The Shrimp-Goby Connection: An Ocean Odd Couple

shrimp goby
Species-wise, this little fish is a spotted prawn goby. Lifestyle-wise, it’s one of nearly 70 species of Indo/Pacific gobies that spend their lives in a mutualistic relationship with snapping shrimps.

GOOGLE THIS FISH, THE SPOTTED PRAWN GOBY, and most of the posts you’ll find are for the aquarium trade. Amblyeleotris guttata appears to be a popular fish for home saltwater aquariums. Www.fishbase.org carries a listing for it, but it’s largely related to it colors, size and distribution (which is the Western Pacific from the Philippines down to the Great Barrier Reef at Australia. This photo was taken on the GBR).

IT’S A SHRIMPGOBY   

All of which ignores the most interesting reason for paying attention to A. guttata (besides its cuteness): it’s a shrimpgoby. Members of this species and of some six dozen more species of shrimp gobies in the Gobiidae family live their lives sharing burrows in sandy bottoms with nearly blind snapping shrimps (or, if you prefer, pistol shrimps).

It’s a mutualistic relationship. A shrimpgoby gets a safe place to live and the shrimp gets a protector and bodyguard. Some sites call the fishes watchman gobies. The shrimpgoby also gets a relentless house cleaner. The drawback to living in a hole in a sandy bottom is that sand keeps piling into it, even collapsing the entrance, and the resident shrimp spends much time moving unwanted sand out and shoring up the burrow.

YOU’RE NUMBER 6  

The most expansive information source for shrimpgobies is the excellent Gerald Allen/Roger Steene/Paul Humann/Ned DeLoach Reef Fish Identification/Tropical Pacific. You can also learn a great deal, in a more breezy format, in an Animal Planet video on “Top 10 Odd Couples.” Shrimpgobies, and their shrimps, are No. 6. To see it, click HERE.

Reef Fish Identification notes that the shrimps (nobody seems to call them gobyshrimps) maintains winding tunnels, often two to four feet long and an inch in diameter, that connect two to three enlarged chambers.

ALWAYS IN CONTACT   

While the shrimp goes about its business, the goby tends to lurk at the entrance, guarding the joint and extracting stuff to eat from mouthfuls of sand. At the entrance, the goby and shrimp are almost always in contact through one of the shrimp’s antennas touching the goby’s body. Twitching movement by the little fish serves as an alarm of approaching danger, and both can disappear into their burrow very quickly. Should the shrimp wander out far enough to get lost, its partner goby goes out to guide it back, Animal Planet says.

On the other hand, one of the aquarium sites says that having a shrimp to live with your spotted prawn goby is not necessary.

But not nearly as interesting.

PRINCIPAL SOURCES: Reef Fish Identification/Tropical Pacific, Gerald Allen/Roger Steene/Paul Humann/Ned DeLoach; Animal Planet, “Top 10 Odd Couples,” “Shrimp and a Goby;” www.reefbase.org.