Bathypolypus sponsalis (Cephalopoda: Octopoda) from the central western Mediterranean Sea

Author(s):  
D. Cuccu ◽  
M. Mereu ◽  
M.C. Follesa ◽  
A.M. Deiana ◽  
A. Cau

A sample of 360 Bathypolypus sponsalis from the central western Mediterranean Sea (the Sardinian Channel and the Tyrrhenian Sea) was analysed in order to describe size, depth distribution and reproductive data. The first record of the species in the Tyrrhenian Sea and of a spent female are reported in this paper. The size-structure of the sample was in between values of documented data from the western and eastern Mediterranean basins and the minimum mature sizes in both sexes and spermatophore length were similar to previous data from the eastern Mediterranean Sea. Low values of gonadosomatic index and fecundity, the asynchronous ovulation, in addition to an extended reproductive period, have been associated with an intermittent spawning strategy.

2014 ◽  
Vol 59 (1) ◽  
Author(s):  
Salvatore Mele ◽  
Maria Pennino ◽  
Maria Piras ◽  
José Bellido ◽  
Giovanni Garippa ◽  
...  

AbstractThe metazoan parasite assemblage of the head of 30 specimens of the Atlantic chub mackerel (Scomber colias) from the western Mediterranean Sea was analysed. Eight species of parasites were found, four mazocraeid monogeneans: Grubea cochlear (prevalence = 10%), Kuhnia scombercolias (59%), K. scombri (52%), Pseudokuhnia minor (86%); three didymozoid trematodes: Nematobothrium cf. faciale (21%), N. filiforme (41%), N. scombri (7%); and one laerneopodid copepod: Clavelissa scombri (7%). Results were compared with previously published data from 14 localities of the eastern Mediterranean Sea and the Atlantic Ocean, using non-parametric univariate and multivariate analyses, and the whole parasite fauna of S. colias was compared with that of the congeners (S. australasicus, S. japonicus and S. scombrus). Parasites showed to reflect the biogeographical and phylogenetic history of host. From a methodological point of view, the use of both non-parametric univariate and multivariate techniques proved to be effective tools to detect dissimilarities between parasite assemblages.


2014 ◽  
Vol 36 (1) ◽  
pp. 104-117 ◽  
Author(s):  
Daniela Giordano ◽  
Adriana Profeta ◽  
Barbara Busalacchi ◽  
Roberta Minutoli ◽  
Letterio Guglielmo ◽  
...  

2017 ◽  
Vol 98 (5) ◽  
pp. 1003-1009 ◽  
Author(s):  
Luca Bittau ◽  
Mattia Leone ◽  
Adrien Gannier ◽  
Alexandre Gannier ◽  
Renata Manconi

Sowerby's beaked whale (Mesoplodon bidens) was previously known in the Mediterranean Sea from a single live stranding of two individuals in the French Riviera. We report here on two live sightings in the western Mediterranean, central-western Tyrrhenian Sea off eastern Corsica (Montecristo Trough) and off eastern Sardinia (Caprera Canyon) in 2010 and 2012, respectively. In both cases single individuals, possibly the same individual, occurred within groups of Cuvier's beaked whales (Ziphius cavirostris) suggesting inter-specific interactions. Based on our close observations of mixed-species groups of Sowerby's and Cuvier's beaked whales, we hypothesize that some previous long-distance sightings of beaked whales in the Mediterranean may not be reliably attributed to Z. cavirostris. The present sightings and previous live stranding indicate that the western Mediterranean Sea is the easternmost marginal area of M. bidens within the North Atlantic geographic range. Notes on behaviour are also provided.


Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 871
Author(s):  
Antonello Mulas ◽  
Andrea Bellodi ◽  
Pierluigi Carbonara ◽  
Alessandro Cau ◽  
Martina Francesca Marongiu ◽  
...  

Cartilaginous fish are commonly recognized as key species in marine ecosystems for their fundamental ecological role as top predators. Nevertheless, effective management plans for cartilaginous fish are still missing, due to the lack of knowledge on their abundance, distribution or even life-history. In this regard, this paper aims at providing new information on the life-history traits, such as age, maturity, reproductive period, in addition to diet characteristics of eleven rare cartilaginous fish inhabiting the Central-Western Mediterranean Sea belonging to the orders Chimaeriformes (Chimaera monstrosa), Hexanchiformes (Heptranchias perlo and Hexanchus griseus), Myliobatiformes (Aetomylaeus bovinus and Myliobatis aquila), Rajiformes (Dipturus nidarosiensis and Leucoraja circularis), Squaliformes (Centrophorus uyato, Dalatias licha and Oxynotus centrina) and Torpediniformes (Tetronarce nobiliana), useful for their assessment and for future management actions. Particularly, the present paper provides for the first time the age estimation of D. nidarosienis and L. circularis which were both found capable of becoming older than ten years. In addition, the present study updates the sizes of first maturity of C. uyato and D. licha, which appeared to be capable of reproducing earlier than what was previously hypothesized, representing very valuable information for a better understanding of these rare species populations status and, eventually, their conservation. On the basis of the stomach content analysis, it was possible to identify five different predator groups.


2011 ◽  
Vol 8 (3) ◽  
pp. 827-840 ◽  
Author(s):  
M. Le Moal ◽  
H. Collin ◽  
I. C. Biegala

Abstract. The Mediterranean Sea is one of the most oligotrophic marine areas on earth where nitrogen fixation has formally believed to play an important role in carbon and nitrogen fluxes. Although this view is under debate, the diazotrophs responsible for this activity have still not been investigated in the open sea. In this study, we characterised the surface distribution and species richness of unicellular and filamentous diazotrophs across the Mediterranean Sea by combining microscopic counts with size fractionated in situ hybridization (TSA-FISH), and 16S rDNA and nifH genes phylogenies. These genetic analyses were possible owing to the development of a new PCR protocol adapted to scarce microorganisms that can detect as few as 1 cell ml−1 in cultures. Low concentrations of diazotrophic cyanobacteria were detected and this community was dominated at 99.9% by picoplankton hybridized to the Nitro821 probe, specific for unicellular diazotrophic cyanobacteria (UCYN). Among filamentous cyanobacteria only 0.02 filament ml−1 of Richelia were detected in the eastern basin, while small (0.7–1.5 μm) and large (2.5–3.2 μm) Nitro821-targeted cells were recovered at all stations with a mean concentration of 3.5 cell ml−1. The affiliation of the small Nitro821-targeted cells to UCYN-A was confirmed by 16S and nifH phylogenies in the western Mediterranean Sea. In the central and the eastern Mediterranean Sea no 16S rDNA and nifH sequence from UCYN was obtained as cells concentration were close to, or below PCR detection limit. Bradyrhizobium sequences dominated nifH clone libraries from picoplanktonic size fractions. A few sequences of γ-proteobacteria were also detected in the central Mediterranean Sea. While low phosphate and iron concentrations could explain the absence of Trichodesmium sp., the factors that prevent the development of UCYN-B and C remain unknown. We also propose that the dominating picoplankters probably developed specific strategies, such as associations with protists or particles, and/or photosynthetic activity, to acquire carbon for sustaining diazotrophy.


Author(s):  
Renata Archetti ◽  
Silvia Bozzi ◽  
Giuseppe Passoni

The cost of the energy extracted by ocean surface waves depends on many technological-physical factors like conversion principle, wave energy potential, water depth, shore distance, and ocean floor characteristics. Economic factors, like assumed discount rate, cost reduction due to technological improvement and fiscal incentives, are extremely important too. The Mediterranean Sea and the Tyrrhenian Sea in particular, possess an interesting energy potential. At some locations offshore Sardinia and Sicily the wave energy density is of the order of 10kW/m. In this paper the energy production has been computed for three different wave energy converters (AquaBuOY AWS and Pelamis), at two promising locations in the western Italian seas.. The energy cost has also been computed for the Pelamis device at Alghero site which has the highest wave energy potential. The results indicate that the existing Pelamis converter is oversized with respect to the typical wavelength of the investigated sites After proper scaling of the device, the performance in the energy conversion could become economically attractive also for Italian seas.


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