On the occurrence of a post-larval specimen of Brosme brosme (Gadiformes: Lotidae) on Porcupine Bank (west Ireland).

The occurrence of a small specimen of Brosme brosme (Gadiformes: Lotidae) from the Porcupine Bank is reported. A single specimen with a total length of 73.2 mm was caught with bottom trawl at a depth of 322 m depth in 2017. The specimen was identified morphologically and confirmed by molecular taxonomy using DNA barcoding. Based on the size and ontogenetic characters found, the specimen was identified as a post-larval individual, and a pelagic habitat of the specimen seems more likely.

Unveiling taxonomic diversity in the deep-sea fish genus Notacanthus (Notacanthiformes: Notacanthidae) with description of Notacanthus arrontei n. sp.

Notacanthid fishes constitute a common part of benthopelagic deep-sea fish communities on seamounts and continental slopes around the world. However, their highly conserved morphology and the usual lack of information on deep-water organisms make it difficult to appropriately address their biodiversity. A multidisciplinary approach combining morphological data with a DNA-based species delimitation analyses was used to explore the taxonomy of Notacanthus species. For this purpose, morphological and molecular data were obtained from 43 individuals, and the resulting information was combined with the available data. The results showed the occurrence of Notacanthus arrontei n. sp. from the Iberian Peninsula and highlighted several taxonomic conundrums regarding the Notacanthus genus. For instance, no significant differences were found between Notacanthus indicus and the recently described Notacanthus laccadiviensis, questioning its taxonomic status. Similarly, the result of the species delimitation molecular analysis coincided with previous DNA barcoding studies supporting the snubnosed spiny eel Notacanthus chemnitzii as a species complex that requires further research. Moreover, two unidentified records from the Indian Ocean were confirmed to belong to an unknown species pending formal description, and barcoding data show for the first time the occurrence of the shortfin spiny eel Notacanthus bonaparte in the Australia-New Zealand area. This research confirms the existence of important gaps in the knowledge of notacanthid fishes and represents a step forward toward a better understanding of their biological diversity.

DNA Barcoding of the Genus Magnisudis (Aulopiformes: Paralepididae) with a Coastal Record and Biological Features of Magnisudis atlantica.

One specimen of the duckbill barracudina Magnisudis atlantica of 402 mm TL was caught in a shallow coastal area in Galician waters, northwest of Spain. Morphometric and meristic parameters along with DNA barcoding, based on cytochrome c oxidase subunit I, were used to confirm the specimen identity. Neighbor-joining analysis of nominal sequences of the genus Magnisudis obtained from the Barcode of Life Data System indicates the presence of six representative groupings of potential species, in contrast to the three that are currently recognized as valid. The stomach contents showed remains of digested crustaceans, tentatively identified as Euphausiids. Histological examination of the gonads revealed the specimen to be an immature female with oocytes at the primary growth stage, indicative of a lack of hermaphroditism. The results add new biological and taxonomic data that contribute to improved understanding of these poorly characterized, mainly deep-water species, demonstrating, once again, the effectiveness of DNA barcoding for identifying deep-sea fishes and characterizing their genetic differences.

Gaidropsarus gallaeciae (Gadiformes: Gaidropsaridae), a New Northeast Atlantic Rockling Fish, with Commentary on the Taxonomy of the Genus.

A new species of rockling fish genus Gaidropsarus is described based on six specimens collected in Galicia and Porcupine Banks, in Atlantic European waters. An analysis of morphological characters has confirmed the specific status of specimens of a previously described clade by comparison of DNA sequences. Gaidropsarus gallaeciae sp. nov. it is distinguished from congeners by the following combination of characters: 43-44 vertebrae; 54-60 third dorsal fin rays; 44-52 anal fin rays; 21-23 pectoral fin rays; head length 21.1-25.2% of standard length (SL); length of the pelvic fin 16.2-19% SL; length of the first dorsal fin ray 15.8-27% of head length (%HL); eye diameter 15.8-20.5% HL; and interorbital space 21.7-28% HL. Using the nucleotide sequence of the 5' end of the mitochondrial COI gene as a molecular marker, the genetic p-distance between the new species and its congeners far exceeds the usual 2%, granting the former the status of an independent taxon, which is in accordance with the morphological identification. A comparison with the other 12 valid species of the genus is presented. The study also highlights the morphological diversity resulting from the meristic and biometric variability of Gaidropsarus species and lays the groundwork for future taxonomic studies on this genus.

Identification of the shell-boring parasite Polydora hoplura (Annelida: Spionidae) on wild stocks of Pecten maximus in Galician waters, NW Spain.

Infestations by shell-boring polychaetes have been gaining attention in recent years due to the harmful effects that their presence can pose to the growth and production of marine bivalves worldwide. The Galician region, located in the north-western corner of the Iberian Peninsula, is one of the major producers of marine bivalves in the word and therefore highly dependent on this industry. The recent finding of an unknown polychaete boring into the shells of the king scallop, Pecten maximus, has raised the attention of producers and authorities due to its potential harm to exploitable populations and the economical losses that could entail. The results from the morphological examination revealed the spionid Polydora hoplura as the only species present. DNA of a specimen was extracted and the mitochondrial 16S rRNA gene was partially sequenced for comparison with published sequences and confirmation of the morphological identification. Consequently, we report for the first time in the area the infestation of wild harvested populations of P. maximus by the mud worm Polydora hoplura. The presence of this shell-boring cosmopolitan invader could pose a threat to king scallop exploitation in Galicia; potential economic impacts need to be evaluated.

Unexpected deep-sea fish species on the Porcupine Bank (NE Atlantic): Biogeographical implications.

Four specimens corresponding to three rare deep-water fish species were caught on the Porcupine Bank (Northeast Atlantic) in September 2019. These catches include the new northernmost records of Azores rockling Gaidropsarus granti and deep-water dab Poecilopsetta beanii in the Atlantic Ocean and the second record of the latter species in its eastern zone. Three of the specimens were retained and their molecular identification also allowed the Cataetyx alleni DNA barcode to be obtained for the first time. The appearance of P. beanii, a West Atlantic species, in its eastern zone is discussed in relation to a possible phenomenon of transoceanic drift in the larval stage.

Apparently contradictory routes in the expansion of two fish species in the Eastern Atlantic.

One specimen of the boreal Clupea harengus (Clupeidae) was caught southerly, in the Gulf of Cádiz (southern Spain), whereas a specimen of the subtropical Epinephelus aeneus (Serranidae) was caught northerly, in Galician waters (north-west of Spain). These catches represent a new southernmost record in the eastern Atlantic for C. harengus and the second northernmost for E. aeneus. The co-occurrence of warm and cold affinity fishes in temperate latitudes is unusual, but the existence of anomalies in the temperature of the Atlantic waters could be behind these findings.

Geographic range expansion of Ephippion guttifer (Tetraodontidae) in the north-eastern Atlantic.

The first record of the prickly puffer Ephippion guttifer (Tetraodontidae) from Galician waters (north-west Spain) is reported based on a male specimen of 570 mm total length (LT ) caught in the Ría de Vigo. Morphometric, meristic and DNA barcode data confirmed the identification. Histological examination of reproductive tissue was carried out in this species for the first time, showing a mature male in an actively spawning phase. A historical revision invalidates a previous record and establishes this as the northernmost confirmed capture ever reported in the north-eastern Atlantic Ocean.

Phylogenetic analysis shows the general diversification pattern of deep-sea notacanthiforms (Teleostei: Elopomorpha).

The Notacanthiformes is an ancient group of deep-sea ray-finned fishes comprising 27 species in two families; Halosauridae and Notacanthidae. Although many studies have tried to reconstruct the phylogenetic relationships among the major clades of Elopomorpha, little is known about the evolutionary history of notacanthiforms. Molecular and morphological data were used to test previous hypotheses regarding the phylogenetic relationships among notacanthiform taxa, and to unravel the origin and evolution of this group. The molecular analyses of notacanthids showed similar results to those previously obtained employing osteological data, which proposed the existence of the Lipogenyinae (Lipogenys) and Notacanthinae (Notacanthus + Polyacanthonotus) subfamilies. Nevertheless, when the external morphology data is considered Lipogenys is more related to Notacanthus than Polyacanthonotus. The analyses could not fully resolve the inner relationships of the halosaurids. The time-calibrated tree of the order Notacanthiformes shows a long process of diversification spanning from the upper Cretaceous, to 50 million years after the K-Pg extinction, with the gradual emergence of all the modern families and genera of the group. This is the first specific phylogeny of the order Notacanthiformes, combining different analyses and data in order to obtain a wider perspective of the evolution and diversification of this group of fishes.

Phylogenetic comparison of opine dehydrogenase sequences from marine invertebrates.

Three cDNA sequences encoding putative opine dehydrogenase (OpDH) enzymes from the mussel Mytilus galloprovincialis were obtained. The deduced amino acid sequences were clearly distinguishable from each other, showing that several OpDH transcripts could occur in the mussel tissues (p distance 0.46-0.55). When these sequences were aligned and compared with published databank proteins, the range of identity among the M. galloprovincialis OpDH and the strombine dehydrogenase from Ostrea edulis was 51-59 %, the best hit in the three comparisons, followed by OpDH enzymes from other marine invertebrates. Sequence alignment revealed structural motifs possibly related to the binding sites of the substrates. A phylogenetic analysis compared M. galloprovincialis OpDH and annotated sequences belonging to five phyla and seven taxonomic classes, including 19 species, representing the five OpDH protein family members. The phylogenetic tree clustered the OpDH enzymes according to the evolutionary relationships of the species and not to the biochemical reaction catalyzed.

Taxonomic study of Bathygadidae fishes (Gadiformes) from Atlantic Spanish waters combining morphological and molecular approaches.

From 2009 to 2011 eleven specimens belonging to four bathygadid species of the family Bathygadidae were captured in two different locations in the northern waters of Spain. The morphometric measurements and meristic characters of these specimens are given. The specimens were identified as belonging to the genera Gadomus Regan, 1903, and Bathygadus Günther, 1878, including the following species: Gadomus dispar (Vaillant, 1888), Gadomus longifilis (Goode & Bean, 1885), Gadomus arcuatus (Goode & Bean, 1886) and Bathygadus melanobranchus Vaillant, 1888. As a result, a new northern limit of distribution of G. arcuatus from the northeastern Atlantic is reported. The first molecular identification and genetic interrelationships of Bathygadidae species, based on the mitochondrial COI nucleotide sequences -DNA barcodes- is reported. Sequences corresponding to specimens from the same species were identical and the overall mean genetic diversity (uncorrected p-distance) was 0.096 ± 0.008. Based on a morphological and meristic examination of the specimens, as well as on the available literature, an updated key of the members of the family Bathygadidae from the north-eastern Atlantic Ocean is provided.

Identification of octopine dehydrogenase from Mytilus galloprovincialis.

A cDNA encoding the putative octopine dehydrogenase (OcDH) from the mussel Mytilus galloprovincialis was cloned and sequenced. The complete coding region was expressed in the bacteria Escherichia coli and the recombinant protein was purified. The M. galloprovincialis OcDH appears to have the highest affinity for the amino acid substrate L-arginine (88.22%), compared to L-alanine (9.04%) and glycine (2.74%). This enzyme showed no activity when taurine or ß-alanine was used as substrate. These data strongly support that this recombinant enzyme is octopine dehydrogenase and not another opine dehydrogenase such as alanopine or strombine dehydrogenases. The superimposition of the theoretical three-dimensional model of the M. galloprovincialis OcDH and the crystal structure of its homologous counterpart from the great scallop Pecten maximus showed interesting changes in the amino acid binding site which could explain the differences found in the substrate affinity between the two molluscs. A phylogenetic analysis was performed comparing M. galloprovincialis OcDH and annotated sequences representing the five opine dehydrogenase (OpDH) protein family members. The phylogenetic tree which was obtained clustered the OpDH enzymes according to the evolutionary relationships of the species and not to the biochemical reaction catalysed. Octopine dehydrogenase has been identified in the Mytilidae family for the first time, having previously only been established in one other marine invertebrate (P. maximus).

A microsatellite genetic map of the turbot (Scophthalmus maximus).

A consensus microsatellite-based linkage map of the turbot (Scophthalmus maximus) was constructed from two unrelated families. The mapping panel was derived from a gynogenetic family of 96 haploid embryos and a biparental diploid family of 85 full-sib progeny with known linkage phase. A total of 242 microsatellites were mapped in 26 linkage groups, six markers remaining unlinked. The consensus map length was 1343.2 cM, with an average distance between markers of 6.5 +/- 0.5 cM. Similar length of female and male maps was evidenced. However, the mean recombination at common intervals throughout the genome revealed significant differences between sexes, approximately 1.6 times higher in the female than in the male. The comparison of turbot microsatellite flanking sequences against the Tetraodon nigroviridis genome revealed 55 significant matches, with a mean length of 102 bp and high sequence similarity (81-100%). The comparative mapping revealed significant syntenic regions among fish species. This study represents the first linkage map in the turbot, one of the most important flatfish in European aquaculture. This map will be suitable for QTL identification of productive traits in this species and for further evolutionary studies in fish and vertebrate species.

Combined use of established and novel tumour markers in the diagnosis of head and neck squamous cell carcinoma.

Serum SCC, CYFRA 21-1, and CEA are the common tumour markers for head and neck squamous cell carcinoma (HNSCC), although diagnostic sensitivity should be yet improved, especially at early stages. In the present study, we have reported the diagnostic value of two novel serum tumour markers in HNSCC: alpha-L-fucosidase (AFU) activity, and total sialic acid concentration adjusted by total protein concentration (TSA/TP). Using the cut-off 4.0 U/ml, AFU showed a sensitivity of 55% with specificity levels of 91%, 85% and 50% to discriminate HNSCC patients from healthy donors, drinking and smoking subjects, and patients with benign diseases, respectively. Furthermore, AFU showed the best sensitivity (71%) in the detection of patients with premalign lesions. Using the cut-off 12.0 ng/mg, TSA/TP showed the best sensitivity levels (63%) in the diagnosis of HNSCC with specificity levels of 94%, 50% and 90%, regarding healthy donors, drinking and smoking subjects, and patients with benign diseases, respectively. It was of special interest that sensitivity in the diagnosis of HNSCC at non-disseminated stages was improved when using combinations of AFU+CYFRA or TSA/TP+CYFRA, up to 86% or 71% in TNM I, 60% or 80% in TNM II, and 80% or 60% in TNM III, respectively.

Purification of human alpha-L-fucosidase precursor expressed in Escherichia coli as a glutathione S-transferase fusion protein.

Alpha-L-fucosidase (FUC) is a glycosidase involved in the degradation of fucose-containing glycoconjugates. A cDNA representing the complete sequence of human FUC was inserted into the prokaryotic expression vector pGEX-2T. High levels of the glutathione S-transferase (GST) fusion protein were detected in Escherichia coli cells after induction with isopropyl thio-beta-D-galactopyranoside. The GST-FUC protein was mostly found as inclusion bodies and attempts to optimise its expression as a soluble form were unsuccessful. Nevertheless, the recombinant protein was purified by affinity chromatography on glutathione-sepharose and its fucosidase activity was characterised. After thrombin cleavage of the GST tag, the FUC precursor protein was purified by electro-elution.

Lectin isolation and detection of N-glycoproteins bearing sialic acid and L-fucose residues in human colorectal mucosa and in adenocarcinoma biopsies.

A method to improve the reactivity to specific lectins of N-glycoproteins isolated from human colorectal mucosa and from adenocarcinoma biopsies was developed using a combination of techniques. Total protein extracts were subjected to affinity chromatography, using the immobilised lectin Concanavalin A coupled to Sepharose, by fast performance liquid chromatography (FPLC). N-glycoprotein enriched fractions were resolved by SDS-PAGE, transferred to PVDF membranes and incubated with various lectins. Digoxigenin-conjugated SNA I and MAA lectins were used to detect sialic acid residues. Biotin-conjugated UEA I lectin was used to detect L-fucose residues. By this method, lectin-binding N-glycoproteins were found in a broad relative molecular mass (Mr) range (from 47 to 205 kDa). No tissue-specific N-glycoproteins were observed when human colorectal mucosa and adenocarcinoma samples were compared.