Diversity and dispersal history of the talitrids (Crustacea: Amphipoda: Talitridae) of Bermuda

Five taxa of talitrid amphipods were found in the archipelago of Bermuda, of which three were recorded there for the first time. Four of these are supralittoral wrack generalists: Platorchestia monodi BOLD:AAB3402, (a unique Molecular Operational Taxonomic Unit according to the Barcode Index Number system), a related species recognized by molecular methods, Platorchestia platensis BOLD:AAA2949, Mexorchestia carpenteri carpenteri BOLD:AAC1491 and Tethorchestia antillensis; and one a terrestrial leaf-litter generalist: Talitroides alluaudi. A key is provided to discriminate between the formally described talitrids of Bermuda. Dispersal mechanisms from the American continent to Bermuda were considered for all taxa based on species distributions along the North American Atlantic coast and also investigated by molecular methods, using genetic population differentiation and haplotype network analysis based on the barcode region of cytochrome c oxidase subunit I gene. For P. monodi BOLD:AAB3402 the genetic results suggest that some dispersal events occurred before human colonization of Bermuda but are equivocal about the source population and therefore the direction of dispersal. Some very recent synanthropic dispersal is possible with this species. For the other two species studied genetically, P. platensis BOLD:AAA2949 and M. c. carpenteri BOLD:AAC1491, the small population samples analysed support dispersal to Bermuda from the American mainland, before human occupation of Bermuda, although the available sample size was limited for these species. The available limited direct, non-genetic evidence supports synanthropic transport for Talitroides alluaudi. Platorchestia monodi BOLD:AAB3402 is found in the same wrack habitat as P. platensis BOLD:AAA2949 on Bermuda, apparently without interbreeding. No evidence was found that driftwood specialist talitrids had become established in Bermuda.     

Further morphological and molecular studies of driftwood hoppers (Crustacea: Amphipoda: Talitridae) from Mediterranean/north-east Atlantic coastlines

An unknown talitrid was discovered in 2011 in the Swale, UK, living in driftwood. Sequencing of multiple mitochondrial and nuclear genes (cytochrome oxidase I, 18S rDNA and 28S rDNA) confirms that the unknown taxon was close to Orchestia mediterranea A. Costa 1857. The driftwood in which it was found was of Douglas fir (Pseudotsuga menziesii), probably imported from North America. Relative growth methods allow us to reject the null hypothesis that the unknown taxon was a juvenile Orchestia mediterranea. This is because the unknown taxon initiates sexual maturation at an earlier moult number (neoteny) and is predicted to reach terminal moult stages at a much smaller size (dwarfism) than its closest relative O. mediterranea. Both molecular and morphological data confirm that the unknown taxon from the Swale, UK, is a new driftwood specialist taxon, distantly related to the driftwood specialist genus Macarorchestia. Additional data for body length and sex ratios are presented for Macarorchestia. In addition, relative growth methods have shown that the driftwood species Orchestia microphtalma Amanieu and Salvat 1964 is closer to the genus Macarorchestia rather than to the wrack generalist one, Orchestia. This evidence is in line with the molecular results that do not cluster morphologically defined species of Orchestia monophyletically.     

Zoogeography and evolutionary ecology of the genus Platorchestia (Crustacea,Amphipoda, Talitridae)

ABSTRACT

Species of the genus Platorchestia occur both in the northern hemisphere (18 species) and southern hemisphere (three species plus a synanthropically introduced species in South America and South Africa). The greater number of endemic Platorchestia species in the North Pacific Ocean suggests that it could be the epicentre of evolution for this genus. North-western Pacific Platorchestia includes 15 species which occupy five ecotopes: wrack (seven species), terrestrial leaf litter (five species), freshwater (one species), marsh (one species) and tentatively present in caves (one species). North-eastern Pacific Platorchestia includes only one putative driftwood specialist, with no other species found in North American coastal habitats. This compares with three good endemic Platorchestia species (plus two putative additional species) and only two ecotopes: wrack (three species) and freshwater (two species) from the North Atlantic Ocean, inclusive of the Gulf of Mexico and Mediterranean Sea. Insufficient data is available to consider Platorchestia zoogeography for the Arabian Sea and Bay of Bengal. Synanthropic dispersal involving Platorchestia in Polynesian outrigger canoes, or in solid ballast carried in the holds of wooden sailing ships has been identified as a potential complicating factor in the zoogeography of this genus. Platorchestia is proposed to have arisen on Laurasia and is therefore basically a northern hemisphere genus. Questions concerning Platorchestia zoogeography and evolutionary ecology are posed and two methods (more intensive field sampling and molecular genetics) are suggested to be the way to solve them.     

Invertebrate faunas and zoogeographic significance of lava tube caves of Arizona and New Mexico

A field survey in caves near Grants, New Mexico, and Flagstaff, Arizona, found only an exceptionally poor fauna of 14 species with no strong patterns of cave restriction. The faunal poverty is judged to be correlated with and influenced by the similarly impoverished boreal forests in nearby mountains. Species of flightless arthropods, suitable for cave colonization and restricted to cool-moist litter of boreal (Hudsonian-Canadian Life Zone) forests, are apparently not now present in suitable, nearby mountain habitats. They may not have dispersed to all available montane sites from the Southern Rocky Mountains during glacial conditions. Either the forests did not exist as continuous dispersal corridors for the litter arthropods, or the fauna could not track the rate of spread of the forests.     

A revision of the genus Stenognatha Felder (Lepidoptera: Arctiidae: Pericopinae)

The acarine faunas of supralittoral tidal debris and lichens were examined on a number of shores; differences in the faunas were attributed to different environmental factors within the two habitats. The Acari may be divided into three ecologically defined groups: (a) maritime species which are confined to the seashore, especially the supralittoral, but may venture into the upper littoral zone; (b) non-maritime species which frequent the seashore, but usually occur inland in soils, leaf litter, and/or vegetation; and (c) nomadic species which migrate freely and regularly between the littoral and supralittoral zones. On the Isles of Scilly some maritime species are absent, and are replaced by non-maritime forms. Freeliving Acari are generally preadapted to the supralittoral zone, and no specializations have been noted among the fauna.     

Notes on the occurrence of the introduced landhopper Arcitalitrus dorrieni (Hunt, 1925) on Guernsey,Channel Islands

The introduced landhopper Arcitalitrus dorrieni (Hunt, 1925) has been recorded at various locations (woodlands, private gardens and garden centres, disused quarries) throughout the island of Guernsey, Channel Is. Landhoppers were present in the leaf litter of most of the deciduous and coniferous woodlands with one exception. Although it possessed a well developed litter layer, the oak/mixed woodland at Fauxquets valley was devoid of landhoppers. Landhopper populations were less dense in confierous cf. deciduous, leaf litter. Generally the population density of landhoppers was low (21–300 individual m^-2) compared with other UK sites (due possibly to the study coinciding with the driest summer for 19 years), but was related to the depth of the litter layer. There was also a direct relationship between the total copper content of the leaf litter/soil and landhopper population density even allowing for different litter thickness. While locating an actual original introduction site is problematic, the date of introduction, for reasons discussed in the text, is likely to have been between the early 1900s and 1950.     

Why are there so few “far southern” myriapods?

There are no extant Antarctic myriapods. The “far southern” islands south of latitude 45° S together with the isolated (south Atlantic) Tristan da Cunha, Gough, (south Indian) St Paul, Amsterdam and (south Pacific) Chatham islands (at 37 to 44° S), harbour only 33 native, introduced and partly identified taxa, including 17 Chilopoda, 11 Diplopoda, two Pauropoda and four Symphyla. The myriapods confined to the extreme edge of the Southern Ocean are entirely derived from pre-glacial Tertiary relicts or post-glacial anthropogenic introductions and show no evidence of co-occurring sibling taxa. This unusual distribution pattern provides a useful “no dispersal/no speciation” benchmark that can be applied to other far-southern non-marine invertebrates where the distinction between pre-glacial and post-glacial endemic taxa is not so clearly defined.     

The terrestrial micro-arthropod fauna of the South Sandwich Islands

The South Sandwich Islands are an isolated maritime Antarctic volcanic island arc 550-600km south-east of South Georgia. The terrestrial biology of the islands, with emphasis on the unique habitats associated with volcanically warmed ground, was investigated in 1997 and compared with the data collected during the only previous (1964) terrestrial expedition to the archipelago. The terrestrial fauna includes 29 free-living micro-arthropod species (nine Collembola and 20 Acari) and two, currently unidentified, enchytraeid worms; a further eight parasitic and sublittoral Acari are recorded in the literature. Freshwater habitats are very restricted in the archipelago and no freshwater fauna was located. Supralittoral pools on a single island contained the marine isopod Cassidinopsis maculata. There are no endemic taxa and no shoreline invertebrates other than the supralittoral Archisotoma brucei (Collembola) and two Enchytraeidae. Diversity on individual islands is, in part, a function of available ice-free ground area. The majority of dominant species throughout the archipelago, Cryptopygus antarcticus (Collembola), Nanorchestes nivalis, Eupodes minutus, Alaskozetes antarcticus and Halozetes belgicae (Acarina), originate on other maritime Antarctic islands, while Ayersacarus tilbrooki (Acarina) is sub-Antarctic. Few (one to three) individuals of several other sub-Antarctic species were recorded by either 1964 or 1997 expeditions, but only Pilellus rykei (Acarina) was reported by both. None of the sub-Antarctic species thought to be associated with geothermally warmed ground in 1964 was confirmed in 1997, despite extensive sampling of the same sites. It is more probable that sub-Antarctic colonists frequently arrive on the South Sandwich Islands but are unable to establish longterm viable populations. Cryptopygus caecus, now widespread on Candlemas I., is a solitary exception to this generalization.     

Natural history of the terrestrial amphipod Cerrorchestia hyloraina Lindeman (Crustacea: Amphipoda; Talitridae) in a Costa Rican cloud forest

The field biology of the Costa Rican landhopper (Crustacea: Amphipoda: Talitridae) Cerrorchestia hyloraina Lindeman was investigated in the Monteverde Cloud Forest Reserve, Costa Rica. On the Pacific (leeward) side of the continental divide, local distribution follows a gradient of moisture, from densities of over 200 m^-2 in the elfin forest at 1600 m, to extremely low densities in drier forest types. Below 1400 m, the leaf litter is apparently too dry to support landhopper populations. On the Caribbean (windward) side of the continental divide, landhoppers occur well below 1400 m. A discussion of geographic distribution is included. Landhoppers prefer aged (microfaunally pre-processed) leaves as food, and move about only at night or in the mornings of heavily overcast days. Average female fecundity is seven eggs, with progressive loss of marsupium contents over time. The sex ratio is biased towards females. In cloud forest, breeding apparently is continuous throughout the year, with some increase after the beginning of the rainy season. There are 9–10 juvenile instars and 5–6 adult instars. The relationship of antennal segment number to total body length is linear.     

The shore-dwelling Acari of the Isles of Scilly and the South-West Peninsula

Seventy-five species of Acari were collected from the littoral and supralittoral zones on a number of shores in the Isles of Scilly, Cornwall, South Devon and Dorset. Many of the species recorded are new records, or at least new shore records to the area. Vulgarogamasus halophilus (Willmann) (Parasitidae) is new to the British fauna.     

Conservation in a changing landscape: habitat occupancy of the critically endangered Tennent’s leaf-nosed lizard (Ceratophora tennentii) in Sri Lanka

Landscape modification is a key driver of global species extinction. Thus, understanding how species react to changes is essential for effective conservation management in modified landscapes. We examined the impact of selected land use patterns on the critically endangered Ceratophora tennentii in the Knuckles mountain range of Sri Lanka where lizards occupy patches of both natural undisturbed forests and modified plantations – evidently, those with a forest canopy. We tested three potential explanations for non-random habitat selection: availability of suitable microhabitat pockets, availability of prey and direct threats from humans. The microhabitat pockets occupied by the lizards were characterised by shade, humidity and the density of perches. Most lizards were found in mixed cardamom forests followed by natural forests and cardamom plantations, but none were observed in the pine plantations. Food availability showed similar patterns among habitats. Direct mortality by humans did not influence the distribution of this species. Our work indicates that habitat modifications that retain the structural complexity of the vegetation would still permit the existence of the species in densities equal to or greater than that of undisturbed forest patches. It adds to a growing body of literature that signifies the importance of disturbed habitats (intermediate disturbance hypothesis) in protecting threatened species of fauna. It is highly unlikely that some disturbed habitats will be ever be returned to their former pristine state in time frames that are important for species’ conservation. Hence, attention is needed in developing suitable approaches to manage and conserve species across disturbed habitats.     

Cladocera and Copepoda of Shokalsky Island: new data from northwest Siberia

Information on the freshwater fauna of the remote Arctic territories is very patchy, and most of the isolated islands of the Arctic Ocean remain absolutely unexplored. The pioneer data on the species composition of microcrustaceans of Shokalsky Island (northwest Siberia, Russia) is reported here. The initial three-year research revealed a total of 31 new for the area species of Cladocera and Copepoda, including new records for the whole of northwestern Siberia. Comparing the interannual differences in faunal composition, we suggested the hypothesis of the existence of a cryptic pool of species’ resting stages, which can invade the community in the event of favourable environmental conditions in the Arctic freshwaters. We also compiled all the available data from different parts of northern Siberia and compared them with the fauna of Shokalsky Island to analyse the connection between the diversity and distributional patterns of copepods and cladoceran species and the climate conditions of different territories.     

Biodiversity and biogeography of non-marine Mollusca on the islands of the Southern Ocean

There are no terrestrial and freshwater molluscs associated with Continental nor Maritime Antarctica. The malacofaunas of the cool-temperate and sub-Antarctic islands of the Southern Ocean are extremely depauperate, comprising a mere 68 site-records of 51 species from 27 genera in 13 families. The South Atlantic records are confined to the Falkland Islands, which harbour nine species (one bivalve, five pond snails and three terrestrial aliens), and South Georgia, where there is one Notodiscus sp. (Charopidae). The fauna of the South Indian Ocean islands of Prince Edward, Crozet, Kerguelen and Heard, comprises two alien slugs and endemic Notodiscus hookeri (Charopidae). The majority of species occur on the South Pacific Ocean Islands of Macquarie, Campbell, Auckland, Snares, Antipodes, Bounty and Chatham to the south and east of New Zealand. The Chatham fauna is dissimilar to that on the other South Pacific Islands, though both represent vicariant remnants of common South Pacific Is./New Zealand Athoracophoridae, Charopidae and Punctidae. There is, other than the broad South Indian Ocean distribution of Notodiscus hookeri, little evidence of Holocene dispersal and colonization. Indeed the Southern Ocean is an effective barrier and the different regional (South Atlantic/Indian/Pacific) faunas are principally vicariant and derived from local survivors of Pleistocene glaciation.     

Geographical distributions and host associations of larval parasitoids of frugivorous Drosophilidae in Japan

In Japan, dominant parasitoids attacking frugivorous Drosophilidae species were Asobara (Braconidae, Alysiinae), Leptopilina, and Ganaspis species (Figitidae, Eucoilinae). Asobara japonica was found throughout Japan, and its populations in the main islands of Japan were parthenogenetic whereas those in the subtropical islands were sexually reproducing. Other parasitoids showed rather restricted distributions; A.tabida, A. rossica, A. rufescens, and Leptopilina heterotoma occurred mainly in northern to central parts of the main islands, Ganaspis xanthopoda from central to southern parts of the main islands, A. leveri in a southern part of the main islands, and A. pleuralis, L. victoriae, and Ganaspis sp. mainly in the subtropical islands. Their major hosts were species of the D. melanogaster species group in the main islands, and species of the D. melanogaster, immigrans, and polychaeta species groups in the subtropical islands. Host use considerably varied among parasitoid species, especially in the subtropical islands.     

Comparison of the species composition of Gamasina mite communities (Acari: Mesostigmata) in selected caves of the Kraków-Częstochowa Upland (southern Poland) and their immediate surroundings

This paper presents the results of a study performed in eight caves located in the area of the Kraków-Cz?stochowa Upland. In total, 586 samples (400 cm³ each) were taken from the caves and sites located up to one metre from the main entrances of the caves. Of 109 species belonging to 13 families that were identified, four were species new for Polish fauna. In this study, cluster analysis and correspondence analysis were used to compare the species composition of mite communities living in the caves and their immediate surroundings. We also examined the possibility of isolating troglophilic species based on IndVal analysis. Those results showed distinct differences between Gamasina mites living in two distinct habitats. We also established indicator species for the examined caves.     

The persistence of an ancient marine fauna in Mediterranean waters: new evidence from misophrioid copepods living in anchihaline caves

Two new species of misophrioid copepods are described from anchihaline cave habitats. Both sexes of Speleophriopsis canariensis are described from material collected on Lanzarote, Canary Is. Expansophria sarda is described from a single male collected on Sardinia. Both genera have widely disjunct distributions which are broadly Tethyan in character. Species of both genera are stenotopic and appear to be restricted to hypogean habitats of near-marine salinities. The presence of species of both genera on Mediterranean islands is interpreted as evidence of the persistence of marine fauna throughout the Messinian Salinity Crisis.     

Diversity and abundance of fungivorous thrips (Thysanoptera) associated with leaf-litter and bark across forest types and two tree genera in subtropical Australia

Leaf-litter thrips were much more common and diverse in dry sclerophyll forest than in wetter forest types in subtropical southeast Queensland, Australia. In dry sclerophyll forest, the species composition of thrips in leaf-litter was strongly differentiated from the thrips fauna associated with bark of the trees Eucalyptus major and Acacia melanoxylon (4 of 34 species in common). The species composition of bark-dwelling thrips was similar across the two tree species and also across two eucalypts with different bark types, Eucalyptus major (flaky) and Eucalyptus siderophloia (rough). The diversity of thrips from the leaf-litter was not differentiated across all of these tree species. Virtually all thrips collected were Phlaeothripidae, subfamilies Idolothripinae and Phlaeothripinae. Idolothripinae were associated almost exclusively with leaf-litter, but Phlaeothripinae were in leaf-litter and bark. The association of fungal-feeding thrips with dry sclerophyll forest raises questions about their ecological requirements and the role they play in nutrient cycling.     

Molecular phylogeny of the Aplodactylidae (Perciformes: Cirrhitoidea), a group of Southern Hemisphere marine fishes

Aplodactylids are temperate marine nearshore fish of New Zealand, southern Australia, several south-west Pacific islands, and western South America. The molecular phylogeny of the five aplodactylid species was reconstructed from mitochondrial DNA sequences. The observed relationships and levels of genetic variation supports the most recent review of the Aplodactylidae in which the monotypic Crinodus is synonymized with Aplodactylus, the only genus presently recognized. Phylogenetic relationships indicate that the Aplodactylidae originated in the approximate region of Australia and New Zealand, with the majority of radiation occurring prior to this family achieving representation in South America. The disjunct trans-Pacific distribution of this family was the result of chance dispersal rather than vicariance accompanying Gondwana fragmentation. Such dispersal was most likely undertaken during the larval phase, mediated by the West Wind Drift current.     

Synopsis of the life cycles of Digenea (Platyhelminthes) from lagoons of the northern coast of the western Mediterranean

The present document reports on the large amount of data relating to digenean parasites recorded from or known to be present in various hosts in lagoons of the northern coast of the western Mediterranean, which has been compiled from the literature of more than a century. In these lagoons, at least 72 nominal species of digeneans have been recorded. This total corresponds to approximately 12% of the 584 “marine” digenean species reported for Europe. Data are provided on the life cycles of 56 digenean species. The life cycle has been totally elucidated for 44 species (25 from fish, 19 from birds), and partly for the other 12 species (seven from fish, five from birds). This means that the life cycle is known for 61.1% of the recorded fauna (44/72) and partly for 16.7%, but remains unknown for 22.2%, making it, in this respect, one of the best understood digenean marine faunas in the world. In addition, a checklist is provided dealing with the cercarial and metacercarial forms recorded from lagoons of the northern coast of the western Mediterranean, which have been described only on the basis of characters of these larval stages and which remain without demonstrated links to a corresponding sexual adult stage in a vertebrate.     

Biodiversity of subterranean amphipod crustaceans: global patterns and zoogeographic implications

Gammaridean amphipod crustaceans are important components of subterranean groundwater communities in many parts of the world. Most subterranean species are stygobionts, which are defined by loss or reduction of eyes and pigment and restriction to hypogean waters. The global subterranean amphipod fauna is composed of about 740 species that are distributed among 36 families and 138 genera; however, 12 families contain about 94% of all hypogean amphipods recorded to date. With respect to number of stygobionts, the four most important families are the Niphargidae, Crangonyctidae, Hadziidae s. lat. (complex), and Bogidiellidae. Many regions of the world contain significant diversities of subterranean amphipods, but the central and southern European-Mediterranean and eastern and southern North American-West Indian regions are clearly superior in taxonomic diversity and species richness. Together these two regions contain about 77% of the world's subterranean amphipod fauna, and their high diversities are attributed in part to geographical heterogeneity and a unique combination of geological and ecological phenomena that include extensive karst terrains, absence of glaciation, and exposure to marine transgressions in the south. Other regions with significant diversities of subterranean amphipods include southern Africa, Australia-New Zealand, eastern Asia, central South America, central Asia, northeastern Africa, and islands of the Atlantic, Pacific, and Indian Oceans. The subterranean fauna of southeastern Asia remains very poorly known to date.