Molecular characterisation of a turbot Mx cDNA.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
E Abollo
Publications and source records attributed to E Abollo.
Occurrence of recombinant genotypes of Anisakis simplex s.s. and Anisakis pegreffii (Nematoda: Anisakidae) in an area of sympatry.
The anisakid nematode populations collected from fish and stranded cetaceans along from Iberian Peninsula waters were morphologically identified as corresponding to the Anisakis simplex complex. In order to realise their molecular identification and to analyse the extent of genetic variation, the entire ITS (ITS1, 5.8S rDNA gene and ITS2) and the mitochondrial small subunit of rRNA were pcr-amplified and sequenced. Digestions of the amplified its region with HinfI and HhaI allowed the identification of three different genotypes, belonging to A. simplex s.s., A. pegreffii and a yet not described recombinant genotype. The ITS sequences of the recombinant genotypes showed the presence of heterozygotes C/T at position 240 and 256 of the aligned sequence. Otherwise, the analysis of mtDNA sequences showed the existence of a different parental origin for recombinant genotypes. In order to check if they can be the products of a polymorphism normally occurring both in A. pegreffii and in A. simplex s.s., and/or the existence of an incomplete concerted evolution, three samples were also collected as controls in isolated geographic areas, where sympatric coexistence between A. simplex s.s. and A. pegreffii does not occur. The results supports the hypothesis that the recombinant individuals may be a product of interspecific hybridisation, and describe the Iberian Peninsula waters as a hybrid zone for the two sibling species.
Animals↗
Observations on associated histopathology with Aggregata octopiana infection (Protista: Apicomplexa) in Octopus vulgaris.
Gamogony and sporogony of Aggregata octopiana were commonly observed during histological examination of the digestive tract of wild Octopus vulgaris from Ria de Vigo (NW Spain). A. octopiana infected noncuticularized caecum and intestine, and cuticularized oesophagus and crop. Infection was also observed in the gills and in covering mesenterium, mainly of the digestive gland and gonad. Histological and ultrastructural lesions associated with A. octopiana included host cell hypertrophy with nuclear displacement, inflammation, phagocytosis, ulceration and destruction of organ architecture. The possible existence of a malabsorption syndrome in the host is deduced.
Animals↗
Fitness of the marine parasitic nematode Anisakis simplex s. str. in temperate waters of the NE Atlantic.
In temperate waters of the NE Atlantic, third-stage larvae of Anisakis simplex sensu stricto collected from 3 paratenic host species were identified by restriction fragment length polymorphisms. The condition of wild larval infrapopulations was assessed by examining morphometric and growth characteristics. The differentiation patterns and the excretory/secretory products of larvae grown in vitro were also examined. An extensive morphometric, growth and differentiation variability was found between parasite larvae collected from different paratenic host sources. Nematode infrapopulation larvae from the squid comprise those smaller individuals with the lowest values of survival rates and moult success. It may be then concluded that the fitness of A. simplex s. str. larvae is not the best possible in the squid, which impaired the competitiveness of the parasite and its chances of developing into an adult. This suggests that the microenvironments impaired by the paratenic host may provide larval infrapopulations with unique ecological factors probably influencing its recruitment to the final host populations.
Animals↗
Anisakis infestation in marine fish and cephalopods from Galician waters: an updated perspective.
A total of 2,673 fresh specimens of cephalopod and fish representing 35 species were obtained from commercial local fisheries in Galician waters (NW Spain). They were examined for anisakid nematodes by digestion of the muscle and elution of the viscera and whole body cavity. All larval nematodes recovered were identified by light microscopy and multilocus electrophoresis as belonging to the species Anisakis simplex sensu stricto and A. pegreffii. Encysted larvae mostly occurred in the viscera but were also found in the flesh of squid and fish. Demographic values for larval nematodes are discussed in relation to host preferences and the ecological niche of both anisakid species at the sampling area. Primary recommendations are also expressed concerning the effects of current fishing and aquaculture practices on the Anisakis problem.
Animals↗
Genetic divergence and reproductive isolation between Anisakis brevispiculata and Anisakis physeteris (Nematoda: Anisakidae)s.
In order to assess the taxonomic status of Anisakis brevispiculata Dollfus, 1966 population samples of this taxon from central and south-eastern Atlantic ocean were compared at 22 enzymatic loci with samples belonging to Anisakis physeteris Baylis, 1923 from the Mediterranean sea and central-eastern Atlantic ocean. Very low interpopulational genetic divergence was observed both within A. brevispiculata (average D(Nei) = 0.008) and within A. physeteris (D(Nei) = 0.009) despite the geographic distance among the samples, indicating high levels of gene flow in both taxa. On the other hand, the average genetic distance between A. brevispiculata and A. physeteris was found to be D(Nei) = 0.80, a value generally observed between well differentiated congeneric species. The reproductive isolation between A. brevispiculata and A. physeteris is indicated by the following observations: (1) no F(1) hybrids or recombinant genotypes were until now observed; and (2) the two Anisakis species do not seem to share their definitive hosts. The main definitive host of A. brevispiculata is the pygmy sperm whale (Kogia breviceps), while for A. physeteris it is the sperm whale (Physeter catodon). Only adult males differ slightly in spicule length, while females and larval stages are not differentiated morphologically. Both A. brevispiculata and A.physeteris show a type II larva. The correct recognition of A. brevispiculata from A. physeteris and from other Anisakis species studied, in either sexes and at any life stage, is made easy by allozyme markers (e.g. Icdh, Gapdh, Sod-1, Np, Aat-2, Adk-2, fEst-2, PepB, PepC-2, Mpi). Diagnostic keys, which can be used for routine identification in the field of these Anisakis worms, based on genetic markers, are given.
Animals↗
Element concentration variability in the whaleworm Anisakis simplex s.l.
Concentrations of the elements C, N, Fe, Na, K, Ca and Mg were analysed by chromatography and atomic absorption spectrometry in the whaleworm Anisakis simplex sensu lato. Nearly all mean inorganic element concentrations measured were higher in adult worms than in larval forms. Similarly, adults contained significantly higher nitrogen (i.e. lower C/N ratio values) than either eggs or larvae. Evidence for the significance of the parasitic life cycle stage and the systematic position of their hosts on the element concentration variability is discussed.
Animals↗
Anisakid infection in the European shag Phalacrocorax aristotelis aristotelis.
A total of 100 specimens of the European shag Phalacrocorax aristotelis aristotelis were examined for anisakid infections in the south-east North Atlantic. The taxonomic status of the anisakid nematodes was studied by structural analysis using light and scanning electron microscopy. Two species, Contracaecum septentrionale and C. rudolphii A (Nematoda: Ascaridoidea), occurred in the European shag with high values of prevalence and mean intensities of infection. These constitute new host records for both parasites, widening their known geographical distribution. Although the histopathology associated with the infections indicated that the anisakids did not have the potential to cause bird death, the parasites are capable of contributing to and hastening avian mortality in the case of heavily-parasitized cormorants and when stressed by xenobiotics and/or through a synergetic effect by other bioagressors.
Animals↗
Elemental analysis of cetacean skull lesions associated with nematode infections.
The elemental composition of both healthy and eroded cetacean skulls associated with nematode infections was evaluated. A total of 27 samples of eroded and non-eroded prepared museum cetacean skulls were characterised by elemental (CHN), X-ray fluorescence, and X-ray diffraction methods. The inorganic composition and crystal line structure (hydroxylapatite-like minerals) were similar for both types of skull samples, but the CHN values clearly differed. The results suggest that the carbon-rich fraction is lost in eroded areas, probably as a result of glycosaminoglycan-degrading Crassicauda enzymes.
Animals↗
Aggregata sagittata n. sp. (Apicomplexa: Aggregatidae), a coccidian parasite from the European flying squid Todarodes sagittatus (Mollusca: Cephalopoda).
A new species of the coccidian genus Aggregata Frenzel, 1885 (Apicomplexa, Aggregatidae) is described from the digestive tract of Todarodes sagittatus (Lamarck), an ommastrephid squid that lives in temperate waters in the northeastern Atlantic Ocean. Using light microscopy. oöcysts were 225-333 microm in length and 220-323 microm in width. Each oöcyst contained 600-1,000 sporocysts. Sporocysts were 16-18 microm in length and 15-17 microm in width, with a smooth surface and thick wall. Each sporocyst contained 4-8 sporozoites each with a length of 11-13 microm. This paper presents the description of a new Agregata species in a nerito-oceanic flying squid. Moreover. it extends the distribution of Aggregata to oceanic cephalopod host species. A. sagittata represents the third named species in the genus Aggregata in European waters and the seventh worldwide.
Animals↗
Larval nematodes (Spiruroidea: Cystidicolidae) in Octopus vulgaris (Mollusca: Cephalopoda: Octopodidae) from the northeastern Atlantic Ocean.
Larval nematode parasites (Spiruroidea: Cystidicolidae) are recorded for the first time in Octopus vulgaris Cuvier, 1797 in the northeastern Atlantic Ocean. Prevalence was 16% and mean intensity was 1.46 worms/host. Body length of larval nematodes ranges from 8.3 to 9.3 mm, with a distance from the anterior end to nerve ring from 187.5 to 200 microm, and to excretory pore 194.6-350 microm. Anatomical characteristics, such as deirid, nerve ring, cephalic alae, excretory pore, pseudolabia amphids, sclerotized protuberance, and anus, examined using light microscopy (LM) or scanning electron microscopy (SEM), are illustrated. The nematode was designed as a cystidicolid "Type A" larva. The hemocytic infiltration present in the host tissue around the nematode capsule and the mechanical compression in the infected organs denote the pathogenicity of this nematode. In the study area, O. vulgaris may play the role of an intermediate or paratenic host in the nematode life cycle.
Animals↗
Macroparasites in cetaceans stranded on the northwestern Spanish Atlantic coast.
An extensive parasitological survey was carried out during autopsy of 80 cetaceans representing 8 species within 4 families (Delphinus delphis, Stenella coeruleoalba, Tursiops truncatus, Grampus griseus, Globicephala melas, Kogia breviceps, Phocoena phocoena and Megaptera novaeangliae) collected on the northwestern Spanish Atlantic coast from February 1991 to October 1996. Two species of tetraphyllidean cestodes (Phyllobothrium delphini and Monorygma grimaldii), 2 ascaridoid nematodes (Anisakis simplex and A. physeteris), a single spirurid nematode (Crassicauda magna), 4 rhabditidiform nematodes (Halocercus delphini, H. invaginatus, Halocercus spp. and Stenurus globicephalae), a single polymorphynae acanthocephalan (Bolbosoma sp.), and 2 amphipods (Isocyamus delphini and Cyamus boopis) were found. This paper presents 6 new geographic records of macroparasites from cetaceans in temperate Atlanto-Iberian waters. A total of 11 component parasite species were found, mainly parasitizing the blubber, mesentery and stomach of cetaceans. Cetaceans harboured a suite of 4 generalist and 8 specialist species.
Animals↗
Long-term recording of gastric ulcers in cetaceans stranded on the Galician (NW Spain) coast.
Long-term (1990-1996) results of recording gastric ulcers in the common dolphin are presented for the NW Spanish Atlantic coast. The occurrence and abundance of cetacean carcasses (belonging to 10 species) with gastric ulcers are also given and discussed. Ulcerations were detected in 17.2% of the animals examined, with 15% for common dolphins and 0 to 29.4% in other cetacean species. A positive relation was noted between ulcer counts and length and maturity of Delphinus delphis. Clusters of the nematode Anisakis simplex could be seen embedded in the gastric ulcers of 3 common dolphins. It could be concluded that gastric ulcers are non-fatal lesions in cetaceans stranded in NW Spain.
Animals↗