Engineer Goby

The Engineer Goby is one of the most fascinating and misunderstood fish in the marine aquarium hobby. Despite its common names suggesting membership in the goby or blenny families, it actually belongs to its own unique family, Pholidichthyidae, and is not closely related to either group. As juveniles, Engineer Gobies are strikingly beautiful, displaying bold horizontal black and white stripes remarkably similar to the venomous striped catfish (Plotosus lineatus), a case of Batesian mimicry that provides protection from predators. Juveniles school together in tight, swirling groups that further enhance the catfish mimicry. As adults, the pattern shifts dramatically to a mottled brown, black, and white pattern with an elongated, eel-like body that can reach an impressive 12 inches in length.

The common name 'Engineer Goby' derives from this species' extraordinary burrowing behavior. Using their mouths and bodies, these fish excavate elaborate tunnel systems beneath the rockwork, moving impressive quantities of sand and rubble to create complex underground networks with multiple entrances and exits. This industrious construction activity is both the species' greatest appeal and its most significant challenge in captivity, as the tunneling can undermine rock structures and cause aquascaping collapses if the rockwork is not securely bonded together. Careful aquascaping with rocks epoxied directly to the glass bottom or to egg crate is essential to prevent dangerous rockslides.

The Engineer Goby is rated as intermediate in difficulty not because it is delicate, but because of its eventual large size and the infrastructure considerations its burrowing demands. It is actually an extremely hardy and disease-resistant fish that eats virtually anything and tolerates a wide range of water conditions. However, many aquarists purchase the adorable two-inch striped juveniles without realizing the fish will eventually grow to a foot long and require a substantially larger aquarium. When housed in an appropriately sized tank with secure rockwork, the Engineer Goby is a rewarding and uniquely entertaining species with behavior unlike any other aquarium fish.