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.     

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.     

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.     

Biogeography of spiders (Araneae: Arachnida) on the islands of the Southern Ocean

The araneofauna of the extreme Southern Hemisphere is highly impoverished and disharmonic. Four dead anthropogenic immigrant spiders have been collected from Antarctica while only 115 verified species from 26 families are reported on the islands of the Southern Ocean. Cluster analysis of the verified Southern Ocean species distribution data identifies a weak, but distinct, Neotropical/South Atlantic association together with robust South Indian and South Pacific biogeographic clusters. These groupings, largely attributed to vicariance and/or endemism, contain little evidence of post-Pleistocene dispersal. Indeed the 14 records of anthropogenic origin suggest that the pace of recent human-mediated introduction has been at least 30 times more rapid than that of Holocene natural dispersal.     

The bark and ambrosia beetles of the Cook Island and Niue (Coleoptera: Scolytidae and Platypodidae)

Twenty-two species of Scolytidae (including one new species), and one species of Platypodidae are recorded from the Cook Islands and Niue in the South Pacific, and a key is given to all species. Corrections are made to earlier records from the islands. Xyleborinus perexiguus (Schedl) comb. n. is transferred from Xyleborus. The faunal composition, breeding habits and geographical distribution of the species are discussed and related to those of other islands in the Pacific. Many species have probably been introduced by man. In the absence of a major timber industry, the species are likely to be of minor economic importance.     

Oribatid mites (Acari: Oribatida) of the Falkland Islands,South Atlantic and their zoogeographical relationships

A total of 21 species of oribatid mites (Acari: Oribatida) are recorded from heat-extracted samples of soil and plant material collected in the Falkland Is., South Atlantic. Previous records of a further 11 species provide a total of 32 species. The distribution of each non-endemic species recorded from the Falkland Is. is figured. The oribatid mite fauna of these islands belongs to the Neotropical Region with strong sub-Antarctic elements and some similarities with New Zealand.     

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.     

Freshwater macroinvertebrates of Lord Howe Island

Studies on freshwater invertebrate fauna on islands are rare but a few suggest species richness can be high. A survey of the freshwater invertebrates of Lord Howe Island (LHI) yielded 38 taxa, bringing the total recorded from LHI to 54. The majority of the taxa from the survey were from the Insecta, with 15 Diptera (true flies), five hemipterans (true bugs) and five trichopterans (caddisflies). Two species of gastropods, three mites and eight other arthropods were also found. The total number of taxa on LHI, although smaller than other islands, is the highest per unit area ever recorded (3.9 taxa per km²). High levels of endemism were recorded for most taxonomic groups and two previously undescribed chironomid species were found. However, further taxonomic and genetic work is necessary in order to assess true levels of endemism by investigating the genetic similarities and differences of these taxa with nearby islands.     

The distribution of New Zealand and Australian terrestrial flatworms (Platyhelminthes: Turbellaria: Tricladida: Terricola) in the British Isles—the Scottish survey and MEGALAB WORMS

The New Zealand flatworm, Artioposthia triangulata, and the Australian flatworm, Caenoplana alba, have become quite widespread in the British Isles since their introduction, probably in the early 1960s. They are considered as pest species since they eat earthworms and consequently may affect soil structure and fertility. The distribution of the two species has been recorded by two surveys: a Scottish survey between 1991 and 1993, and a national survey, MEGALAB WORMS, in March 1995. The latter was organized as part of National Science Week by BBC TV Tomorrow's World, The Daily Telegraph newspaper and the Office of Public Service and Science. Results of both surveys are presented as distribution maps of confirmed records. New Zealand flatworms are common and widespread in Northern Ireland and Central Scotland, and occur less commonly in other parts of Scotland, and in Northern England. There are a few scattered records from Southern England. The Scottish survey has resulted in retrospective distribution maps. Australian flatworms are widespread in South West England, and are found in several places in North West England. There are also records from South and North Wales, Northern Ireland and one from Southern Scotland. There were many false and negative reports. There are records of both species from the Republic of Ireland.     

Oribatid mites (Acari: Oribatida) of the maritime Antarctic and Antarctic Peninsula

Eleven species of oribatid mites are reported from 26 maritime Antarctic islands. The oribatid faunas of Fredriksen, Atriceps (South Orkney Is.), Cockburn, Seymour, Vega, Brabant, Adelaide, Lagoon, Léonie, Horseshoe, Alexander Islands and Peter I Øy were studied for the first time. Austroppia crozetensis (Richters, 1908) and Magellozetes processus Hammer, 1962 are first records for the Antarctic Region. Halozetes belgicae longiseta Wallwork, 1967 is a new record for the South Orkney Is., Edwardzetes dentifer Hammer, 1962, is new for the South Shetland Is., Magellozetes processus Hammer, 1962 is new for Graham Land whilst Globoppia loxolineata longipilosa Covarrubias, 1968 and Magellozetes antarcticus (Michael, 1895) are new records for Palmer Land. The distribution patterns of the 11 species of oribatid mites are figured and their zoogeographical relationships are discussed.     

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.     

Review of the southern temperate fish family Aplodactylidae (Pisces: Perciformes)

The southern temperate perciform fish family Aplodactylidae is reviewed. The monotypic genus Crinodus is relegated to the synonymy of the genus Aplodactylus, which is recognized as containing five species: A. arctidens Richardson from New Zealand and Australia (Victoria, South Australia and Tasmania); A. lophodon (Günther) restricted to south-eastern Australia (New South Wales and Victoria); A. westralis Russell restricted to south Western Australia; A. etheridgii (Ogilby) from the south-west Pacific (north-eastern New Zealand, Kermadec Islands, Lord Howe Island and Norfolk Island); and A. punctatus Valenciennes from the west coast of South America (Peru and Chile). A key to the species is given.     

The marine red algae of Rodrigues (Mauritius,Indian Ocean)

This paper reports on the red algae of Rodrigues, collected in the framework of the Shoals of Capricorn Programme (10 September to 5 October 2001). In total 68 species are reported, of which 65 represent new records for the island. Although most taxa represent rather common species, which are generally widespread in the Indian and western Pacific Ocean, some are of special interest to algal systematists and biogeographers. Renouxia antillana is reported for the first time for the Indian Ocean. The presence of Renouxia also constitutes the first record of the order Rhodogorgonales for the entire Indian Ocean. A few species have interesting distribution patterns. Halydictyon sp. is restricted in its distribution to South Africa, Mauritius and Australia. Despite these interesting records, the red algal flora of Rodrigues is most remarkable by the absence of several ‘ubiquitous' species.     

Bryozoa collected by the United States Antarctic Research Program: new taxa and new records

Thirty-two species of cheilostomate Bryozoa are described and illustrated from 26 stations sampled by the United States Antarctic Research Program, including 29 new species and two new genera. A further new genus is introduced for two species formerly attributed to Osthimosia Jullien, 1888. One station was located in the Ross Sea and three in the cold temperate South Pacific; 14 stations were sampled in the region of the Scotia Arc, south of the Antarctic Convergence, and eight from the subantarctic southwest Atlantic, mostly in the vicinity of Tierra del Fuego. Nine new species were present in the Antarctic samples, whereas those from the southwest Atlantic yielded 18 new species and the two new genera. Three of the new subantarctic species are attributed to genera formerly considered to be Antarctic endemics, while the two newly assigned species of Osthimosia are presently known only from Antarctic localities.     

Three species of the genus Diastylis (Crustacea: Cumacea) from the Yellow Sea

One new species and two new records of diastylid cumaceans (Crustacea: Cumacea) are described from the Yellow Sea, North West Pacific. The new species Diastylis inplicata sp. nov. resembles D. nitens Gamo, 1968, but it is characterized by a smooth antero-lateral margin of the carapace without ridges or spines. It is widely distributed either in the intertidal mud flats of the Korean West coast or in shallow waters of the eastern Yellow Sea. The other two diastylids are newly recorded in the faunal inventory of the Yellow Sea: Diastylis loricata Lomakina, 1955 and Diastylis paratricincta Kang and Lee, 1996.     

A biogeographical analysis of the tenebrionid beetles (Coleoptera,Tenebrionidae) of the island of Thasos in the context of the Aegean Islands (Greece)

This research aimed to study the origin and the biogeographical relationships of the tenebrionid beetle (Coleoptera, Tenebrionidae) fauna of the island of Thasos, with reference to the other Aegean Islands. A total of 32 Aegean Islands and 170 taxa (species and subspecies), 23 of which occur on Thasos, were included in this study. Nine tenebrionid species are here reported for the first time from Thasos, including the first records of Platydema europaeum and Nalassus plebejus from the Aegean Islands. Several models (linear, exponential, power, logistic, Gompertz, Weibull and Lomolino functions) were used to test the species–area relationship. The power function appeared to be the most appropriate model and the parameters of the curve suggest a possible relict character for this fauna. The proportion of Balkan taxa on the islands sharply decreases from west to east, whereas the Anatolian taxa follow an opposite trend. Multi‐dimensional scaling, Parsimony Analysis of Endemicity and discriminant function analysis revealed a clear faunal discontinuity between the western and central Aegean Islands on one side, and the islands close to the Anatolian coast on the other. This discontinuity, consistent with the persistence (from Messinian to Pleistocene) of a sea barrier between these two groups of islands, strongly supports the importance of Pleistocene island configurations in determining present distributional patterns. The comparative richness of the tenebrionid fauna on Thasos is enhanced by the proximity of the island to the mainland and the diversity of its surviving habitats.     

Some copepods parasitic on elasmobranch fishes from the Peruvian coast,with the description of two new species of Eudactylina van Beneden, 1853 (Eudactylinidae) and four new records

Six species of copepods parasitic on elasmobranch fishes from the Peruvian coast has been recorded. Two of them, Eudactylina peruensis and E. myliobatidos parasitic on Rhinobatos planiceps (Rhinobatidae) and Myliobatis chilensis (Myliobatidae), are considered new species. New geographical and host records for Pseudocharopinus narcinae Pillai, Pseudocharopinoides myliobatidos Castro and Baeza, Perissopus oblongus (Wilson) and Trebius latifurcatus (Wilson) are included, as also is a checklist of copepod species parasitic on elasmobranch fishes from the coast of the South American Pacific.     

The colonial ascidian fauna of Fiordland,New Zealand,with a description of two new species

A total of 17 species from the families Styelidae, Polyclinidae, Polycitoridae, Pseudodistomidae, Ritterellidae and Didemnidae are described for the first time in collections from remote fiords with steep-sided walls, high rainfall and high tidal flow on the south-west coast of New Zealand. The Fiordland ascidian assemblages are composed of endemic species, species with trans-Tasman affinities, species found in southern New Zealand and species found New Zealand wide, some of which have global distributions. Two Australian native species, Diplosoma velatum Kott, 2001 and Didemnum jucundum Kott, 2001 from South Australia are new records to New Zealand and a further eight species remain undescribed. Two new colonial ascidians Aplidium coronum sp. nov. and Trididemnum shawi sp. nov. are described in this paper.

http://zoobank.org/urn:lsid:zoobank.org:pub:5ADC2C9D-28AC-4348-8B4D-F26-2A43DEA66     

Description of a new species of Asymmetrione (Isopoda: Bopyridae: Pseudioninae) infesting the hermit crab Paguristes tomentosus (Anomura: Diogenidae) from Peru,with a key to species and a review of southeastern Pacific bopyrids

A new species of bopyrid isopod is described from a host hermit crab Paguristes tomentosus collected from Pisco, Peru and assigned to the pseudionine isopod genus Asymmetrione Codreanu, Codreanu and Pike, 1965. This is the second species in the genus with less than 20° asymmetry in females, but agrees with all other species in the genus in having the characteristic “socket” on the propodus of the female's pereopods, and in all characters of the males. A key is provided to the 10 species now in Asymmetrione. New records of an Anathelges sp. from Pagurus villosus collected in central Chile are given but additional material is required to determine whether these specimens represent the eastern Pacific A. thompsoni or the western Atlantic A. hyptius. A review of all the bopyrid species known from the western South American coast, with remarks on their taxonomy and biology, is provided.