Nearly all of the world’s 2,000+ Gobies (the largest family of marine fishes) are small, elongated fishes that dart about the substrate, often seeming more to “run” than swim. Goby fans are fortunate in so many exhibit very interesting behaviors, and are both colorful and hardy. Sand-sifting species, for example, dive headfirst into the substrate and munch on it (seeking small invertebrates) while the various Shrimp Gobies form long-term commensal relations with colorful shrimp (and are happy to do so in the aquarium). While Gobies get along well with most fish, they are, with the exception of mated pairs, usually intolerant of other family members.