Characteristics of palinurids (Decapoda; Crustacea) in larval culture

Complete development of phyllosomas wasaccomplished in Palinurus elephas, Panulirus japonicus, Jasus edwardsii and J. verreauxi. Larval development differsbetween species in duration and moult frequency aswell as morphology. The highest percent survival was obtained during the phyllosoma stage forJ. verreauxi. Phyllosomas of P. elephas were the mostdifficult to cultureregardless of the fact that they hatch at arelatively advanced stage. Culture experiments werecarried out to improve the percent survival of P. elephas. First instars of P. elephasexhibited vigorous predation upon the larvae ofJapanese sandfish Arctoscopus japonicus.Duration of the first instar was shorter at 12.8days when reared at 18 °C and percent survival wasapproximately 30%. Better results were obtainedfor first instars cultured in water inoculated withChaetoceros sp. and fed enriched Artemianauplii. Phyllosomas of J. edwardsii and P. japonicus were cultured without particulardifficulty. Most distinguishing features of P. elephasis the heavily setose six or seven longspines on the distal edges of the scaphognathite ofthe second maxillae while only four long spines arefound in other species. These facts suggest thatphyllosomas of P. elephas are initiallyplankton feeders and from first instar becomerapacious predators.     

Characterization and sequence elucidation of a novel peptide with molt-inhibiting activity from the South African spiny lobster, Jasus lalandii

We have isolated a peptide from extracts of sinus glands from a South African spiny lobster species, Jasus lalandii, by high-performance liquid chromatography (HPLC) and identified it as a putative molt-inhibiting hormone (MIH) by (i) an in vitro assay with J. lalandii Y-organs to measure the inhibition of ecdysteroid synthesis and (ii) an immunoassay using antiserum raised against MIH of the edible crab. The MIH of J. lalandii has 74 amino acid residues, a molecular mass of 9006 Da, a free N-terminus and an amidated C-terminus. The full primary sequence has been obtained from sequencing various digest fragments (tryptic, endoproteinase Asp-N, cyanogen bromide) of the unreduced (native) peptide: RFTFDCPGMMGQRYLYEQVEQVCDDCYNLYREEKIAVNCRENCFLNSWFTVCLQATMREHETPRFDIWR SIILKA-NH(2). Structural comparisons with other peptides show that the J. lalandii MIH belongs to the peptide family which includes the crustacean hyperglycemic hormone, molt-inhibiting hormone and vitellogenesis-inhibiting hormone (cHH/MIH/VIH). This novel peptide has 36-43% sequence identity to putative MIHs from other decapod crustaceans and 32-34% identity to the two cHH peptides previously identified in this spiny lobster species. This is the first report of a peptide with MIH activity in the Palinuridae infraorder.     

Molecular cloning and localization of a cDNA encoding a crustacean hyperglycemic hormone from the South African spiny lobster,Jasus lalandii

A cDNA, encoding a crustacean hyperglycemic hormone (cHH) of the South African spiny lobster, Jasus lalandii has been cloned. The cDNA consists of 1773 bp with an open reading frame of 399 bp that encodes a preprohormone of 133 amino acid residues. The preprohormone consists of a 25 amino acid hydrophobic signal peptide, a 32 amino acid cHH precursor-related peptide (CPRP) and the cHH sequence of 72 amino acid residues. The cHH sequence is flanked N-terminally by a Lys-Arg cleavage site and C-terminally by Gly-Lys, where Gly serves as an amidation site. The deduced amino acid sequence of the CPRP is in complete agreement with a peptide previously elucidated from sinus glands of J. lalandii, code-named CPRP 2 and the sequence of the cHH peptide matches that of the minor cHH isoform of J. lalandii, i.e. crustacean hyperglycemic hormone-II (cHH-II), which was also previously obtained by peptide sequencing. In situ hybridization on eyestalks revealed strong cHH-II mRNA expression in a subset of neurosecretory cells of the X-organ.     

Genetic diversity and relations of the Goitered gazelle (<Emphasis Type="Italic">Gazella subgutturosa</Emphasis>) groups from Uzbekistan,Turkmenistan, and Azerbaijan: Analysis of the D-loop of mitochondrial DNA

Polymorphism of the nucleotide sequence of a hypervariable fragment of the D-loop (985 bp) of mtDNA in 76 Goitered gazelles of subspecies Gazella subgutturosa subgutturosa from Uzbekistan, Turkmenistan, and Azerbaijan was studied. The genetic similarity of gazelles from Turkmenistan and Uzbekistan has been identified. The population of gazelles from Shirvanskaya steppe reserve (Azerbaijan) is unique and strictly isolated from other groups studied. A high haplotypic (H = 0.9649 ± 0.0091) and relatively low nucleotide diversity (π = 0.0212 ± 0.0105) were noted for all investigated groups of gazelle based on this mtDNA fragment, which is probably related to ecological peculiarities of the species and the history of formation of regional populations.     

MtDNA polymorphisms: evolutionary significance in adaptation and speciation of subterranean mole rats

Patterns of mtDNA diversity in subterranean mole rats of the Spalax ehrenbergi superspecies (2n = 52, 54, 58 and 60) were previously studied in the main ranges of the four chromosomal species, and specifically in the 2n = 60 species and its peripheral steppe semi-isolates and desert isolates. In the present study we correlated mtDNA diversity indices, nucleon diversity, h , and nucleotide divergence, π, with physical (climatic), biotic (parasites) and biological (genetical, morphological, physiological and behavioural) factors, showing that mtDNA diversity is structured ecogeographically and biologically. The following significant correlations of mtDNA diversity were indicated with: (i) climatic heterogeneity and unpredictability; (ii) levels of ecto- and endoparasites; and (iii) biological diversities, primarily with physiological diversity associated with the energy budget. Small steppe semi-isolates and desert isolates harbour high levels of mtDNA haplotype diversity, some novel, which may be a prerequisite for future speciation events. We conclude that the ecogeographical and biological correlates, as well as the maintenance of mtDNA polymorphisms in small isolated populations, strongly suggest that mtDNA diversity is not neutral. Diversifying natural selection appears to be an important differentiating factor of mtDNA diversity in the twin evolutionary processes of adaptive radiation and active speciation. We suggest critical experiments to substantiate our conclusions and highlight the contribution of mtDNA diversity to fitness, i.e. to the biological function of mtDNA diversity in the evolutionary process.     

Mitochondrial DNA phylogeny and morphological diversity in the genus Mastus (Beck, 1837): a study in a recent (Holocene) island group (Koufonisi, south-east Crete)

Three endemic Cretan land snail species of the genus Mastus (Beck, 1837) from the island group of Koufonisi (south-east Crete) and the eastern part of Crete, were studied by multivariate analysis of shell morphology and analysis of mtDNA sequences. The phylogeny of the populations studied and the processes effecting the genetic and morphological diversity of the species were investigated. Extremely high mtDNA sequence divergence was observed both within and between populations. The Cretan populations could not be distinguished morphologically, while the populations of the islets were more distinct. We argue that the active geological past of the area (including sea level changes) and the long-term presence of humans has produced a mixing up of Mastus populations leading to the accumulation of high divergence of mtDNA sequences on a small spatial scale. The limited morphological diversity and the distinct shell 'identity' of the islets' populations can be attributed to the selective pressures of the island group.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 78, 383–399.     

The subunit structure of the hemocyanin from the crayfish Jasus edwardsii.

The hemocyanin from the crayfish Jasus edwardsii(=lalandii) has been studied using ultracentrifugation, viscosity, circular dichroism and oxygen binding techniques. Sedimentation velocity experiments at pH 7.0 indicated the presence of principal species with S 20w=16.4 S, and at higher pH the presence of a species with S20,w=5.2S. Sedimentation equilibrium experiments yielded molecular weights of 490 000 and 81 000 respectively, indicating that the larger unit is a hexamer of the monomer unit. However, preliminary experiments with gel filtration and electrophoresis under denaturing conditions indicate that more than one monomer species may be present with molecular weight in the range 76-100 000. Circular dichroism (CD) spectra are presented at pH 7.0,8.6,10.0 and 11.0 for oxy-, deoxy- and apo-hemocyanins. Slight differences were observed in the magnitude of the bands in the presence or absence of Mg++. Oxygen binding studies have been made at pH 6.1,7.0,8.8 and 10.6, in the presence of 0.01 M MgCl2. The extent of cooperative binding was indicated by a maximum value of n=3.7, and a pronounced bohr effect was observed.     

Population structure and phylogeography of Aphyocypris kikuchii (Oshima) based on mitochondrial DNA variation

Aphyocypris kikuchii is a cyprinid species endemic to northern and eastern Taiwan and is the only primary freshwater fish native east of the Coastal Mountain Range. In total, 92 individuals of A. kikuchii from seven populations in three regions of the island were surveyed for mitochondrial DNA (mtDNA) variation. High haplotype diversity ( h = 0·989) and low nucleotide diversity ( π = 0·009) of mtDNA were detected. Negative values of Tajima's D and unimodal mismatch distributions probably reflect a history of recent demographic expansions from small populations. Three major haplotype clusters displayed geographically non-overlapping distributions, indicating a long-term isolation between regions. Hierarchical analysis of molecular variance showed significant genetic structuring among populations ( Φ _ST= 0·66). Significant haplotype heterogeneity was also detected among populations within regions ( Φ _SC= 0·41, P < 0·001) and among regions ( Φ _CT= 0·43, P < 0·05). Molecular clock estimates of coalescence in the three major mtDNA lineages indicated coalescence in the most recent common ancestor c. 0·11–0·39 million years ago. Haplotypes of cluster B nested as interior nodes in the haplotype network, indicating that migrations from Shueilian (SL) populations to the northern region (cluster A) and to the eastern region (cluster C) may have occurred independently. Lineages A and B + C should be managed as two distinct evolutionarily significant units, while the northern, SL and southern groups should be managed as separate management units.     

Georgian and kurd mtDNA sequence analysis shows a lack of correlation between languages and female genetic lineages

Mitochondrial DNA sequences from Georgians and Kurds were analyzed in order to test the possible correlation between female lineages and languages in these two neighboring West Eurasian groups. Mitochondrial sequence pools in both populations are very similar despite their different linguistic and prehistoric backgrounds. Both populations present mtDNA lineages that clearly belong to the European gene pool, as shown by 1) similar nucleotide and sequence diversities; 2) a large number of sequences shared with the rest of European samples; 3) nonsignificant genetic distances; and 4) classification of the present lineages into the major European mtDNA haplogroups already described. The outlier position of the populations from the Caucasus according to classical genetic markers is not recognized in the present Georgian mtDNA sequence pool. This result suggests that the differentiation of mtDNA sequences in West Eurasia and the outlier features of Caucasian populations should be attributed to different processes. Moreover, the putative linguistic relationship between Caucasian groups and the Basques, another outlier population within Europe for classical genetic markers, is not detected by the analysis of mtDNA sequences.     

Phylogeographic differentiation in the mitochondrial control region in the koala, Phascolarctos cinereus (Goldfuss 1817)

The koala, Phascolarctos cinereus, is a geographically widespread species endemic to Australia, with three currently recognized subspecies: P.c. adustus, P.c. cinereus, and P.c. victor. Intraspecific variation in the mitochondrial DNA (mtDNA) control region was examined in over 200 animals from 16 representative populations throughout the species’ range. Eighteen different haplotypes were defined in the ≈ 860 bp mtDNA control region, as determined by heteroduplex analysis/temperature gradient gel electrophoresis (HDA/TGGE). Any single population typically possessed only one or two haplotypes yielding an average within-population haplotypic diversity of 0.180 ± 0.003, and nucleotide diversity of 0.16%. Overall, mtDNA control region sequence diversity between populations averaged 0.67%, and ranged from 0% to 1.56%. Nucleotide divergence between populations averaged 0.51%, and ranged from 0% to 1.53%. Neighbour-joining methods revealed limited phylogenetic distinction between geographically distant populations of koalas, and tentative support for a single evolutionarily significant unit (ESU). This is consistent with previous suggestions that the morphological differences formalized by subspecific taxonomy may be interpreted as clinal variation. Significant differentiation in mtDNA-haplotype frequencies between localities suggested that little gene flow currently exists among populations. When combined with microsatellite analysis, which has revealed substantial differentiation among koala populations, we conclude that the appropriate short-term management unit (MU) for koalas is the local population.     

HISTORICAL DEMOGRAPHY AND PRESENT DAY POPULATION STRUCTURE OF THE GREENFINCH,CARDUEUS CHLORIS—AN ANALYSIS OF mtDNA CONTROL-REGION SEQUENCES

Genetic variability within and among 10 geographically distinct populations of Greenfinches (Carduelis chloris) was assayed by directly sequencing a 637 BP part of the mtDNA control region from 194 individuals. Thirteen variable positions defined 18 haplotypes with a maximum sequence divergence of 0.8%. Haplotype (h = 0.28–0.77) and nucleotide (π = 0.058–0.17%) diversities within populations were low, and decreased with increasing latitude (h:r_s = –0.81; π: r_s = –0.89). The distribution of pairwise nucleotide differences fit better with expectations of a “sudden expansion” than of an “equilibrium” model, and the estimates of long term effective population sizes were considerably lower than current census estimates, especially in northern European samples. Selection is an unlikely cause of observed patterns because the distribution of variability conformed to expectations of neutral infinite alleles model and haplotype diversity across populations was positively correlated with heterozygosity (H_E) in nuclear genes (r_s = 0.74, P < 0.05). Hence, a recent bottleneck, followed by serial bottlenecking during the process of post-Pleistocene recolonization of northern Europe, together with recent population expansion provide a plausible explanation for the low genetic diversity in the north. Genetic distances among populations showed a clear pattern of isolation-by-distance, and 14% of the haplotypic variation was among populations, the rest being distributed among individuals within populations. In accordance with allozyme and morphological data, a hierarchical analysis of nucleotide diversity recognized southern European populations as distinct from northern European ones. However, the magnitude of divergence in mtDNA, allozymes and morphology were highly dissimilar (morphology > mtDNA > allozymes).     

Phylogeography and conservation of the bull shark (Carcharhinus leucas) inferred from mitochondrial and microsatellite DNA

The bull shark (Carcharhinus leucas) is a widely distributed, large coastal shark species known to travel long distances. These characteristics, coupled with the species?? long life span and late age of maturity, would lead one to predict significant global genetic exchange among bull shark populations. By contrast, data show localized depletion in some areas of large coastal shark fisheries, indicating some geographic isolation may exist. We examined genetic variation in the control region of mitochondrial DNA and at five nuclear microsatellite loci in bull sharks sampled from the western Atlantic to investigate the degree of population subdivision. The average per sample haplotype and nucleotide diversity in the mtDNA (0.51 ± 0.26 and 0.12% ± 0.12, respectively) and expected heterozygosity (0.84) in the microsatellite loci contrast sharply in having lower and higher values (respectively) relative to many other shark species. Significant structure exists between the Brazilian and all northern populations at the mtDNA control region (pairwise ??_ST > 0.8, P < 0.001), but not at the nuclear microsatellite loci. Adjacent northern populations show weak to no genetic differentiation for both markers. These results are congruent with restricted maternal gene flow between populations caused by female site fidelity to nursery areas. We estimate the current effective population size to be around 160,000 and 221,000 individuals for the southern and northern Atlantic populations, respectively. The philopatric habits and the relatively low levels of mtDNA genetic diversity observed in bull sharks must be considered in the conservation of this species. Our results indicate that effective bull shark management strategies will require local, regional, and international attention and cooperation.     

Ancient DNA perspective on the failed introduction of mongooses in Italy during the XXth century

We used ancient DNA techniques to amplify mitochondrial DNA fragments [cytochrome b (cyt b ) and control region (CR)] from four museum specimens that represent, to our knowledge, the last testimony of the introduction of – now extinct – mongooses in Italy. We assessed the identity, origin and genetic variability of Italian mongooses using a species-level assignation Bayesian approach and haplotype network analysis. The genetic diversity (cyt b and CR) among Italian individuals was null. The cyt b sequences from the four museum specimens clearly established the Indian grey mongoose Herpestes edwardsii as the species having been introduced in Italy in the mid-XXth century. The latter had at least been released twice within a period of 10 years (Circeo NP and Capalbio, c . 200 km northward), probably from the same captive stock of the Giardino Zoologico di Roma. Assessment of genetic variability and haplotype network including native representatives of H. edwardsii suggested that the introduced pool likely originated from Pakistan or India. It appears that a combination of deleterious factors including low genetic diversity, restricted range and nonadaptation to western Palaearctic winter conditions is responsible for the extinction of the species in Italy. However, the lack of knowledge on the life-history traits and population dynamics of H. edwardsii prevents from further discussion of the factors that likely promoted its extinction process.     

Phylogeographic structure suggests multiple glacial refugia in northern Victoria Land for the endemic Antarctic springtail Desoria klovstadi (Collembola, Isotomidae)

We carried out a phylogeographic study using mtDNA (COII) for the endemic springtail Desoria klovstadi (formerly Isotoma klovstadi ) from northern Victoria Land, Antarctica. Low levels of sequence divergence (≤ 1.6%) across 26 unique haplotypes (from 69 individuals) were distributed according to geographic location. Cape Hallett and Daniell Peninsula contained the highest nucleotide (both > 0.004) and haplotype (both > 0.9) diversity with 10 (of 16) and 8 (of 12) unique haplotypes, respectively. All other populations (Football Saddle, Crater Cirque, Cape Jones) had lower diversity with 2–4 unique haplotypes. Across the 69 individuals from five populations there was only a single haplotype shared between two populations (Daniell Peninsula and Football Saddle). Furthermore, nested clade analyses revealed that some of the Daniell Peninsula haplotypes were more closely related to Football Saddle haplotypes than to any other population. Such discrete haplotype groupings suggest historical (rare) dispersal across the Pleistocene (1.8 mya−11 kya) and Holocene (11 kya–present), coupled with repeated extinction, range contraction and expansion events, and/or incomplete sampling across the species range. The nested clade analyses reveal that a common pattern of climatic and geological history over long-term glacial habitat fragmentation has determined the geographic and haplotype distributions found for D. klovstadi .     

Genetic diversity and maternal origin of Bangladeshi chicken

Local domestic chicken populations are of paramount importance as a source of protein in developing countries. Bangladesh possesses a large number of native chicken populations which display a broad range of phenotypes well adapted to the extreme wet and hot environments of this region. This and the fact that wild jungle fowls (JFs) are still available in some regions of the country, it urges to study the present genetic diversity and relationships between Bangladeshi autochthonous chicken populations. Here, we report the results of the mitochondrial DNA (mtDNA) sequence polymorphisms analyses to assess the genetic diversity and possible maternal origin of Bangladeshi indigenous chickens. A 648-bp fragment of mtDNA control region (D-loop) was analyzed in 96 samples from four different chicken populations and one red JF population. Sequence analysis revealed 39 variable sites that defined 25 haplotypes. Estimates of haplotype and nucleotide diversities ranged from 0.745 to 0.901 and from 0.011 to 0.016, respectively. The pairwise differences between populations ranged from 0.091 to 1.459 while most of the Phi_ST (Φ_ST) values were significant. Furthermore, AMOVA analysis revealed 89.16 % of the total genetic diversity was accounted for within population variation, indicating little genetic differentiation among the studied populations. The median network analysis from haplotypes of Bangladeshi chickens illustrated five distinct mitochondrial haplogroups (A, D, E, F and I). Individuals from all Bangladeshi chicken populations were represented in the major clades D and E; those maternal origins are presumed to be from Indian Subcontinent and Southeast Asian countries, more particularly from South China, Vietnam, Myanmar and Thailand. Further, phylogenetic analysis between indigenous chicken populations and sub-species of red JFs showed G. g. gallus and G. g. spadiceus shared with almost all haplogroups and had major influence than G. g. murghi in the origin of indigenous chicken of Bangladesh. These results suggest that Bangladeshi indigenous chickens still have abundant genetic diversity and have originated from multiple maternal lineages, and further conservation efforts are warranted to maintain the diversity.     

Genetic analysis of populations of threatened snake species using RAPD markers

Snakes are a particularly threatened vertebrate taxon, with distributions of many species and populations becoming increasingly fragmented. At present, little is known about the degree of genetic differentiation that exists between isolated populations even though such information may be critical to their survival and conservation. As an example of how recently developed RAPD genetic markers can be used in conservation genetics, we present preliminary results from a study which used these DNA-based markers to assess population divergence in two threatened Canadian snakes, the black rat snake ( Elaphe o. obsoleta ) and the eastern massasauga rattlesnake ( Sistrurus c. catenatus ). We present information on the levels of variation and reliability of amplification for fragments generated from five primers. We then use a recently developed analytical technique to estimate levels of nucleotide diversity within populations and sequence divergence between populations. Our results show that intrapopulation levels of divergence as estimated by the methods of Clark & Lanigan ( Molecular Biology and Evolution 1993, 10 , 1096–1111) approximate those found for mtDNA in vertebrates and that diversity between snake populations is small and non-significant when tested using randomization procedures. Thus, our study provides an example of how RAPDs can be applied to conservation genetic studies of vertebrates and suggest that the snake populations we examined have only recently become isolated and maybe considered genetically equivalent from a conservation perspective, although this conclusion needs to be confirmed with other DNA-based markers.     

Evaluation of cytochrome b mtDNA sequences in genetic diversity studies of <Emphasis Type="Italic">Channa marulius</Emphasis> (Channidae: Perciformes)

Channa marulius (Hamilton, 1822) is a commercially important freshwater fish and a potential candidate species for aquaculture. The present study evaluated partial Cytochrome b gene sequence of mtDNA for determining the genetic variation in wild populations of C. marulius. Genomic DNA extracted from C. marulius samples (n = 23) belonging to 3 distant rivers; Mahanadi, Teesta and Yamuna was analyzed. Sequencing of 307 bp Cytochrome b mtDNA fragment revealed the presence of 5 haplotypes with haplotype diversity value of 0.763 and nucleotide diversity value of 0.0128. Single population specific haplotype was observed in Mahanadi and Yamuna samples and 3 haplotypes in Teesta samples. The analysis of data demonstrated the suitability of partial Cytochrome b sequence in determining the genetic diversity in C. marulius population.     

How closely do measures of mitochondrial DNA control region diversity reflect recent trajectories of population decline in birds?

Monitoring levels of genetic diversity in wildlife species is important for understanding population status and trajectory. Knowledge of the distribution and level of genetic diversity in a population is essential to inform conservation management, and help alleviate detrimental genetic impacts associated with recent population bottlenecking. Mitochondrial DNA (mtDNA) markers such as the control region have become a common means of surveying for within-population genetic diversity and detecting signatures of recent population decline. Nevertheless, little attention has been given to examining the mtDNA control region’s sensitivity and performance at detecting instances of population decline. We review genetic studies of bird populations published since 1993 that have used the mtDNA control region and reported haplotype diversity, number of haplotypes and nucleotide diversity as measures of within-population variability. We examined the extent to which these measures reflect differences in known demographic parameters such as current population size, severity of any recent bottleneck and IUCN Red List status. Overall, significant relationships were observed between two measures of genetic diversity (haplotype diversity and the number of haplotypes), and population size across a number of comparisons. Both measures gave a more accurate reflection of recent population history in comparison to nucleotide diversity, for which no significant associations were found. Importantly, levels of diversity only correlated with demographic declines where population sizes were known to have fallen below 500 individuals. This finding suggests that measures of mtDNA control region diversity should be used with a degree of caution when inferring demographic history, particularly bottleneck events at population sizes above N = 500.     

Seeds as natural matrices for immobilization of Aspergillus niger mycelium producing pectinases

J. FIEDUREK, J. SZCZODRAK AND J. ROGALSKI. 1995. A simple method for the immobilization of Aspergillus niger mycelium producing polygalacturonase (PG) and pectinesterase (PE) is described. Fungal conidia were immobilized on wheat, rye, barley, peas, buckwheat and mustards seeds. Spongy mycelia overgrowing the seed surfaces on mineral medium with pectin produced extracellular PG and PE; the highest production was reached on the wheat carrier. Some of the variables influencing the enzymatic activity have been optimized. After every 24 h, a culture liquid with 6˙8–7˙8 U of PG ml⁻¹ and 7˙0–10˙1 U of PE ml⁻¹ was obtained. This procedure also made possible repeated batch enzyme production and, as many as eight subsequent 24-h batches could be fermented by using the same carrier without any loss of PG activity. The addition of sodium orthovanadate (1 mmol) into the medium with pectin caused a significant increase in PG and PE activity produced by free cells of A. niger (by 1˙59-fold and 1˙67-fold respectively), and only 0˙47-fold of PG activity in case of the immobilized mycelium.     

Genetic structure of the endangered species <Emphasis Type="Italic">Pinna nobilis</Emphasis> (Mollusca: Bivalvia) inferred from mtDNA sequences

This study examines the population genetic structure of the endangered bivalve Pinna nobilis (Mollusca: Bivalvia), based on novel mtDNA sequences (partial COI and 16S rDNA mtDNA genes). The analyzed nucleotide sequences of COI were 729 bp in size, coding for a 243 amino acid peptide, while the analyzed nucleotide sequences of 16S rDNA were 489 bp in size. These sequences of P. nobilis were the first DNA sequences of the species submitted to any Genetic Data Base. Population samples from four geographic regions from Greece, as well as a population sample of Atrina fragilis (as an outgroup) were used. High values of haplotypic diversity were found in the population samples of P. nobilis, based on the COI sequences. A single base in the analyzed 16S rDNA sequences was different in all analyzed individuals from a single population sample (Chios island) differentiating it from the other ones. These mtDNA sequences could be informative for further genetic analyses of the endangered species, contributing in conservation plans for its protection and/or aquaculture investigations.