Discover the Largest Hermit Crabs (One is 3 Feet Long!)

School shopping for the hermit crabs involves picking out a new shell! As their bodies grow, they must find a new shell to accommodate their bigger bodies. But how big can these little crabs get? What is the largest hermit crab ever? Let’s find out all about hermit crabs.

How many kinds of hermit crabs are there?

There are around 800 species of hermit crabs which are broken down into two main groups, land hermit crabs and marine hermit crabs. Most hermit crab species are marine, meaning they live in the ocean and are aquatic, but you may be most familiar with land hermits, because these are the ones that are most commonly kept as pets. There are only around 12 land (terrestrial) hermit crab species with the Ecuadorian and Caribbean crabs being the most common hermit crab pets.

In fact, one of the land hermit crabs holds the title of the largest terrestrial arthropod. It’s not a common pet, but we will learn more about them later. Let’s learn about the five largest land hermit crabs and then look at the three largest marine hermits.

What are the Five Largest Land Hermit Crabs?

Land hermit crabs range from a fraction of an inch to 40 inches. Let’s examine some of the more interesting species of land hermit crabs and examine their size.

5. Ecuadorian crab: ½ inch – 1 inch

There are many hermit crabs that are less than an inch. The Ecuadorian crab which is one of the most popular crabs falls in this category. They are sometimes nicknamed “Eccies” for short. Their claws and legs are the same color, from brown to some having a bluish hue. Hermit crabs are identified by the kind of shells they prefer to inhabit and Eccies prefer shells with a D-shaped opening. But they don’t have to be very big shells, because Eccies only get to be at most 1 inch long. Other small hermit crabs are Ruggie’s (Coenobita rugosus), which typically only get to be ½ inch at the biggest, and the Blueberry hermit which is colored blue and comes only from Japan. These little guys grow just a tad more than a ½ inch. If you’re looking for a pet hermit crab, make sure to give them proper care as few reach their full lifespans in captivity.

4. Strawberry crabs: 1 inch – 3 inches

If blueberry crabs are blue then what do you think they call a red hermit? Yep, Strawberry crabs. These crabs are easy to recognize due to their bright reddish-orange color. They are also common pets but do need access to both fresh and saltwater. They can grow to be 3 inches in length and they prefer turbo shells with a round opening. Strawberry crabs are from the Indo-Pacific region. Other crabs that are medium in size include the Australian hermit crab which is a common pet and grows to around 1 ½ inches.

3. Indonesian Crab: 3-5 inches

The Indonesian crab has one claw that is much bigger than the other and has a purplish coloration. These crabs are kept as pets and entertain their owners with cute little chirps! They can grow to be 4 inches or more and weigh up to a half pound.

2. Caribbean Crab: 5-6 inches

Caribbean crabs are the most popular crab to have as a pet. They are also called the “Purple Pincher Crab” due to their coloration and having one purple claw larger than the other. They also have cute beady round black eyes. They come from the shores around the Western Atlantic and are easier to spot due to the fact that they can get up to 6 inches long. Their shell of preference is turbo shells with a round opening, often choosing the shells of West Indian Snails.

1. Coconut Crabs: 40 inches

The world’s largest hermit crab is the coconut crab. These giants can reach 40 inches long and weigh 10 pounds! They get their name because they eat coconuts, using their strong pincher to crush the coconut shells. They can also climb trees and pinch off coconuts so they fall to the ground and break open. Surprisingly they also hunt instead of just scavenging for what is left behind. They may hunt rats, rodents, and even seabirds, hunting at night to provide cover. Makes me cautious to take a midnight stroll on the beach. As adults, they do not live in a shell but when they are in their juvenile stage they do use a shell as cover just like other hermit crabs. They hold the Guinness World Record as the largest terrestrial arthropod!

What are the Three Largest Marine Crabs?

The vast majority of hermit crabs are marine hermit crabs. Let’s dive into the different sizes of marine crabs, and see which one is the largest in the world.

3. Marine crabs that are 1-2 inches (Dwarf hermits)

There are a few different dwarf hermit crab species that are also sometimes kept as pets in a reef tank. Remember marine hermit crabs are aquatic and live entirely underwater. Some of the dwarf hermits include the dwarf red tip, dwarf blue leg, dwarf yellow tip and zebra (pictured above). Their names give away the characteristics that make them each different, but they are all between 1-2 inches in length, with the red tip being the largest of the four. The zebra hermit has a shell that has what looks like black and white stripes and has distinct blue eyes!

2. Marine crabs that are 3+ inches (Elegant crab)

These crabs are from Hawaii and are also kept as pets in reef tanks. They can help keep your tank clean by eating the algae and waste as they drag their larger shells around. Their legs look striped, but it is their knuckles that are showing as a different color. They have brown legs with knuckles that can be blue, yellow, or red. These crabs can grow to be 3 inches or more.

1. The largest marine hermit crabs ever…12 inches (Giant Red Hermit Crab)!

The giant red hermit crab can get to be 12 inches long and is the largest marine hermit crab on Earth. The species can be found off the coast of the eastern U.S. and is red in color and with blue eyes. Their right claw is a little bigger than their left and is used to defend themselves and to break open shells for food. They are mostly scavengers but will also hunt for prey like mollusks and worms. Their shell of choice…queen conch shells!

The photo featured at the top of this post is © Chase Clausen/Shutterstock.com