Proximate Composition, Antioxidant Properties, and Hepatoprotective Activity of Three Species of Shellfish of the Pacific Coast of Russia.

The objective of the present study was to investigate the proximate composition, antiradical properties and hepatoprotective activity of three species of shellfish, Corbicula japonica, Spisula sachalinensis, and Anadara broughtonii, from the coastal areas of Far East Russia. Biologically active peptides such as taurine (3.74 g/100 g protein) and ornithine (2.12 g/100 g protein) have been found in the tissues of A. broughtonii. C. japonica contains a high amount of ornithine (5.57 g/100 g protein) and taurine (0.85 g/100 g protein). The maximum DPPH and ABTS radical scavenging activity (36.0 µg ascorbic acid/g protein and 0.68 µmol/Trolox equiv/g protein, respectively) was determined for the tissue of C. japonica. The protein and peptide molecular weight distribution of the shellfish tissue water extracts was investigated using HPLC. It was found that the amount of low molecular weight proteins and peptides were significantly and positively correlated with radical scavenging activity (Pearson's correlation coefficient = 0.96), while the amount of high molecular weight proteins negatively correlated with radical scavenging activity (Pearson's correlation coefficient = -0.86). Hepatoprotective activity, measured by the survival rate of HepG2 hepatocytes after cotreatment with t-BHP, was detected for C. japonica. The highest protection (95.3 ± 2.4%) was achieved by the cold water extract of C. japonica at the concentration of 200 mg/mL. Moreover, oral administration of hot water extract of C. japonica to rats before the treatment with CCl4 exhibited a markedly protective effect by lowering serum levels of ALT and AST, inhibiting the changes in biochemical parameters of functional state of rat liver, including MDA, SOD, GSH and GST.

Bioactive fatty acids in seafood from Ionian Sea and relation to dietary recommendations.

The objective of the present study was to determine lipid content, fatty acid composition and the recommended daily portion of 13 fish species, nine bivalves, six crustacean, three echinoderm and three cephalopod species, from the Mediterranean Sea (Southern Italy). Fatty acids profile varied significantly among species (p < .05); polyunsaturated fatty acids represented an important proportion, with docosahexaenoic and eicosapentaenoic acids in the highest amount. A high n3/n6 ratio was found in all species (from 1.0 in body wall of Holothuria polii and H. tubulosa to 10.9 in Mytilus galloprovincialis). The lipid nutritional quality indices (atherogenic index, thrombogenicity index and hypocholesterolaemic/hypercholesterolaemic fatty acid ratio) showed crustaceans Parapaeneus longirostris, Plesionika martia, Melicertus kerathurus, Nephrops norvegicus, as likely to be more beneficial for the consumer health. This paper will be of practical value from a health perspective for populations who consume seafood and a powerful marketing tool for farmers.

A comparison of virus concentration methods for molecular detection and characterization of rotavirus in bivalve shellfish species.

The objectives of this study were to develop a method for concentrating rotavirus, to assess the detection rate, and to characterize the genotype of naturally occurring rotavirus in bivalve shellfish species; including oysters (Saccostrea forskali), cockles (Anadara nodifera), and mussels (Perna viridis). The results demonstrated that an adsorption-twice elution-extraction method was less-time consuming method of concentrating the spiked rotavirus, yielding high sensitivity of 1.14 genome copies/g of digestive tissues from all three shellfish species, as detected using an RT-nested PCR. In seeding experiments, rotavirus as low as 1.39 genome copies was able to be detected in 4 g of digestive tissues or per sample. In the period of August 2011 to July 2012, of the 300 bivalve shellfish samples collected and tested, 24 (8.0%) were found to be contaminated with rotavirus, the figures being: oysters, 13/100 samples; mussels, 10/100 samples; and cockles, 1/100 samples. By DNA sequencing of the RT-nested PCR products and phylogenetic analysis, the rotaviruses detected were classified into G1, lineage II (4 samples); G3 (10 samples): lineage I (3 samples), lineage IIIc (3 samples), lineage IIId (3 samples), lineage IV (1 sample); G9 (6 samples); and G12, lineage III (1 sample). These findings suggest that this virus concentration method provides high sensitivity for the detection of rotavirus from the three bivalve shellfish species. The prevalence of rotavirus and the identified genotypes contribute to the molecular epidemiology of rotavirus in different shellfish species.

Growth and production of Donax striatus (Bivalvia: Donacidae) from Las Balsas beach, Gibara, Cuba.

Clams of the genus Donax are worldwide the dominating group of the invertebrate community on sandy beaches. They are primary consumers that provide a significant abundance and biomass to the ecosystem. In the Caribbean, Donax striatus has an important role for nature and human, nonetheless studies on the population dynamics of this beach clam are scarce and no information exists on secondary production of this species. Growth parameters and secondary production of D. striatus were estimated from February 2008 to November 2009 at Las Balsas beach, Northeastern Cuba, in order to provide basic information for management purposes. In each month 45 samples were taken by means of a PVC corer of 0.025 m2 area and sieved with a 1 mm mesh. Animals were measured and weighted with and without shell. A total of 5 471 specimens were collected during the sampling period. Shell length ranged from 2.7-33.3 mm. Growth parameters estimated from length frequency data were L∞ = 36.1 mm, K= 0.8/yr and t0= 0.2/yr. The growth performance resulted in values of Φ'= 3.02. Life span was 2.4 yrs and mortality rate was 3.07 /yr. In 2008, mean abundance of D. striatus ranged between 17.1 - 770.7 ind./m2. In 2009 the lowest mean abundance was 34.4 and the highest was 892.5 ind./m2. During 2009 biomass and production was more than twice higher in comparison with 2008. Individual production showed highest values in the 24 mm shell size (3.74 g/m2.yr) and 25 mm (0.71 g/m2.yr), considering mass with shell and without shell, respectively. During 2009 abundance of individuals with 15 mm shell length or more increased resulting in higher biomass and production, compared to 2008. Using the conversion factor of wet mass to ash free dry mass (AFDM), annual production ranged between 2.87-6.11 g AFDM/m2.yr, resulting in a turnover rate (P/B) between 5.11 and 3.47 in 2008 and 2009, respectively. The rapid growth and high turnover rate of D. striatus suggest a rapid recovery of the population. These results support the idea that this beach clam is an important resource at Las Balsas beach. Thus its exploitation must continue with caution, and only at the level of a recreational fishery.

Species identification of the Northern shrimp (Pandalus borealis) by polymerase chain reaction-restriction fragment length polymorphism and proteomic analysis.

Genomic and proteomic techniques for species identification of meat and seafood products are being widely used. In this study, a genomic approach was used to differentiate Pandalus borealis (the Northern shrimp), which belongs to the superfamily Pandaloidea, from 30 crustaceans consisting of 19 commercially relevant prawns/shrimps species that belong to the superfamily Penaeoidea, which include the families Penaeidae and Solenoceridae, and 11 other crustacean species, including prawns, shrimps, lobsters, and crabs. For this purpose, a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was designed based on the amplification of the 16S rRNA/tRNA(Val)/12S rRNA mitochondrial regions using the primers 16S-CruF and 16S-CruR. The 966-bp PCR products were produced and cleaved with the restriction enzymes AluI, TaqI, and HinfI, which provided species-specific restriction patterns. In addition, a proteomic approach, based on matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and electrospray ionization-ion trap (ESI-IT) mass spectrometry, was used to identify and characterize new P. borealis-specific peptides that could be useful as potential markers of this species in protein-based detection methods. To our knowledge, this is the first time a molecular method has been successfully applied to identify a wide range of prawn and shrimp species, including P. borealis, for either whole individuals or processed products. However, validation of the methods proposed here is required by applying them to a larger sample of individuals from different populations and geographic origins in order to avoid mainly false-negative results.

Reservoirs of Red-Spotted Grouper Nervous Necrosis Virus (RGNNV) in Squid and Shrimp Species of Northern Alboran Sea.

The production of the aquaculture industry has increased to be equal to that of the world fisheries in recent years. However, aquaculture production faces threats such as infectious diseases. Betanodaviruses induce a neurological disease that affects fish species worldwide and is caused by nervous necrosis virus (NNV). NNV has a nude capsid protecting a bipartite RNA genome that consists of molecules RNA1 and RNA2. Four NNV strains distributed worldwide are discriminated according to sequence homology of the capsid protein encoded by RNA2. Since its first description over 30 years ago, the virus has expanded and reassortant strains have appeared. Preventive treatments prioritize the RGNNV (red-spotted grouper nervous necrosis virus) strain that has the highest optimum temperature for replication and the broadest range of susceptible species. There is strong concern about the spreading of NNV in the mariculture industry through contaminated diet. To surveil natural reservoirs of NNV in the western Mediterranean Sea, we collected invertebrate species in 2015 in the Alboran Sea. We report the detection of the RGNNV strain in two species of cephalopod mollusks (Alloteuthis media and Abralia veranyi), and in one decapod crustacean (Plesionika heterocarpus). According to RNA2 sequences obtained from invertebrate species and reported to date in the Mediterranean Sea, the strain RGNNV is predominant in this semienclosed sea. Neither an ecosystem- nor host-driven distribution of RGNNV were observed in the Mediterranean basin.

Fine-scale genetic structure, phylogeny and systematics of threatened crayfish species complex.

Systematic uncertainties in the crayfish Austropotamobius pallipes are well grounded by the number of species and subspecies described using different approaches, causing scientists to define this taxon as "complex". However, a key task that conservation programmes are facing regarding the recent and drastic decline of European populations, is the coherent systematic classification of this threatened species. Here we present results obtained by coupling mtDNA and genome analysis suggestive of a novel evolutionary framework to explain the relationships among phylogenetic lineages of A. pallipes. The direct sequencing of mtDNA COI gene fragment revealed a strong geographic structure with four distinct haplogroups separated by a range of 5-25 mutations. However, mitochondrial data were not supported by genomic fingerprinting based on 535 AFLP polymorphisms. Nuclear markers showed an unexpected moderate level of genetic differentiation and the absence of any geographic structure. Consequently, this study proposes that the taxonomic hypothesis of a single species of A. pallipes settling the Italian continental waters, is affected by complex evolutionary events. To solve the paradox, we hypothesized an evolutive scenario in which the separation of ancient mtDNA lineages likely occurred before the latest glacial periods. However, the speciation process remained incomplete due to secondary intensive postglacial contacts that forced the mingling of the genomes, and confounds the phylogeographic signature still detectable within mtDNA. Postglacial dispersion and the following demographic events, such as founder effects, drift and bottlenecks, abruptly depleted the local mtDNA variation, and shaped the current genetic population structure of white-clawed crayfish.

Relevant shellfish consumption data for dietary exposure assessment among high shellfish consumers, Western Brittany, France.

Shellfish consumption can be a major pathway of exposure to pollutants for humans. It is fundamental to know if people eat enough shellfish to cause health problems, firstly in high consumers as recreational shellfish harvesters. The objectives of this study were to investigate the types of shellfish eaten, number of meals, portion size, sources of shellfish and shellfish consumption rates among French recreational shellfish harvesters; to determine factors affecting consumption patterns and to examine the reliability of the two methods used: a Food Frequency Questionnaire and a one-month food diary. The mean consumption rates were 11.63 and 26.21 g/person/day for shellfish derived from a self-harvested source only and from all sources, respectively. Harvester consumption rates were between 6- and 15-fold higher than the general French population. The comparison between the FFQ and the food diary showed that results were reliable. Thereby, our results are relevant to assess risk due to shellfish consumption.

Levels of total arsenic in edible fish and shellfish obtained from two coastal sectors of the Atacama Desert in the north of Chile: use of non-migratory marine species as bioindicators of sea environmental pollution.

The Camarones (CB) and Vitor (VB) Bays are situated in the middle of Atacama Desert, and their economies are based on activities entirely associated with the extraction of marine produce. The aim of this study was to determine the total arsenic content in three species of fish and seven species of shellfish from these two bays. The quantification of the total arsenic content in these products was performed by Hydride-Generation Atomic Absorption Spectrometry, HG-AAS. The results showed that marine species associated with the CB sector had higher total arsenic levels than the same species in the area of VB, a finding attributed to much higher total arsenic concentrations in the water and soils of CB than VB. The species with the highest total arsenic concentration was the Venus antique (7.50 mg kg (-1)) from the CB, and the lowest total arsenic content was found in Cheilodactylidae variegatus (0.34 mg kg(-1)) from VB.

DNA barcoding of brackish and marine water fishes and shellfishes of Sundarbans, the world's largest mangrove ecosystem.

The present study aims to apply a DNA barcoding tool through amplifying two mitochondrial candidate genes i.e., COI and 16S rRNA for accurate identification of fish, aquatic molluscs and crustaceans of Sundarbans mangrove wetland, to build a reference library of fish and shellfishes of this unique ecosystems. A total of 185 mitochondrial COI barcode sequences and 59 partial sequences of the 16S rRNA gene were obtained from 120 genera, 65 families and 21 orders of fish, crustaceans and molluscs. The collected samples were first identified by examining morphometric characteristics and then assessed by DNA barcoding. The COI and 16S rRNA sequences of fishes and crustaceans were clearly discriminated among genera in their phylogenies. The average Kimura two-parameter (K2P) distances of COI barcode sequences within species, genera, and families of fishes are 1.57±0.06%, 15.16±0.23%, and 17.79±0.02%, respectively, and for 16S rRNA sequences, these values are 1.74±.8%, 0.97±.8%, and 4.29±1.3%, respectively. The minimum and maximum K2P distance based divergences in COI sequences of fishes are 0.19% and 36.27%, respectively. In crustaceans, the K2P distances within genera, families, and orders are 1.4±0.03%, 17.73±0.15%, and 22.81±0.02%, respectively and the minimum and maximum divergences are 0.2% and 33.93%, respectively. Additionally, the present study resolves the misidentification of the mud crab species of the Sundarbans as Scylla olivacea which was previously stated as Scylla serrata. In case of molluscs, values of interspecific divergence ranges from 17.43% to 66.3% in the barcoded species. The present study describes the development of a molecular and morphometric cross-referenced inventory of fish and shellfish of the Sundarbans. This inventory will be useful in future biodiversity studies and in forming future conservation plan.

Detoxification of paralytic shellfish poisoning toxins in naturally contaminated mussels, clams and scallops by an industrial procedure.

Paralytic shellfish poisoning (PSP) episodes cause important economic impacts due to closure of shellfish production areas in order to protect human health. These closures, if are frequent and persistent, can seriously affect shellfish producers and the seafood industry, among others. In this study, we have developed an alternative processing method for bivalves with PSP content above the legal limit, which allows reducing toxicity to acceptable levels. A modification of the PSP detoxifying procedure stablished by Decision 96/77/EC of the European Union in Acanthocardia tuberculata, was developed and implemented for PSP elimination in other bivalves species. The procedure was applied to 6 batches of mussels, 2 batches of clams and 2 batches of scallops, achieving detoxification rates of around 85%. A viable industrial protocol which allows the transformation of a product at risk into a safe product was developed. Although a significant reduction was obtained, in a sample circa 9000 µg STX diHCl equiv/kg, the final toxin level in these highly toxic mussels did not fall below the European limit. The processing protocol described may be applied efficiently to mussels, clams and scallops and it may be a major solution to counteract the closure of shellfish harvesting areas, especially if persistent.

Marketplace shrimp mislabeling in North Carolina.

Seafood mislabeling occurs in a wide range of seafood products worldwide, resulting in public distrust, economic fraud, and health risks for consumers. We quantified the extent of shrimp mislabeling in coastal and inland North Carolina. We used standard DNA barcoding procedures to determine the species identity of 106 shrimp sold as "local" by 60 vendors across North Carolina. Thirty-four percent of the purchased shrimp was mislabeled, and surprisingly the percentage did not differ significantly between coastal and inland counties. One third of product incorrectly marketed as "local" was in fact whiteleg shrimp: an imported and globally farmed species native to the eastern Pacific, not found in North Carolina waters. In addition to the negative ecosystem consequences of shrimp farming (e.g., the loss of mangrove forests and the coastal buffering they provide), North Carolina fishers-as with local fishers elsewhere-are negatively impacted when vendors label farmed, frozen, and imported shrimp as local, fresh, and wild-caught.

Authentication of Frozen Chilean Blue Mussel (Mytilus chilensis) Commercialized in the Town of Osorno, Southern Chile, Using PCR-RFLP Analysis.

BACKGROUND: DNA-based technologies are reliable authentication methods for food products, enabling the detection of fraud, non-intentional substitution and control of mislabeling. The Chilean blue mussel (Mytilus chilensis) is a seafood commercialized in Chile under different formats, including packages of frozen specimens. In this format, the valves of mussels are removed during processing, thus impeding identification of the product by the consumer due to the lack of external characters. OBJECTIVE: To assess the authenticity of frozen Chilean blue mussels commercialized in southern Chile, particularly in the town of Osorno. METHODS: Six commercial brands of frozen Chilean blue mussel were authenticated by the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method, based on the analysis of an 18S rDNA fragment. RESULTS: Restriction patterns obtained indicate that three brands (50%) proved to be 100% authentic, given that all specimens contained in the package were Chilean blue mussels. The other three brands (50%) contained specimens of other commercial mytilids, particularly the cholga mussel (Aulacomya ater), in a variable percentage (12.5-50%). CONCLUSION: This study based on the PCR-RFLP method provides evidence that Chilean blue mussels commercialized in a town located in southern Chile lack authenticity. This finding highlights the necessity for national producers to improve the production and/or packaging processes of this seafood. The authentication of commercial mussels is a matter of consumer interest and has been described in a recent patent on this issue that proposes an alternative methodology.

Identification of the razor clam species Ensis arcuatus, E. siliqua, E. directus, E. macha, and Solen marginatus using PCR-RFLP analysis of the 5S rDNA region.

Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis of the 5S ribosomal DNA region has been applied to the establishment of DNA-based molecular markers for the identification of five razor clam species: Ensis arcuatus, E. siliqua, E. directus, E. macha, and Solen marginatus. PCR amplifications were carried out using a pair of universal primers from the coding region of 5S rDNA. S. marginatus was simply distinguished by the different size of the amplicons obtained. Species-specific restriction endonuclease patterns were found with the enzymes Hae III for E. arcuatus, E. siliqua, and E. directus, and Acs I for E. macha, and when two enzymes were combined, the four species were also identified. Thus, this work provides a simple, reliable, and rapid protocol for the accurate identification of Ensis and Solen species in fresh and canned products, which is very useful for traceability and to enforce labeling regulations.

Freshwater mollusks at designated areas in eleven provinces of Thailand according to the water resource development projects.

The study was conducted at 75 collecting loci in 15 districts of 11 provinces in Thailand during 1999-2004. A total of 12,079 live mollusks were collected, 11,874 were snails and 205 were clams. The snails were comprised of 39 species and classified into 9 families: Ampullariidae, Bithyniidae, Buccinidae, Potamiopsidae, Stenothyridae, Thiaridae, Viviparidae, Planorbidae and Lymnaeidae. The clams were comprised of 14 species classified into 2 families: Amblemidae and Corbiculidae. Fifteen species were medically important snails: Pomacea canaliculata, Pila ampullacea, P. pesmei, P. polita, Bithynia (Digoniostoma) funiculata, B. (D.) siamensis goniomphalos, B. (D.) s. siamensis, Filopaludina (Siamopaludina) martensi martensi, F. (Filopaludina) sumatrensis polygramma, Melanoides tuberculata, Tarebia granifera, Helicorbis umbilicalis, Gyraulus convexiusculus, Indoplanorbis exustus and Radix rubiginosa. Of these 3 snail species harbored trematode cercariae. I. exustus harbored Echinostoma malayanum, Xiphidio and Schistosoma spindale, and R. rubiginosa and B. (D.) siamensis goniomphalos harbored Xiphidio and intestinal flukes, respectively.

Studies on the morphology of cercariae obtained from freshwater snails at Erawan Waterfall, Erawan National Park, Thailand.

The morphology of cercariae of freshwater snails from Erawan Waterfall, Erawan National Park, Kanchanaburi Province was studied between December 2002 and August 2003. The snail samples were collected by handpicking using a counts per unit of time sampling method. The cercariae, larva stage of a trematode, were investigated using the shedding method where they were categorized into three groups and six species. The first group, Pleurolophocercous cercariae, consists of Haplorchis pumillo (C1) and Stictodora tridactyla (C3). The second group, Furcocercous cercariae, consisted of Mesostephanus appendicalatus (C2), Transversotrema laruei (C6) and Cardicola alseae(C4). The third group, Xiphidio cercariae, has only one species which is Loxogenoides bicolor (C5). Out of 1163 snails, only 62 were found to be infected by cercariae, equivalent to a 5.33% infection rate. The infections grouped by species of the cercariae are as follows: C, 22 (1.9%), C, 29 (2.5%), C2 1 (0.1%), C6 1 (0.1%), C4 6 (0.5%) and C5 3 (0.3%). The freshwater snail samples consist of four species. From a total of 1163 samples, there are 687 Melanoides jugicostis, 91 Tarebia granifera, 296 Thiara scabra and 89 Melanoides tuberculata. Infections were found in 45 (6.5%), 6 (6.6%), 1 (0.3%) and 10 (11.2%), respectively.

Comparative proteomic analysis of two clam species: Chamelea gallina and Tapes philippinarum.

Clams have long been a fisheries and aquaculture sector of great importance in Italy, the main resource of fisheries is the Chamelea gallina of indigenous origin, whereas clams breeding is supported almost entirely by the Tapes philippinarum, a species of Indo-Pacific origin. Bivalve molluscs quality depends mainly on the water quality, and then by a series of factors such as water temperature and salinity, gametogenic cycle, food availability, and environmental conditions, that affect the Condition Index. In this work crude extracts obtained from the edible part of Chamelea gallina and Tapes philippinarum were analyzed by a proteomic approach based on a two-dimensional gel electrophoresis followed by liquid chromatography-tandem mass spectrometry, in order to detect biomarkers useful for identification of the two kinds of clams and to assess their nutritional characteristics. As a result, four differentially expressed spots were found and identified, namely enolase, cyclophilin-A, ribosomal protein L13 and actin-1.

Use of shape to distinguish Chamelea gallina and Chamelea striatula (Bivalvia: Veneridae): Linear and geometric morphometric methods.

The commercially fished striped venus clams Chamelea gallina and C. striatula (Bivalvia: Veneridae) are difficult to distinguish by inexperienced observers and the taxonomy of these species is still an issue of discussion. The differences in shape between C. gallina and C. striatula from Portuguese coastal waters were studied through conventional linear and geometric morphometric analysis, using both contour (elliptic Fourier analysis) and landmark-based methods. The relationships shell length vs. height, width, and total weight were significantly different between species. However, because there was a considerable overlap in the data sets, the species could not be distinguished using any combination of those linear measurements. Geometric morphometric methods provided shape variables that led to 0-6% misclassification rates between species; linear morphometric measures led to 16.8% error. Contour analysis revealed differences primarily in the shell umbo and lunular area. The umbo was more "sharp" and the lunula less pronounced in C. striatula than in C. gallina. Generalized procrustes superimposition (landmark analysis) showed that the main differences between species reside in the length of the pallial sinus. Thus, an index was developed (PI: Pallial Index = pallial sinus length/shell length), which was successfully used to separate the species (with 100% correct classification), i.e., specimens with PI lower than 0.119 belonged to C. gallina, whereas greater PI values were attributed to C. striatula. The use of these geometric morphometric methods allowed the detection of differences in shape between these two species and to develop an easy-to-use identification index. We encourage the development of analogous indices that apply the methods of geometric morphometrics to distinguish between other species whose identification is complicated.

[Determination of 27 microelements in 11 shellfishes].

Shellfish samples were prepared by microwave, and 27 microelements including Ca, Mg, K, Na, P, S, Zn, Mn, Fe, Cu, Cr, Co, Se, Sn, Ni, Al, Ti, V, Mo, Ba, Ge, Si, Cd, I, Pb, As and Hg were determined by ICP-AES. It was showed that ICP-AES had an obvious advantage in the determination of microelements, and shellfishes contained upwards of 20 kinds of microelements. Calcium in fresh water was higher than that in seawater, and As and Pb were the major pollutants.

PCR-based assessment of shellfish traceability and sustainability in international Mediterranean seafood markets.

Two mitochondrial markers (cytochrome oxidase COI and 16S rDNA) were employed for species identification of commercial shellfish from two Mediterranean countries. New COI Barcodes were generated for six species: Pleoticus robustus, Metapenaeopsis barbata, Parapenaeus fissuroides, Hymenopenaeus debilis, Metapenaeus affinis and Sepia aculeata. Biodiversity of the seafood species analyzed was greater in Egypt, with nine crustacean and two cephalopod species found compared with only three crustaceans and three cephalopods in Spain. In total, 17.2% and 15.2% products were mislabeled in Egypt and Spain, respectively. Population decline is a problem for some of the substitute species. Others were exotic and/or invasive in exporters' regions. This study offers the first comparable study of shellfish traceability in these Mediterranean markets. The PCR-based method used in this study proved to be reliable, effective and, therefore, could be employed for routine seafood analysis.