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We provide an account of two newly recorded non-indigenous tropical seaweed species, Siphonocladus tropicus (Cladophorales, Chlorophyta) and Caulerpa integerrima (Caulerpaceae, Chlorophyta), from the northern and central Levantine Mediterranean shores of Israel. Reports are supported by morphological and molecular evidence. The new record of C. integerrima, thought to be endemic to the Red Sea, increases the number of non-indigenous Caulerpa species in the Mediterranean Sea to eight. Siphonocladus tropicus, a widespread tropical species, is also being reported from the northern Red Sea. Furthermore, morphological comparison of populations from the northern Red Sea and the Levantine Mediterranean shore of Israel revealed that there might be a regional variant or form of this species in the northern Red Sea and might indicate that this new invader does not necessarily originate from the Red Sea. The increasingly tropical conditions in the eastern Levantine Sea as a result of global warming probably paved the way for the establishment of both species in the region. Aspects of the new invaders' ecology in the Israeli Levantine Sea, the possible vectors of introduction and origins, as well as the status of other Caulerpa species from both Levantine and Red Sea shores, are discussed. Siphonocladus tropicus and Caulerpa integerrima are new non-native species found lately in the Mediterranean Sea. Caulerpa integerrima originated from the Red Sea whereas the origin of Siphonocladus tropicus is uncertain. The introduction of these two alien species, especially Caulerpa integerrima, might pose a threat to the local marine flora and fauna. [ABSTRACT FROM AUTHOR]

The minute red alga Crouania pumila (Callithamniaceae: Rhodophyta), recently described from the Caribbean Sea, is reported for the first time from the Red Sea, approximately 12,000 km from the type locality, based on microscope slide specimens collected 40 years ago by Dr. Yaacov Lipkin. These samples contribute new information regarding the reproduction of this algal species. [ABSTRACT FROM AUTHOR]

Calliblepharis rammediorum sp. nov. (Gigartinales, Rhodophyta) is described from the northern Levant Mediterranean shore of Israel. The new species has a prostrate creeping habit. It usually grows as an epiphyte, strongly attached by several discoidal holdfasts to the base of branches of some seaweed species, mainly on some non-native species and particularly on Laurencia chondrioides. Phylogenetic analyses of sequence data indicate that C. rammediorum is closely related to an unidentified species from the Cocos (Keeling) Islands, Australia. These two are sister to a complex of two genetic groups both assigned to the morphospecies Calliblepharis fimbriata, whose species identity clearly requires further research. Calliblepharis rammediorum is the fourth that is newly described for the genus Calliblepharis since the beginning of the last decade. Aspects of its biology and ecology are also discussed. [ABSTRACT FROM AUTHOR]

Codium pulvinatum sp. nov. (Bryopsidales, Chlorophyta) is described from the southern shores of Oman and from the Mediterranean shore of Israel. The new species has a pulvinate to mamillate-globose habit and long narrow utricles. Molecular data from the rbcL gene show that the species is distinct from closely related species, and concatenated rbcL and rps3-rpl16 sequence data show that it is not closely related to other species with similar external morphologies. The recent discovery of well-established populations of C. pulvinatum along the central Mediterranean coast of Israel suggests that it is a new Lessepsian migrant into the Mediterranean Sea. The ecology and invasion success of the genus Codium, now with four alien species reported for the Levantine Sea, and some ecological aspects are also discussed in light of the discovery of the new species. [ABSTRACT FROM AUTHOR]

We provide the first detailed description of the tetrasporophyte of the red algal speciesMonosporus indicusBørgesen (Wrangeliaceae, Ceramiales) and its first record from the Mediterranean Sea. This prostrate, filamentous epiphytic species, which has been recorded from tropical and subtropical locations in the Indian, Pacific and Atlantic Oceans, has invaded and established healthy populations in the warm Levant Mediterranean Sea of Israel. Plants invariably have propagules and are rarely observed with tetrasporangia. With the description of tetrasporangia inM. indicus, doubt is cast on the integrity of the genusDesikacharyellabecause their presence as well as sexual reproduction was used to separate that genus fromMonosporus. [ABSTRACT FROM AUTHOR]

Evidence is presented that the marine macroalga Pseudobryopsis papillata Nasr (Bryopsidaceae, Chlorophyta), described by Nasr in 1944 from the Red Sea, is conspecific with the Mediterranean generitype Pseudobryopsis myura (J. Agardh) Berthold in Oltmanns. Although Ps. myura was originally depicted as having non-papillate gametangia, recent and past collections of this species in the Mediterranean clearly show papillate gametangia, thus erasing the primary reason for distinguishing it from Red Sea populations. In addition, similar branch patterns and thallus lengths support the synonymization of these two species. [ABSTRACT FROM AUTHOR]

The occurrence of the red algal species Hypoglossum caloglossoides (Delesseriaceae, Ceramiales) is reported for the first time from shallow sub-littoral sites in both the Mediterranean Sea and the Red Sea. This small but morphologically distinctive species, originally described from Lord Howe Island in the southwestern South Pacific Ocean, has been recorded from scattered tropical and subtropical locations around the globe. Some aspects of its ecology in the north Israeli Mediterranean are also discussed. [ABSTRACT FROM AUTHOR]

The Mediterranean coast of Israel is well known as a hotspot of invasive marine species, mostly from the Indian and Pacific oceans. Here, we report the first occurrence of the red seaweed Laurencia chondrioides in the eastern Mediterranean Sea. Large quantities of this species were observed in the algal drift on the sandy shores as well as on rocky surfaces of the upper and middle infralittoral zone. This highly abundant invasive species, present along the northern shore of Israel, represents a serious threat to the local marine flora. Some aspects of its ecology and invasive behavior in this region are also discussed. [ABSTRACT FROM AUTHOR]

Since the beginning of the 21st century, the Mediterranean shores of Israel have experienced invasions of several alien Indo-Pacific seaweed species. This phenomenon has been observed mainly on the northern Israeli Mediterranean shore, particularly near the port of Haifa. Here we report and discuss the first record of the common Indo-Pacific seaweed Codium arabicum from the Mediterranean Sea, namely, from the Levant coast of Israel. This macroalga was first identified morphologically, and the determination later confirmed by molecular techniques using two plastid DNA sequences: rbcL exon 1 and rps3- rpl16. High water temperatures for most of the year and free habitat space appear to facilitate the successful settlement and establishment of this species, as has been the case for hundreds of other invasive Indo-Pacific organisms along the Israeli Mediterranean shore. [ABSTRACT FROM AUTHOR]

Effective monitoring of non-indigenous seaweeds and combatting their effects relies on a solid confirmation of the non-indigenous status of the respective species. We critically analysed the status of presumed non-indigenous seaweed species reported from the Mediterranean Sea, the Northeast Atlantic Ocean and Macaronesia, resulting in a list of 140 species whose non-indigenous nature is undisputed. For an additional 87 species it is unclear if they are native or non-indigenous (cryptogenic species) or their identity requires confirmation (data deficient species). We discuss the factors underlying both taxonomic and biogeographic uncertainties and outline recommendations to reduce uncertainty about the non-indigenous status of seaweeds. Our dataset consisted of over 19,000 distribution records, half of which can be attributed to only five species (Sargassum muticum, Bonnemaisonia hamifera, Asparagopsis armata, Caulerpa cylindracea and Colpomenia peregrina), while 56 species (40%) are recorded no more than once or twice. In addition, our analyses revealed considerable variation in the diversity of non-indigenous species between the geographic regions. The Eastern Mediterranean Sea is home to the largest fraction of non-indigenous seaweed species, the majority of which have a Red Sea or Indo-Pacific origin and have entered the Mediterranean Sea mostly via the Suez Canal. Non-indigenous seaweeds with native ranges situated in the Northwest Pacific make up a large fraction of the total in the Western Mediterranean Sea, Lusitania and Northern Europe, followed by non-indigenous species with a presumed Australasian origin. Uncertainty remains, however, regarding the native range of a substantial fraction of non-indigenous seaweeds in the study area. In so far as analyses of first detections can serve as a proxy for the introduction rate of non-indigenous seaweeds, these do not reveal a decrease in the introduction rate, indicating that the current measures and policies are insufficient to battle the introduction and spread of non-indigenous species in the study area. Non-indigenous seaweed species in the Northeast Atlantic Ocean, the Mediterranean Sea and Macaronesia are critically reanalysed. > 19,000 distribution records revealed considerable variation in diversity of non-indigenous seaweed species in the study area. Taxonomic and biogeographic uncertainties hamper a critical evaluation of the non-indigenous status of many seaweed species. [ABSTRACT FROM AUTHOR]

Of the 452 multicellular non-indigenous species (NIS) recorded off the Israeli Mediterranean coast, nearly 90% are considered to have been introduced through the Suez Canal (Erythraean NIS). The Israeli shelf serves as an important way station and breeding ground for Erythraean NIS, with 260 and 91 species already recorded in the greater Levant Sea and Central Mediterranean, respectively. The positive relationship between time since first record and spread indicates that Erythraean NIS populations may not be at equilibrium and are likely to spread further. Thus, the greater NIS numbers recorded in the past half century augur a sizable invasion debt. A review of the policy of the State of Israel concerning marine NIS, as reflected in recent official documents and regulations, reveals how these enhance their establishment, proliferation and spread in Israeli waters and in waters under the jurisdiction of other Mediterranean States. The continued role of the enlarged Suez Canal as corridor for invasion, and the increasing temperature of Mediterranean seawater, portend unceasing propagule pressure and likely rising establishment success of species not yet introduced. Recognition that factors driving the introduction and establishment of marine NIS are increasing, and the large-sized accrued invasion debt, impel us to urge the Contracting Parties to Barcelona Convention to undertake prevention and control measures to curb marine introductions into the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Marine representatives of Phytomyxea (SAR: Rhizaria: Endomyxa), a peculiar class of obligate endobiotic parasites, are a greatly understudied ecological group of protists infecting many algal, diatom, and seagrass species. Very little is known about the actual diversity, ecology, and pathogenic potential of these organisms and their taxonomic treatment in many cases follows outdated morphotaxonomic concepts. Here we focused on resolving the phylogenetic relations of the phytomyxean parasites of the widespread seagrass genus Halophila. We report the first finding of Plasmodiophora halophilae, the parasite of ovate-leaf Halophila species, after more than 100 years since its original description in 1913. We provide additional information on its anatomy, morphology, distribution, and host range, together with a phylogenetic evidence that it is congeneric with the recently rediscovered species infecting the invasive seagrass Halophila stipulacea in the Mediterranean Sea. Despite the previously hypothesized affiliation of the latter to Tetramyxa, our phylogenetic analyses of the 18S rRNA gene place Tetramyxa parasitica (a parasite of brackish water phanerogams and the type species of the genus) in the freshwater/terrestrial phytomyxean order Plasmodiophorida and reveal that phytomyxids associated with Halophila spp. form a separate deep-branching clade within the class proposed here as Marinomyxa gen. nov. We further argue that M. marina infecting H. stipulacea is most likely a species-specific parasite and implies their comigration through the Suez Canal. [ABSTRACT FROM AUTHOR]

After publication of the above mentioned article, previously undisclosed material was made available resulting in an altered population status for the below mentioned species: [ABSTRACT FROM AUTHOR]

After publication of the above mentioned article, previously undisclosed material was made available resulting in an altered population status for the below mentioned species: [ABSTRACT FROM AUTHOR]

Paracaprella pusilla Mayer, 1890 is a tropical caprellid species recently introduced to the Eastern Atlantic coast of the Iberian Peninsula and the Mediterranean Sea. In this study, we used direct sequencing of mitochondrial (COI and 16S) and nuclear (28S and ITS) genes to compare genetic differences in presumed native and introduced populations in order to infer its introduction pattern and to shed light on the native range of this species. The temporal pattern of genetic diversity at the westernmost limit of the geographic range of P. pusilla in Europe (the Atlantic coast of southern Spain) over an eight-year period was also investigated. Our results confirm P. pusilla as a neocosmopolitan species and suggest that the species is native to the Atlantic coast of Central and South America. Paracaprella pusilla seems to have been introduced into European waters from multiple introduction pathways and source populations, which are likely to include populations from coastal waters of Brazil. Multiple introduction pathways may have been involved, with the most important being commercial shipping through the Strait of Gibraltar. While this tropical species appears to be expanding in the Mediterranean, populations from the westernmost limit of its geographic range in Europe showed a temporal instability. This study constitutes the first molecular approach focused on this species, but it is also the first study of temporal change in genetic diversity of any introduced marine amphipod. Additional intensive sampling of this species, including both native and non-native populations, and detailed temporal studies are still necessary to properly understand how genetic diversity influences the introduction and survival of P. pusilla in invaded areas. [ABSTRACT FROM AUTHOR]