Can Lobsters Regrow Their Limbs? (Explained)

Many marine animals have this outstanding availability to regrow their limbs. Some can even clone themselves by using a small piece of their body (starfish). But can lobsters regenerate their lost limbs, such as claws, legs, or others? In this blog post, we’ll talk all about this but let’s begin with a quick answer:

Lobsters can regrow some of their limbs, including claws, walking legs, and antennae. The process of regenerating can take from a few months to a few years, depending on the lobster’s size, species, and conditions.

However, this certainly doesn’t tell the whole story. Below, I’ll explain more about lobsters regrowing their lost limbs, how long they regrow them and what the whole process looks like. Furthermore, I’ll explain how lobsters can detach their limbs themselves and if they can survive without their appendages. Read on!

What limbs can lobster regrow?

As I mentioned previously, lobsters can regrow their claws, walking legs, and antennae. They can’t regrow other limbs like tails, eyes, or others. Below, I’ll explain more about each of the appendages that lobsters can regrow.

Lobsters regrowing their claws

Lobsters can regenerate their lost claws in about two years or more, depending on the individual and how bad the damage is. This ability is crucial as many lobster species use their claws to defend themselves from predators.

The clawed lobster species, such as the American lobster, have one pair of large claws in front of their bodies and two pairs of smaller ones to rip the food apart. The two big claws actually differ in appearance as they’re used for different reasons.

The crusher claw is larger and, as the name suggests, is used for crushing the prey. This claw is more massive and can exert more pressure than the other one. The pincher claw is sharper and used to rip into the prey. The position of the claws differs depending on the lobsters’ handedness.

Lobsters can be right or left-handed (or clawed), and the position of the pincher claw determines it. Therefore, the lobster is left-handed if the pincher claw is located on the left side of the lobster’s body. If a lobster loses a crusher claw, the pincher claw will transform into a crusher with the next molt. Next, the new cutter will grow in the place of the crusher.

Interestingly, if a lobster didn’t lose a claw entirely, but the claw is only damaged, regeneration chances decrease because the body doesn’t perceive the damage. If this scenario happens, lobsters sometimes cut off their own claws to be able to regenerate them.

Lobsters regrowing their walking legs

Lobsters can regrow their walking legs that are located right behind the claws (for clawed lobsters). In general, lobsters have five pairs of walking legs (pereiopods), but they’re slightly modified, depending on the lobster’s family. For instance, in clawed lobster species, the first pair of legs is modified into large claws.

Lobsters use their legs to walk along the ocean floor to search for food or hide in their shelters. They also use them in feeding, mostly to rip the food apart and put it in their mouths. Moreover, female lobsters, when they lay their eggs, they use their legs for grooming.

Lobsters regrow their antennae

Lobsters can regrow their antennae, and it’s actually the fastest-growing limb. All lobster species have one long pair of antennae on their heads used for touching and finding their way around. The other two pairs of smaller antennae are sensitive to odors, helping them to identify chemical signals and locate food.

Antennae are also used for protection, especially for spiny lobster species that don’t have claws, and their antennae are very long. These lobsters usually hide in their shelters, with their antennae protecting the entrance.

Some lobsters also use their antennae for communication. They produce sounds by rubbing them together, and the rapid contraction of internal muscles causes their carapaces to vibrate. As a result, it creates a low-frequency sound analogous to the ‘buzzing’ sound.

As you can see, antennae are crucial parts of lobsters’ bodies, and the availability to regrow them, it’s so essential to animals’ survival. They’re also easy to lose as they’re much longer than the other parts of their bodies. When their predators are trying to attack, their antennae will probably be the first thing in their mouths.

How do lobsters regrow their lost limbs?

When a lobster loses its leg, the signal of regeneration is sent from the wound. The injury triggers a physiological reaction response, and the animal’s body knows it should immediately begin a regeneration process.

First, the fibrotic tissue on the wound is created, and as it heals, new blood vessels and neurons start growing together with the tissue, preparing the body for regenerating new, functional walking legs. Next, lobster slowly grows lost appendages through a molting process.

Very often, a limb bud starts to grow shortly after the loss, but most of the limb bud growth takes place during a premolt stage. Typically, at the next successive molt, the entire appendage appears fully formed but smaller than normal. This especially occurs in the case where claws are being regenerated.

The size and appearance of the regenerated appendage depend on its size, the lobster’s age, and in which molt cycle the animal lost it. The lost leg, claw, or antenna should reach the normal size after several molts. Lobsters usually molt once or two every year, so it might take a few years to grow them back.

How do lobsters detach their appendages?

As I mentioned previously, if lobsters injure their legs or claws, they won’t be able to regenerate them, so sometimes they cut their limbs with their claws to be able to regrow a new functional limb. However, not all lobsters have claws, and they have another method to release their limbs.

The method is called autonomy, which means the animal is able to discard the appendage, just like lizards can detach their tail. Lobsters do it with their claws, legs, or antennae as a response to danger. This way, they can escape predators and later regenerate their lost limbs.

The regeneration of the lost limbs is a reflex initiated by large sensory stimuli. They’re influenced by the action of two levator muscles, which are also involved in the animal’s normal walking. The smaller muscle contracts when the limb is grossly stimulated, breaking the tendon of the larger one.

This switches the application of the larger muscle to a small skeletal plug that crosses the plane of the fracture. Next, the larger muscle withdraws the plug from its socket distal to the breaking plane, and ultimately a small force applied externally to the limb is sufficient to remove it.

After autotomy, the membrane of the breaking plane seals the wound and prevents blood loss. Interestingly, the autotomy abilities will slightly differ depending on the lobster species. For instance, Palinurus species can detach their second antennae.

How do lobsters lose their limbs?

Marine crustaceans commonly lose and regenerate their appendages. This typically happens due to aggressive encounters with each other as they often fight for their territory and mating rights. These fights can get pretty brutal, ending up with lost limbs.

Another reason is the predatory attacks. Some of the biggest lobsters’ predators are triggerfish, flounder, cod, sculpins, eels, rock gunnels, crabs, seals, and even other lobsters. Lobsters sometimes show cannibal behavior, which you can read more about it in my other blog post here.

Another reason is humans – unfortunately, the number one predator. When humans try to catch lobsters, they often catch antennae, claws, or legs. In order to escape, the lobster typically induces autonomy and regenerates limbs later.

How long does it take lobsters to regrow the lost limbs?

Moreover, the probability of regrowing a lost appendage decreases with age and the number of limbs previously lost. In general, lobsters fully regrow their lost limbs in one to several years. However, new limbs are usually already there after the first molt but are much smaller and weaker.

When it comes to claws, smaller claws take less time to regenerate. Claw size is related to lobsters’ age, so juvenile lobsters will require less time to regrow them than older lobsters. Juvenile lobsters grow at in faster rate than older lobsters and molt several times a year.

With that being said, in order to fully regrow claws for juvenile lobsters, it may take several months to about three years. For adult lobsters, it may take a few years, strongly depending on how old the lobster is and how big its claw it.

Other appendages regrow usually faster than claws, and the full regeneration may take a few months. A female lobster in National Lobster Hatchery in Cornwall lost her two claws and four legs and was able to regrow them all in one molt. The claws were small, but the legs were almost the same size.

Can lobsters live without lost limbs?

Lobsters have the availability to regenerate their claws, legs, or antennae as they’re crucial body parts for their survival. But how do they survive during the regeneration process?

Can lobsters survive without antennae?

Antennae are essential survival body parts of lobsters as they’re used to detect food and defend themselves from predators. They’re especially important for species without claws, such as the Caribbean spiny lobster (Panulirus argus).

This lobster uses two long, armored, spiny, mobile antennae to defend against predators such as the gray triggerfish. If the spiny lobster loses one or both antennae, it leaves it highly vulnerable to
attacks.

The study shows that the removal of one antenna reduces a spiny lobster’s defensive ability but less than it was expected. The adjustments in the use and timing of certain actions and in body posture compensated for the loss.

Nevertheless, a non-clawed lobster missing one antenna probably is not as effective in defense as a lobster with both antennae and will be much more difficult to survive in its natural habitat before the antenna regrows fully. The lobster without any antennae will definitely have very low chances of survival.

Can lobsters survive without a claw?

After clawed lobsters lose one of their claws, it can be difficult to survive as they’re more vulnerable to their predators. They can survive, but they have to be more careful, and they’ll most likely hide in their shelters for most of the time.

If a lobster loses both claws, the survival chances are very low because not only is the animal very vulnerable to its predators, but also it can be difficult for it to eat enough to survive. Lobsters that lost their first pair of claws can still use the other two smaller pairs, but they’re not as efficient as the big ones.

Can lobsters survive without their legs?

If a lobster loses all of its legs, it can be difficult for it to survive since it can’t walk to hunt. However, when a lobster loses only one or a few legs, it will be slower, but it can still hunt or escape predators. Lobsters escape danger by using their flexible tail to swim away, so missing legs shouldn’t be a problem in this case.

Sources

• J. Cobb, Bruce Phillips “The Biology and Management of Lobsters.” Academic Press, 1980
• Govind CK, Pearce J, Potter DJ. Neural attrition following limb loss and regeneration in juvenile lobsters. J Neurobiol. 1988 Dec;19(8):667-80. doi: 10.1002/neu.480190802. PMID: 3235998.
• Amy Parsons , H. Reeves “I Can Beat You One Handed: Spiny Lobster Self Defense After the Loss of an Antenna.” Florida State University, 2005.