 inches long.
- Color: They have black and white stripes on their bodies, giving them a zebra-like appearance.
- Origin: Coastal areas of the tropical Indian and Pacific oceans.
- Shell Modification: Hermit crabs cannot make their own shells, so they find empty shells and live inside them. They change shells regularly as their bodies grow.
- Behavior: Zebra hermit crabs are generally peaceful but can sometimes get into fights with other crabs over large shells. They are quite active and can always be seen roaming around the aquarium.
- Lifespan: They usually live for 2 to 4 years.
Residence
It is recommended to keep 1 to 2 zebra hermit crabs per 5 gallons of water, but a minimum 20-gallon tank is fine for them. If you want to keep more zebra hermit crabs, add an additional 4 to 5 gallons of water for each crab. Also, use rocks, twigs, and bark in the aquarium for them to shelter in.
Zebra Hermit Crab Care
Water Conditions and Parameters: Water temperature should be maintained at 22 to 26°C (72 to 78°F). The pH level should be 8.1 to 8.4, and salinity should be 1.019 to 1.025. Ammonia and nitrite should be kept at 0 ppt.
Diet: The zebra hermit crab feeds primarily on algae, detritus, and aquarium waste. They are known as a clean-up crew, as they help keep the aquarium free of algae.
Breeding
Breeding the zebra hermit crab is a somewhat complicated process, and they usually should not be bred in an aquarium because it is challenging.
Suitable Partners
There are a few things to consider when choosing a suitable mate for a zebra hermit crab, such as their calm nature, adaptability to saltwater, and similar eating habits. A few species mentioned that are useful as companions include Nassarius snails, Turbo snails, Cleaner shrimp, Peppermint shrimp, Clownfish, and Blennies, etc.
7. Blue Knuckle Hermit Crab
Blue-Knuckle-Hermit-Crab
Species Overview
- Scientific name: Calcinus elegant
- Family: Paguridae
- Size: Full-grown crabs can be about 2 to 3 inches in size.
- Behavior: They are peaceful and can coexist with other animals, but sometimes fight over snail shells, as hermit crabs depend on snail shells for their own protection.
- Color: The leg joints of their body are bright blue, and the rest of the body is usually reddish-brown in color. They also have white and black markings on their legs.
- Origin: Various seabeds of the Pacific and Indian Ocean regions
- Lifespan: Usually lives up to 3–5 years
Residence
Aquariums larger than 20 gallons should be used, and natural rocks of various sizes and shapes should be included. Place some coral, which will provide shelter and food for them. Place different sizes of snail shells in the tank. This will provide them protection. Remember, crabs will change shells as they grow, so keep new shells to their liking.
Blue Knuckle Hermit Crab Care
Water Conditions and Parameters: Water temperature should be maintained at 22–26°C, and the pH level should be between 8.1 and 8.4, with a specific gravity of 1.20–1.23. Ammonia and nitrite must be 0 ppm, as these are toxic elements. 20–25% of the water should be changed every week to maintain tank water quality.
Diet: They are primarily omnivorous and feed on discarded aquarium food, algae, and detritus (dead plant and animal matter). This helps keep the aquarium clean.
Breeding
The breeding process of the Blue Knuckle Hermit Crab is quite challenging, especially in the aquarium environment, and the reproduction rate is very low.
Suitable Partners
Blue Knuckle Hermit Crabs are generally peaceful creatures in the aquarium, and they can easily coexist with other marine animals. Suitable companions for them can include Nassarius Snails, Astrea Snails, Clownfish, and Blennies, etc.
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