Paracheilinus hemitaeniatus Randall & Harmelin-Vivien, 1977

Boury-Esnault, Nicole, Bellan, Gerard, Bellan-Santini, Denise, Boudouresque, Charles-Francois, Chevaldonné, Pierre, Dias, Alrick, Faget, Daniel, Harmelin, Jean-Georges, Harmelin-Vivien, Mireille, Lejeusne, Christophe, Perez, Thierry, Vacelet, Jean & Verlaque, Marc, 2023, The Station Marine d’Endoume, Marseille: 150 years of natural history, Zootaxa 5249 (2), pp. 213-252 : 238

Paracheilinus hemitaeniatus Randall & Harmelin-Vivien, 1977 ( Fig. 10 ): the half-banded flasherwrasse of mesophotic habitats off Madagascar

Paracheilinus hemitaeniatus is a rare brightly colored fish species sampled for the first time in 1972, at 45 m depth on the outer slope of the barrier-reef off Toliara, SW Madagascar. Created in 1961 as a branch of the SME, the marine station of Toliara (Tuléar) hosted many scientists who studied the coral reef communities and described a number of new species of marine organisms, contributing largely to improve our knowledge on coral reef diversity. The half-banded flasherwrasse is known only from the south-west of the Indian Ocean, Madagascar and Comoro Islands, where this elusive and beautiful species remains a ‘holy grail’ for photographers. It belongs to the Labridae , a highly diversified fish family, where sexual dimorphism is so pronounced that males, females and juveniles have often been described as separate species by early ichthyologists! Such color dimorphism is viewed as an adaptation to sexual selection and life in coral reefs, where it is more conspicuous than in other environments. Labrids play an important role in the trophic functioning of coral reefs due to their high abundance and diverse feeding behaviors, from small zooplanktivores, crustacean and mollusk feeders to large-sized piscivores. P. hemitaeniatus is a small (<12 cm) species feeding mainly on tiny planktonic crustaceans and participating with other species to the carbon transfer from the water column to mesophotic coral reef habitats.

Figures

FIGURE 10. Paracheilinus hemitaeniatus: A) Original drawing by M. Harmelin-Vivien. B). Underwater picture from Madagascar, author unknown.