Sleeper Gobies

I find the Sleeper Goby often short lived unless you can find a mated pair. Most sold in pet stores are males. Finding a female is almost impossible:

This genus is comprised of 15 species that are usually highly recommended as sand sifters. Even though they have scoop-like jaws, they are often short lived unless kept as a mated pair. Most sold in pet stores are males, and finding a female is almost impossible. They feed mostly on tiny crustaceans and worms, and the species V. strigata may eat small fishes, such as Neon Gobies. These fishes are burrow dwellers, and will normally seek protection under low overhanging rocks or actually burrow underneath rock to from a secure home. Often, in the wild, their burrows will be occupied with juveniles from the surgeonfish family. They should be housed in aquariums with a sandbed of at least two inches in depth and not housed with aggressive fishes such as groupers, dottybacks, triggerfishes or aggressive angelfishes. Usually, they stave to death in closed systems unless there are few competitors for their food supply, or they may simply jump out of the aquarium