Thalassoma

Thalassoma is a genus of marine ray-finned fish belonging to the family Labridae, commonly known as wrasses. These fish are found in tropical and subtropical waters worldwide, with a particular abundance in the Indo-Pacific region and the eastern Pacific. Thalassoma species are characterized by their elongated, laterally compressed bodies, prominent lips, and a single, continuous dorsal fin. They exhibit striking and often vibrant colorations, which can vary significantly between sexes and even within the same species as they mature.

These wrasses are generally small to medium-sized, with most species ranging from 10 to 30 centimeters in length. They are active swimmers and are often observed darting around coral reefs, rocky substrates, and seagrass beds. Thalassoma species are typically diurnal, feeding on a variety of small invertebrates, such as crustaceans, mollusks, and polychaete worms. Some species may also consume small fish eggs or algae.

Reproduction in Thalassoma often involves complex social structures and distinct sex changes. Many species are protogynous hermaphrodites, meaning they are born female and can transition to male later in life. The coloration patterns play a crucial role in their social interactions and mating behaviors. Due to their widespread distribution and often colorful appearance, some Thalassoma species are popular in the aquarium trade, though their specific care requirements can vary.