Browsing by Author "Maia, Carla"
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- First record of Philometra ovata (Nematoda) infection in Gobio lozanoi in PortugalPublication . Saraiva, A.; Hermida, M.; Costa, M. J.; Maia, Carla; Reis, A. R.; Cruz, C.; Valente, AlexandreGobio lozanoi, from the River Febros northern Portugal, contained female Philometra ovata in the body cavity causing abdominal swelling. A mild chronic inflammation and some tissue necrosis were observed in infected fish. Significant correlations were found between occurrence of infection and host length, and gonado-somatic index; and between intensity of infection and condition factor.
- Influence of macrohabitat preferences on the distribution of European brook and river lampreys: Implications for conservation and managementPublication . Ferreira, Ana F.; Quintella, Bernardo R.; Maia, Carla; Alexandre, Carlos S.; Capinha, Cesar; Almeida, Pedro R.The European river lamprey, Lampetra fluviatilis (L.), and the European brook lamprey, Lampetra planeri (Bloch, 1784), are considered highly threatened in Portugal. However, the lack of information about the ecology and distribution of these species poses difficulties to the identification of concrete actions directed to their conservation. A total of 401 sampling sites, randomly distributed throughout the entire Portuguese mainland territory were selected, and Lampetra sp. ammocoetes presence or absence checked with electrofishing. These data, together with 11 macrohabitat predictors, were analyzed using Boosted Regression Trees (BRTs). The BRT models consistently identified five environmental variables as the most important for predicting the distribution of European brook and river lamprey ammocoetes: altitude, distance to coast, sand, maximum temperature of the warmest month and precipitation of the driest month. The relationships of these variables with the species probability of occurrence suggest that lampreys occur in low altitude river stretches (<170 m), relatively close to the coast (<150 km) and with a sandy substrate (>70% sand). In addition, intermediate values of temperature and precipitation were also found to have a positive correlation with the species occurrence. A map with the probability of occurrence of Lampetra sp. in Portugal was generated and stretches of rivers were delimited with different conservation priorities. Rivers classified with the highest level of conservation priority were considered to be proposed as Special Areas of Conservation, under the Natura 2000 Networking Programme.
- Mitochondrial DNA fails to reveal genetic structure in sea-lampreys along european shoresPublication . Almada, Vítor Carvalho; Pereira, Ana Martins; Robalo, Joana Isabel; Fonseca, João Paulo; Levy, André; Maia, Carla; Valente, AlexandreInexistente
- Phylogeographical analysis reveals multiple conservation units in brook lampreys Lampetra planeri of portuguese streamsPublication . Pereira, Ana Martins; Robalo, Joana Isabel; Freyhof, J.; Maia, Carla; Fonseca, João Paulo; Valente, Alexandre; Almada, Vítor CarvalhoThe populations of brook lamprey Lampetra planeri of Portuguese Rivers were analysed phylogeographically using a fragment of 644 bp of the mitochondrial control region of 158 individuals from six populations. Samples representing L. planeri and migratory lampreys Lampetra fluviatilis of rivers draining to the North Sea and the Baltic Sea were also included to assess the relationships of Portuguese samples. The data support a clear differentiation of all the populations studied. Several populations, which are isolated among themselves and also from the migratory lampreys, proved to be entirely composed of private haplotypes, a finding that supports some time of independent evolutionary history for these populations. This, combined with the geographic confinement to small water bodies, justifies the recognition of at least four conservation units in the Portuguese rivers Sado, São Pedro, Nabão and Inha.