Sleeper gobies are large showy sand-sifting gobies of the genus Valenciennea, of which there are many popular species in aquariums. A newly discovered specimen from Mauritius hints that there could be yet another new addition to this highly desirable and attractive group of reef fish.
The new Mauritius sleeper goby was brought to our attention by Jason Edward of Greenwich Aquaria. Lately Mr. Edward has enjoyed the discovery of new fish as much as he’s enjoyed the aquarium hobby, with the co-authorship of the recently described Pseudojuloides zeus, and the Pseudojuloides edwardi being named in his honor.
Unlike some of the new species of reef fish which show only the minutest differences in colors, patterns, habitat or behavior, the new Mauritius Valenciennea sleeper goby shows a clear difference in color pattern, and similarities with two currently known species.
Valenciennea decora is a species of sleeper goby with a milky white base coloration, and slightly oblique orange stripes. Meanwhile the orange spotted sleeper goby, Valenciennea puellaris is a very common aquarium fish that has the same base coloration as V. decora, but only has orange color in a series of spots across the dorsal part of its body, and a thin body stripe at the midline.
The Mauritius sleeper goby has a color pattern that is near completely a blend of these two Valenciennea sleeper goby species, and although the orange spotted sleeper goby does occur in the Indian Ocean, the decorated sleeper goby is only known from the Western Pacific Ocean.
Unless the decorated sleeper goby has a natural distribution much further west than currently recorded, it’s simply not possible to consider this unusual sleeper goby from Mauritius as a hybrid of V. puellaris and V. decora. And with only a lone specimen of this uniquely patterned sleeper goby, it’s hard to say with confidence that it is a new species, instead of single unusual specimen. Hopefully our friends in Mauritius will keep an eye out for more examples of this cool “new” form of sleeper goby and only if they find more of them will we better understand what the Mauritius sleeper goby represents.