In reef environments throughout the world’s tropical waters, an amazing phenomenon takes place between several different species of goby and burrowing shrimps. Incredible to witness, this partnership is one of the best examples of symbiosis anywhere – two completely different species living in harmony and providing one another with essentials for life. Let’s take a closer look into this miniature and colorful world.
Gobies: The Basics
Gobies are one of the world’s largest families of fish, with more than 2,000 known species in over 200 genera. Most gobies are tiny, never growing larger than about four inches in length. The smallest species is less than a centimeter long when fully grown, and the largest grows to be as much as two feet long, but these are exceptions.
Most gobies have a few anatomical features in common. First, their pelvic fins have fused together to form a sucker shaped like a disc. This allows them to stick to rocks and corals with ease, enabling them to stay close to safe shelter. Second, their eyes tend to be elevated and almost froglike in appearance; some species, particularly those living in fresh water, can almost be mistaken for tadpoles. Third, their dorsal fins tend to be pronounced, and in many cases, quite ornate, often divided into two separate sections that run the length of their bodies. One of the most spectacular examples is the Yasha White Ray Shrimp Goby, which is sometimes called the Candy Stripe Goby. Its first dorsal spine is held erect, like the mast on a sailboat, and is nearly as long as the goby’s body. This species, unlike most others, lives in deep water below thirty meters, and can also be identified by its bright or rusty orange horizontal stripes, which provide a stunning contrast to its white body.
Some of the most commonly encountered shrimp gobies include the Orange Spot Prawn Goby, which is native to the Indo-Pacific region. Mostly white, it is covered in bright orange spots and has black pelvic fins and maroon or dark brown bands that rise up from the ventral side. Yellow Watchman Prawn Gobies are bright yellow, with tiny white spots, and are found throughout Micronesia and into Singapore. The Diamond or Maiden Goby, which is sometimes referred to as the Orangespotted Sleeper Goby, is white with horizontal rows of diamond-shaped orange spots running the length of its body. This particular species loves to make little pyramids of sand outside its burrow, seemingly for entertainment. The Pink Spot Shrimp Goby, which is found throughout the western central Pacific, has light pink spots and stripes on its body, while the Yellownose Prawn Goby has a bright yellow face and slanted, vertical stripes across its body.
These are just a few of the many goby species you might encounter while diving; and no matter what your level of expertise, you are likely to find them with relative ease if you are spending time in shallow tropical waters. With the exception of a few species, gobies prefer to inhabit tide pools, coral reefs, seagrass meadows, and mangroves; all places even the least experienced diver can normally explore without difficulty. Some gobies are found in salt marshes and estuaries, making them difficult to find, and a few do live in freshwater. These species are not normally in relationships with shrimp; in order to coexist, conditions must be ideal for both species.