The Bird Wrasse is one fish that can be identified easily by sex because of its colors. The Greenbird is the male and the Blackbird/Brownbird is the female.
The male has an all green body. The green can range in color from a light olive to a dark green to sometimes a deep greenish-blue. The female body is a light white-cream color on the front half and a black or dark brownish color on the back half. The lighter front half of the body has black markings on each scale. The "beak" is a peach or light orange color.
They can be a veryflighty fish, they can move rapidly and have a tendency to jump out of a tanks.
It is one of the Wrasses that prefer to hide under rocks and corals rather than bury itself in the sand or gravel. It will bury itself, but it doesn't happen very often. They are great at figuring out where to hide. The females catch on very quickly that they can go down inside the up-flow tubes of the undergravel filter. If startled they'll head right for this hiding place and it's next to impossible to get them to come out.
The females average a length to about six inches. The males can reach a stunning length of up to 11 inches, and have actually heard of a few at almost 14 inches. It is one species where the females will change sex into males. Sometimes you will get a female that is making the change over to a male and it possesses a combination of both color patterns, a Greenbird/Blackbird. Bird Wrasses eat small crustaceans like crabs and shrimp. Their long beak nose is designed for picking these out of rocks and corals. They will eat tank fed foods like shrimp and flake food and are fairly easy to care for. Not sure what else you wanted to know, so hope this helps.