Novaculichthys taeniourus (Rockmover Wrasse, Dragon Wrasse or Reindeer Wrasse) is a wrasse

Wrasse

The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 82 genera, which are divided into nine subgroups or tribes....

 that is mainly found in coral reef

Coral reef

Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...

s and lagoons in the Indo-Pacific region. These include those of the Gulf of California

Gulf of California

The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...

 to Panama

Panama

Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...

; tropical Pacific Ocean

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 islands including Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

; the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

, Indonesia

Indonesia

Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

 and Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

; and the Indian Ocean

Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

 to the east coast of Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

. The common name, "Rockmover Wrasse", comes from their behavior of upending small stones and reef fragments in search of prey.

Description

The Rockmover Wrasse is a colorful fish, 27–30 cm (10.6–12 in) in length. It has an oblong, laterally compressed body and a wedge-shaped head. Except for two scales on the upper part of the gill coverings and an almost vertical row of small scales behind each eye

Eye

Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...

, their head is scaleless.

There is a marked difference in appearance between juveniles and adults. 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 mature, the elongated rays are lost. Adult fish have a dark greenish-brown body with an elongated white spot on each scale. Their head is gray-blue with brown lines radiated from their eyes. There are two black spots in front of the dorsal fin and a wide vertical white bar on base of the caudal fin. The posterior part of their caudal fin and pelvic fins are black. Juveniles found in Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

 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 Novaculichthys taeniourus is so striking that the common name

Common name

A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

 "Rockmover Wrasse" is used for adult Novaculichthys taeniourus and "Dragon Wrasse" for juveniles.

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 where there is 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, it is believed that, 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. Large adults, usually in pairs, move over their large section of a reef. 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

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 and mimic the movements of detached, drifting seaweed

Seaweed

Seaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae...

 by swaying back and forth in the currents.

Distribution

They are widely distributed in tropical Indian Ocean

Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

 and Pacific Ocean

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

reefs and lagoons.