MANY-HOST GHOST GOBY
Pleurosicya mossambica Smith, 1959
   Most ghost gobies of the genus Pleurosicya are commensal with other specific organisms, typically a coral, gorgonian, or sponge. That means they live on that host, and are always found on it. Indeed, since these gobies often look alike, knowing their host organism can help identify them. The Many-Host Ghost Goby, however, is an exception. As its name implies, it can live on almost anything. It is also extremely variable in color, and in one of its iterations can look very much like Michel's Ghost Goby.

For many years the only ghost goby known from Hawaii has been Michel's Ghost Goby (Pleurosicya micheli), which lives exclusively on hard stony corals, In July 2025, however, Jonathan Goldberger photographed an apparent Pleurosicya on an old algae-covered tire off Maui. Michel's Ghost Goby would not normally be found on a tire. Jonathan posted his find on iNaturalist. Looking at his photo closely, it seemed to have some dark pigment at the base of the dorsal fin, a defining character of the Many-Host Ghost Goby according to Helen Larson's revision of the genus Pleurosicya, available online.

Jonathan's photo reminded me of a photo (above) that I took years ago of a Pleurosicya goby on the seat of an old bicycle at bottom of Honokohau Harbor, Hawaii. I assumed at the time that it was a Michel's Ghost Goby that had somehow strayed from its stony coral host. I dug up the old photo and was excited to see speckles of dark pigment at the base of its dorsal fin. On the basis of Jonathan's photos and mine, taken years apart, I conclude that Pleurosicya mossambica is quite probably established in Hawaii. Careful examination of a specimen would be needed to confirm the species, but I am pretty confident in the ID. The Many-Host Ghost Goby is the most widespread of its kind, ranging from East Africa to the Marquesas Islands of French Polynesia, so finding it in Hawai'i would not be too surprising.