The Yellowback Tubelip wrasse (Labropsis xanthonota) is also known as the Wedge-tailed wrasse, Blacklobe wrasse and V-tail wrasse. They are fairly rare on Tanzanian Reefs and tend to favor shallower areas of the reef and if one dives in these areas one will occasionally see them. They are highly specialized feeders with their tube like lips adapted to feeding on coral polyps.
As with many wrasses the colouration changes dramatically from the adults to the juveniles. The juveniles pictured further below have a black body with a thin white lines across the body. As they mature into initial phase females so the body becomes more blue particularly on the head and caudal area. The larger more dominant females will turn into males on social cues. As can be seen in the image above the lines become dotted and yellow, blue lines develop over the face and mouth. Two lobes develop on the caudal fin and there is a bright yellow mark just above the pectoral fin.
YELLOWBACK TUBELIP WRASSE IN THE WILD
The adult Yellowback Tubelip Wrasse are very active fish and are usually seen singularly feeding across the reef. In Tanzania the adults seem more common on the shallower coral rich semi protected reefs rather than on the deeper reefs. They are shy fish and head away from a diver making them difficult to watch or photograph.
The Yellowback Tubelip Wrasse, is found across the Indian Ocean from the Red Sea down to South Africa and across into the Pacific to the Line and Marquesas Islands. In Tanzania adults are usually seen on reef tops above 15 meters. They are most common between 4 meters to 10 meters.
The Tubelip Wrasse are corallivorous and use their tube shaped lips to feed on coral polyps. Research in Australia has shown that they place their lips over a hard stony coral polyp and suck the mucus off of coral polyps. Their lips produce a mucous which protects them from the stinging cells in the coral. They are active fish constantly on the move feeding and because of their relatively dark colouration are difficult to photograph. The juveniles have been documented acting as cleaners to other fish.
The Yellowback Tubelip Wrasse is a Protogynous hermaphrodite, they first develop into females. Some specimens based on social cues transform into males. They are Oviparous, with the dominant male running a harem or possibly several harems of females. Little or nothing is known of their breeding habits.
Yellowback Tubelip Wrasse are not commonly kept in aquariums mainly because of their diet of live coral mucus which requires live corals.