Caulerpa taxifolia var. distichophylla: a further stepping stone in the western Mediterranean

Mariagrazia Picciotto,Salvatore Giacobbe,Nunziacarla Spanò,Clara Bertuccio

doi:10.1186/s41200-016-0038-1

Abstract

In the Mediterranean sea, about 150 species of invasive macroalgae are recorded until now these alien species have produced serious effect due to their capability to modify the physical and chemical property of the invaded habitats and to compete with native assemblages so as threatening the biodiversity and the ecosystem functioning. Based on morphological characters, the invasive green alga Caulerpa taxifolia var. distichophylla, has been recognised for the first time in the Strait of Messina area, off the northeastern coast of Sicily (Tyrrhenian Sea, western Mediterranean). This record confirms the rapid spread of this taxon from the Levantine area towards the western basins, and suggests a human-mediated dispersion. The new invader occurs in different habitats than C. taxifolia (Vahl) C. Agardh, and the respective habitats do not overlap in the Strait of Messina. A previously undescribed association of this species with tropical–subtropical phanerogams and green algae, is a further example of the global change-mediated reorganisation of Mediterranean benthic assemblages. This record expands the known distribution range of this invasive green algae in Mediterranean Sea.

Highlights

In the Mediterranean sea, about 150 species of invasive macroalgae are recorded until now these alien species have produced serious effect due to their capability to modify the physical and chemical property of the invaded habitats and to compete with native assemblages so as threatening the biodiversity and the ecosystem functioning
Agardh, which is not invasive in tropical regions, is known in the Mediterranean as an invasive lineage, the so called “aquarium strain”, which spreads on a variety of substrata and forms dense beds (Meinesz et al 1993) that represent a threat to benthic assemblages (Villele & Verlaque, 1995; Ceccherelli & Cinelli, 1997; Piazzi et al, 2001)
This paper reports the occurrence of C. taxifolia var. distichophylla from the northern borders of the Messina Strait, a crucial area in the spread of introduced species, since it directly connects the western and eastern basins

Summary

Introduction

In the Mediterranean sea, about 150 species of invasive macroalgae are recorded until now these alien species have produced serious effect due to their capability to modify the physical and chemical property of the invaded habitats and to compete with native assemblages so as threatening the biodiversity and the ecosystem functioning. The spread of green algae belonging to the genus Caulerpa in the Mediterranean is considered one of the most important examples of biological invasion in recent years (Verlaque et al, 2004; Piazzi et al, 2005). Since the first Mediterranean report in 1984, C. taxifolia has rapidly colonised very large areas of the Ligurian and Tyrrhenian Seas (Meinesz et al, 2001) and has developed a major centre of diffusion in the Strait of Messina (Orestano et al 2001). Distichophylla from the northern borders of the Messina Strait, a crucial area in the spread of introduced species, since it directly connects the western and eastern basins. This paper reports the occurrence of C. taxifolia var. distichophylla from the northern borders of the Messina Strait, a crucial area in the spread of introduced species, since it directly connects the western and eastern basins.

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