Does anyone know of another one of these Jawfish — Opistognathus seminudus or the Semi-naked jawfish — in captivity in the world? We believe this rarely seen species has only found its way into the aquarium trade a couple times but we’re asking if anybody has one of these little beauties in the aquarium right now?
Opistognathus seminudus is one of 12 Australian Jawfish that is endemic to a relatively small area around the location they were first discovered (Smith-Vaniz, 2004). In this case its limited range is the Great Barrier Reef in Queensland. O. seminudus has a distinctive black false-eye spot on the anterior part of the dorsal fin and an irregular banded and barred pattern on the body.
As with most Opistognathids, the Semi-naked Jawfish has large eyes and a large trap-door style jaw. This family has the peculiar habitat of oral egg incubation and it has been suggested this method of rearing limits their dispersal and may explain the small range of many of the species in this family.
Like most of the smaller Jawfish, O. seminudus constructs a den in the substrate but requires slightly larger pieces of coral rubble and broken shell to adequately support the structure. If an aquarium housing this Jawfish contains only fine sand the den will inevitably collapse leading to an endless cycle of construction and rearrangement of the substrate.
We’re putting out the call to see if we can find another one this rarely seen Jawfish. So if you have one of these Semi-naked Jawfish or know of one in captivity please post and let us know.
Smith-Vaniz, William F., 2004. Descriptions of six new species of jawfishes (Opistognathidae: Opistognathus) from Australia. Records of the Australian Museum 56 (2): 209–224.