Rockmover Wrasse

Q: Where can you find Rockmover Wrasse?

Rockmover Wrasse can be found in: Egypt East, Laccadive Islands, Mariana Islands, Cocos Island, Australia West, Saudi Arabia West, Malaysia East, Costa Rica, Taiwan, Malpelo Island, Costa Rica West, Marshall Islands, Malaysia West, Galapagos, Hawaii, Pacific East, Colombia West, Somalia East, Vanuatu, Sudan, Brunei, China, Ecuador, Myanmar, Eritrea, Australia, Kenya, India, Israel, USA West, Revillagigedo Islands, Mexico West, Japan South, India East, India West, Thailand East, Thailand West, Panama West, Israel South, Oman, Oman East, Somalia North, Australia East, Nicaragua West, Honduras South, Sri Lanka, Maldives, Vietnam, Seychelles, Cambodia, Indo-Pacific, Papua New Guinea, French Polynesia, Polynesia, Singapore, Tanzania, Malaysia, USA, Honduras, South Africa, Red Sea, Japan, Indonesia, Chagos Islands, Mexico, Mozambique, Jordan, Palau, Philippines, Solomon Islands, New Caledonia, Micronesia, Egypt, Tonga and Samoa, Yemen, Mascarene Islands, Madagascar, Kiribati, Djibouti, El Salvador, Comoros, Fiji, Thailand, Panama, Saudi Arabia, Pacific Ocean, Colombia, Somalia, Nicaragua, Guatemala.

Novaculichthys taeniourus

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Max Depth

25 m

Novaculichthys taeniourus is a species of wrasse mainly found in coral reefs and lagoons in the Indo-Pacific region. These include habitats in the Gulf of California to Panama; tropical Pacific Ocean islands including Hawaii; the Philippines, Indonesia and Australia; and the Indian Ocean to the east coast of Africa. The common name, "rockmover wrasse", comes from their behavior of upending small stones and reef fragments in search of prey. This species is the only known member of its genus.

Other names: Dragon Wrasse or Reindeer Wrasse.

Description

The rockmover wrasse is a colorful fish, 27–30 cm (11–12 in) in length. It has an oblong, laterally compressed body and a wedge-shaped head. Its head is scaleless except for two scales on the upper part of the gill coverings and an almost vertical row of small scales behind each eye.

Juveniles and adults have markedly different appearances. In juveniles, the first two dorsal fin spines are long and extended, drooping over the fish's forehead to form a "cowlick". As the fish matures, the elongated rays are lost. The adult fish has a dark greenish-brown body with an elongated white spot on each scale. Its head is gray-blue with brown lines radiated from the eyes. Two black spots occur in front of the dorsal fin and a wide vertical white bar is found on the base of the caudal fin. The posterior part of the caudal fin and the pelvic fins are black. Juveniles found in Hawaii are usually green and those in the western Pacific are burgundy to brownish. Both are spotted in white.

The difference in appearance between juvenile and adult N. taeniourus is so striking, the common name "rockmover wrasse" is used for adults and "dragon wrasse" is used for juveniles.

Distribution

They are widely distributed in tropical Indian Ocean and Pacific Ocean reefs and lagoons.

Habitat

Adult fish live on shallow, semi-exposed reef flats and in lagoons and seaward reefs to depths of 14–25 m (46–82 ft). They prefer hard-bottomed grassy areas of mixed sand and rubble with exposure to a mild surge. Juveniles favor shallow areas on rubble among large patch reefs or protected open patches on reef crests.

Reproduction

Although little is known about reproduction of these fish, like other wrasses, they probably are able to change sex and are pelagic spawners, broadcasting eggs and sperm into the water column.

Behavior

These fish are highly territorial and pairs of adults often protect large areas of reef.

The fish feed on benthic invertebrates including molluscs, crabs and polychaete worms. One fish turns or shifts large pieces of debris or rubble, grabbing or pulling it with its mouth or pushing it with its snout. When the working member of the pair has revealed the prey, the other fish quickly grabs and eats it. Juveniles do not usually work in pairs, doing all the work themselves. Facing danger, these wrasses quickly dive into the sand for protection.

Juveniles resemble algae and mimic the movements of detached, drifting seaweed by swaying back and forth in the currents.