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Almeida Pinheiro de Carvalho, Miguel Angelo

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Now showing 1 - 5 of 5
  • 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.
  • Evaluation of wheat germplasm from the Madeira and Canary archipelagos using a single molecular marker. A rapid screening method for identification of durum wheat accessions
    Publication . Andrade, V.; Santos, T.; Afonso Morales, D.; Costa, G.; Carvalho, M. Pinheiro de
    This 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.
  • Soil conditions and evolution of aluminium resistance among cultivated and wild plant species on the Island of Madeira
    Publication . 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 de
    Soil 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 coast
    Publication . Costa, G.; Moreira, E. Melo; Carvalho, M. A. P. de
    Monthly 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.
  • Helminth parasites of the oceanic horse mackerel Trachurus picturatus Bowdich 1825 (Pisces: Carangidae) from Madeira Island, Atlantic Ocean, Portugal
    Publication . Costa, G.; Moreira, E. Melo; Carvalho, M. A. A. Pinheiro de
    The helminth parasite fauna of the oceanic horse mackerel Trachurus picturatus Bowdich 1825, caught off the Madeira Islands was composed of six different taxa. Prevalence and abundance of larval Anisakis sp. (Nematoda: Anisakidae) and Nybelinia lingualis (Trypanorhyncha: Tentaculariidae), the most common parasite taxa, were 24.3%, 0.9 and 37.9%, 0.7, respectively. Bolbosoma vasculosum (Acanthocephala: Polymorphidae) and the monogeneans Heteraxinoides atlanticus (Monogenea: Heteraxinidae) and Pseudaxine trachuri (Monogenea: Gastrocotylidae) were comparatively rare. The depauperate helminth fauna of the oceanic horse mackerel at Madeira compared to other geographical regions of the north-eastern Atlantic, namely the Azores banks and the West African coast, may be attributed to the paucity of nutrients off oceanic islands and to a low density of the fish population.