Environmental heterogeneity and lizard assemblages in riparian areas in Cyprus

The island of Cyprus hosts a rich diversity of reptiles, including several endemic species. Reptiles are morecommon in Mediterranean-type shrubland and other open habitats in Cyprus, although riparian formations offeradditional cover and food sources, especially during dry, hot summers. Riparian habitats are often very heterogeneous,an attribute that can be important for lizards since they can utilize a variety of microhabitats crucial for different aspectsof their ecology. Nevertheless, reptilian diversity in riparian systems remains understudied and Cyprus is no exception.The aim of this study was to compare lizard diversity and abundance patterns across seasons and elevations, as well astheir relationships with habitat heterogeneity and protected status of areas along riverbanks, as expressed by presencein or out of Natura 2000 sites. We examined the effects that these factors can have on lizard communities by studyingthree rivers that exhibit variations in environmental conditions. Additionally, we evaluated separately the abundancesof four common species (Snake-eyed Lizard, Ophisops elegans; Troodos Rock Lizard, Phoenicolacerta troodica; CyprusRock Agama, Laudakia cypriaca; and Schreiber’s Fringe-toed Lizard, Acanthodactylus schreiberi) while recording in riparian habitats seven of the 11 Cypriot species of lizards. Diversity and richness were not significantly associated withany of the explanatory variables examined (season, elevation, habitat heterogeneity, and protected status). Moreover,we found no relationship between the abundances of each of the four species and habitat heterogeneity, even thoughthey responded differently to elevation, season, and protected status. Our results suggest that lizard diversity in ripariansystems is high compared to the total number of lizard species found on Cyprus, reaching 60% of the overall richness

The diverse nature of island isolation and its effect on land bridge insular faunas

Aim: Isolation is a key factor in island biology. It is usually defined as the distance to the geographically nearest mainland, but many other definitions exist. We explored how testing different isolation indices affects the inference of impacts of isolation on faunal characteristics. We focused on land bridge islands and compared the relationships of many spatial and temporal (i.e., through time) isolation indices with community‐, population‐ and individual‐level characteristics (species richness, population density and body size, respectively). Location: Aegean Sea islands, Greece. Time period: Current. Taxon: Many animal taxa. Methods: We estimated 21 isolation indices for 205 islands and recorded species richness data for 15 taxa (invertebrates and vertebrates). We obtained body size data for seven lizard species and population density data for three. We explored how well indices predict each characteristic, in each taxon, by conducting a series of ordinary least squares regressions (controlling for island area when needed) and a meta‐analysis. Results: Isolation was significantly (and negatively) associated with species richness in 10 of 15 taxa. It was significantly (and positively) associated with body size in only one of seven species and was not associated with population density. The effect of isolation on species richness was much weaker than that of island area, regardless of the index tested. Spatial indices generally out‐performed temporal indices, and indices directly related to the mainland out‐performed those related mainly to neighbouring islands. No index was universally superior to others, including the distance to the geographically nearest mainland. Main conclusions: The choice of index can alter our perception of the impacts of isolation on biological patterns. The nearly automatic, ubiquitous use of distance to the geographically nearest mainland misrepresents the complexity of the effects of isolation. We recommend the simultaneous testing of several indices that represent different aspects of isolation, in order to produce more constructive and thorough investigations and avoid imprecise inference

A molecular phylogeny of Porcellionidae (Isopoda, Oniscidea) reveals inconsistencies with present taxonomy

Porcellionidae is one of the richest families of Oniscidea globally distributed but we still lack a comprehensive and robust phylogeny of the taxa that are assigned to it. Employing five genetic markers (two mitochondrial and three nuclear) we inferred phylogenetic relationships among the majority of Porcellionidae genera. Phylogenetic analyses conducted via Maximum Likelihood and Bayesian Inference resulted in similar tree topologies. The mtDNA genes cytochrome oxidase I (COI) and 16s rRNA (16s) were used for clade dating using previously published mutation rates. Our results provide evidence against the monophyly of both Porcellionidae and the largest genus of the family Porcellio. These results are compared to previous published work based on morphological evidence. The genera Leptotrichus and Brevurus are not grouped with the rest of Porcellionidae whereas Agnaridae are grouped with part of Porcellionidae. Armadillidium and Schizidium (Armadillidiidae) occupy a basal position on the phylogenetic tree. Even though the African genera Tura and Uramba (distributed in East Africa) are grouped together there is no general geographical pattern in other sub-clades. Additional taxonomic issues that arise in this work such as the assignment of the recently described genus Levantoniscus, arealso discussed. The status of Porcellionidae should be further revised and morphological characters traditionally used in Oniscidea taxonomy should be reconsidered in view of molecular evidence. The origin of the monophyletic clade within Porcellionidae as indicated in the present work is dated back to the Oligocene (~32 mya)

Genetic Data Suggest Multiple Introductions of the Lionfish (Pterois miles) into the Mediterranean Sea

Widespread reports over the last six years confirm the establishment of lionfish (Pterois miles) populations in the eastern Mediterranean. Accumulated knowledge on lionfish invasions in the western Atlantic Ocean has shown that it is a successful invader and can have negative impacts on native species, indirect ecological repercussions and economic effects on local human societies. Here we analysed genetic sequences of lionfish from Cyprus as well as data from the whole distribution of the species, targeting the mtDNA markers cytochrome c oxidase subunit 1 (COI) and the control region (CR). Our results reflect a pattern of repeated introductions into the Mediterranean from the northern Red Sea and a secondary spread of this species west to Rhodes and Sicily. Presented results agree with previously published studies highlighting the genetic similarity with individuals from the northern Red Sea. Nevertheless, some individuals from Cyprus, in addition to those coming via the Suez Canal, were genetically similar to fish from the Indian Ocean, indicating genetic homogeneity among populations of P. miles across its current distribution, possibly facilitated by the ornamental fish trade and/or transport through ballast water.</jats:p

Tackling the lionfish invasion in the Mediterranean. the EU-LIFE RELIONMED Project: progress and results

The lionfish invasion in the Western Atlantic has been characterised as one of the most ecologically harmful marine fish introductions to date; associated with habitat modifications, and severe impacts on native communities. In the Mediterranean, lionfish followed similar expansion trends and raised significant concerns among the scientific community due to its potential to cause devastating ecological and socioeconomic impacts. The coastal ecosystems of Cyprus, near the Suez Canal, are amongst the first Mediterranean waters to be affected by the lionfish invasion. Cyprus sentinel location offers therefore, an ideal site for the development of an early warning and rapid response system of marine bioinvasions. RELIONMED (Preventing a LIONfish invasion in the MEDiterranean through early response and targeted REmoval) is a four-year project, funded by the EU LIFE instrument, aiming to make Cyprus the first line of defence against the invasion of lionfish in the Mediterranean. The project has started successfully on September 2017 with a number of early (preparatory) project actions including stakeholder consultation and baseline assessment of social awareness, biological analyses of a small lionfish sample, and the development of a lionfish risk assessment following the guidelines of the Regulation 1143/2014 to include the species in the EU IAS priority list. Forthcoming project’s actions strongly rely on citizen scientists’ and stakeholders’ participation and RELIONMED aims to develop the capacity and tools for control of lionfish, particularly in priority habitats. Preliminary results such as early maturity, high growth rates, generalist diet, and reproduction throughout the year indicate that lionfish can become a ferocious invader for the basin and RELIONMED calls for regional collaborations and coordinated management measures against lionfish invasion in the basin

Can additive beta-diversity be reliably partitioned into nestedness and turnover components?

Aims: Quantifying β‐diversity (differences in the composition of communities) is central to many ecological studies. There are many β‐diversity metrics, falling mostly into two approaches: variance‐based (e.g., the Sørensen index), or diversity partitioning (e.g., additive β‐diversity). The former cannot be used when species–sites matrices are unavailable (which is often the case in island biogeography in particular) and only species richness data are provided. Recently, efforts have been made to partition additive β‐diversity, a metric calculated using only α‐diversity and γ‐diversity, into nestedness and turnover components (termed here “richness‐only β‐diversity partitioning”). We set out to test whether this form of β‐diversity partitioning generates interpretable results, comparable with metrics based on species incidence β‐diversity partitioning. Location: Global. Time period: Present day. Major taxa studied: Multiple taxa. Methods: We first provide a brief review of β‐diversity partitioning methods, with a particular focus on the development of richness‐only β‐diversity partitioning. Second, we use 254 empirical incidence matrices (provided with the paper) sourced from the literature to measure turnover and nestedness using incidence β‐diversity partitioning, comparing the resulting values with those calculated using richness‐only β‐diversity. Results: We provide an account of the emergence of β‐diversity partitioning, with particular reference to the analysis of richness‐only datasets, and to the definition and usage of the relevant metrics. Analytically, we report weak correlations between turnover and nestedness calculated using the two different approaches. We show that this is because identical values of α‐diversity and γ‐diversity can correspond to incidence matrices with a range of different structures. Main conclusions: Our results demonstrate that the use of richness‐only β‐diversity partitioning to measure turnover and nestedness is problematic and can produce patterns unrelated to conventional measures of turnover and nestedness. We therefore recommend that more accurate definitions are adopted for these terms in future studies.</br

Phylogeography of Aegean green toads (Bufo viridis subgroup): continental hybrid swarm vs. insular diversification with discovery of a new island endemic

BACKGROUND: Debated aspects in speciation research concern the amount of gene flow between incipient species under secondary contact and the modes by which post-zygotic isolation accumulates. Secondary contact zones of allopatric lineages, involving varying levels of divergence, provide natural settings for comparative studies, for which the Aegean (Eastern Mediterranean) geography offers unique scenarios. In Palearctic green toads (Bufo viridis subgroup or Bufotes), Plio-Pleistocene (~ 2.6 Mya) diverged species show a sharp transition without contemporary gene flow, while younger lineages, diverged in the Lower-Pleistocene (~ 1.9 Mya), admix over tens of kilometers. Here, we conducted a fine-scale multilocus phylogeographic analysis of continental and insular green toads from the Aegean, where a third pair of taxa, involving Mid-Pleistocene diverged (~ 1.5 Mya) mitochondrial lineages, earlier tentatively named viridis and variabilis, (co-)occurs. RESULTS: We discovered a new lineage, endemic to Naxos (Central Cyclades), while coastal islands and Crete feature weak genetic differentiation from the continent. In continental Greece, both lineages, viridis and variabilis, form a hybrid swarm, involving massive mitochondrial and nuclear admixture over hundreds of kilometers, without obvious selection against hybrids. CONCLUSIONS: The genetic signatures of insular Aegean toads appear governed by bathymetry and Quaternary sea level changes, resulting in long-term isolation (Central Cyclades: Naxos) and recent land-bridges (coastal islands). Conversely, Crete has been isolated since the end of the Messinian salinity crisis (5.3 My) and Cretan populations thus likely result from human-mediated colonization, at least since Antiquity, from Peloponnese and Anatolia. Comparisons of green toad hybrid zones support the idea that post-zygotic hybrid incompatibilities accumulate gradually over the genome. In this radiation, only one million years of divergence separate a scenario of complete reproductive isolation, from a secondary contact resulting in near panmixia

Small-scale coexistence of two mouse lemur species (Microcebus berthae and M. murinus) within a homogeneous competitive environment

Understanding the co-occurrence of ecologically similar species remains a puzzling issue in community ecology. The species-rich mouse lemurs (Microcebus spec.) are distributed over nearly all remaining forest areas of Madagascar with a high variability in species distribution patterns. Locally, many congeneric species pairs seem to co-occur, but only little detailed information on spatial patterns is available. Here, we present the results of an intensive capture–mark–recapture study of sympatric Microcebus berthae and M. murinus populations that revealed small-scale mutual spatial exclusion. Nearest neighbour analysis indicated a spatial aggregation in Microcebus murinus but not in M. berthae. Although the diet of both species differed in proportions of food categories, they used the same food sources and had high feeding niche overlap. Also, forest structure related to the spatial distribution of main food sources did not explain spatial segregation because parts used by each species exclusively did not differ in density of trees, dead wood and lianas. We propose that life history trade-offs that result in species aggregation and a relative increase in the strength of intra-specific over inter-specific competition best explain the observed pattern of co-occurrence of ecologically similar congeneric Microcebus species