Morphology and vegetative reproduction of the introduced species Hypnea cornuta (Rhodophyta, Gigartinales) in the Mar Piccolo of Taranto (Italy), Mediterranean Sea

2004 ◽  
Vol 47 (5) ◽  
Author(s):  
Ester Cecere ◽  
Antonella Petrocelli ◽  
Marc Verlaque
Keyword(s):  
Mediterranean Sea ◽  
Introduced Species ◽  
Vegetative Reproduction ◽  
Mar Piccolo Of Taranto

Spatial and seasonal distribution of ascidians in a semi-enclosed basin of the Mediterranean Sea

2008 ◽  
Vol 88 (5) ◽  
pp. 1053-1061 ◽  
Author(s):  
F. Mastrototaro ◽  
G. D'Onghia ◽  
A. Tursi
Keyword(s):  
Mediterranean Sea ◽  
Marine Pollution ◽  
Ciona Intestinalis ◽  
Abundant Species ◽  
Artificial Substrates ◽  
Larval Recruitment ◽  
Styela Plicata ◽  
Mar Piccolo Of Taranto ◽  
The Mediterranean ◽  
Shallow Water Species

A total of 25 species of ascidians were collected in the Mar Piccolo of Taranto, a semi-enclosed Mediterranean basin. Three are non-indigenous for the Mediterranean Sea: Microcosmus squamiger, Polyandrocarpa zorritensis and Distaplia bermudensis. The substrate features, season and depth affect the distribution of ascidians in the study area. Some species, such as Pyura dura and Pyura microcosmus, were found only on artificial substrates, while Ascidiella aspersa was almost exclusively recovered on natural bottoms. Seasonal variation in the ascidian distribution and abundance seems to be due mainly to their biological cycles, larval recruitment and adaptation. During the autumn and winter the most abundant species were Clavelina phlegraea and Ciona intestinalis, while A.aspersa was particularly abundant during spring. Depth and more directly light intensity play an important role in ascidian distribution. In the upper few metres the shallow-water species Polyandrocarpa zorritensis was abundant due to its photopositive larvae. Even though the distribution and abundance changed significantly between substrates, seasons and depths, the most abundant species in the Mar Piccolo of Taranto were Clavelina phlegraea, Ciona intestinalis and Styela plicata all of which are able to tolerate the variations in environmental conditions, low rate of water renewal and continuous silting of this semi-enclosed sea. Assuming the role that the above mentioned species have as marine pollution indicators and the abundance recorded for some of them, a high degree of environmental stress can be confirmed for the Mar Piccolo of Taranto. A comparative list of the ascidians recorded in this and previous studies is also reported.

scholarly journals Alien species in the Mediterranean Sea by 2010. A contribution to the application of European Union’s Marine Strategy Framework Directive (MSFD). Part I. Spatial distribution

2010 ◽  
Vol 11 (2) ◽  
pp. 381 ◽  
Author(s):  
A. ZENETOS ◽  
S. GOFAS ◽  
M. VERLAQUE ◽  
M.E. CINAR ◽  
J.E. GARCIA RASO ◽  
...  
Keyword(s):  
Alien Species ◽  
Mediterranean Sea ◽  
Introduced Species ◽  
Cold Water ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Marine Strategy Framework Directive ◽  
Central Mediterranean ◽  
Total Species Richness ◽  
The Mediterranean

The state-of-art on alien species in the Mediterranean Sea is presented, making distinctions among the four subregions defined in the EU Marine Strategy Framework Directive: (i) the Western Mediterranean Sea (WMED); (ii) the Central Mediterranean Sea (CMED); (iii) the Adriatic Sea (ADRIA); and (iv) the Eastern Mediterranean Sea (EMED). The updated checklist (December 2010) of marine alien species within each subregion, along with their acclimatization status and origin, is provided. A total of 955 alien species is known in the Mediterranean, the vast majority of them having being introduced in the EMED (718), less in the WMED (328) and CMED (267) and least in the Adriatic (171). Of these, 535 species (56%) are established in at least one area.Despite the collective effort of experts who attempted in this work, the number of introduced species remains probably underestimated. Excluding microalgae, for which knowledge is still insufficient, aliens have increased the total species richness of the Mediterranean Sea by 5.9%. This figure should not be directly read as an indication of higher biodiversity, as spreading of so many aliens within the basin is possibly causing biotic homogenization. Thermophilic species, i.e. Indo-Pacific, Indian Ocean, Red Sea, Tropical Atlantic, Tropical Pacific, and circum(sub)tropical, account for 88.4% of the introduced species in the EMED, 72.8% in the CMED, 59.3% in the WMED and 56.1% in the Adriatic. Cold water species, i.e. circumboreal, N Atlantic, and N Pacific, make up a small percentage of the introduced species, ranging between 4.2% and 21.6% and being more numerous in the Adriatic and less so in the EMED.Species that are classified as invasive or potentially invasive are 134 in the whole of the Mediterranean: 108 are present in the EMED, 76 in the CMED, 53 in the Adriatic and 64 in the WMED. The WMED hosts most invasive macrophytes, whereas the EMED has the lion’s share in polychaetes, crustaceans, molluscs and fish.

Competition and propagule density affect sexual and clonal propagation of a weed

2017 ◽  
Vol 10 (01) ◽  
pp. 17-25 ◽  
Author(s):  
Daniel Z. Atwater ◽  
Wonjae Kim ◽  
Daniel R. Tekiela ◽  
Jacob N. Barney
Keyword(s):  
Introduced Species ◽  
Vegetative Reproduction ◽  
Common Garden ◽  
Total Carbon ◽  
Invasive Grass ◽  
Total Carbon Content ◽  
Natural Processes ◽  
Trade Offs ◽  
Site Variation ◽  
Negative Density Dependence

Many introduced species are capable of both sexual and vegetative reproduction. Our understanding of the ecology of such species depends on the trade-offs between vegetative and sexual reproduction and the ecological conditions that favor both modes of reproduction and how those factors influence the population ecology of introduced species. Here, we studied the efficacy of propagation via both seeds and rhizomes in Johnsongrass, a widespread invasive grass whose success is due to its prolific production of shattering seeds and rhizomes, the latter of which are readily dispersed by anthropogenic and natural processes. In a common garden in Virginia, we varied the density of seeds and rhizomes and manipulated whether recruits experienced interspecific competition. Johnsongrass recruited from both seeds and rhizomes. We compared the efficacy of seeds and rhizomes on a per propagule basis and by standardizing them according to their total carbon content. Rhizomes were more efficient than seeds on a per propagule basis, but seeds propagated more efficiently than rhizomes on a per unit of carbon basis, establishing in nearly all plots and obtaining much greater biomass than rhizomes. We also found that rhizomes were subject to stronger negative density dependence than seeds and were more sensitive to site variation and competition. Our results suggest that, provided sufficient dispersal, a single Johnsongrass plant produces enough propagules to establish over more than a hectare, even at relatively low propagule densities. Proper understanding of both seed and vegetative propagation is crucial for understanding the ecology of this and other invasive species that utilize multiple reproductive modes.

scholarly journals Errata to the Review Article (Medit. Mar. Sci. 11/2, 2010, 381-493): "Alien species in the Mediterranean Sea by 2010. A contribution to the application of European Union’s Marine Strategy Framework Directive (MSFD). Part I. Spatial distribution"

2011 ◽  
Vol 12 (2) ◽  
pp. 509 ◽  
Author(s):  
A. ZENETOS ◽  
S. GOFAS ◽  
M. VERLAQUE ◽  
M.E. CINAR ◽  
J.E GARCIA RASO ◽  
...  
Keyword(s):  
Alien Species ◽  
Mediterranean Sea ◽  
Introduced Species ◽  
Cold Water ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Marine Strategy Framework Directive ◽  
Central Mediterranean ◽  
Total Species Richness ◽  
The Mediterranean

The state-of-art on alien species in the Mediterranean Sea is presented, making distinctions among the four subregions defined in the EU Marine Strategy Framework Directive: (i) the Western Mediterranean Sea (WMED); (ii) the Central Mediterranean Sea (CMED); (iii) the Adriatic Sea (ADRIA); and (iv) the Eastern Mediterranean Sea (EMED). The updated checklist (December 2010) of marine alien species within each subregion, along with their acclimatization status and origin, is provided. A total of 955 alien species is known in the Mediterranean, the vast majority of them having being introduced in the EMED (718), less in the WMED (328) and CMED (267) and least in the Adriatic (171). Of these, 535 species (56%) are established in at least one area.Despite the collective effort of experts who attempted in this work, the number of introduced species remains probably underestimated. Excluding microalgae, for which knowledge is still insufficient, aliens have increased the total species richness of the Mediterranean Sea by 5.9%. This figure should not be directly read as an indication of higher biodiversity, as spreading of so many aliens within the basin is possibly causing biotic homogenization. Thermophilic species, i.e. Indo-Pacific, Indian Ocean, Red Sea, Tropical Atlantic, Tropical Pacific, and circum(sub)tropical, account for 88.4% of the introduced species in the EMED, 72.8% in the CMED, 59.3% in the WMED and 56.1% in the Adriatic. Cold water species, i.e. circumboreal, N Atlantic, and N Pacific, make up a small percentage of the introduced species, ranging between 4.2% and 21.6% and being more numerous in the Adriatic and less so in the EMED.Species that are classified as invasive or potentially invasive are 134 in the whole of the Mediterranean: 108 are present in the EMED, 76 in the CMED, 53 in the Adriatic and 64 in the WMED. The WMED hosts most invasive macrophytes, whereas the EMED has the lion’s share in polychaetes, crustaceans, molluscs and fish.

How the unattached form of Acanthophora nayadiformis (Rhodophyta: Ceramiales) produces storage and perennating organs

2007 ◽  
Vol 87 (2) ◽  
pp. 389-392 ◽  
Author(s):  
Ester Cecere ◽  
Antonella Petrocelli ◽  
Cesira Perrone
Keyword(s):  
Mediterranean Sea ◽  
Growth Pattern ◽  
Structural Changes ◽  
Southern Italy ◽  
Morphological Features ◽  
Cortical Thickening ◽  
Free Living ◽  
Floridean Starch ◽  
Mar Piccolo Of Taranto ◽  
Vegetative Cycle

In the Mar Piccolo of Taranto (southern Italy, Mediterranean Sea), an enclosed basin with lagoonal features, Acanthophora nayadiformis is one of the major components of the free-living seaweed community to which the related attached population does not contribute consistently. Loose thalli of A. nayadiformis exhibit morphological features very different from those of the attached specimens and possess a peculiar vegetative cycle including an overwintering phase. Free-living morphs are characterized by monopodial stoloniferous growth; in contrast, both determinate and indeterminate branching as well as the typical ramisympodial growth pattern of the species are lacking. In autumn, free-living thalli fragment giving rise to stolon pieces which undergo deep structural changes in their sub-apical parts including both storage of floridean starch and extensive cortical thickening. Soon afterwards the uncorticated parts decay, whilst the modified fragments are able to overwinter and give rise to new fronds during next spring.

scholarly journals Settlement and Spreading of the Introduced Seaweed Caulacanthus okamurae (Rhodophyta) in the Mediterranean Sea

Diversity ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 129 ◽  
Author(s):  
Antonella Petrocelli ◽  
Marion A. Wolf ◽  
Ester Cecere ◽  
Katia Sciuto ◽  
Adriano Sfriso
Keyword(s):  
Mediterranean Sea ◽  
Venice Lagoon ◽  
Molecular Evidence ◽  
Bisphosphate Carboxylase ◽  
Tropical Regions ◽  
Intertidal Zones ◽  
Mar Piccolo Of Taranto ◽  
The Mediterranean ◽  
Ionian And Adriatic Seas ◽  
Introduced Seaweed

In this study, we report the first finding of the non-indigenous seaweed Caulacanthus okamurae (Rhodophyta) in the Ionian and Adriatic Seas (Mediterranean). Specimens were identified through molecular analyses based on the plastid ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) marker. The sequences obtained during this study represent the first molecular evidence of the presence of this taxon in the Mediterranean Sea. Stable populations have been detected in some areas of the Mar Piccolo of Taranto (Italy) and in the whole lagoon of Venice, forming dense patches of low turf that reach high biomasses. Turf-forming algae are common in the intertidal zones of tropical regions, but are rare in temperate ones. The particular environmental conditions of transitional water systems, such as the Mar Piccolo of Taranto and the Venice Lagoon, together with the water temperature increase observed in the last years could have favored the settlement and spread of this introduced species.

Evidence of a predation event on a tagged Mediterranean spearfish (Tetrapturus belone; Pisces, Istiophoridae), inferred from pop-up satellite tagging data

2020 ◽  
Vol 33 ◽  
pp. 23
Author(s):  
Danilo Malara ◽  
Pietro Battaglia ◽  
Pierpaolo Consoli ◽  
Erika Arcadi ◽  
Simonepietro Canese ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Research Group ◽  
Marine Mammals ◽  
Biodiversity Hotspot ◽  
Pelagic Species ◽  
Archival Tag ◽  
Abiotic Parameters ◽  
Predation Event ◽  
Satellite Tagging ◽  
First Time

The Strait of Messina is located at the centre of the Mediterranean Sea and is considered a biodiversity hotspot and an obligatory seasonal passage for different pelagic species such as sharks, marine mammals, and billfishes. For the first time, in the Strait of Messina, our research group tagged a Mediterranean spearfish (Tetrapturus belone) using a pop-up satellite archival tag (PSAT). The observation of abiotic parameters (depth, light, and temperature) recorded by the PSAT confirmed that the tagged specimen was predated after about nine hours. The tag was then regurgitated 14 days after the tag deployment date. The analysis of collected data seems to indicate that the predator may be an ectothermic shark, most likely the bluntnose sixgill shark (Hexanchus griseus).

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