Abstract Halophila stipulacea is a dioecious seagrass that colonised the Mediterranean basin probably following the opening of the Suez Canal in 1869. We investigated its occurrence in the southern Mediterranean. This was done by conducting targeted surveys in two countries (Tunisia and Libya) and compiling existing information from former research. Four new meadows of H. stipulacea were found in the study area: Al-wahesh Lagoon and Tobrouk Bay in Libya, and Kerkennah Island-Allama and Cap Monastir in Tunisia. The new record in Cap Monastir (Tunisia) documents a displacement of approximately 150 km north of the previous limit of H. stipulaceain the southern Mediterranean, which probably represents the westernmost extension of H. stipulacea’s distribution 3000 km west along the coast from the site of first colonisation at the mouth of the Suez Canal in Port Said. In the Cap Monastir meadow, the shoot density (±SD) was 9900±3509 m-2and the leaf area index was 3.15±0.5 m2 m-2. In Libya, a small meadow of H. ...
Yassine Ramzi Sghaier; Rym Zakhama-Sraieb; Ibrahem Benamer; Faouzia Charfi-Cheikhrouha
Abstract We report for the first time a range extension of Mesophyllum engelhartii to the eastern Pacific Ocean. We focus on the Gulf of California, where samples were collected in Punta Perico at a depth of 30 m. Tetrasporangial and gametangial materials were found. The material clearly ha ... mehr
Abstract To test the postulate that diatom assemblage structures differ between those growing on macroalgae and those on rocks used as substratum by macroalgae, we analyzed 29 samples of macroalgae and 15 of rocky substrata from localities in Bahía de La Paz, México. Assemblage structure wa ... mehr
Abstract This paper is written in honour of the influential career of Professor T.J. Smayda. It celebrates the brief, but productive, period in which we collaborated on the formulation of the principles and mechanisms of community assembly in plankton. The topics considered then provide the ... mehr