Deep genetic divergences and geographic distribution of the red algal genus Caulacanthus (Gigartinales)

An increasing number of studies have demonstrated that genetic differentiation and cryptic diversity in the sea occur over considerably smaller spatial scales than previously comprehended, considering wide distribution range many morphologically defined macroalgal species. However, knowledge turf-forming red alga Caulacanthus is incomplete regarding its species diversity, as well within genus. We analyzed specimens from NW Pacific, NE Central SW SE Indian, Atlantic, Atlantic Ocean using mitochondrial cytochrome oxidase subunit I (COI-5P), plastid ribulose-1,5-bisphosphate carboxylase/oxygenase ( rbc L), Rubisco spacer L-S). The objectives this study were to 1) determine exhibit morphology C. ustulatus , 2) investigate present pattern species, 3) estimate degree connectivity between populations different regions. Our results revealed molecular evidence genus comprises at least seven with deep divergence, which indicative not only a strong geographical subdivision but also relatively long temporal discontinuity. Most exhibited limited geographic distribution, showing considerable divergence isolated by distance. provides greater evolutionary independence populations, undergone series allopatric diversification events.