The Shrimp Goby and Blind Shrimp -

The Strange Science of Mutualism

The Shrimp Goby and Blind Shrimp

Article by Cathryn Castle Garcia

One of the most endearing relationships taking place on the seafloor is that between a fish called a shrimp goby and its companion, the burrowing “blind” shrimp.

The blind shrimp is also known as the pistol shrimp. It isn’t totally blind, but it doesn’t see well enough to avoid predators. It digs a deep burrow in the sand, which it uses as a retreat from danger. The shrimp invites the goby as a roommate – and “seeing eye” fish.

An Odd Pairing

Wondering how this odd pairing of two wildly different creatures works? The shrimp goby has excellent vision and quick reflexes. It uses its pelvic fins as a pedestal to prop itself up at the entrance of the burrow, like a security guard or a bouncer at a nightclub. In exchange for guarding the door, the shrimp goby gets a free place to live. The blind shrimp is an obsessive-compulsive construction worker, tirelessly sculpting and tidying its burrow. Knowing the shrimp goby has its back allows the blind shrimp to work without fear of being eaten. It’s win-win.

The goby and blind shrimp communicate through chemical cues which researchers don’t fully understand. The two also rely heavily on the sense of touch. They remain in near-constant physical contact, with the shrimp extending one of its long antennae onto the body of the shrimp goby. The goby wiggles its fins in ways that signal “safety” or “danger” to the shrimp. When the shrimp goby signals danger, the pair retreats to the bottom of the burrow.

When the coast is clear, the goby goes back to guarding the door and the shrimp emerges from their burrow to tidy up or forage for food. Speaking of food, here’s another tidbit about their relationship; the shrimp picks the goby clean of parasites and clears away its poop. Which it eats. Yes, you read that right. The shrimp is a poop eater. What a pal, huh?

The blind shrimp fortifies the burrow entrance with a cache of small rocks and coral rubble. At dusk, once the goby settles into their shared home, the shrimp pulls a few bits of rubble over the top of them like a hatch cover, hopefully deterring creatures that hunt in the night.

A Mutually Beneficial Relationship

Marine researchers call their relationship an example of symbiosis known as mutualism, in which members of different species live in proximity and benefit from one another. About 130 species of shrimp gobies are associated with about 20 species of shrimp, most of which are found in the Indo-Pacific and adjacent regions.

Examples of mutualism exist practically everywhere we look. In the marine realm, the relationship between corals and zooxanthellae is mutualism. Same with the darling anemonefish and its host anemone. Ditto for the relationship between the shark and the remora. On land, birds and bees and butterflies do their mutualistic thing by flying from one flowering plant to the next, enjoying a sip of sweet nectar while serving as the plants’ pollinating partner. In your own body, your gut biome stays healthy thanks to beneficial bacteria that aids digestion. All are examples of the win-win of mutualism.

The Ocean Metaphor of Mutualism

In Ocean Metaphor: Unexpected Life Lessons from the Sea, which I co-wrote with my dive buddy and husband Gui Garcia, we tagged the shrimp goby and the blind shrimp as the “poster creatures” of devotion. The concept of devotion is often thought of in a religious construct, referring to the prayer practices of those who worship a particular deity. The goby and the blind shrimp illustrate a different form of devotion, one in which allegiance toward each other and a common goal benefits each devotee.

Like most mammals, humans aren’t meant to be solitary creatures. The Beatles said it best, “I get by with a little help from my friends.” We do better together, whether our devotion is to a beloved companion, family or close friends, our dive buddies, or our community at large. By devoting our energy to the people and causes that are important to us, we make our lives – and the world around us – better.

We might not need someone to pile rocks on us so we can make it safely through the night, but we all benefit from close personal relationships – a helping hand or a shoulder to lean on.

Mutualism isn’t the only symbiotic relationship taking place under the waves. To learn more about symbiosis in the sea, check out the article, “Symbionts, Parasites, Hosts and Cooperation,”