Morpho-anatomical, and chemical characterization of some calcareous Mediterranean red algae species

• Published in: Botanical studies 2023-04, Vol.64 (1), p.10-10, Article 10
• Main Authors: Ismail, Mona M., Ismail, Gehan A., Elshobary, Mostafa E.
• Format: Article
• Language: English
• Subjects: 18S rRNA gene; Abundance; Algae; Amphiroa rigida; Aragonite; Autumn; Biomarkers; Biomedical and Life Sciences; Calcification; Calcite; Calcium carbonate; Calcium oxalate; Calcium signalling; Carbohydrates; Carbonates; Carotenoids; Chemical analysis; Chemical composition; Chlorophyll; Climate change; Corallina officinalis; Correlation analysis; Ecology; Environmental assessment; Geographical distribution; Global climate; Indigenous species; Jania rubens; Life Sciences; Lipids; Morphology; Nutrients; Original; Original Article; Phycobiliproteins; Physiochemical parameters; Pigments; Plant Genetics and Genomics; Plant Sciences; Proteins; Proximate contents; Rhodophyta; rRNA 18S; Sea level rise; Seasonal variations; Seasons; Seawater; Seaweeds; Species diversity; Summer; Systematics; Threatened species; Tidal waves; Water analysis
• ISSN: 1817-406X; 1999-3110; 1999-3110
• DOI: 10.1186/s40529-023-00373-0

Climatic changes are anticipated to have a detrimental effect on calcifying marine species. Calcareous red algae may be especially vulnerable to seasonal variations since they are common and essential biologically, but there is little research on the morpho-anatomical, and chemical characterization of such species. This study conducted the seasonal investigation of the three dominant Mediterranean calcified red algae. Morphological and 18S rRNA analysis confirmed the identification of collected species as Corallina officinalis, Jania rubens, and Amphiroa rigida . In general, C. officinalis was represented in the four seasons and flourishing maximum in autumn (70% of total species individuals). While J. rubens species was represented in winter, autumn, and spring and completely absent in summer. A. rigida was abundant only in the summer season by 40%. A full morphological and anatomical description of these species were examined, and their chemical compositions (carbohydrate, protein, lipid, pigments, and elements content) were assessed in different seasons, where carbohydrates were the dominant accumulates followed by proteins and lipids. Pearson correlation analysis confirmed a positive correlation between salinity level and nitrogenous nutrients of the seawater with the pigment contents (phycobiliproteins, carotenoids, and chlorophyll a) of the studied seaweeds. The results proved that calcified red algae were able to deposit a mixture of calcium carbonates such as calcite, vaterite, calcium oxalate, calcite-III I calcium carbonate, and aragonite in variable forms depending on the species. Highlights The abundance and diversity of the Rhodophyta species are threatened by global climate changes, rising sea levels, and stronger tidal waves. Shoreline hardening had direct impacts on the abundance and distribution of native species. Calcified species can be used as biomarker species for assessing climate changes. The morphological and 18S rRNA analysis confirmed the identified species. Only three species of red calcified algae viz. Corallina officinalis, Jania rubens, and Amphiroa rigida were recorded during seasons of autumn 2019−summer 2020.