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- A comparative study of the feeding ecology of Nephrops norvegicus (L.), (Decapoda : Nephropidae) in the bathyal Mediterranean and the adjacent AtlanticPublication . Cristo, Margarida; Cartes, JEA comparative study of the feeding ecology of Nephrops norvegicus was carried out on a seasonal basis simultaneously in seven locations in the Eastern and Western Mediterranean and the adjacent Atlantic: the south coast of Portugal, Fare; the Alboran Sea, Malaga; the Catalan Sea, Barcelona; the Ligurian Sea, Genoa; the Tyrrhenian Sea, Pisa: the Adriatic Sea, Ancona and the Aegean Sea, Gulf of Euboikos. The major groups observed (frequency of occurrence method) in the stomachs of Nephrops norvegicus were decapod crustaceans, other crustaceans (euphausids and peracarids) and fish. The results obtained showed no significant differences between sites or seasons, and can be considered very consistent. All major taxa were present in the diet at all sites and for all seasons, a fact that can be explained by the great similarity of the bathyal fauna in all sites, which provide a major trophic resource for N. norvegicus. The percentage of full ness was also estimated per site and season, and we registered a clear decrease of this value during the summer period for all sites, except the Tyrrheanian Sea, where the lowest value was found in autumn. PCA - analysis did not clearly separate the regions (sites). The Shannon-Weaver (H'), index of diversity, was also determined per site and season, and we found a significant difference between the values of the Atlantic coast and the Western Mediterranean when compared with those of the Eastern Mediterranean.
- Distinctive genetic signatures of two fairy shrimp species with overlapping ranges in Iberian temporary pondsPublication . Lopes Da Cunha, Regina; Sala, Jordi; Machado, Margarida; Boix, Dani; Madeira, Celine; Madeira, Pedro M.; Cristo, Margarida; Cancela Da Fonseca, Luís; Castilho, RitaTemporary lentic water bodies host biotic assemblages adapted to the transient nature of these freshwater habitats. Fairy shrimps (Crustacea, Branchiopoda, Anostraca) are one of the most important biological components of these unique environments and have a fossil record dating back to the Middle Jurassic (>150 million years). Some anostracan species show a geographically restricted distribution, whereas others are widely dispersed. We aimed to investigate the relationship between different geographic extents and patterns of genetic structure in species of Anostraca. Following this objective, we selected two species with contrasting ranges but overlapping geographic distributions and similar life-history traits in the study area. We analysed additional information that, from an ecological (e.g. egg-bank, niche breadth, and pond connectivity) and evolutionary (e.g. crown-group age of each species) perspective, may explain the obtained phylogeographic patterns. Between 2005 and 2018, we sampled two species of fairy shrimps (309 specimens of Branchipus cortesi and 264 specimens of Tanymastix stagnalis) from 53 temporary ponds of Portugal. We added five other locations from Spain and France to include other European locations for T. stagnalis. Additionally, we also sampled Branchipus schaefferi from two temporary water bodies (Spain and Morocco) to include in the dating analysis. Reconstructed phylogenies based on mitochondrial sequence data indicate the existence of deeply divergent clades with an unequivocal phylogeographic structure in T. stagnalis and shallower divergences in B. cortesi with a less clear geographic correspondence. We found evidence of frequent local and rare long-distance dispersal events in both species and limited intermediate dispersal, which was more common in B. cortesi. A Bayesian dating analysis using the Branchiopoda fossil record estimated the age of the most recent common ancestors of T. stagnalis and B. cortesi at 32.4 and 12.8 million years, respectively. Haplotype accumulation curves indicated that only a portion of the genetic composition of the species was sampled on each hydroperiod and showed the existence of large, genetically diverse egg banks that remain in the soil. These egg banks represent a genetic reservoir that guarantees the survival of the species because active populations from different hydroperiods may be genetically different and adapt to a changing environment. We hypothesise that the contrasting phylogeographic patterns displayed by the two fairy shrimp species may result from: (1) the earlier age of the most recent common ancestor of T. stagnalis, as older species have more time to accumulate mutations and, thus, are expected to exhibit higher genetic differentiation among populations; (2) slight differences in adult behaviour, life-history traits and cyst morphologies of T. stagnalis and B. cortesi favouring different animal dispersal vectors with distinct dispersal abilities. Therefore, phylogeographic patterns may be explained by both evolutionary and ecological processes, which operate in different time scales.
- Assessing the conservation status of Mediterranean temporary ponds using biodiversity: a new tool for practitionersPublication . Marques, J. T.; Belo, A. F.; Cristo, Margarida de Lurdes de Jesus Bastos; Fernandes, M.; Galioto, D.; Machado, M.; Mira, A.; Sa-Sousa, P.; Silva, R.; Sousa, L. G.; Pinto-Cruz, C.The assessment of the habitat condition is the first step of conservation actions and several tools are available to assess wetlands. However, only a few tools are adapted to the priority habitat Mediterranean temporary ponds. Thus, our objectives were (i) to identify biological indicators associated with the different conservation status of Mediterranean temporary ponds and (ii) to create an efficient evaluation tool for non-experts using indicators of conservation status. A total of 87 ponds were sampled in southwest Portugal to assess the presence of plants, large branchiopods, amphibians, threatened voles and bats. Ponds with favourable conservation status showed higher species richness of plants, large branchiopods and amphibians. We identified eighteen indicators for favourable ponds: 15 plants, one large branchiopod and two amphibian taxa. We propose a new tool to assess the conservation status of Mediterranean temporary ponds based on the presence of these indicators. This tool is an alternative to other common, but time-consuming, methods and can be readily used by trained practitioners. The replication and adaptation of this tool to other regions and habitats enables the collection of comparable data and the geographical scaling-up of the assessments.
- Freshwater large branchiopods in Portugal: an update of their distributionPublication . Machado, Margarida; Cancela Da Fonseca, Luís; Cristo, MargaridaThis study is based largely on 20 years of field and laboratory work, with surveys conducted by the authors and some other researchers. During this period several studies dealing with freshwater large branchiopods (FLB) were carried out, resulting in scientific publications and project reports. The distribution of FLB in Portugal was presented in 2 international scientific meetings, but apart from a first paper by Vianna-Fernandes in 1951 and an update done by ourselves in 1999 concerning the southwest Portugal, no other information has been published. Therefore, this work intends to bring up to date the known distribution of this faunal group in freshwater temporary systems. This is pertinent because of the recent revision of the taxon Triops cancriformis on the basis of genetic analyses. The Portuguese populations were assigned either to the Portuguese endemism T. vicentinus, or to T. baeticus, the more widely spread Iberian species, both belonging to the T. mauritanicus complex. Furthermore, a new species, Tanymastigites lusitanica was found and described in Portugal. More recently, a male free (or, at least, a strongly female-biased) metapopulation of T cancriformis was discovered in a rice field in the central region of Portugal. Here we present an updated status of FLB species of Portuguese temporary lentic systems and their distribution, plotted on a UTM (10 x 10 km) grid. A total of 505 sites (temporary ponds or assemblages of closely located, not individual temporary pools) have been surveyed (455 by us). In 241 of these (47.7%) at least one species of FLB was found on at least one occasion. Of the 505 sites, only 87 are located north of the Tagus River and of these, at least one species was found in only 17 (19.5%). South of the Tagus River (Alentejo and Algarve), 53.6% of the sites were inhabited by at least one species. This list comprises 7 anostracans, 2 spinicaudatans and 4 notostracans, including 3 species endemic to the Iberian Peninsula and another 3 to Portugal.
- Trophic ecology of the Norway lobster Nephrops norvegicus (L.) (crustaces: Nephropidae) in the Mediterranean and adjacent Atlantic: diets, evacuation rates and daily rationsPublication . Cristo, Margarida de Lurdes de Jesus Bastos; Castro, MargaridaThe subject of this Ph.D. thesis is the feeding ecology of the Norway lobster - Nephrops norvegicus (Linnaeus, 1758), and related aspects.
- First record of the spottail mantis shrimp, Squilla mantis (Stomatopoda, Squillidae), in the Ria Formosa lagoon (Algarve coast, southern Portugal)Publication . Vasconcelos, Paulo; Carvalho, Andre N.; Pilo, David; Gaspar, Miguel; Cristo, Margarida
- Gut evacuation rates in Nephrops norvegicus (L., 1758): laboratory and field estimatesPublication . Cristo, MargaridaEstimates of gut evacuation rates of Nephrops norvegicus (Linnaeus, 1758) (Crustacea, Decapoda) were obtained during laboratory and field experiments. Individuals were collected off the south coast of Portugal in December 1997 and July 1998. Gut evacuation rates (R.h(-1)) were calculated from the slope of the regression of the natural logarithm of dry stomach content weight versus time, using data obtained by the "serial slaughter method". The values obtained during laboratory (R = 0.172 h(-1)) and field experiments (R = 0.177 h(-1)) are compared with gut evacuation rates reported for other marine organisms. The results obtained for both experiments are within the range of the values in the literature, even in the case in which different methodologies were used.
- Defining the importance of landscape metrics for large branchiopod biodiversity and conservation: the case of the Iberian Peninsula and Balearic IslandsPublication . Sala, Jordi; Gascon, Stephanie; Cunillera-Montcusi, David; Alonso, Miguel; Amat, Francisco; Cancela Da Fonseca, Luís; Cristo, M.; Florencio, Margarita; Garcia-de-Lomas, Juan; Machado, Margarida; Rosa Miracle, Maria; Miro, Alexandre; Luis Perez-Bote, Jose; Lluis Pretus, Joan; Prunier, Florent; Ripoll, Javier; Rueda, Juan; Sahuquillo, Maria; Serrano, Laura; Ventura, Marc; Verdiell-Cubedo, David; Boix, DaniThe deficiency in the distributional data of invertebrate taxa is one of the major impediments acting on the bias towards the low awareness of its conservation status. The present study sets a basic framework to understand the large branchiopods distribution in the Iberian Peninsula and Balearic Islands. Since the extensive surveys performed in the late 1980s, no more studies existed updating the information for the whole studied area. The present study fills the gap, gathering together all available information on large branchiopods distribution since 1995, and analysing the effect of human population density and several landscape characteristics on their distribution, taking into consideration different spatial scales (100 m, 1 km and 10 km). In overall, 28 large branchiopod taxa (17 anostracans, 7 notostracans and 4 spinicaudatans) are known to occur in the area. Approximately 30% of the sites hosted multiple species, with a maximum of 6 species. Significant positive co-occurring species pairs were found clustered together, forming 4 different associations of large branchiopod species. In general, species clustered in the same group showed similar responses to analysed landscape characteristics, usually showing a better fit at higher spatial scales.