Margarida Machado

Phylogeny, molecular ecology and taxonomy of southern Iberian lineages of Triops mauritanicus (Crustacea: Notostraca)

We investigated the phylogeography of the main lineages in the tadpole shrimp Triops mauritanicus Ghigi in the south-western Iberian Peninsula, using mitochondrial 12S and 16S rDNA sequences. Our results indicate that a fourth, hitherto unknown main phylogenetic lineage occurs in Iberia, so that in total, the species is divided into six distinct clades, comprising T. m. mauritanicus, T. m. simplex Ghigi, and four as yet unnamed lineages that appear to be endemic to Iberia. Percentages of sequence divergence among the main clades in T. mauritanicus reach the range reported for recognized species in other notostracan lineages. A thorough morphological investigation also revealed that the differentiation among these lineages is higher than previously thought, and that populations of three of the main clades within T. mauritanicus can be reliably separated from each other and from the remaining lineages based on the morphology of adult males. The remaining clades also show a significant level of morphological differentiation, but include a certain proportion of populations for which the additional application of molecular methods is needed for a reliable determination. The geographic distributions of 12S haplotypes are indicative of frequent dispersal events and gene flow among populations belonging to the same main lineage, but give no evidence of recent migration events among different main lineages, suggesting that there is no gene flow among the latter. Our data thus suggest that the six main lineages within T. mauritanicus represent distinct species. We therefore describe the Iberian lineages as T. baeticus Korn n. sp., T. emeritensis Korn & Pérez-Bote n. sp., T. gadensis Korn & García-de-Lomas n. sp., and T. vicentinus Korn, Machado, Cristo & Cancela da Fonseca n. sp., and reinstate T. simplex Ghigi to full species status. Our data confirm the general, previously recognized pattern of a lower dispersal probability in gonochoric Triops taxa. However, we found evidence that passive dispersal in Triops may be further complicated by a strong habitat dependence of dispersal probability, mediated by prevailing dispersal vectors.

Sister species within the Triops cancriformis lineage (Crustacea, Notostraca)

We investigated the phylogenetic relationships among the three presently recognized subspecies of the tadpole shrimp, Triops cancriformis, using mitochondrial 16S and 12S rDNA sequences. Our results indicate that the taxon is divided into two distinct lineages. One lineage is formed of T. c. cancriformis populations and samples from northern Spain that had been classified as T. c. simplex in the most recent literature. The second lineage comprises all populations of T. c. mauritanicus and northern African populations of T. c. simplex. These two main lineages separated 2.3 to 8.9 million years ago, based on the range of inferred molecular clocks recognized for crustacean mtDNA sequence divergence. Percentages of divergence are in the range reported for recognized species in other notostracan lineages and we therefore propose to recognize them as two species, Triops cancriformis and Triops mauritanicus. The latter would comprise two subspecies in northern Africa, one consisting of the Moroccan populations of the former T. c. mauritanicus, the other comprising the African populations of the former T. c. simplex. It also includes three as‐yet unnamed lineages. A comparison of morphological characters with the molecular data revealed that the former T. c. simplex cannot be reliably separated from T. c. cancriformis, using morphological characters that have hitherto been used to distinguish among subspecies of T. cancriformis. Our investigation is the first to demonstrate the presence of T. c. cancriformis in Africa (Tunisia). The genetic haplotypes of these populations are identical with haplotypes also occurring in Central and Western Europe, as well as in Sicily. Therefore, we hypothesize that the African populations of T. c. cancriformis represent a result of repeated long‐distance dispersal across the Mediterranean Sea.

Spatial characteristics and species niche attributes modulate the response by aquatic passive dispersers to habitat degradation

Therelativeinfluencesoflocalandregionalfactorsonthedistributionofpassivedispersersmaybealteredby habitatdegradation,partlyviadifferentialeffectsonspeciesdependingontheirnichebreadths.Tostudythis,wecompared the effects of local (pond, water and vegetation characteristics) and regional (Morans eigenvector maps) factors on passively dispersing large branchiopod crustaceans from two areas of the Iberian Peninsula differing in habitat condition (i.e. well preserved vs impacted). Species were arranged from generalists to specialists based on niche breadth. We hypothesised that (1) habitat degradation would favour functional homogenisation, resulting in higher occurrences of generalist species in the impacted area; because generalist species are likely to be less dependent on local factors, we alsohypothesisedthat(2)regionalfactorswouldbemoreimportantintheimpactedarea.Aspredicted,themostgeneralist species had higher occurrences in the impacted area, resulting in functional homogenisation. Ultimately, this process affected metacommunity dynamics that were more influenced by regional than local factors because generalist species were widely distributed regardless of habitat degradation. Additional keywords: Anostraca, habitat conservation, logistic regression, Mediterranean ponds, Notostraca, OMI analyses, spatial ecology, Spinicaudata, temporary pool.

Assessing the conservation status of Mediterranean temporary ponds using biodiversity: a new tool for practitioners

AbstractThe 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.

Phylogenetic analysis of the north-east Atlantic and Mediterranean species of the genus Stenosoma (Isopoda, Valvifera, Idoteidae)

Xavier, R., Santos, A. M., Harris, D. J., Sezgin, M., Machado, M., Branco, M. (2012). Phylogenetic analysis of the north‐east Atlantic and Mediterranean species of the genus Stenosoma (Isopoda, Valvifera, Idoteidae). —Zoologica Scripta, 41, 386–399.

Genetic Divergence for the Amphibian Pleurodeles waltl in Southwest Portugal: Dispersal Barriers Shaping Geographic Patterns

Abstract 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.

A new species of Onuphis (Polychaeta: Onuphidae) from Southern Portugal, with comments on the validity of O. pancerii Claparède, 1868.

Onuphis farensis sp. nov. (Annelida, Polychaeta) is described, based on a population inhabiting intertidal sandbanks in the mesotidal coastal lagoon of Ria Formosa (Southern Portugal). It can be distinguished from all other known species within the genus by having bi- and tridentate pseudocompound hooks on the first 4 chaetigers, single filament branchiae from chaetiger 5, and subacicular hooks from chaetiger 9. The species was previously collected in the Bay of Cádiz and Isla Cristina (SW Spain), in a similar habitat to Ria Formosa, but referred to O. geophiliformis Moore, 1903. The taxonomic status of other Onuphis species recorded in the European waters is also discussed. On the whole, O. pancerii Claparède, 1868, described from the Gulf of Naples, has been treated as a junior synonym of O. eremita Audouin & Milne-Edwards, 1833, but taking the more restrictive definition of this species accepted today, should be considered as a valid Mediterranean species. Finally, O. opalina (Verrill, 1873) and O. rullieriana (Amoureux, 1977) may be synonymous, as both species are similar morphologically, occur at similar depths, and have partially overlapping geographical distributions. The different diagnostic characters utilised for the new species are analysed, with the number of chaetigers with postchaetal lobes determined to be a poor taxonomic character for the genus Onuphis, proving to be size-related. A synoptic table with all worldwide species of the genus Onuphis is provided, together with a dichotomic key for the species hitherto recorded in the European and nearby waters.

Ampelisca lusitanica (Crustacea: Amphipoda): new species for the Atlantic coast of Morocco

BackgroundThis study reports for the first time the presence of the Lusitanian ampeliscid amphipod Ampelisca lusitanica Bellan-Santini & Marques, 1986 in the northwestern Atlantic coast of Morocco.MethodsSpecimens were collected in January 2015 from intertidal rock pools along the El Jadida shoreline associated with the brown algae Bifurcaria bifurcata and Sargassum muticum.ResultsSystematic description of the species is presented, as well as a discussion of its ecological and geographical distribution.ConclusionThis new finding extends the geographical distribution from the Lusitanian (Europe) to the Mauritanian (Africa) region and increases knowledge of the ecology and the global distribution of A. lusitanica found, previously, only on Portuguese and Spanish coasts.

How threatened are large branchiopods (Crustacea, Branchiopoda) in the Iberian Peninsula?

The 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.

Colonization process in soft-bottom macrofauna communities using azoic sediments: comparison of two wetland systems with different organic loads

The main goal of the study was to follow the colonization process of soft-bottom macrofauna commu- nities in two wetland systems with different organic inputs: a lagoon reservoir and a fish-farm system in the Ria Formosa, Portugal. After a previous treatment in the natural sediments, the resulting experimental azoic sediments were placed in suspended boxes. Two sets of boxes were used to study seven cumulative colonization periods of increasing duration, and seven colonization periods of one month each. Community structure was studied and percentage of organic matter in surface sediments was measured. Descriptors of the macrozoobenthic community included abundance, density, number of species, and diversity, dominance and evenness indices for polychaete taxa. Significant differences were observed in the community structure between colonization periods and between systems. Cumulative experiments revealed that organic enrichment is associated with sediment colonization which is marked by a macroinvertebrate community of increasing total abundance of settlers and diversity in the reser- voir, and several peaks for abundance of a few opportunistic polychaete species in the fish-farm which is typical of a highly disturbed system. Comparison of experimental and natural bottom sediments revealed that predation and organic inputs are important factors determining the community structure, for density in the case of predation and diversity in the case of organic loads. We observed that the duration of the colonization period is a key factor in the community structure of the less disturbed system, as shown by the higher diversity in bottom sediments of reservoir.