Molecular data suggest a hybrid origin for the invasive Caulerpa racemosa (Caulerpales, Chlorophyta) in the Mediterranean Sea

2002 ◽  
Vol 15 (1) ◽  
pp. 122-133 ◽  
Author(s):  
C. Durand ◽  
M. Manuel ◽  
C. F. Boudouresque ◽  
A. Meinesz ◽  
M. Verlaque ◽  
...  
2020 ◽  
Vol 63 (6) ◽  
pp. 527-535
Author(s):  
Donatella Serio ◽  
Giovanni Furnari ◽  
Yola Metti

AbstractIt was noted that Mediterranean specimens collected at different stations from around Sicily, Italy and referred to as Laurencia dendroidea (as Laurencia majuscula) were similar to the recently described species Laurenciella marilzae. Presented in this study are the results of an integrative approach using both morphology and molecular data (COI-5P + rbcL) to establish which taxon these specimens should be referred to. Molecular analyses show these specimens belong to Laurenciella, and strongly suggest they are within the species L. marilzae. Morphological examinations of these Mediterranean specimens were also detailed and found to support the conclusion that they belong to L. marilzae.


2017 ◽  
Vol 65 (3) ◽  
pp. 1022 ◽  
Author(s):  
Fernando Gómez ◽  
Dajun Qiu ◽  
Rubens M. Lopes ◽  
Senjie Lin

Ostreopsis cf. ovata is a toxic epiphytic dinoflagellate widely distributed in warm waters that often co-occur with species of the genera Coolia, Fukuyoa, Gambierdiscus and Prorocentrum. We investigated a strain isolated from the coast of Ubatuba, Brazil (South-West Atlantic Ocean) by light and epifluorescence microscopies; we also report molecular data based on the LSU rDNA and ITS markers. Cells were 35-65 µm in the dorso-ventral diameter and 20-40 µm wide. We obtained the sequence of a ~1900 base pair region of the rRNA gene cistron. In the LSU rDNA phylogeny, the sequences under the names O. ovata and O. cf. ovata branched into three clades. The ITS marker showed greater resolving power and the sequences of O. ovata/O. cf. ovata split into five clades. Our ITS sequence branched in a clade with sequences of strains from the Mediterranean Sea, European Atlantic coasts, subtropical NE Atlantic, other sequences from Brazil at Rio de Janeiro, and a few sequences from Japan. The cell dimensions and thecal plate arrangement were under the variability range reported in other ocean regions. Our observations confirm O. cf. ovata as the most commonly recorded species of Ostreopsis in the SW Atlantic Ocean. Ostreopsis cf. ovata co-occurred with Coolia malayensis in Brazil and Asia, but it has been commonly reported from the Mediterranean Sea, where C. malayensis has not yet been recorded; while Coolia malayensis has been reported from the Caribbean Sea, but not O. ovata. With the current knowledge, it is difficult to understand the factors that determine the biogeography of the tropical epiphytic dinoflagellates. 


2020 ◽  
Vol 30 (4) ◽  
pp. 183-194
Author(s):  
Irina A. Ekimova ◽  
Tatiana I. Antokhina ◽  
Dimitry M. Schepetov

Flabellina rubrolineata was believed to have a wide distribution range, being reported from the Mediterranean Sea (non-native), the Red Sea, the Indian Ocean and adjacent seas, and the Indo-West Pacific and from Australia to Hawaii. In the present paper, we provide a redescription of Flabellina rubrolineata, based on specimens collected near the type locality of this species in the Red Sea. The morphology of this species was studied using anatomical dissections and scanning electron microscopy. To place this species in the phylogenetic framework and test the identity of other specimens of F. rubrolineata from the Indo-West Pacific we sequenced COI, H3, 16S and 28S gene fragments and obtained phylogenetic trees based on Bayesian and Maximum likelihood inferences. Our morphological and molecular results show a clear separation of F. rubrolineata from the Red Sea from its relatives in the Indo-West Pacific. We suggest that F. rubrolineata is restricted to only the Red Sea, the Arabian Sea and the Mediterranean Sea and to West Indian Ocean, while specimens from other regions belong to a complex of pseudocryptic species.


2020 ◽  
Vol 71 (4) ◽  
pp. 518 ◽  
Author(s):  
Douglas Bearham ◽  
Myrto Robert ◽  
Jennifer A. Chaplin ◽  
Glenn I. Moore ◽  
David V. Fairclough ◽  
...  

The discovery and identification of species is fundamental to the documentation, conservation and management of biodiversity. The taxonomy of the antitropical Pseudocaranx dentex complex (Carangidae) is confused and inconsistently reported. Previous morphological analyses concluded that this complex consisted of three species, namely P. sp. ‘dentex’, P. georgianus and P. dinjerra, in Australian waters. This study used genetic (COI sequence) and morphological data to evaluate the validity of this conclusion. The COI data showed the presence of three discrete lineages within this complex, which appear to correspond to the above-mentioned three species. They also suggested that P. sp. ‘dentex’ is closely related to, and possibly the same species as, P. dentex from southern Africa and the Mediterranean Sea. Also, the extent of morphological and geographical overlap between P. georgianus and P. dinjerra was greater than previously documented which, uncorrected, could lead to identification errors and present challenges for monitoring and management of harvested stocks of these species. By answering important taxonomic questions, our results will facilitate the proper interpretation of the results of past studies and the design of future studies of the P. dentex complex. They have also highlighted the value of molecular data for identifying species in morphologically conservative taxa.


Author(s):  
F. Crocetta ◽  
P. Mariottini ◽  
D. Salvi ◽  
M. Oliverio

The Mediterranean Sea is currently under siege by a conspicuous alien pressure, and, within some families (e.g. the Ostreidae), the number of native species seems to be remarkably outnumbered by that of the alien ones. We wanted to test the reliability of the molecular data currently available on the small alien oysters recently invading the Mediterranean Sea. Samples from Greece and Turkey, encompassing the known species-specific morphological variation, were sequenced for the markers with the widest taxonomic coverage in the group of small oysters (i.e. the 16S rDNA and the COI). The sequences obtained have been compared with those available in GenBank, and a possible identification at the species level has been finally tested in a DNA-barcoding fashion. The present results clearly demonstrated that our samples belong to a single, morphologically highly variable species. Their 16S sequences were closely related to a sequence registered under the name Dendostrea folium, with a genetic distance which does not warrant conspecificity. Additionally, a remarkable number of sequences retrieved from the GenBank (of both genes) did not form a monophyletic group according to the published classification of the vouchers, suggesting—at least in part—an origin from specimens not properly identified. Both genes seem promising for use as DNA-barcode, although the COI will probably prove more effective. Therefore, we urge the availability of a baseline of oyster pedigreed DNA barcode sequences in the public databases, to allow the use of such genetic data to reliably monitor bio-invasions in the Mediterranean Sea.


2012 ◽  
Vol 13 (1) ◽  
pp. 126 ◽  
Author(s):  
L. CAVAS ◽  
S. CENGIZ ◽  
Z. ABIDIN KARABAY

Caulerpa racemosa var.cylindracea (C.racemosa) is an invasive marine seaweed in the Mediterranean Sea. Since no valid eradication method has been existed in the scientific literature on this species, it has currently been continuing its invasion along the coastlines of 13 Mediterranean countries. One of the important factors responsible for its invasion is thought as its toxic secondary metabolite, caulerpenyne (CYN). The present paper investigates seasonal changes in the secondary metabolite CYN, and rubisco enzyme (EC 4.1.1.39) activities of the invasive C. racemosa and native C. prolifera. Inasmuch as no correlation between CYN level and rubisco enzymic activity was observed in these species, it is considered that the regulation of CYN synthesis caulerpenyne and rubisco enzymic activity might be controlled independently. In conclusion, the further analysis on the rubisco enzymic activity determinations with MEP and mevalonate pathway which are considered responsible for CYN bio-synthesis should be studied in great detail in invasive and native Caulerpa species in the Mediterranean Sea to get the overall picture.


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