[show abstract][hide abstract] ABSTRACT: A parasitological study of rays captured on the Atlantic continental shelf off the estuary Muros-Noia in NW Spain (42 degrees 35' to 42 degrees 41' N, 9 degrees 2' to 9 degrees 10' W; mean capture depth 11.6 +/- 4.1 m) was performed. A total of 128 rays were examined: 52 specimens of Raja microocellata, 60 of R. brachyura, 6 of R. montagui, 3 of R. undulata and 7 of an unidentified Raja species, known locally as 'fancheca'. A total of 23 macroparasite species were detected: 5 monogeneans (Acanthocotyle sp., Calicotyle kroyeri, Empruthotrema raiae, Merizocotyle undulata, Rajonchocotyle emarginata), 11 cestodes (Acanthobothrium sp., Crossobothrium sp., Echeneibothrium sp., Echinobothrium brachysoma, Grillotia erinaceus, Grillotia sp., Lecanicephalum sp., Nybelinia lingualis, Onchobothrium uncinatum, Phyllobothrium lactuca, Tritaphros retzii), 6 nematodes (Anisakis simplex, Hysterothylacium sp., Histodytes microocellatus, Piscicapillaria freemani, Proleptus sp., Pseudanisakis baylisi) and a copepod (Holobomolochus sp.). All parasite species were present in several ray species, except for Acanthocotyle sp. and G. erinaceus (detected only in R. brachyura), H. microocellatus (detected only in R. microocellata) and T. retzii (detected only in R. montagui). Three species (C. kroyeri, M. undulata, E. brachysoma) have not been reported previously from Spain. The host with the highest parasite species richness was R. brachyura (18 species), followed by R. microocellata (17) and the unidentified Raja species (14). The parasite with the highest prevalence in R. microocellata was M. undulata, followed by R. emarginata, Acanthobothrium sp. and Echeneibothrium sp. The species with the highest prevalence in R. brachyura was R. emarginata, followed by C. kroyeri and P. baylisi. Some differences in parasite prevalence were detected between sexes and among size classes in both R. brachyura and R. microocellata.
Diseases of Aquatic Organisms 07/2006; 70(1-2):93-100. · 1.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Blood smears from 132 skates Raja spp. captured on the continental shelf off Galicia (NW Spain) were examined for blood parasites. The skate species were Raja brachyura (n=60), R. microocellata (n=52) and a total of 20 specimens belonging to R. undulata, R. montagui and another 2 unidentified Raja species, all captured between March 1999 and March 2000. Two blood parasite species were found, Trypanosoma giganteum and Haemogregarina delagei. Of the 132 skates, 16% were infected only by T. giganteum, 17% only by H. delagei, and 5% by both T. giganteum and H. delagei. Both parasites showed highest prevalence in R. brachyura (22% T. giganteum only, 38% H. delagei only, 12% T. giganteum and H. delagei). Mean leucocyte percentages (n=132 fish) were lymphocytes (43%), eosinophils (35%), neutrophils (20%) and monocytes (2%); basophils were not found. As far as we are aware, this eosinophil percentage is the highest reported to date for elasmobranchs. We did not detect any statistically significant differences in leucocyte percentages between infected and uninfected fish, between male and female fish, among species or among weight groups.
Diseases of Aquatic Organisms 07/2005; 65(1):63-8. · 1.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: In a study of the parasite fauna of the European eel (Anguilla anguilla L.) in northwest Spain, we found frequent mixed infection of branchial tissues by the myxosporidian Myxidium giardi (prevalence 95%) and by two monogeneans (Pseudodactylogyrus anguillae and P. bini; joint prevalence 56%). All three species are common parasites in this host. In one of the 323 eels examined, hyperparasitism of P. bini by M. giardi was detected. This eel contained 281 individuals of Pseudodactylogyrus spp., of which 94% were P. bini. Spores of the myxosporidian were detected in 30% of the P. bini individuals, while corpuscles of unknown origin were detected in all of the P. bini individuals (but not in any P. anguillae individuals, or in P. bini individuals in other eels).
Bulletin- European Association of Fish Pathologists 01/2004; 24(6):287-292. · 0.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: We describe a new genus, Histodytes, within the family Guyanemidae (Nematoda: Spirurida: Camallanina: Dracunculoidea). The type species, Histodytes microocellatus n. sp., is found in the gill, heart, kidney, spleen and gonad tissues of Raja microocellata from the continental shelf off the estuary of Muros y Noia (north-western Iberian Peninsula). Histodytes differs morphologically from the three other genera described to date in this family ( Guyanema, Travassosnema, Pseudodelphys) because the vulva is situated a long way back from the oesophageal-intestinal union, and the anterior uterine branch almost reaches to the level of this union. In addition, it can be distinguished from Guyanema and Travassosnema by the absence of caudal alae in the male, and from Travassosnema by the much greater length of the glandular oesophagus and the lack of an oesophageal appendix. Histodytes is the only guyanemid genus described to date from an elasmobranch and the first one to be found on the European Atlantic coast.
Parasitology Research 11/2002; 88(10):932-40. · 2.85 Impact Factor
[show abstract][hide abstract] ABSTRACT: This study investigated the spatial distribution of Tetramicra brevifilum spores in the musculature of infected turbot Scophthalmus maximus, with the aim of identifying the most appropriate body locations for diagnostic assays. A PCR protocol optimized for the detection of T. brevifilum spores in turbot muscle is also described. In fish showing low- and moderate-intensity infection, the spatial distribution of spores was best fitted by a negative binomial distribution, indicating a clumped spatial pattern; the negative binomial coefficient k was lower for fish with low-intensity infection, indicating a more markedly clumped pattern in these fish. In fish with high-intensity infection, the spatial distribution of spores was best fitted by the Poisson distribution, indicating a random pattern. In both low- and moderate-intensity infection, spores were present at highest density in the musculature adjoining the dorsal fins. Samples for PCR were therefore obtained from this location. PCR amplification was of the small subunit ribosomal DNA (SSUrDNA), using a pair of species-specific primers that amplify the 1250 bp product. The PCR protocol developed showed better sensitivity than microscopical techniques (detection rate by microscopy 25%, versus 42% by PCR), suggesting that it may be useful for routine screening for Tetramicra brevifilum infection in cultured turbot.
[show abstract][hide abstract] ABSTRACT: Durante el período comprendido entre marzo de 1999 y marzo de 2000, se realizó
el análisis de la helmintofauna presente en el intestino en espiral de 132 rayas
(Raja brachyura, R. microocellata, R. montagui. R. undulata y Raja spp.),
capturadas en la plataforma continental gallega. En la región anterior del intestino
en espiral de R. brachyura. R. microocellata y R. montagui se encontró un cestodo
identificado como Echinobothrium brachysoma Pintner, 1889, el cual se caracteriza
por poseer un rostelo armado con 9 ganchos largos en cada botridio, situados en
una hilera y flanqueados por 3 ganchos pequeños. El pedúnculo cefálico consta de 8
hileras formadas por 14 ganchos cada una. La segmentación es acraspedota, cirro
armado y ovario posterior lobulado. Tiene 8 y 9 testículos por segmento. La
prevalencia es del 10% y la intensidad media de 26 parásitos. Se realizó un estudio
detallado de la morfología interna mediante microscopía óptica y de la superficie
externa haciendo uso de la microscopía electrónica de barrido. Por primera vez se
informa sobre este grupo de cestodo parasitando peces en la Península Ibérica.