Misura della connettività e della dispersione dell’aragosta rossa Palinurus elephas (Fabricius, 1787) in Sardegna con l’uso di marcatori genetici STRs e mitocondriali

Measures of connectivity and dispersion of the spiny lobster Palinurus elephas (Fabricius, 1787) in Sardinia through the use of STRs and mitochondrial genetic markers The spiny lobster Palinurus elephas is an important alieutic resource for all the Mediterranean Sea and especially Sardinia. For this reason, recently, in order to protect the intensively exploited stocks of the species, several no-take areas have been created in Sardinia seas. Apart from the first area (Su Pallosu), established in 1998, 14 new no-take areas have been created in 2009, after the encouraging results of the first experimentation. On the basis of this new important project, for the first time a genetic survey was established, through the development of this thesis, in order to achieve several important objectives. In fact, the present work permitted to: i) evaluate the genetic effects of the first pilot project established in Su Pallosu in 1998, comparing the molecular data of individuals sampled at the time of the institution and after twelve years; ii) provide the first genetic data and characterize the populations living in the new no-take areas, which will serve as a future baseline for comparison in assessing the effectiveness of new project; iii) estimate the extent of the gene flow and thus the connectivity and genetic structuring among populations of Palinurus elephas in Sardinia; iv) assess the health status of the stock, through the measurement of genetic variability and any demographic changes over time; v) verify the efficiency and the differences of two genetic markers here implemented. The study was accomplished through the use two different molecular markers: 10 different microsatellite loci, of nuclear origin, and a portion of the mitochondrial control region. The two types of markers have substantial differences in terms of measuring the spatial and temporal variability, thus can be considered complementary in the study. In order to achieve all the objectives, 305 individuals of spiny lobsters were sampled, representing 7 of the 15 no-take areas, and genetically characterised for all microsatellite loci and mitochondrial control region. Results evidenced a positive increment in genetic variability in the first experimental area Su Pallosu from 1998. This results enforces the success of the repopulation action. Moreover, mitochondrial marker did not reveal any significant structure among sampling sites, whereas the individuals seem to belong to the same unique population. From a demographic point of view, Su Pallosu sample seems to be stable, mainly because of the release in the area of tagged spiny lobster during the restocking project, while all other samples are most probably expanding at the moment. Once again, all efforts towards the establishment of an active repopulation seems to be positive. Microsatellite loci, on the other side, seem to reveal a fable population structure, also because of the higher resolution degree of the marker, nevertheless this structure is not to be considered as consequence of a reduced gene flow. This weak structure could be the result of two important opposite forces driving the gene flow: a very dispersive larval phase versus a more sedentary adult lifestyle. In conclusion, the results here shown demonstrate the efficacy of a more aware and conscious policy towards such an important ecological and economic resource. All efforts to repopulate and make recover the Sardinian spiny lobsters population seem to be effective and should be maintained and improved whenever and wherever possible. The results obtained today, originating in 1998, give strong support for locally defined management and conservation plans strategies that have been demonstrated to be effective

An unusual finding of Sepietta oweniana (Cephalopoda: Sepiolidae) egg clutch

An unusual finding of Sepietta oweniana egg clutch at 544 m depth is described within an updating study of the reproductive aspects of the species in Sardinian waters. Egg species identity was determined by genetic analysis and morphological and biometrical data of the eggs, embryos and one newly hatched specimen are reported and discussed. Illustrations of the eggs, spermatophores and spermatangia by photographic material are also included. Data on bathymetric distribution and sexual maturity are reported and compared with data already available for the species in other geographical areas of distributio

Descubrimiento inusual de una puesta de Sepietta oweniana (Cephalopoda: Sepiolidae)

An unusual finding of Sepietta oweniana egg clutch at 544 m depth is described within an updating study of the reproductive aspects of the species in Sardinian waters. Egg species identity was determined by genetic analysis and morphological and biometrical data of the eggs, embryos and one newly hatched specimen are reported and discussed. Illustrations of the eggs, spermatophores and spermatangia by photographic material are also included. Data on bathymetric distribution and sexual maturity are reported and compared with data already available for the species in other geographical areas of distribution.Se describe un descubrimiento inusual de una puesta de Sepietta oweniana a 544 m de profundidad, en el ámbito de un estudio de aspectos reproductivos de la especie en aguas de Cerdeña. Los huevos se identificaron por medio de análisis genéticos. En este trabajo se presentan y discuten datos morfológicos y biométricos de los huevos, embriones y de un especimen recién nacido. Se incluye material fotográfico de los huevos, espermatóforos y espermatangia. Se presentan datos de distribución batimétrica y madurez sexual y se comparan con datos existentes de la especie en otras áreas geográficas de distribución

POPULATION GENETICS OF THE RED AND BLUE SHRIMP ARISTEUS ANTENNATUS IN THE WESTERN MEDITERRANEAN SEA

To investigate on the presence of distinct stocks in the Western Mediterranean Sea, genetic variation at 8 microsatellite loci was analyzed for eleven samples of the blue and red shrimp Aristeus antennatus (Crustacea, Decapoda) from the Western Mediterranean basin. High level of gene flow and no evidence of genetic partitioning were discovered. No significant genetic variation was found even when populations from exploited versus deep-water unexploited grounds were compared. All the results are consistent with the biology of the species, in particular the extensive pelagic larval stage and adult migration that allow high dispersal and connectivity, at least at the spatial scale investigated in this study

Further insights on the genetic structure and connectivity in Octopus vulgaris (Mollusca, Cephalopoda) inferred by mitochondrial COI sequences

The genetic variability of the COI gene was studied in the common octopus, Octopus vulgaris Cuvier, 1797. A total of 222 individuals from 7 sampling sites were analysed with the aim of elucidating patterns of genetic variation along the coasts of Sardinia (Western Mediterranean). A total of 17 different haplotypes were identified with four principal haplotypes recorded in all locations. The pairwise Fst and AMOVA revealed a high gene flow and the lack of significant genetic differentiation among populations. All COI sequences were compared with those available in GenBank for the species; the results obtained show a high sequence divergence among O. vulgaris from different geographic locations and emphasize the need for more detailed phylogeographic and/or taxonomic studies to exclude the presence of cryptic specie