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- Spatiotemporal variation of the epifaunal assemblages associated to Sargassum muticum on the NW Atlantic coast of MoroccoPublication . Belattmania, Zahira; Chaouti, Abdellatif; Engelen, Aschwin; Serrao, Ester; Machado, Margarida; Reani, Abdeltif; Sabour, BrahimEpifaunal assemblages inhabiting the non-indigenous macroalga Sargassum muticum (Yendo) Fensholt were investigated on two physically distinct intertidal rocky (S1) and sandy (S2) sites along the Atlantic coast of Morocco. The objective of this study was to test whether the habitat-forming marine alga S. muticum invasive in these sites supported different epifaunal assemblages under different environmental conditions and through time. The gastropods Steromphala umbilicalis, S. pennanti, and Rissoa parva and the isopod Dynamene bidentata were the most contributive species to the dissimilarity of epifaunal assemblage structure between both sites throughout seasons. SIMPER analysis showed a dissimilarity of 58.3-78.5% in the associated species composition of S. muticum between study sites with respect to sampling season. Species diversity and total abundance were significantly higher at the rocky site compared to the sandy site. PERMANOVA analyses showed significant differences of associated epifaunal assemblage structure for the season and site interaction. Accordingly, site and season were determinant factors conditioning the role of habitat in structuring epifaunal assemblages.
- 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.
- Biodiversity consequences of Caulerpa prolifera takeover of a coastal lagoonPublication . Parreira, Filipe; Martínez-Crego, Begoña; Lourenço Afonso, Carlos Manuel; Machado, Margarida; Oliveira, Frederico; Gonçalves, Jorge Manuel Santos; Santos, RuiThe genus Caulerpa has attracted much attention because many of its species were introduced into non-native regions and became notoriously invasive. This is the case of Caulerpa prolifera that has been rapidly expanding in Ria Formosa lagoon, taking over the deeper unvegetated soft bottoms and competing with seagrass meadows in the shallower areas. Here we address how C. prolifera invasion may affect the support of biodiversity, and specifically, the provision of habitat and nursery for commercial species by the native habitats of this coastal lagoon. Even though no significant differences in total species richness, diversity and evenness were found between C. prolifera and the native unvegetated habitat, the dissimilarity between these two habitats was highest, mostly driven by the extreme reduction of the gastropod Bittium reticulatum and of the tanaid Apseudopsis formosus. This may implicate changes in the trophic interactions of the ecosystem, for example decreasing the tanaid food source for seahorses, which are presently endangered in the lagoon. On the other hand, the fauna species richness, diversity and evenness were significantly higher in the native seagrass habitat than in C. prolifera. Juveniles of valuable flat and sparid fish were only observed in unvegetated sediments and seagrass meadows, respectively. The aggressive spread of C. prolifera in Ria Formosa may alter the structure of native faunal communities, with likely negative implications on fisheries. Nevertheless, the global biodiversity of the lagoon will not be likely drastically affected unless the seaweed takes over the seagrass meadows.
- Genetic Divergence for the Amphibian Pleurodeles waltl in Southwest Portugal: Dispersal Barriers Shaping Geographic PatternsPublication . Van Vliet, Mirjam; Diekmann, Onno; Machado, Margarida; Beebee, Trevor J. C.; Beja, Pedro; Serrao, Ester A.Dispersal and vicariance are the principal mechanisms responsible for the formation of biogeographic patterns, driven or maintained by the role of past and current barriers to dispersal. Southwest Portugal harbors a rich endemic fauna and flora where strongly differentiated taxa can be observed, suggesting ancient isolating mechanisms acted in this region. In this study, we used information from two partial mitochondrial sequences, combined with information from microsatellite loci and amplification success, to investigate biogeographic patterns of genetic divergence in populations of Pleurodeles waltl in Portugal. Our results demonstrate genetic differentiation at different time frames creating distinct populations in southwest Portugal, which might have arisen following isolation by a large river estuary and mountainous barriers. Habitat destruction associated with agricultural intensification raises conservation concerns over the unique biodiversity in this region.
- 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.
- How threatened are large branchiopods (Crustacea, Branchiopoda) in the Iberian Peninsula?Publication . Garcia-de-Lomas, Juan; Sala, Jordi; Barrios, Violeta; Prunier, Florent; Camacho, Antonio; Machado, Margarida; Alonso, Miguel; Korn, Michael; Boix, Dani; Hortas, Francisco; Garcia, Carlos M.; Serrano, Laura; Munoz, GonzaloThe Iberian Peninsula harbours 24 taxa of native large branchiopods (LBs). Most of them inhabit Mediterranean temporary ponds, which are priority habitats under the EU Habitats Directive. In this work, Iberian LBs were evaluated using IUCN Red List criteria based on geographic range (extent of occurrence, area of occupancy, number of locations, habitat fragmentation and expected decline). Our results show that 46% of the Iberian LBs are threatened: four taxa should be considered as Critically Endangered (Linderiella baetica, Triops emeritensis, Cyzicus tetracerus and Leptestheria mayeti), three taxa fall under the category Endangered (Artemia salina, Tanymastigites lusitanica and Triops vicentinus) and four species (Artemia sp. parthenogenetic strains, Branchinecta orientalis, Lepidurus apus and Triops gadensis) are Vulnerable. Two species (Phallocryptus spinosus, and Maghrebestheria maroccana) are considered Near Threatened. Our results highlight the worrying risk of extinction of Iberian LBs at the regional level, mainly related to the disappearance and degradation of their habitats and the relatively low degree of habitat protection. For Iberian endemic species, this evaluation is also valid at the global level and gives strong support for their inclusion in the IUCN Red List.
- First record of the tadpole shrimp Triops cancriformis (Lamarck,1801) (Crustacea: Branchiopoda: Notostraca) in PortugalPublication . Machado, Margarida; Sousa, Luis Guilherme; Fonseca, Luís Cancela da; Galioto, Eliana Dinamene; Caramujo, Maria JoseNotostracan crustaceans identified as Triops cancriformis according to the presently accepted morphological criteria were recorded for the first time in Portugal in 2007. All previous records of Triops in Portugal belong to mauritanicus lineage species i.e. T vicentinus or T baeticus. A specimen purportedly belonging to T cancriformis (Carvalho, 1944) has been re-identified by Machado in 2014 as T. baeticus after morphological examination. During 2007, hundreds of individuals of T. cancriformis were observed throughout the rice paddies on the northern margin of Sorraia River (Vale do Sorraia, Coruche). In the last 9 years, monthly checks during the rainy season have failed to record high population abundances and only a few specimens have been observed in the flooded tracks left by trucks and other heavy machinery on the elevated margins of the paddies. The low number of individuals observed in the latter years possibly results from changes of ecological conditions. Thus far, males of T cancriformis have not been recorded, which may indicate that the observed population is either androdioecious or made of hermaphrodite or parthenogenetic populations. This situation contrasts with the other confirmed populations of this species in the Iberian Peninsula that are gonochoric. Parthenogenetic/hermaphrodite/androdioecious lineages, present in Northern and Central Europe, are considered to have derived from gonochoric Iberian populations in the Pleistocene which makes this finding all the more interesting in evolutionary terms. Has this population resulted from a recent recolonization from non-Iberian populations? Or has it derived directly from the assumed Iberian Pleistocene refuge? The potentially high dispersal abilities of Triops diapausing cysts and the possibility of hermaphrodite/parthenogenetic reproduction favour the 1st hypothesis of recolonization. Possible sources of individuals are (i) cysts attached to migratory birds arriving possibly from Southern France or Northern Italy and that are regularly seen feeding at these rice fields or ii) cysts unwittingly transported with the rice seeds used in the Vale do Sorraia. Both are in accordance with the assumption that nongonochoric reproductive mode confers a colonization advantage over gonochoric populations, which lack evidence of fast long distance dispersal ability. Future multilocus phylogenetic analysis is expected to clarify the origin of T. cancriformis found in the Sorraia's rice fields.
- Linderiella baetica Alonso & Garcia-de-Lomas 2009 (Crustacea, Branchiopoda, Anostraca): On the verge of extinction?Publication . Garcia de Lomas, Juan; Garcia, Carlos M.; Hortas, Francisco; Prunier, Florent; Boix, Dani; Sala, Jordi; Leon, David; Serrano, Laura; Prenda, José; Diego Gilbert, Juan; Guerrero, Francisco J.; Marrone, Federico; Sahuquillo, Maria; Camacho, Antonio; Olmo, Carla; Rosa Miracle, Maria; Zamora-Munoz, Carmen; Mura, Graziella; Machado, Margarida; Sanchez, Inigo; Angel Galvez, José; Florencio, Margarita; Luis Perez-Bote, José; Alonso, MiguelThe province of Cadiz (South of Spain) hosts the only known locality in the world of Linderiella baetica Alonso & Garcia-de-Lomas 2009 (Anostraca). In this paper, the geographical distribution of the species based on published sampling data focused on large branchiopods and temporary pools in Andalusia and the entire Iberian Peninsula is assessed. The current situation is summarized based on the threats to their survival, which are mainly related to habitat alteration. In the Iberian Peninsula, at least 1,648 bodies of water (about 720 in Andalusia) have been explored. Prevalence data suggest that L. baetica is a rare species (localities with presence / sample locations = 6.07 . 10-4). The application of the IUCN (2012) criteria suggests that L. baetica is a threatened species, catalogued as "critically endangered". Several emergency solutions such as translocation of individuals or their propagules to newly created ponds and to sustain the efforts of exploration have been proposed. However, conservation of the species in the current circumstances it is not considered viable if the natural habitat remains unprotected. The legal protection of L. baetica is proposed.
- Drivers of variation in seagrass-associated amphipods across biogeographical areasPublication . Navarro-Mayoral, Sandra; Tuya, Fernando; Prado, Patricia; Marco-Méndez, Candela; Fernandez-Gonzalez, Victoria; Fernández-Torquemada, Yolanda; Espino, Fernando; Antonio de la Ossa, Jose; Vilella, David Mateu; Machado, Margarida; Martínez-Crego, BegoñaAmphipods are one of the dominant epifaunal groups in seagrass meadows. However, our understanding of the biogeographical patterns in the distribution of these small crustaceans is limited. In this study, we investigated such patterns and the potential drivers in twelve Cymodocea nodosa meadows within four distinctive biogeo-graphical areas across 2000 Km and 13 degrees of latitude in two ocean basins (Mediterranean Sea and Atlantic Ocean). We found that species abundances in the assemblage of seagrass-associated amphipods differed among areas following a pattern largely explained by seagrass leaf area and epiphyte biomass, while the variation pattern in species presence/absence was determined by seagrass density and epiphyte biomass. Seagrass leaf area was also the most important determinant of greater amphipod total density and species richness, while amphipod density also increased with algal cover. Overall, our results evidenced that biogeographical patterns of variation in amphipod assemblages are mainly influenced by components of the habitat structure, which covary with envi-ronmental conditions, finding that structurally more complex meadows harboring higher abundance and rich-ness of amphipods associated.
- 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.