Browsing by Author "Moreira, E. Melo"
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- 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.
- Helminth parasites of the oceanic horse mackerel Trachurus picturatus Bowdich 1825 (Pisces: Carangidae) from Madeira Island, Atlantic Ocean, PortugalPublication . Costa, G.; Moreira, E. Melo; Carvalho, M. A. A. Pinheiro deThe 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.
- 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.
- A review of the parasites of deep-water fishes from Macaronesian Islands, North-East Atlantic OceanPublication . Costa, Graça; Costa, Luísa; Santos, Maria João; Moreira, E. MeloThe deep-water fish fauna of Macaronesian islands is currently estimated at a total of 1029 different fish species, but records of both ecto- and endoparasites are from only about 30 of those species. This fact presents an exciting field of research for scientists interested in fish parasitology, by exploring the structure of parasite communities and their connections with ecological and oceanographic variables. Research on the effect of climatic changes on the parasite faunas, on the occurrence of fish parasites in man and its impact on human health, has not been carried out to date. The present review aims to collate our present knowledge about the parasites of deep-water fishes of Macaronesia, and to suggest directions for future research on the parasites of fishes from the deepwater realm. A checklist of the parasites infecting the deep-water fishes from this region is included.