First molecular analysis of the genus Bryopsis (Bryopsidales, Chlorophyta) from Brazil, with an emphasis on the Pernambuco coast

The green algal genus Bryopsis has simple morphology and high phenotypic plasticity, making it difficult to identify its species based on morphological characteristics alone. This study evaluated the diversity of Bryopsis in northeastern Brazil (the State of Pernambuco), based on morphological and molecular data using the markers tufA and rbcL. Molecular analyses were incongruent with morphology, demonstrating the existence of cryptic and polymorphic species in the genus. Of the four taxa cited for the area based only on morphological data (Bryopsis corymbosa, B. pennata, B. plumosa, Bryopsis sp.), only B. pennata was recorded. Typical specimens of B. pennata and B. plumosa were grouped with low genetic divergence, 0-0.21 % for tufA and no divergence for rbcL, indicating that B. pennata is an extremely plastic species that includes specimens with morphotype B. plumosa. Bryopsis pennata var. secunda is cited for the first time for northeastern Brazil, with divergence from the typical variety of 0.96-1.57 % for tufA and 0.4 % for rbcL. This study showed that broader sampling of Bryopsis is necessary in order to confirm the taxonomic status of the species referenced for Brazil, whose phenotypic plasticity may cause overestimation of diversity or reveal cryptic species.

Automated summary

This study evaluated the diversity of Bryopsis in northeastern Brazil using morphological and molecular data, finding incongruence between morphology and molecular analysis, indicating the presence of cryptic and polymorphic species in the genus. The research demonstrated that Bryopsis pennata is an extremely plastic species inclusive of specimens with morphotype B. plumosa, and also identified Bryopsis pennata var. secunda for the first time in northeastern Brazil.