Adaptive Traits of Bloom Forming Sphaerospermopsis aphanizomenoides in a Mediterranean Ramsar Wetland: Morphology, 16S Phylogeny and Nutrient/Light Responses

ZELLAL, Aicha; LAMARA, Sid-Ahmed Chawki; ABI-AYAD, Sidi Mohammed El-Amine

doi:10.21608/ejabf.2025.433779.6830

Adaptive Traits of Bloom Forming Sphaerospermopsis aphanizomenoides in a Mediterranean Ramsar Wetland: Morphology, 16S Phylogeny and Nutrient/Light Responses

Document Type : Original Article

Authors

¹ Department of Biotechnology, University of Oran1 , Faculty of Natural Sciences and Life, Algeria

² Department of Biotechnology. University of Oran 1, Faculty of Natural Sciences and Life.

³ fDepartment of Biotechnology. University of Oran1, Faculty of Natural Sciences and Life.

10.21608/ejabf.2025.433779.6830

Abstract

Sphaerospermopsis aphanizomenoides is an invasive cyanobacterial species recently detected in the Macta Marshes, a Ramsar-listed wetland in northwestern Algeria recognized for its ecological importance to Mediterranean biodiversity. In recent years, this area experienced advanced eutrophication affecting numerous watercourses and small lakes. The present study provides a morphological, molecular and physiological characterization of S. aphanizomenoides strain isolated from a summer bloom in the marshes, where chlorophyll a concentration reached 141.6µg/l, indicating an eutrophic aquatic ecosystems with high phytoplankton biomass. Morphological identification supported by 16SrDNA gene sequencing confirmed the species identity. Physiological assays revealed that the strain can grow in nitrate-free media, whereas phosphate limitation significantly reduced its development. Moreover, the ability of the strain to grow under complete darkness highlights its adaptive strategies to low light conditions. These findings demonstrate the remarkable adaptability of Sphaerospermopsis aphanizomenoides and its potential role in algal blooms, underscoring the need for further research into its ecological impact and proliferation mechanisms.

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