Search results for "mediterranean sea."
showing 10 items of 830 documents
A study on Pomatoschistus tortonesei Miller 1968 (Perciformes, Gobiidae) reveals the Siculo-Tunisian Strait (STS) as a breakpoint to gene flow in the…
2009
The current genetic structure of P. tortonesei, exclusively inhabiting lagoons, may reflect a Plio-Pleistocene colonisation of an ancestor line which has undergone phases of population decline and expansion, following alternate cooling phases. Regarding the calculation of divergence time, it has been estimated that P. tortonesei seems to be the most recent species within the Pomatoschistus genus. It appears also that the discrepancy of P. tortonesei into two distinct phyletic lineages occurred 0.1 Mya. Recurring shifts in sea level and sea surface temperatures of Mediterranean Sea caused the desiccation of shallower lagoons and the consequent bottleneck phenomena of the brackish populations…
RAD SNP markers as a tool for conservation of dolphinfish Coryphaena hippurus in the Mediterranean Sea: Identification of subtle genetic structure an…
2016
Dolphinfish is an important fish species for both commercial and sport fishing, but so far limited information is available on genetic variability and pattern of differentiation of dolphinfish populations in the Mediterranean basin. Recently developed techniques allow genome-wide identification of genetic markers for better understanding of population structure in species with limited genome information. Using restriction-site associated DNA analysis we successfully genotyped 140 individuals of dolphinfish from eight locations in the Mediterranean Sea at 3324 SNP loci. We identified 311 sex-related loci that were used to assess sex-ratio in dolphinfish populations. In addition, we identifie…
Isolation By Distance (IBD) signals in the deep-water rose shrimp Parapenaeus longirostris (Lucas, 1846) (Decapoda, Panaeidae) in the Mediterranean S…
2013
Abstract The identification of boundaries of genetic demes is one of the major goals for fishery management, and few Mediterranean commercial species have not been studied from a genetic point of view yet. The deep-water rose shrimp Parapenaeus longirostris (Lucas, 1846) is one of the most important components of commercial landings in Mediterranean, its fishery aspects have received much attention, regrettably without any concern for the genetic architecture of its populations. The population structure in the central and eastern Mediterranean Sea (captures from six Italian and two Greek landings) has been analysed on the basis of surveys carried out with mitochondrial and AFLP markers. Dat…
Kudoa trifolia sp. n. ? molecular phylogeny suggests a new spore morphology and unusual tissue location for a well-known genus
2006
A new species of myxozoan, Kudoa trifolia sp. n., was found in various organs of the golden grey mullet, Liza aurata (Risso), and the thinlip mullet, L. ramada (Risso), from the western Mediterranean. Spores developed in subspherical plasmodia of 0.28-1 mm diameter within connective tissue, predominantly in the spleen, the outer wall of the gall bladder and the gut, the mesenteries and occasionally also in the gills. The spores of K. trifolia differ from the commonly known shape of Kudoa by considerable enlargement of one of the four valve cells, thus forming a 'spore body', which contains the major part of the binucleate sporoplasm. Scanning electron microscopy of the spores revealed the p…
Genetic Variability of Mediterranean Sea red mullet Mullus barbatus (Pisces, Mullidae)
1999
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Conventional karyotype, nucleolar organizer regions and genome size in five Mediterranean species of Syngnathidae (Pisces, Syngnathiformes)
1998
Conventional karyotypes, NOR-bearing chromosomes by means of silver impregnation and genome size were investigated in five Mediterranean species in three genera of the Syngnathidae. A karyotype of 48 subtelocentric-acrocentric chromosomes was found in the seahorse Hippocampus hippocampus (FN=48) while a diploid value of 44 occurred in H. guttulatus (2 sm-m+42 a; FN=46) and the pipefish Syngnathus abaster (44 a; FN=44) and S. typhle (44 a; FN=44). The pipefish Nerophis ophidion, possessing a diploid chromosomal set of 58 made up of 50 meta-submetacentric and eight subteloacrocentric elements (FN=108) and a genome size three to four times larger than those known to date, differs cytogenetical…
Congruence in genetic markers used to describe Mediterranean and Atlantic populations of European hake (Merluccius merluccius L. 1758)
2004
Summary Eight samples of the hake, Merluccius merluccius L., from the Mediterranean basin (370 fishes total) and one from the Atlantic ocean (50 fishes) were analysed in order to assess genetic variability and describe genetic population structure. Five polymorphic protein coding loci were scored (ADH*, PGI-1*, PGI-2*, PGM* and SOD-1*) in eight samples, together with a haplotype variation of four samples, obtained from polymerase chain reaction/restriction fragment length polymorphism (PCR–RFLP) analysis on the mitochondrial DNA control region. The average value for observed heterozygosity was typically higher than expected (showing an excess of heterozygotes among the samples) whereas the …
Allozymic variation in Mediterranean hake, Merluccius merluccius (Gadidae)
1998
Abstract Four hundred and twenty individual hake from 10 sample sites in the Mediterranean Sea were analysed in order to study genetic variability and identify genetic stock structure. Twenty loci were identified, four of which were polymorphic at the 95% level: ADH*, PGI‐1*, PGI‐2* and SOD‐1*. Average observed and expected heterozygosity were 0.084 and 0.090, respectively. PG1–1* deviated from Hardy‐Weinberg expectations due to an excess of heterozygotes and F‐statistic analysis showed also a significant excess of heterozygosity at SOD‐1*. FST was not significant for each locus except for PGI‐2*, where a single sample from the Channel of Sicily (C5) showed a different pattern in allelic fr…
Alteration effects of volcanic ash in seawater: Anomalous Y/Ho ratios in coastal waters of the Central Mediterranean sea
2007
This paper presents the results of a study based on data collected during the oceanographic cruise ANSIC 2001 carried out in the Ionian Sea during the explosive activity of Mount Etna in the summer of 2001. Anomalous low values of Y/Ho ratios in seawater suggest extensive scavenging processes on the surfaces of smectitic alteration products, with Y and Ho fractionation controlled by the differences in their electronic configurations and behaviour during solution/surface complexation equilibria. These processes can also be traced through the presence of significant tetrad effects recorded in the chondrite-normalised Rare Earth Elements and Yttrium (YREEs) patterns of suspended particulate ma…
Invasions of the non-indigenous red alga Lophocladia lallemandii (Montagne) F. Schmitz off the Island of Ischia (Tyrrhenian Sea, Italy)
2021
This paper describes the distribution and spread of the non-indigenous red alga Lophocladia lallemandii (Montagne) F. Schmitz along the coast of the Island of Ischia (Tyrrhenian Sea, Italy). Lophocladia lallemandii was monitored through surveys from July 2019 to January 2020 at the Capo Sant’Angelo (Ischia), where L. lallemandii was observed, but not reported, in the years preceding the invasion of the upper rocky infralittoral shore reported here. It is noteworthy that a large portion of the study area is included within one of the two “B no-take” zones of the Marine Protected Area of the “Regno di Nettuno” (“Neptune’s Realm”). During the surveys, the alga was first observed in the middle …