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What color is a female hermit crab?

What color is a female hermit crab?

Hermit crabs are fascinating creatures that come in a variety of colors. The color of a female hermit crab depends on the species. Hermit crabs belong to the superfamily Paguroidea and are commonly found in tidal pools and along shorelines in tropical and subtropical areas. There are over 800 known species of hermit crabs, most of which possess a soft spirally curved abdomen that is protected from predators by salvaged empty seashells. Hermit crabs are quite social despite their name and often live in large groups. When a hermit crab grows too large for its shell, it will seek out a more spacious shell to inhabit. Shell-switching is a common behavior seen in hermit crabs where they evaluate prospective new shells by inspecting the inner volume and checking if they can fit comfortably inside.

Common Hermit Crab Species

Some of the most common hermit crab species kept as pets or found in the wild include:

  • Ecuadorian hermit crab (Coenobita compressus) – Ecuadorian hermit crabs have brown legs with red banding. Their bodies can be a cream color to a light tan or brown. Their claws are equal in size.
  • Caribbean hermit crab (Coenobita clypeatus) – The Caribbean hermit crab has dark brown legs with bright red banding. Their bodies are brownish-orange to reddish-brown. They have one large and one small claw.
  • Australian hermit crab (Coenobita variabilis) – Australian hermit crabs are often maroon or dark brown with bands of white dots. Their legs fade to a tan color near the tips. These hermit crabs have equal-sized claws.
  • Rugosus hermit crab (Coenobita rugosus) – The rugosus hermit crab has reddish-brown legs with bright red bands. Their body color ranges from yellow to reddish-brown. Their claws are unequal in size.
  • Purple pincher hermit crab (Coenobita spinosus) – As the name suggests, this crab has purple-tipped pincers. Their legs are banded shades of purple and tan. Their body is often yellowish.
  • Strawberry hermit crab (Coenobita perlatus) – This brightly colored hermit crab has red legs with white banding. Their claws are bright red and their bodies are light orange to pinkish.

Female Hermit Crab Colors

The coloration of male and female hermit crabs is mostly identical in each species. There are a few subtle differences that can help determine the sex of a hermit crab:

  • Females tend to have shorter, wider abdomens while males have longer, narrower abdomens.
  • Females may have a slightly duller color than males in some species but it can be hard to distinguish.
  • Female Caribbean hermit crabs often have brownish-gray legs compared to the very dark brown legs of males.
  • Female rugosus hermit crabs can be identified by their broader pleopods which are paddle-like appendages under their abdomen.

While color is not the most reliable indicator of sex, females often do appear subtly duller in shade compared to males of the same species. However, the best way to determine the gender of a hermit crab is to observe their behavior and abdominal shape.

Shell Selection

The type of seashell that a hermit crab inhabits can also influence its overall coloration. Hermit crabs will sometimes match the color of their shell. Darker shells can make a crab appear darker in color, while lighter shells give them a lighter hue.

Female hermit crabs are particular when choosing new shells and prefer light-colored shells that are larger and more spacious. The extra room is needed to carry eggs. In comparison, male hermit crabs prefer heavier, more protective shells since they do not need to accommodate eggs.

Molting

Hermit crabs grow by periodically shedding their exoskeleton in a process called molting. A female hermit crab that is preparing to molt will bury herself underground for the 10-14 days it takes to shed and harden a new exoskeleton. The new exoskeleton will initially be very soft and pale after molting.

The color will darken and become more vibrant over the next few days as the new exoskeleton hardens. The original colors and banding patterns will return but often appear slightly brighter on a newly molted crab. Molting also allows female crabs to grow larger and provide more space for carrying eggs.

Egg Color

Female hermit crabs carry bright orange or red eggs under their abdomen. The eggs are a sure sign of a female crab. The eggs start out a muted orange color and become a more vibrant reddish-orange as they develop before hatching. A female hermit crab with eggs will have hundreds to thousands of tiny eggs attached underneath her curled abdomen.

Table of Hermit Crab Species and Color

Species Leg Color Body Color Claw Color
Ecuadorian hermit crab Brown with red bands Cream to light brown Equal size claws
Caribbean hermit crab Dark brown with red bands Orange to reddish brown One large, one small claw
Australian hermit crab Maroon with white dots Tan Equal size claws
Rugosus hermit crab Reddish brown with red bands Yellow to reddish brown Unequal size claws
Purple pincher hermit crab Purple and tan bands Yellowish Purple tipped claws
Strawberry hermit crab Red legs with white bands Light orange to pink Bright red claws

Conclusion

In summary, while female hermit crabs can exhibit slightly duller shades than males in some species, there are no major color differences between genders. The abdominal shape and size along with behavior provides more insight into determining if a hermit crab is female or male. Molting allows female crabs to grow larger to carry eggs and can temporarily alter their coloration. When it comes to hermit crab species, factors like leg banding, body hue, claw size, and more can help identify the type of hermit crab along with gender.