The horn eyed ghost crab, little crustacean that runs with incredible speed, opening its horned eyes. It is an unpopular species of ghost crab that didn’t gain fame in the hobby.
It has interesting characteristics and is easy to care for, which makes the horn eyed ghost crab a great pet. Here, I’ll talk about everything you need to know in this guide so that your crabs keep thriving.
Quick overview of horn eyed ghost crab
| Names | Horn eyed ghost crab, Horned ghost crab |
| Scientifc name | Ocypode ceratophthalmus |
| Size | Up to 3.5 inches |
| Care level | Easy |
| Color | Brown, white, and yellowish |
| Temperament | Semi aggressive |
| Diet | Omnivore |
| Sleeping nature | Nocturnal |
| Habitat type | Saltwater paludarium |
| Lifespan | 3 years |
| Optimal temperature | 75-85°F (24-29°C) |
Horned ghost crab facts
Appearence
The horned ghost crab, Ocypode ceratophthalmus, can be easily recognized by its unique eyes, which have a pointed extension. It can be distinguished from other similar crabs by the unique patterns on its claws. The upper part of the main claw has 10–11 small bumps, the middle part has 8 thick lines, and the lower part has 20–30 closely spaced lines. Additionally, the smaller claw has pointed tips, and the reproductive organs have a unique shape with a box shaped body.
They have eyestalks that extend beyond the eyes into long points; juvaniles have shorter and as they grow, their eyestalks become larger and more pointy. These eyestalks (360 degrees) look like horns, which is the most attractive part of their appearance, and from there they got their “horn eyed” and “ghost crab” because they can vanish like a ghost (by running), can change their color, and are nocturnal. All ocypode genera are fast, as their name suggests – “Ocy” means swift and “podi” means foot in Greek.
Color changing ability
Changing color according to our wishes is like a superpower to us but not for the horned eyed ghost crabs. They change their color daily to camouflage with the environment. A study found about their slow color change – is that this crab becomes lighter during the day and darker at night, which enhances its camouflage on sand. These color changes are controlled by a circadian rhythm.
A research project of the Linnean Society of London found that their color is more influenced by the substrate than the light. When placed on different colored substrates, the crabs adjusted their color. They became brighter on white surfaces compared to black ones.
Habitat and distribution
Ocypode ceratophthalmus spreads throughout the Indo-West Pacific, from Africa to Hawaii and French Polynesia.
They live on the seashore, and their burrows are in the intertidal zone (the area between high and low tide), where they have easy access to sea water and sand that is moist with sea water. They burrow in the sand and stay there during the day, which protects them from predators like birds. Their burrowing can reach more than 3 feet and they can run really fast, at speeds of up to 2.1 metres per second or 10 miles per hour, which makes catching horn eyed ghost crabs really tough to catch.
Here are some photos and videos of horn eyed ghost crabs that I took 3 years ago, from Kuakata Sea Beach. Though it is not Ocypode ceratophthalmus, it is Ocypode macrocera. (They were really cool.)
If you want to capture one from the beach (of course for petting purposes), here is a useful tip from my friend – “Initiate a sudden chase when the crabs are clustered together. Due to the abrupt movement, they will quickly scatter and lose track of their burrows, providing an ideal opportunity to capture one.” Capturing them from their deep holes is really hard. Another interesting fact is that the horn eyed ghost crabs can fold their eyestalks into grooves on the body when they burrow, like this:
Incredible speed
While using their excellent vision to navigate, ghost crabs can move across the sand at a speed of 100 body lengths per second, even surpassing cheetahs and cockroaches. Tiger beetles are the only animals faster than the horn eyed ghost crabs.
Behavior
Horn eyed ghost crabs are mostly active at night but quite a bit of movement can be seen during the day, especially juveniles, who are more active during the day. They can easily adapt to a variety of shore environments, and the tides have a big impact on their activity levels. 1
They have one claw that’s bigger than the other, and it can be on either side of their body. If the big claw is on the right, they dig their burrows to spiral to the right. If the big claw is on the left, the burrow spirals to the left.
With a vertical ridge of the palm, they produce a rasping sound rubbing against the surface. It is assumed they do it to declare territory and communicate with each other.
How to care for horn eyed ghost crab
Tank setup
Size
As they are territorial, they’ll need a lot of space to avoid territorial dispute. Choose a minimum 30 gallon tank for 5 to 6 horn eyed ghost crabs. Close the opening with a lid or something; they are not good climbers but who knows when they will escape?
Substrate
Choose sand for the substrate, as it mimics their natural habitat. You can find beach sand on online stores like Amazon. There should be around 30% water and 70% land.
Average substrate depth should be a minimum of 8 inches; create a slope from one side to the other, ensuring the lowest sand level is 2 to 3 inches deep and the highest level is 8 to 10 inches deep. Deeper, if possible.
Here is a cute video of their burrowing. They make this shape to attract females for mating.
Decoration
These crabs need neither decoration nor extra hiding places; only sand is enough for all their hiding related problems, which is an advantage of petting them. But if you want to create a more comfortable environment, you can go for driftwood and stone caves.
Water and temperature
The temperature should be between 75 and 85°F (24-29°C). Try to keep the temperature stable and monitor it with a thermometer. A humid environment of approximately 70 to 80 percent is required to keep the environment more habitable.
They need to moisten their gills with sea water to breathe air, this is one of the reasons why they live in the intertidal zone. Their deep burrowing allows them to wet their gills with wet sand.
Pour water, remembering the crabs should fully submerge but don’t get drowned as their gills are not modified to extract oxygen from air. The saltwater gravity should be between 1.005 and 1.010.
Diet of horn eyed ghost crabs
They rely on shore animals that come floating by or animals that live near the shore, in the wild, such as fire worms, small crabs, fish, shrimps, insects, decaying organisms and algae.
Despite being omnivorous scavengers, horn eyed ghost crabs prefer more meaty food. So you can give meaty foods like bloodworms, brine shrimp, fish, frozen food and vegetables like cucumber and spinach. Give them calcium rich foods like cuttlebone and additionally, give them crustaceans food, flakes, pellets and nori.
