The Orange-spotted sleeper-goby (Valenciennea puellaris) is also known as the Orange-dashed goby, Maiden goby and Diamond Watchman goby.
They lack swim bladders which given that they spend most of their time on the substrate are not needed and although they do not have a lateral line, they have sensory organs around the head. The genus is differentiated from other gobies by having completely separated pelvic fins, a single row of teeth in the upper jaw and a fleshy flap located at the gill arch.
The Orange-spotted sleeper-goby has a typical goby shaped body with an elongated cylindrical body shape with two dorsal fins. The body is a light blue grey colour and there are a series of six orange bars running across the upper body. In between each bar at the termination point is an orange dot. Below these is another line of intermittently connected orange lines.
The dorsal and caudal fins are speckled with orange spots and there are a series of dotted light blue lines across the cheek extending back over the gill plate. They have a proportionally large mouth and orange rings around the eyes. Males have a more prominent dorsal fin than the females. Despite their colorful looks they are well camouflaged in lower light over sand. They grow up to 20cm in length.
DECORATED GOBY IN THE WILD
The Orange-spotted sleeper-goby is fairly common in Tanzanian coastal waters. They are usually seen on the sand in mixed rubble and reef areas and if feeding they are sifting sand. When they feel threatened they swim low over the substrate and go into one of their burrows. They are usually in pairs but feed individually while the other keeps watch.
The burrows are normally under a small stone or coral and we have never seen them on open sand. Their slightly bulbous eyes allow them to look backwards and when swimming away they tend to keep one eye backwards on the perceived threat. They usually have more than one burrow and feed in the areas surrounding these burrows.
The Orange-spotted sleeper-goby is found across the Indo west Pacific area from East Africa to southern Japan and south to the Great Barrier Reef including Lord Howe Island. They are mainly seen on the rubble and sandy areas between corals and generally swim low close to the bottom. They are more common between 12 to 15 meters in depth on the mainland but we have seen them down to 18 meters.
Orange-spotted sleeper-goby feed on small microorganisms that live in the sand. They take in mouth full’s of sand and filter the microorganisms out the sand. The sand is then expelled out the gills and copepods, ostracodes, amphipods, nematodes and foraminiferans make up the bulk of their diet. With their proportionally large mouths they are able to dig up to 2.5 cm into the sand which is deeper than the other members of their genus.
Orange-spotted sleeper-goby form monogamous pairs and the eggs are laid in the burrow and cared for by the male. When the eggs are ready to hatch the male seals the burrow and then re opens it at night giving the fry a chance to disperse.
There is an interesting piece of research done on the breeding habits of this genus here. Essentially males mate with the largest female that is available and will transfer from a smaller female to a larger if one is available. Females guard larger males and benefit from having a larger male who provides larger and more burrows which provide more shelter.
Orange-spotted sleeper-goby can make an interesting and useful contribution to a tank by filtering the sand, provided that this is what one wants done in ones tank. This species have a proportionally larger mouth than other members of the genus and are therefore likely to filter a lot more sand. A full grown specimen can reach 20 cm and this equates to a lot of sand being filtered.
Although their personality varies from specimen to specimen , provided that they are in a sufficiently large tank with deep fine sand and good water conditions and no other aggressive species they are likely to be quite active.
They tend to be easy to feed and are considered reef safe but may dump sand on invertebrates on the lower parts of the tanks. Provided one has the correct environment for them with mature live sand, they are easy to keep. Because of their bottom feeding habits they may have parasites and it is a good idea to deworm them.
They are happier in pairs and seem to live longer if kept as a pair. They may become territorial with other similar feeders who potentially threaten their food supply. You can read a very good article here on keeping these fish and other members of their genus.
DECORATED GOBY CLASSIFICATION
Genus: Valenciennea puellaris
Species: V. puellaris
- The Reef Guide: Southern Africa’s East and South Coasts