Systematics of freshwater gobies from Greece (Teleostei: Gobiidae)

Five species of gobiid fish are recognized in the fresh waters of Greece. Most distinctive is the south-western Hellenic (West Balkanian component) endemic genus Economidichthys Bianco, Bullock, Miller & Roubal, 1987, with the type-species E. pygmaeus (Holly, 1929) from Lefkas, Epirus and Lake Trichonis, and E. trichonis sp. nov., from Lake Trichonis, the latter probably the smallest freshwater European teleost at maturity (female, 18·0 mm) and maximum size (male, 30·0 mm). In tributaries of the northern Aegean basin (north-eastern Hellenic freshwater fauna), two species of the Ponto-Caspian genus Knipowitschia can be identified, the widespread Kn. caucasica (Kawrajsky in Berg, 1916) (coastal plain of Macedonia and Thrace) and the endemic Kn. ihessala (Vinciguerra, 1921) (Pinios river system, Thessaly). The larger Ponto-Caspian tubenose goby, Prolerorhinus marmoratus (Pallas, 1811), occurs in the Evros (= Maritsa) (Thrace) and Strymon (Macedonia) systems. Only the genera Economidichthys and Knipowitschia are considered in this paper, being redefined in terms of osteology and head lateral-line system, and the species described in detail, with special reference to meristic variation and squamation, and, in Economidichthys , the unique perianal organ of this genus. The relationships of Economidichthys and Kn. thessala are discussed and possible scenarios for their evolution are suggested in the light of Miocene to Recent events.     

Phytogeography of Italian deciduous oak woods based on numerical classification of plant distribution ranges

Abstract. 358 vascular plant species occurring in the deciduous oak woods of Italy were subdivided into 18 phytogeographical groups (chorotypes) through a numerical classification of their total ranges. The distribution patterns of the chorotypes are illustrated by chorograms, i.e. isopleth maps showing the joint distribution of species in Europe and surroundings regions. Except for Mediterranean species, which occur only occasionally in deciduous forests, the oak-wood flora of Italy consists of four main phytogeographical elements, which have a similar incidence (ca. 25 % each): (a) narrow-ranging, southern European species, (b) southeastern European species of submediterranean woodlands, (c) central-European species, (d) widely distributed European species. The oak woods of Italy differ from their central-European counterparts as to the relatively high floristic diversity, and in the presence of several narrow-ranging taxa, centred in different refugial areas for forest vegetation during the glacial period. There is a relation between the distribution patterns of the chorotypes and their relative frequencies in different communities; the latitudinal and longitudinal extensions of the ranges reflect the thermic and hygric conditions of the communities. The oak woods of northern and southern Italy are phytogeographically well-characterized; the former have a maximum of wide-ranging, central European species, the latter host several narrow-ranging taxa. The woodlands of central Italy have intermediate phytogeographical features, which is one of the main reasons for the difficulties in their syntaxonomical arrangement.     

Lichens from the Lake Burano Nature Reserve (Tuscany,central Italy)

Fourty-nine lichen species are reported from the Lake Burano Nature Reserve (Tuscany, central Italy). Three taxa are new to Tuscany. In agreement with the climatic features of the study area, its lichen flora is characterized by a high incidence of Mediterranean and suboceanic species.     

The feeding habits of wolves in relation to large prey availability in northern Italy

We investigated wolf feeding habits in relation to the abundance of wild and domestic ungulates to test the hypothesis that large prey are preferred and that their abundance affects the use of other food categories and diet breadth. We determined diet composition by scat analysis from December 1987 to December 1992. The research was carried out in three study areas located in northern Italy and characterised by marked differences in wild and domestic ungulate abundance. In study area A (low wild and domestic ungulate availability) fruits, livestock, other vertebrates and wild ungulates made up the bulk of the diet (71% in volume). In area B (high availability of livestock) wolf diet was mainly based on sheep and wild boars (80% in volume). In study area C (high availability of wild ungulates) wild ungulates were the main food of wolves (90% in volume). Significant differences were found among study areas in the mean percentage volume of all food categories and in particular for wild ungulates, livestock, other vertebrates and fruits (p < 0.0001 in all cases). Diet breadth decreased in areas with high availability of large wild and domestic herbivores. The use of livestock species was lower where there was high abundance, richness and diversity of the wild ungulate guild. Selection for wild ungulate species was partially affected by their abundance: however other factors as prey social behaviour, adaptability to the habitat (for introduced species), and body size could have an important role in species selection by wolves. In particular in area C wild boars were selected for, roe and red deers avoided, and fallow deers and mouflons used as available. Livestock species were used in relation to their abundance and accessibility, in particular sheep were selected for and cattle avoided; but if calves bom in the pastures were considered as the only available cattle, they were selected for and sheep were used as available. Large and in particular wild herbivores were found to be of great importance for the wolf population maintenance in northern Italy, one of the most important recovery areas of Mediterranean wolves.     

Isozyme genetics and the phytogeny of Italian freshwater gobies (Teleostei: Gobioidei)

Although predominantly a marine group in the Atlantic/Mediterranean fish fauna, three species of exclusively freshwater gobies (Teleostei: Gobiidae) occur in Italy. These are Padogobius marltmsii of north Italy and parts of Croatia, P. nigricans from the Tyrrhenian catchment area of Tuscany and Lazio, and Knipowitschia punctatissima from north-eastern Italy. Using horizontal starch-gel electrophoresis, isozyme polymorphism in 12 enzymes encoded at 18 loci was investigated in these species and related euryhaline forms. Genetic distance, and morphological cladistic analysis, indicates that the Italian freshwater gobies do not form a monophyletic group, with the Padogobius species well separated from other taxa, and K. punctalissima closest to its morphological congener, the lagoonal K. panizzae . No close correlation was found between genetic variation and environmental heterogeneity.     

Reevaluating sponge diversity and distribution in the Mediterranean Sea

The aim of this paper was (1) to update sponge diversity and distribution in the Mediterranean and (2) to re-examine faunal relationships among the Mediterranean areas on the basis of their sponge fauna. The Mediterranean demosponge faunal list was updated to 629 species by taking into consideration recent data from previously poorly studied areas. The species lists of 14 Mediterranean areas were compared on the basis of their sponge species richness, species composition, and taxonomic relatedness of species using multivariate analyses and diversity measures, such as PD, Delta+, and Lambda+. The 14 Mediterranean areas examined for their diversity and affinities were assembled into four major zoogeographic groups: the northwestern, northeastern, the central zone, and southeastern areas. Richest in species numbers were the areas belonging to the two northern groups. The species richness comparisons and similarity analyses performed at the generic level showed that it can be safely used as a surrogate for sponge species diversity in the Mediterranean. The results of this study showed that the simple traditional division of the Mediterranean Sea into a western, central, and eastern basin cannot reliably describe the distribution of sponges in the area. Thus, the W to E faunal decline previously presented for several faunal groups shifts to a general NNW-SSE pattern when one examines separately the northern and the southern parts of the traditional basins. This gradient seems to be in agreement with differences in key environmental variables, such as latitude, salinity, temperature, and water circulation, besides the typically examined distance from Gibraltar. Handling editor: T. P. Crowe     

Historical biogeography and morphological differentiation ofStreptocephalus torvicornis (Waga) since the Würm III-glaciation

We argue that the Würm III glaciation eradicated possible European populations ofS. torvicornis, and that today, a reconquest of Europe takes place on two fronts.A western wave has reached the Pyrenees, an eastern one now occupies most of eastern and northern Europe. The western route probably started in the Maghreb, the eastern one in the Levant and the Ponto-Caspian. Animals in the west had to move north by crossing, at right angles, a series of east-west oriented river valleys and progressed slowly; animals in the east could move up river valleys extending north-east, and moved quickly. Italy was not occupied, becauseS.torvicornis is a warm stenotherm, and by the time the climate had warmed sufficiently for it to reach the southern shore of the mediterranean (ca 6000 BP), the gap with Italy was probably too large for a crossing. Cold-loving species (of the generaBranchipus, Chirocephalus) conversely, and could freely flow across the Central Mediterranean at low sea-levels (ca 12000 BP), and now occur in Italy (and the rest of Europe) as well as in Northern Africa.A prediction of our hypothesis is that the pioneer populations in Spain and Central Europe should have been isolated longest. Thisis tested and confirmed by their comparative morphology, and two subspecies,S. t. torvicornis andS. t. bucheti are reinstated.A gap across the Nile Valley where onlyS. rubricaudatus seems to occur, deserves further study.     

Global diversity of cumaceans &; tanaidaceans (Crustacea: Cumacea &; Tanaidacea) in freshwater

Cumacea and Tanaidacea are marginal groups in continental waters. Although many euryhaline species from both groups are found in estuaries and coastal lagoons, most occur only temporarily in non-marine habitats, appearing unable to form stable populations there. A total of 21 genuinely non-marine cumaceans are known, mostly concentrated in the Ponto-Caspian region, and only four tanaids have been reported from non-marine environments. Most non-marine cumaceans (19 species) belong in the Pseudocumatidae and appear restricted to the Caspian Sea (with salinity up to 13‰) and its peripheral fluvial basins, including the northern, lower salinity zones of the Black Sea (Sea of Azov). There are nine Ponto-Caspian genera, all endemic to the region. Only two other taxa (in the family Nannastacidae) occur in areas free of any marine–water influence, in river basins in North and South America. Both seem able to survive in waters of raised salinity of the lower reaches of these fluvial systems; but neither has been recorded in full salinity marine environments. The only non-marine tanaidacean thus far known lives in a slightly brackish inland spring in Northern Australia. The genus includes a second species, from a brackish-water lake at the Bismarck Archipelago, tentatively included here as non-marine also. Two additional species of tanaidaceans have been reported from non-marine habitats but both also occur in the sea. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment     

A unique teleost dermal organ in a new European genus of fishes (Teleostei: Gobioidei)

The freshwater fish fauna of Greece is a diverse assemblage of mediterranean, Ponto-Caspian, and endemic western Greek elements. In the last category, a gobiid from Epirus has been found to possess a dermal perianal organ unique among teleosts, as well as systematic features warranting recognition of a new genus, Economidichthys gen. nov. ( type-species Gobius pygmaeus Holly, 1929). The perianal organ is a sharply-demarcated, pitted area on the rear abdomen. Light-and electron-microscopy has revealed numerous specialized microvillous cells lining the pits and evidently secretory in function. Presence of the organ in both sexes, its ventral position and the secretory activity originally suggested an attachment role rather than involvement in reproduction, but obvious correlation with habitat is lacking and alternative functions are discussed.     

Rare arctic-alpine plants of the European Alps have different immigration histories: the snow bed species Minuartia biflora and Ranunculus pygmaeus

Minuartia biflora and Ranunculus pygmaeus are circumarctic plants with a few isolated occurrences in the European Alps. We analysed amplified fragment length polymorphism (AFLP) and chloroplast DNA sequence data to unravel the history of their immigration into the Alps and to provide data on their circumpolar phylogeography. In spite of the similar ecological requirements of the two species, they exhibit strikingly different immigration histories into the Alps. In M. biflora, the Alpine populations are most probably derived from source populations located between the Alpine and Scandinavian ice sheets, in accordance with the traditional biogeographic hypothesis. In contrast, the Alpine populations of R. pygmaeus cluster with those from the Tatra Mountains and the Taymyr region in northern Siberia, indicating that the distant Taymyr area served as source for the Alpine populations. Both species showed different levels of genetic diversity in formerly glaciated areas. In contrast to the considerable AFLP diversity observed in M. biflora, R. pygmaeus was virtually nonvariable over vast areas, with a single phenotype dominating all over the Alps and another, distantly related one dominating the North Atlantic area from Greenland over Svalbard to Scandinavia. The same pattern was observed in chloroplast DNA sequence data. Thus, postglacial colonization of R. pygmaeus was accompanied by extreme founder events.     

Global diversity of mysids (Crustacea-Mysida) in freshwater

In this article we present a biogeographical assessment of species diversity within the Mysida (Crustacea: Malacostraca: Peracarida) from inland waters. Inland species represent 6.7% (72 species) of mysid diversity. These species represent three of the four families within the Mysida (Lepidomysidae, Stygiomysidae, and Mysidae) and are concentrated in the Palaearctic and Neotropical regions. The inland mysid species distributional patterns can be explained by four main groups representing different freshwater invasion routes: (1) Subterranean Tethyan relicts (24 spp.); (2) Autochthonous Ponto-Caspian endemics (20 spp.); (3) Mysis spp. ‘Glacial Relicts’ (8 spp.); and (4) Euryhaline estuarine species (20 spp.). The center of inland mysid species diversity is the Ponto-Caspian region, containing 24 species, a large portion of which are the results of a radiation in the genus Paramysis. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Guest editors: E. V. Balian, C. Lévêque, H. Segers and K. Martens Freshwater Animal Diversity Assessment     

Immature Stages of Neotropical Enochrus (Coleoptera: Hydrophilidae): E. (Methydrus) lampros Knisch, 1924 and E. (Hugoscottia) tremolerasi Knisch, 1922

The preimaginal stages of the Neotropical species E. (M.) lampros Knisch, and Enochrus (H.) tremolerasi Knisch, are described and illustrated for the first time. They are compared to the immatures of the Neotropical species E. (M.) vulgaris (Steinheil) and E. (Hugoscottia) scutellaris (Bruch), the Nearctic E. (M.) fimbriatus (Melsheimer) and E. (M.) pygmaeus nebulosus Say, and the Australian E. (M.) maculiceps (MacLeay). Bionomical notes on the two species are included.     

Dispersal of the Ponto-Caspian amphipod Echinogammarus ischnus: invasion waves from the Pleistocene to the present

The geographical range of the amphipod crustacean Echinogammarus ischnus has expanded over the past century from the Ponto-Caspian region to Western Europe, the Baltic Sea, and the Great Lakes of North America. The present study explores the phylogeographic patterns of this amphipod across its current distribution, based on an examination of nucleotide diversity in the mitochondrial cytochrome c oxidase subunit I (COI) gene. Marked genetic divergence exists among populations of E. ischnus from the Black and Caspian Seas, as well as those from the drainage system of the Black Sea. This divergence suggests the prolonged geographic isolation of these native populations, reflecting the limited dispersal capability of E. ischnus. By contrast, invading populations are characterized by a lack of genetic variation; a single mitochondrial genotype of Black Sea origin has colonized sites from the Rhine River to North America. The dispersal pattern in E. ischnus is very similar to that in the Ponto-Caspian cladoceran Cercopagis pengoi. Despite their contrasting life history strategies, these invading species followed the same route of invasion from the northern Black Sea to the Baltic Sea region, and subsequently to North America.     

Biogeographic zonation of the Black Sea and Caspian Sea basin based on Mysid fauna (Crustacea: Mysidacea)

A biogeographic analysis of the Black Sea and Caspian Sea basin and adjacent Aegean Sea and the Sea of Marmara was conducted based on the distribution of 55 mysid species. The Black and Caspian Sea basin proper is inhabited by 35 mysid species belonging to 12 genera, among them 26 species and 3 genera are endemic to the region. Ponto-Caspian and Caspian species are predominant. The explored areas were included into two provinces of the Mediterranean subrealm of the East-Atlantic Subtropical realm and three provinces of the Ponto-Caspian realm.     

Influences of area, isolation and habitat features on distribution of snakes in Mediterranean fragmented woodlands

The effects of isolation-related and vegetational parameters on presence and relative abundance of snakes in patchy forested fragments of Mediterranean central Italy are studied. The most abundant species was Coluber viridiflavus (accounting for 47.7% of the total snake sample observed) followed by Vipera aspis (22%), Elaphe longissima (21.5%), Natrix natrix (7.7%), and Coronella austriaca (1.1%). There was a clear trend for bigger species to be less distributed among the various forest fragments than the smaller species. Presence of Coluber viridiflavus, Coronella austriaca and Natrix natrix was not influenced by woodland area, whereas that of Vipera aspis and Elaphe longissima was positively influenced by woodland area. Woodland isolation parameters did not influence the presence of Coluber viridiflavus, Coronella austriaca and Natrix natrix, but of Vipera aspis and Elaphe longissima. Discriminant stepwise analysis suggested that specific environmental features influenced the occurrence and abundance of the various snake species, Vipera aspis being the taxon more affected by isolation-related parameters. Some conservation implications of our observations are also discussed.     

A new species of Pomatoschistus (Teleostei,Gobiidae): the Mediterranean's smallest marine fish

The new sand goby species Pomatoschistus nanus (Teleostei: Gobiidae) is described from the northern coast of the Levantine Sea (eastern Mediterranean Sea) based on both morphological and DNA barcoding data. The new species is the smallest fish in the Mediterranean Sea and may be distinguished from congeners by the following features: predorsal area, first dorsal‐fin base and breast naked; δ‐pore missing; anterior point of the suborbital row b not reaching level of posterior point of suborbital row d; slightly emarginated caudal fin and nape coloration pattern. DNA barcode data clearly discriminate Pomatoschistus spp. in the neighbour‐joining tree with an average of 17·7% interspecific K2P distance. The most closely related taxon to P. nanus sp. nov. is Pomatoschistus bathi and the most distantly related is Pomatoschistus tortonesei with 11·9 and 21·9% K2P distances respectively. Morphometric and genetic data are also provided for Pomatoschistus bathi.     

The Mechanism of Replacement of Red Squirrels by Grey Squirrels: A Test of the Interference Competition Hypothesis

Introduced American grey squirrels have replaced native red squirrels in most of the range currently occupied in Britain and northern Italy. The mechanisms of the replacement are not yet fully understood. We restated the commonly cited Interference Competition Hypothesis (ICH) that grey squirrels interfere with the behaviour of red squirrels in three possible ways: 1. by direct aggressive interactions; 2. by interrupting red squirrel mating-chases; or 3. by forcing red squirrels to actively avoid areas intensively used by grey squirrels. We compared the activity pattern, behaviour and reproductive performance of red squirrels in two study areas in northern Italy, one with only red squirrels (control area C1), the other with both species (experimental area E1). The following predictions were tested: 1. the total time spent in both intraspecific and interspecific interactions by red squirrels increases in the experimental area; 2. most interspecific interactions are aggressive, with grey squirrels being the dominant species; 3. the proportion of breeding female red squirrels that are unsuccessful at weaning offspring increases in area E1; 4. grey squirrels take part and interfere with red squirrel mating-chases, and thereby decrease the reproductive output of red squirrel females; 5. the activity pattern of red squirrels in the mixed-species area is shifted with respect to that in the control area to the hours of the day during which grey squirrels show little activity; and 6. red squirrels will shift their home range (or at least their core-area) when grey squirrel densities increase to avoid interspecific core-area overlap. Our results supported only the first prediction of the ICH: they failed to support all the other predictions. Moreover, the increase in the percentage of active time red squirrels spent interacting with other squirrels in the experimental study area was very small (only 1–2 min/day). Red squirrels did not avoid the woodland patches most intensively used by grey squirrels and the interspecific core-area overlap was similar to red squirrel intraspecific core-area overlap. This suggested that red squirrels avoided spatial overlap with grey squirrels in a similar manner as with conspecifics and that an increase in grey squirrel numbers will augment the intensity of resource competition. We therefore conclude that our results do not lend support to the Interference Competition Hypothesis and that interference competition by grey squirrels cannot explain the large-scale replacement of red by grey squirrels that has occurred in Britain and in Piedmont.     

The species of Pseudaphya (Teleostei: Gobiidae) and the evolution of aphyiine gobies

The Mediterranean gobiid genus Pseudaphya Iljin, 1930, formerly containing two nominal species, the type Ps. ferreri (O. De Buen & Page, 1908) and Ps. pelagica De Buen, 1931, is now believed to be monotypic after examination of Adriatic material originally identified as Gobius pusillus Canestrini, 1861. The last is here provisionally regarded as Pomato-schistus knerii (Steindachner, 1861). The genus Pseudaphya is redefined, with additional osteological features, and its single species, Ps. ferreri , redescribed. In comparison with other small transparent gobiids, Pseudaphya is shown to possess certain primitive features and a possible mode of evolution for this group of tiny gobies by neoteny from postlarvae of hill-stream sicydiines is discussed. An origin from less specialized gobiines seems more acceptable.     

Bryophytes in Mediterranean coastal dunes: ecological strategies and distribution along the vegetation zonation

The bryophytic flora has been widely studied in Atlantic coastal dune environments while bryological literature addressing the Mediterranean bryophytes is still scarce and fragmented, although they are an important component of this area, especially considering their ability to colonize and stabilize sandy soils. The aims of this study were: (i) to analyze the taxonomy, chorology and ecology of coastal dunes bryoflora; (ii) to analyze distribution patterns of bryophytic species along a coastal dune vegetation zonation. We used as coastal dune model system a particularly well-preserved study area of the Sardinian coast (Italy), which includes several habitats listed in European Habitats Directive 92/43/EEC. We conducted a general survey of the area and a random sampling. A total of 20 bryophytic species were detected most of which were acrocarpous mosses and, to a lesser extent, pleurocarpous and liverworts. Most bryophytes are pioneer colonizers, reflecting their adaptation to environments with high levels of stress/disturbance conditions such as those of coastal dunes. Finally, in this study we described for the first time how bryophytic species are distributed along a Mediterranean coastal dune vegetation zonation, focusing also on their chorological and ecological characteristics and on how they seem to follow the sea-land gradient, probably in response to different environmental conditions developing along this gradient.