Introduction of a New Potential Invader into the Mediterranean Sea: The Indo-PacificAvrainvillea amadelpha(Montagne) A. Gepp & E.S. Gepp (Dichotomosiphonaceae, Ulvophyceae)

Abstract

The Indo-Pacifics pecies Avrainvillea amadelpha (Montagne) A. Gepp &E .S. Gepp is reported for the first time from the Mediterranean Sea (Kerkennah Islands, Tunisia). The species is considered as introduced and invasive in the Hawaiian Archipelago. The Mediterranean specimens are studied and the reproductive structures are described and illustrated here for the first time.The possible origins and vectors of this introduction and the risk of propagation of the species in the MediterraneanS ea are discussed. Avrainvillea amadelpha /U lvophyceae /T unisia /M editerranean /I ntroduced species / Invasive species Résumé-L'espèce Indo-Pacifique Avrainvillea amadelpha (Montagne) A. Gepp &E.S. Gepp, est signaléep our la première fois en Méditerranée(Iles Kerkennah, Tunisie). L'espèce est considéréec omme introduite et invasive dans l'archipel Hawaiien. Les spécimens méditerranéens sont étudiése tl es organes reproducteurs sont décrits et illustrésp our la première fois. Les origines et les vecteurs possibles de cette introduction sont discutés, ainsi que les risques de propagation de l'espèce en Méditerranée.

A new record of Avrainvillea cf. erecta (Berkeley) A. Gepp & E. S. Gepp (Bryopsidales, Chlorophyta) from urbanized estuaries in the Hawaiian Islands

“…Given that A. erecta was originally described from specimens collected from 15-36 m (Gepp and Gepp 1911), and additional records indicate that this species is also common in the intertidal to shallow subtidal (Natural History Museum 2017), this new record for the Hawaiian Islands is of serious concern, especially considering the prevalence and impacts of “ A. amadelpha ” in Hawai‘i and the “ A. amadelpha ” recently recorded in the Mediterranean Sea (Verlaque et al 2017). “ A. amadelpha ” now inhabits the intertidal, subtidal, and mesophotic environments in Hawai‘i (Spalding 2012), and is considered invasive (Peyton 2009, Cox et al 2017), altering the benthic ecosystem (Martinez et al 2009), and competing with native species (Peyton 2009).…”

“…Thus, throughout the manuscript this species will be referred to provisionally as “ A. amadelpha ”. Interestingly, an invasive alga identified as " A. amadelpha " was recently recorded in the Mediterranean as well (Verlaque et al 2017). …”

New records of benthic marine macroalgae from the Caribbean coast of Costa Rica

“…A. amadelpha is currently a highly successful invasive species in Hawaii, competing with native species such as Halophila hawaiiana Doty & B. C. Stone, 1966(Smith, Hunter, & Smith, 2002. Recently, A. amadelpha was first recorded in the Mediterranean Sea (Verlaque, Langas, Hmida, Pergent, & Pergent, 2017). The proliferation of this Avrainvillea mats have shown effects on the above-ground polychaete communities (Magalhães & Bailey-Brock, 2014).…”

Progress in Mediterranean bioinvasions two years after the Suez Canal enlargement

“…This alga was common and was growing gregariously in colonies, between 20-22 m depth, in sunny places (sub-horizontal substrates), in Cymodocea nodosa (Ucria) Ascherson meadows, Posidonia oceanica beds, on dead mattes of P. oceanica meadows and coarse sand bottoms (VERLAQUE et al, 2017).…”