Cryptic diversity of Eviota (Teleostei: Gobiidae) and their habitat use in the shallow waters of Okinawa Island

Abstract

Eviota, known as dwarf gobies, is a diverse genus of marine shes comprising more than 120 species found throughout the Indo-Paci c Ocean. A previous study has suggested that morphologically similar cryptic species of Eviotamay exist and that the species diversity may be signi cantly underestimated. This study evaluated the diversity of Eviotaspecies in three habitat types (tidal ats, reef ats, and moats) in the shallow waters (0-1 m in depth at low tide) of Okinawa Islandusing morphological characteristics and molecular phylogenetic analysis. Eleven morphospecies were classi ed into 17 molecular optical units(MOTUs), and cryptic species for which speciation may have occurred relatively recently were detected in the morphospecies Eviota abax, Eviota japonica, Eviota queenslandica, and Eviota prasina. Most MOTUs exhibited only one habitat use, whereas three MOTUs were found in multiple habitats. Among each cryptic Eviota species, both habitat segregation and habitat overlaps were found. Therefore, speciation in Eviota may occur without habitat segregation, and multiple other factors should be considered regarding speciation in Eviota.

Habitat Use of Two Coral-Associated Cryptobenthic Gobiid Fishes (Family: Gobiidae) in the Southern Caribbean

“…They provide a habitat for various invertebrates, such as barnacles [11], copepods [12,13], crabs [11,14], shrimps [15][16][17], gastropods [18][19][20][21][22], bivalves [23], hydrozoans [24], acoel flatworms [25], and polycheate worms [26][27][28]. Additionally, they provide a habitat for various fishes, such as blennies [29,30], cardinalfishes [31], damselfishes [32,33], gobies [34][35][36][37], labrids [38], and pipefishes [39,40]. Many of these fishes are cryptobenthic species, which are defined by a length of less than 50 mm, cryptic morphology, hiding behaviour, and a close association with the benthos [41][42][43].…”