Maria Chatzaki

Evolution of Mesobuthus gibbosus (Brullé, 1832) (Scorpiones: Buthidae) in the northeastern Mediterranean region

Sequence data derived from two mitochondrial markers, 16S rRNA and COI genes, were used to infer the evolutionary history of 47 insular and mainland populations covering most of the distributional range of the northeastern Mediterranean scorpion species Mesobuthus gibbosus. Based on the estimated divergence times of Mesobuthus lineages, the temporal frame of the genus differentiation in the northeastern Mediterranean region is placed in middle Miocene (15 million years ago). The biogeographic affinities of M. gibbosus populations point towards a mainly vicariant pattern of differentiation of the species which is consistent with the geological events that transformed the Aegean region during the period from 12 to 5 million years ago. M. gibbosus is an old northeastern Mediterranean species that has retained valuable bits of genetic information, reflecting some of the oldest vicariant events that have occurred in the area. Most importantly, the history witnessed by M. gibbosus has not been obscured by more recent palaeoevents of the region. Therefore, the case of M. gibbosus is in favour of a taxon‐oriented ‘perception’ of the natural history of a given area.

Biogeographic patterns of tenebrionid beetles (Coleoptera, Tenebrionidae) on four island groups in the south Aegean Sea

New records on Tenebrionidae from four island groups of the southern Aegean (Santorini, Astypalaia, Nisyros and Kalymnos, with their satellite islets – 26 islands in total) allowed investigation of the biogeography of the taxon in the area. All tenebrionid records from small islets are new, with the exception of those from Pserimos and the satellite islets of Santorini. Chorological and nestedness analyses, species‐area relationships and various measures of faunal similarity based on binary and quantitative data matrices were applied in order to explore biogeographic patterns. The Anatolian and east Mediterranean faunal elements dominate on the island groups of Kalymnos and Nisyros, with a considerable decrease on Astypalaia and Santorini, where circum‐Mediterranean elements prevail. Analyses of faunal similarities clustered together the well defined island groups of Santorini and Astypalaia, while Kalymnos and Nisyros groups were clustered together rather vaguely. Astypalaia and Santorini were also the most nested island groups in the studied area. The biogeographic position of Astypalaia within the central Aegean islands is well supported by the data.

Ground beetles respond to grazing at assemblage level, rather than species-specifically: the case of Cretan shrublands

Phrygana, maquis and subalpine shrublands are the most typical ecosystem types on the island of Crete. However, these formations are mostly mismanaged and poorly studied in terms of their fauna and the effect of long term land-use. We studied the impact of goat and sheep grazing on the diversity patterns of carabid beetles at 40 sites in relation to possible habitat uniqueness and geographic zonation. In total, 19,322 individuals belonging to 42 Carabidae species were identified. The composition of site assemblages was mainly determined by altitude. The six Cretan endemic species collected were widely distributed on the island and most of them were dominant. Species richness and equitability were significantly lower at overgrazed sites compared to areas with low grazing intensity. The diversity patterns of carabids were influenced by the level of grazing in each study area. As species richness and diversity were maximal under moderate/relatively high levels of grazing (hump-shaped pattern), our results support the intermediate disturbance hypothesis. Low tolerance of carabid taxa to intensive grazing was also ascertained through the significantly high values of temporal beta diversity at overgrazed sites, independent of local species richness. We conclude that Carabidae are good indicators of grazing pressure in Crete at assemblage level, rather than species-specifically. To maintain diversity and enhance niche space of invertebrate fauna, the spatiotemporal discontinuity of grazing is essential.

Peeking through the trapdoor: Historical biogeography of the Aegean endemic spider Cyrtocarenum Ausserer, 1871 with an estimation of mtDNA substitution rates for Mygalomorphae.

The Aegean region, located in the Eastern Mediterranean, is an area of rich biodiversity and endemism. Its position, geographical configuration and complex geological history have shaped the diversification history of many animal taxa. Mygalomorph spiders have drawn the attention of researchers, as excellent model systems for phylogeographical investigations. However, phylogeographic studies of spiders in the Aegean region are scarce. In this study, we focused on the phylogeography of the endemic ctenizid trap-door spider Cyrtocarenum Ausserer, 1871. The genus includes two morphologically described species: C. grajum (C.L. Koch, 1836) and C. cunicularium (Olivier, 1811). We sampled 60 specimens from the distributions of both species and analyzed four mitochondrial and two nuclear markers. Cyrtocarenum served as an example to demonstrate the importance of natural history traits in the inference of phylogeographic scenarios. The mtDNA substitution rates inferred for the genus are profoundly higher compared to araneomorph spiders and other arthropods, which seems tightly associated with their biology. We evaluate published mtDNA substitution rates followed in the literature for mygalomorph spiders and discuss potential pitfalls. Following gene tree (maximum likelihood, Bayesian inference) and species tree approaches ((*)BEAST), we reconstructed a time-calibrated phylogeny of the genus. These results, combined with a biogeographical ancestral-area analysis, helped build a biogeographic scenario that describes how the major palaeogeographic and palaeoclimatic events of the Aegean may have affected the distribution of Cyrtocarenum lineages. The diversification of the genus seems to have begun in the Middle Miocene in the present west Aegean area, while major phylogenetic events occurred at the Miocene-Pliocene boundary for C. cunicularium, probably related to the Messinian Salinity Crisis. Our results also demonstrate the clear molecular distinction of the two morphologically described species, but possible cryptic lineages may exist within C. cunicularium.

Phenology of Opiliones on an altitudinal gradient on Lefka Ori Mountains, Crete, Greece

Abstract The harvestman fauna was studied along an altitudinal gradient on the southern slope of Lefka Ori Mountains, Crete, Greece for one year. Four sampling areas were defined at 800, 1200, 1600, and 2000 m elevation and they were sampled with pitfall traps that were emptied at monthly intervals. In total, six species were collected: Histricostoma creticum (Roewer 1927), Lacinius insularis Roewer 1923, Graecophalangium cretaeum Martens 1966, Opilio insulae Roewer 1956, Rafalskia cretica (Roewer 1923) and Leiobunum ghigii Di Caporiacco 1929. Species richness was the same (5 spp.) at the three lower zones and then declined to three species at 2000 m. Catches were more than double at this elevation. Differences of phenological patterns were observed among species and among altitudinal zones within the same species. High activity during spring and autumn and a summer recession were characteristic of most taxa. Opiliones did not seem strongly affected by the severe harshness of climatic conditions at higher elevations, as observed in other taxa, indicating a strong physiological tolerance and/or behavioral adaptation in order to withstand environmental stress.

Diversity of spiders and orthopterans respond to intra-seasonal and spatial environmental changes

Our understanding of arthropod responses to environmental pressures is limited, especially for the poorly studied Mediterranean region. In the light of likely further environmental change and the need for protocols for rapid biodiversity assessment, we measured how the abundance and species richness of two taxa, ground spiders and Orthoptera, belonging to different functional groups, fluctuates intra- seasonally (early-mid-late summer) and across habitat types (grasslands, maquis, forests). We also tested their surrogate value. Spiders were found to have higher species richness and abundance almost throughout the investigation. Orthoptera had lower species richness and abundance in forests compared to grasslands and maquis, while no significant difference between habitats was revealed for spiders. Early-summer was the richest period for spiders while mid-summer was the richest for Orthoptera. Canopy cover was found to significantly influence community composition of both groups, while herb height and cover of stones was a determinant factor for Orthoptera only. There was a significant congruence between the two groups and Orthoptera provided the best complementary network. Our results show that diversity patterns of both spiders and Orthoptera are sensitive to environmental changes even over short time-scales (e.g. within the summer period) and space (e.g. across different habitat types), suggesting that small inexpensive experimental designs may still reveal community dynamics. For conservation purposes, we advise a focus on variables regulating habitat heterogeneity and microhabitat characteristics. We provide a list of the most influential species and propose the most effective network for obtaining information on the local fauna.

Exploring the role of within-island ecogeographical factors: insights from the genetic diversity of Cretan trap-door spiders (Cyrtocarenum cunicularium, Ctenizidae : Araneae)

Abstract. Crete (Aegean Sea, Greece), like other Mediterranean islands, has a complex palaeogeographical history, including several cycles of fragmentation into palaeoislands and subsequent reconnection. Here, we use the Cretan trap-door spider Cyrtocarenum cunicularium as a model organism to explore the importance of within-island evolutionary processes, such as palaeogeographic events and climatic changes. We assessed the phylogeny, population clustering and historical demography of 61 specimens with mitochondrial (COI) and nuclear (H3) markers. We investigated the isolation-by-distance and spatial diffusion processes that have shaped their past and current distribution and estimated the effect of niche divergence, using species distribution modelling. Two genetic lineages have continuously been distributed in the west and east part of Crete during the last 2 million years. Their genetic structure is concordant with Crete’s fragmentation into palaeoislands during the Pliocene and additionally affected by the sea-level oscillations and climatic changes due to the Pleistocenic glacial cycles. In central Crete, some evidence of genetic admixture between them was found, which needs to be further explored. According to species distribution modelling, the niche of each lineage corresponds to different environmental parameters, while isolation-by-distance was also detected. The divergence between the ‘West’ and ‘East’ lineages was promoted by palaeogeographical factors but seems to be maintained by the species’ poor dispersal abilities and the local ecological adaptation of each lineage. The case of the Cretan C. cunicularium highlights the additive effect of ecogeographical and behavioural factors in shaping insular biodiversity.

Discovering the still unexplored arachnofauna of the National Park of Dadia-Lefkimi-Soufli, NE Greece: a taxonomic review with description of new species

The National Park of Dadia in NE Greece (Thrace) was established as a nature reserve in 1980, mainly due to its great diversity in birds of prey. Since then many studies have taken place, focusing on other birds, reptiles, amphibians and some invertebrates (grasshoppers, beetles and butterflies), but up to now none was conducted on spiders. The aim of the present paper was to create the first extensive checklist on the spiders of this important natural reserve. For this purpose, pitfall traps were set in 15 sites located in and around the National Park, resulting in a large spider collection. The results of the taxonomical revision of this collection are here presented, giving rise to 132 species in total, which belong to 24 families. Of them, 11 species (Centromerus valkanovi Deltshev, 1983, Crosbyarachne silvestris (Georgescu, 1973), Ipa terrenus (L. Koch, 1879), Sintula spiniger (Balogh, 1935), Tenuiphantes floriana (van Helsdingen, 1977), Alopecosa taeniopus (Kulczyñski, 1895), Liocranum rupicola (Walckenaer, 1830), Zodarion turcicum Wunderlich, 1980, Gnaphosa modestior Kulczyñski, 1897, Philodromus krausi Muster & Thaler, 2004, Cozyptila thaleri Marusik & Kovblyuk, 2005) are new records for the Greek territory. Seven species (Dysdera kati sp. n., Dysdera krisis sp. n., Harpactea ice sp. n., Harpactea wolfgangi sp. n.-Dysderidae, Phrurolithus thracia sp. n.-Phrurolithidae, Zodarion beroni sp. n.-Zodariidae, Drassyllus dadia sp. n.-Gnaphosidae) are here proposed as new species for science.

Description of a New Altella Simon, 1884 (Araneae: Dictynidae) from Greece

Summary Altella emilieae Lissner, n. sp. is described from specimens collected from a beach in Crete and in upwash on the coast of Telendos, Dodecanese islands, Greece. The affinity of this species to its congeners and its ecology is briefly discussed.

On the ground spider genera Marjanus gen. n., Lasophorus gen. n. and Turkozelotes Kovblyuk & Seyyar, 2009 (Araneae: Gnaphosidae) from Greece

New taxonomic data on the ground spiders of the family Gnaphosidae from Greece are presented. Two genera are proposed as new to science (Marjanus gen. n. and Lasophorus gen. n.) together with two new species (Lasophorus zakkak sp. n. and Lasophorus zografae sp. n.) and a new combination (Marjanus platnicki comb. nov.). Additionally the genus Turkozelotes Kovblyuk Seyyar, 2009 is here rediagnosed and the female of the type species T. microb Kovblyuk Seyyar, 2009 is described for the first time. The finding of the matching male of Setaphis mccowani Chatzaki Russell-Smith, 2017 suggests the transfer of this species to Turkozelotes and hence the male of T. mccowani comb. nov. is described for the first time. Taxonomic affinities of these genera and species are discussed.