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- What can metazoan parasites reveal about the taxonomy of Scomber japonicus Houttuyn in the coast of South America and Madeira Islands?Publication . Oliva, M. E.; Valdivia, I. M.; Costa, G.; Freitas, N.; Carvalho, M. A. Pinheiro de; Sánchez, L.; Luque, J. L.The metazoan parasites of four populations of the chub mackerel Scomber japonicus were analysed from two localities in the Atlantic Ocean (Madeira Islands, Portugal, and Rio de Janeiro, Brazil) and two localities in the Pacific Ocean (Callao, Peru, and Antofagasta, Chile), collected during 2002 and 2003. A total of 373 fish specimens were studied and 34 metazoan parasite species were obtained. Parasites identified from the populations of chub mackerel studied could be separated into three categories: parasites with a wide distribution, present in the Pacific and Atlantic, parasites proper of the Pacific Ocean and parasites proper of the Atlantic Ocean. The analyses of some highly specific parasites of the genus Scomber (i.e. monogeneans of the genus Kuhnia and didymozoid digeneans) strongly suggest the need for a revision of the taxonomic status of chub mackerels from the Atlantic and Pacific coast of America. The results demonstrated the usefulness of parasites as adequate tools to clarify the taxonomic status of their hosts.
- Suspected viral erythrocytic necrosis (VEN) in the intertidal fish Mauligobius maderensis from Madeira, PortugalPublication . Eiras, J. C.; Costa, G.; Biscoito, M.; Davies, A. J.Suspected viral erythrocytic necrosis (VEN) was detected in two specimens of the intertidal fish Mauligobius maderensis (Teleostei: Gobiidae) from Madeira, Portugal. While one host was lightly infected, the other showed intraerythrocytic cytoplasmic inclusions within all mature erythrocytes examined. The inclusions were round to oval, 0-8-2-0 |im in diameter, and most were associated with dense eosinophilic granular areas of various sizes and shapes. Up to three of these granular regions accompanied each inclusion body, but they were sometimes widely separated from it. In a number of infected erythrocytes, a granular halo was observed surrounding the nucleus. The cytoplasm enclosed by the halo often had a different refringence from that outside. None of the 120 other fishes examined from Madeira, representing 43 species of intertidal, pelagic, and deep-sea origin, had detectable infections.
- Genetic markers in the study of Anisakis typica (Diesing, 1860): larval identification and genetic relationships with other species of Anisakis Dujardin, 1845 (Nematoda: Anisakidae)Publication . Mattiucci, S.; Paggi, L.; Nascetti, G.; Portes Santos, C.; Costa, G.; Di Beneditto, A.P.; Ramos, R.; Argyrou, M.; Cianchi, R.; Bullini, L.Genetic variation at 21 gene-enzyme systems was studied in a sample of an adult population of Anisakis typica (Diesing, 1860) recovered in the dolphin Sotalia fluviatilis from the Atlantic coast of Brazil. The characteristic alleles, detected in this population, made it possible to identify as A. typica, Anisakis larvae with a Type I morphol ogy (sensu Berland, 1961) from various fishes: Thunnus thynnus and Auxis thazard from Brazil waters, Trachurus picturatus and Scomber japonicus from Madeiran waters, Scomberomorus commerson, Euthynnus affinis, Sarda orientalis and Coryphaena hippurus from the Somali coast of the Indian Ocean, and Merluccius merluccius from the Eastern Mediterranean. Characteristic allozymes are given for the identification, at any life-stage and in both sexes, of A. typica and the other Anisakis species so far studied genetically. The distribution of A. typica in warmer temperate and tropical waters is confirmed; the definitive hosts so far identified for this species belong to delphinids, phocoenids and pontoporids. The present findings represent the first established records of intermediate/paratenic hosts of A. typica and extend its range to Somali waters of the Indian Ocean and to the Eastern Mediterranean Sea. A remarkable genetic homogeneity was observed in larval and adult samples of A. typica despite their different geographical origin; interpopulation genetic distances were low, ranging from DNei = 0.004 (Eastern Mediterranean versus Somali) to DNei = 0.010 (Brazilian versus Somali). Accordingly, indirect estimates of gene flow gave a rather high average value of Nm = 6.00. Genetic divergence of A. typica was, on average, DNei = 1.12 from the members of the A. simplex complex (A. simplex s.s, A. pegreffii, A. simplex C) and DNei = 1.41 from A. ziphidarum, which all share Type I larvae; higher values were found from both A. physeteris (DNei = 2.77) and A. brevispiculata (DNei = 2.52), which have Type II larvae (sensu Berland, 1961). Genetic relationships among these species are shown using multidimensional scaling ordination (MDS). The genus Anisakis appears to be phylogenetically heterogeneous and includes two distinct groups of species, which are morphologically and genetically differentiated.
- Evaluation of wheat germplasm from the Madeira and Canary archipelagos using a single molecular marker. A rapid screening method for identification of durum wheat accessionsPublication . Andrade, V.; Santos, T.; Afonso Morales, D.; Costa, G.; Carvalho, M. Pinheiro deThis work aims to present a rapid and precise screening method of wheat germplasm and identification of durum wheat accessions in germplasm collections. Fifty-two wheat accessions maintained in the ISOPlexis germplasm bank at the Madeira University, Portugal, and 72 accessions from the Centre for Conservation of Crop Biodiversity of Tenerife (CCBAT), Spain, have been screened for their specific ploidy status using the molecular marker Dgas44. We have demonstrated that the Dgas44 sequence is effective in the screening of Madeiran and Canarian wheat accessions. This screening method permitted the detection of 10 and 11 durum accessions among Madeiran and Canarian wheats, accounting for 19.2 and 15.3% of screened collections, respectively. The obtained results have shown a 100% of cases correspondence with the previously performed morphological identification of the Madeiran wheats. It also permitted rectification and clarification of previous classification of some accessions based only on the morphological traits. The PCR based assay was directly applicable to the screening of seeds and was suitable for detecting seed mixtures in accessions. This rapid method has been proven to be a useful tool in gene bank accessions management including verification of their ploidy status and detection of seed lots adulteration.
- A checklist of digenean parasites (Platyhelminthes: Digenea) infecting molluscs and fishes in Portuguese waters (Northeast Atlantic)Publication . Costa, G.; Soares, S.; Moreira, E. MeloThe present work is a compilation of the digenean parasites infecting molluscs (gastropods and bivalves), crabs and fishes of the Atlantic coast of Portugal and the Archipelagos of Azores and Madeira, based on literature sources, including research conducted by the present authors. A total of 65 digenea taxa were found, belonging to 24 families, infecting gastropods, bivalves, shore crabs and fishes. The most representative families of digeneans were the Hemiuridae (11 taxa), followed by the Bucephalidae (5 taxa), Opecoelidae (5 taxa) and the Zoogonidae (5 taxa). Hosts, site of infection, sampling locality and life cycle strategy are given when available. Further fields of research on the digenean parasites are suggested.
- Soil conditions and evolution of aluminium resistance among cultivated and wild plant species on the Island of MadeiraPublication . Ganança, J. F. T.; Abreu, I.; Sousa, N. F.; Paz, R. F.; Caldeira, P.; Santos, T. M. M. dos; Costa, G.; Slaski, J. J.; Carvalho, M. Â. A. Pinheiro deSoil samples collected from different soil formations throughout the Island of Madeira were analysed for pH, aluminium (Al) and organic matter content. On average, the Madeira soils appeared to be acid with a mean pH of 5.01, containing 0.79 cmol/kg of ionic Al and 3.02% organic matter, which may create favourable conditions for the development of Al resistance among plant species inhabiting the island. Six plant species were evaluated for their resistance to Al using the erichrome cyanine R tests: three agricultural species including wheat (Triticum aestivum L. and Triticum turgidum L.) and corn (Zea mays L.) and three wild species from the genus Sinapidendron. Profound differences in adaptation to local edaphic parameters (Al content, acidity, organic matter, altitude) between cultivated and wild species were observed. Comparison of the distribution patterns of the cultivated and wild species on the island may indicate that the anthropogenic activities played a pivotal role in the development of enhanced Al resistance among the cultivated species, while edaphic conditions seem to be a secondary factor.
- Occurrence of microsporidians Glugea hertwigi and Pleistophora ladogensis, in smelt Osmerus eperlanus from two German rivers, North Sea coastPublication . Costa, G.; Moreira, E. Melo; Carvalho, M. A. P. deMonthly samples of smelt Osmerus eperlanus (Linnaeus, 1758) were collected from July 1985 to May 1986, in the river Elbe (Germany), and examined for infections with microsporidi ans. Two microsporidians were found: Glugea hertwigi Weissenberg, 1911, infecting the digestive tract and Pleistophora ladogenis Voronin, 1978, infecting the skeletal musculature. G. hertwigi in fection led to the formation of xenomas, whereas P. ladogensis was characterized by diffuse infec tions, with the production of macroscopic visible thread-like or oval-shaped infection foci. Develop ment of G. hertwigi in the host cells showed characteristics typical of the genus Glugea. The ultrastructural development of P. ladogensis showed features typical of the genus Pleistophora, without evidence of the production of 2 types of spores. Host reaction consisted of inflammatory tis sue surrounding some of the infection foci as well as phagocytosis of spores. G. hertwigi was only found in juvenile smelt (<10 cm in length), whereas P. ladogensis infected smelts from 6 to 26 cm in length. Prevalence increased with fish length to a maximum value of 9.6%. Seasonal fluctuations in prevalence of infection were also found, with the lowest value in the winter months (2.5% in January 1986) and the highest in summer (11.8% in July 1985). The differences in prevalence of in fection with fish length and date of sampling were significant. Additionally, samples of smelt caught in April 1986 from the rivers Eider and Ems revealed infections with P. ladogensis in the first river system only.
- Larval trypanorhynchs (Platyhelminthes: Eucestoda: Trypanorhyncha) from black-scabbard fish,Aphanopus carboand oceanic horse mackerel,Trachurus picturatusin Madeira (Portugal)Publication . Costa, G.; Veltkamp, C. J.; Chubb, J. C.Four different types of trypanorhynch postlarvae were found attached to the stomach mucosa, external stomach wall or free in the body cavity of two marine fishes from Madeira, namely black scabbard fish, Aphanopus carbo and oceanic horse mackerel, Trachurus picturatus. Morphological features shown by SEM indicated that the postlarvae belonged to the species Tentacularia coryphaenae, Sphyriocephalus tergestinus, Nybetinia lingualis and possibly N. yamagutii. Prevalence [mean intensity (range)] of T. coryphaenae, S. tergestinus and Nybetinia spp. in A. carbo (n = 135) was 12.6 % [1.65 ± 1.27 (1-6)], 5.9 % [1.57 ± 0.79 (1-3)] and 2.2 % [1.33 ± 0.58 (1-2)] respectively. The prevalence of T. coryphaenae and S. tergestinus showed some seasonality, with a rise in prevalence of T. coryphaenae corresponding to a decrease in prevalence of S. tergestinus. However these differences were not significant. In T. picturatus (n = 304) only N. lingualis was found at a prevalence of 9.6 %. Both 5. tergestinus and N. lingualis were recovered only from the stomach mucosa or external stomach wall, while T. coryphaenae was observed either attached to the stomach mucosa or free in the visceral cavity of the fish. The paper presents the first scanning electron micrographs (SEM) of Sphyriocephalus tergestinus and a new geographical record of N. lingualis in T. picturatus.
- Gill monogeneans of the chub mackerel, Scomber japonicus from Madeiran waters of the Atlantic Ocean, PortugalPublication . Costa, G.; Freitas, N.; Dellinger, T. H.; MacKenzie, K.Five species of monogeneans were recovered from the gill filaments of 181 chub mackerel, Scomber japonicus, from the Madeiran waters of the Atlantic Ocean, Portugal, during 2004/2005. The monogenean Pseudokuhnia minor showed the highest prevalence (98.68%) and a mean intensity of 28.23, followed by Kuhnia scombri (prevalence of 43.71% and mean intensity of 2.69) and K. scombercolias (prevalence of 39.1% and a mean intensity of 1.81). Kuhnia sprostonae and Grubea cochlear were rare, occurring in only one and five fish hosts respectively. No correlation between fish host length and mean intensity of infection with the three most abundant monogeneans was found. However, significant differences in prevalence and abundance were found in relation to date of sampling for P. minor, and all parasites were aggregated in their distribution.