Relationship between boxer crab and sea anemone

8 Facts About the Pom-Pom Crab

relationship between boxer crab and sea anemone

Boxer crabs acquire anemones by stealing from each other, and splitting center, investigated various aspects of the crab-anemone association. A first experiment showed that when a sea anemone is taken from a crab, . Hundreds of horseshoe crabs—known as "living fossils" as they are among the. Image: Flickr. Boxer crabs feed sea anemones in exchange for defense from danger — serving as a prominent example of symbiosis in the animal kingdom. Boxer Crab and Sea Anemone By: Madison Hook Symbiotic Relationships: The relationship between a boxer crab and an anemone is that they.

Their study focused on trying to resolve a long-standing mystery—how the crabs acquire their sea anemones.

Over the course of several years more than Lybia crabs were observed or collected from the shallow waters of the Red-Sea on the south shore of Israel in Eilat. These crabs are no more than a couple of centimeters across and have a similar color to the boulders under which they live—hence even finding them was a task in itself. Throughout the entire study, every single crab was found holding a pair of sea anemones which were identified as belonging to the genus Alicia, probably a newly recorded species.

Part 5: boxer crab

A video acceleration X8. Yisrael Schnytzer Remarkably, despite extensive searching the team was unable to find any 'free living' Alicia. Thus, a series of laboratory experiments was employed, to gain an insight into how the crabs might come by their sea anemones in the wild.

A first experiment showed that when a sea anemone is taken from a crab, leaving it with just one, it will split the other into two fragments which then regenerate over the course of several days into two new clones.

Boxer Crabs Have an Unusual Relationship With Sea Anemones

In the second part of the study a series of trials were conducted whereby a crab with sea anemones was placed in an aquarium together with one which had its anemones removed. The crabs would then proceed to wrestle—the crab without anemones would move to restrain one of the opponent's claws, and then remove part, or all, of a sea anemone.

relationship between boxer crab and sea anemone

Most such encounters ended in a successful theft, and with no apparent damage incurred to either of the crabs. Then, they watched what happened. The crab proceeds to stretch and split the anemone into two, ending with one on each claw. Yisrael Schnytzer hide caption toggle caption Yisrael Schnytzer The crab split its one anemone in two.

Crab Teases Anemone, Anemone Splits In Two, Crab And Anemone Live On : The Two-Way : NPR

The splitting process could take anywhere from one minute to two hours, but it usually lasted about 20 minutes and went something like this: The crab held the single anemone, mouth facing down, and reached across to clutch the anemone with a second claw.

With the anemone "face" down its mouth was on the bottom while this happened and hanging between two claws, the crab slowly began to stretch the anemone.

relationship between boxer crab and sea anemone

The crab's front walking legs teased at the anemone's flesh, tearing it little by little down the center until it broke in two. It's a slow process, and despite the inherently violent nature of one animal tearing another in half, it looks more like a tickling, teasing interaction than a brutal ripping one.

Boxer crabs acquire anemones by stealing from each other, and splitting them into clones

In fact, as the authors note, "fission" — or, dividing oneself down the middle to create a clone — is "a well-known form of sea anemone asexual reproduction.

In most cases, when a crab with anemones encountered one without, a fight ensued, even when the anemone-endowed crab was hopelessly larger than the naked one.

relationship between boxer crab and sea anemone

The researchers found that in nearly half of cases, the anemone-less crab stole one anemone. Sometimes, it would manage to steal a piece of one anemone. Rarely, it would manage to steal both.