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.     

Tardigrades from Signy Island,South Orkney Islands,with particular reference to freshwater species

Seventeen species of Tardigrada from lakes and catchments on Signy Island, South Orkney Islands, are described. Two species, Echiniscus punctus and Isohypsibius laevis are new to science, and two, Oreella minor and Pseudechiniscus suillus, are new to the Signy Is. records.     

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.     

New species of cheilostomate Bryozoa collected by the US Antarctic Research Program

Four new species of cheilostomate Bryozoa are described in the genera Chartella, Ogivalia, Melicerita and Cellarinella. The circumArctic genus Chartella is recorded for the first time from the subAntarctic. Alloeoflustra gen. nov. is introduced for three endemic Antarctic Flustridae.     

The first record of a benthic polar chaetognath: a new Spadella from the Antarctic

A new benthic chaetognath, Spadella antarctica n. sp., is described from depths between 193 and 500 m in the Weddell Sea (Antarctic Ocean) and comparisons are made with related species of Spadella. Ecological remarks on this genus are provided.     

Species of Oswaldella Stechow, 1919 (Cnidaria: Hydrozoa: Kirchenpaueriidae) from US Antarctic expeditions,with the description of three new species

Seventeen species of the genus Oswaldella Stechow have been studied, three of which are new to science (Oswaldella frigida sp. nov., O. medeae sp. nov. and O. monomammillata sp. nov.). The material studied was collected by several US Antarctic expeditions. Each species is described and figured, the systematic position amongst allied species is discussed and available data concerning autecology and geographical distribution are given. The remaining eight known species of the genus are also considered, regarding synonymy, autecology and geographical distribution. Finally, a general survey of the bathymetrical and biogeographical distribution of the known species of Oswaldella is given.     

Alien vs. Predator: interactions between the colossal squid (Mesonychoteuthis hamiltoni) and the Antarctic toothfish (Dissostichus mawsoni)

Data collected onboard two South Korean longliners in 2011–2014 targeting Antarctic toothfish provided insights into trophic interactions between two Antarctic top predators: the colossal squid Mesonychoteuthis hamiltoni and the Antarctic toothfish Dissostichus mawsoni. Adults of each species opportunistically prey upon weakened representatives of the other species: squid will feed on longline-caught toothfish, and toothfish on dying and dead squid. The highest occurrence of squid attacks was recorded in the Davis Sea and Commonwealth Sea, and the lowest in the Ross Sea. Squid depredation rates were around 1% on average, though regionally they might rise to 2–3%, which is of a similar magnitude to rates caused by sperm whales and killer whales in some areas.     

Species of Staurotheca Allman, 1888 (Cnidaria: Hydrozoa: Sertulariidae) from US Antarctic expeditions,with the description of three new species

Seventeen species of the genus Staurotheca Allman have been studied, three of which are new to science (Staurotheca abyssalis sp. nov., S. densa sp. nov. and S. profunda sp. nov.). The material studied was collected by several US Antarctic expeditions. Each species is described and figured, the systematic position amongst allied species discussed and available data concerning autecology and geographical distribution given. The remaining six known species of the genus are also considered, regarding synonymy, autecology and geographical distribution. The type material of two poorly known species of Staurotheca, S. juncea (Vanhöffen) and S. pachyclada (Jäderholm) has been re-examined, re-described and figured. Finally, a general survey of the bathymetrical and biogeographical distribution of the known species of Staurotheca is given.     

Species of Schizotricha Allman, 1883 (Cnidaria: Hydrozoa: Halopterididae) from US Antarctic expeditions with the description of two new species

Twelve species of the genus Schizotricha Allman have been studied, two of which are new to science (Schizotricha heteromera sp. nov. and S. trinematotheca sp. nov.). The material studied was collected by several US Antarctic expeditions. Each new species is described and figured, the systematic position amongst allied species discussed and available data concerning autecology and geographical distribution given. The remaining 10 species are considered regarding diagnosis, autecology and geographical distribution. Finally, a general survey of the bathymetrical and biogeographical distribution of the known species of Schizotricha is given.     

Bionomics of the myrmecophilous oribatid mite Protoribates myrmecophilus (Acari: Oribatida) in the Oriental tropics

Behavioural interactions between the myrmecophilous oribatid mite Protoribates myrmecophilus and the host ant Myrmecina spp. are described and compared to those of Aribates javensis which shows a very specialized myrmecophily. The behaviour of P. myrmecophilous is similar to free-living oribatids: they can walk by themselves and can survive without ant attendance. In the ant nests, the mites are sometimes cared for by ants and they are brought by ants into a new nest site. Protoribates myrmecophilus is eaten by non-host species of Myrmecina. Protoribates myrmecophilus is a less specialized myrmecophilous oribatid species.     

Oribatid mites of Liebstadia (Acari: Oribatida: Scheloribatidae) from Mongolia,with notes on taxonomy of the genus

Three new species of oribatid mites belonging to the genus Liebstadia are described from Mongolia. The new species are characterized by the poorly developed pteromorphae; the club-shaped head of the sensilli; the absence of the dorsosejugal suture; the dorso-ventral thickness, and the length and arrangement of notogastral setae. In addition, L. similis (Michael, 1888) is redescribed and recorded for the first time in Mongolia. Protoribates serratomarginatus Mahunka, 1983 is synonymized with L. similis. A key to the known species of the genus Liebstadia is given.     

New contributions to the marine benthic ciliates from the Antarctic area,including description of seven new species (Protozoa,Ciliophora)

Twenty‐six marine benthic ciliates including seven new species were isolated from King George Island, Antarctic. The morphology and taxonomy of 19 of them are described in the present paper: Aegyriana paroliva, Amphileptus sp., Amphisiella antarctica nov. spec., Condylostoma cf. magnum, Dysteria parovalis nov. spec., Folliculina ? sp., Hartmannula cf. angustipilosa, Hemigastrostyla szaboi nov. spec., Heterostentor coeruleus, Holosticha sp., Intranstylum antarcticum nov. spec., Metaurostylopsis rubra, Orthodonella shenae, Philasterides cf. armatalis, Pithites pelagicus nov. spec., Pleuronema coronatum, Strombidium apolatum nov. spec., Telotrochidium sp., and Thigmokeronopsis magna nov. spec. Based on the new observations, an improved diagnosis for the genus Aegyriana is suggested: dorsoventrally flattened Dysteriidae with tail‐shaped podite, which is positioned subcaudally in a glabrous region within somatic kineties; oral structure in two parts: ca three close‐set fragments on right and one preoral kinety on left; left postoral kineties shortened posteriorly and continuous with right ones, leaving no median gap or suture; cytopharyngeal rods dominant. According to the new understanding and information obtained, a refined diagnosis of the genus Hemigastrostyla is also suggested: hypotrich with Oxytricha‐like cirral pattern; eight to ten frontal (including one buccal) and five to seven ventral cirri; five transverse and three caudal cirri; no right‐lateral anlagen of dorsal kineties occurring and the old adoral zone will be partly replaced by newly formed structure during morphogenesis; dorsal cilia located in small pits, fibre system highly developed; marine habitat.     

Snout mites from caves in Brazil,with description of a new species (Acari: Trombidiformes: Bdellidae)

In this paper we describe the first species of the genus Cyta from Brazil, Cyta troglodyta sp. nov., with a key to the world species of the genus. New records of mites of the family Bdellidae are reported from caves in Brazil.     

Xanthocalanus gracilis and Tharybis magna (Copepoda: Calanoida) rediscovered from the Antarctic Ocean with baited traps

Two species of calanoid copepods, Xanthocalanus gracilis Wolfenden, 1911 (Phaennidae) and Tharybis magna Bradford, 1983 (Tharybidae) collected with baited traps from the Antarctic Ocean are redescribed including some scanning electron microscopic observations. The morphological features and ecological data of these species which both bear maxillary sensory setae strongly suggest that they are detritivores and/or scavengers.     

Redescription and systematic status of the Antarctic genus Abietinella Levinsen, 1913 (Lafoeidae,Hydrozoa, Cnidaria)

The Antarctic–Patagonian genus Abietinella, comprising two known species, Abietinella operculata (Jäderholm, ) and Abietinella grandis (Vanhöffen, ), is reviewed. The holotype of Abietinella operculata is fully redescribed, including morphometry and cnidome, unknown up to now. Its distinctive characters are the growth habit, hydrothecal shape and, most important, the presence of a dish‐shaped operculum attached to the adcauline side of the hydrothecal aperture. We corroborate its conspecificity with A. grandis and, therefore, the monotypic condition of Abietinella.     

Species of Arachnopusia (Bryozoa: Cheilostomata) collected by discovery investigations

Eighteen species of the cheilostome bryozoan genus Arachnopusia Jullien are described from Antarctic, Subantarctic and southern cold temperate localities. Eleven species are considered to be new to science. The morphology of Arachnopusia species is discussed, with particular reference to features of taxonomic value, and the zoogeography of the genus is considered briefly.     

Species of Antarctoscyphus Pena Cantero,Garcia Carrascosa and Vervoort, 1997 (Cnidaria,Hydrozoa, Sertulariidae) from recent Antarctic expeditions with R.V. Polarstern,with the description of two new species

Six species of the genus Antarctoscyphus Peña Cantero, García Carrascosa and Vervoort, have been studied, two of which are new to science (Antarctoscyphus admirabilis sp. nov. and A. fragilis sp. nov.). The material studied originates from the Weddell Sea and was collected by several French and German Antarctic expeditions with the R.V. Polarstern. Each species is described and figured, the systematic position amongst allied species discussed and available data concerning autecology and geographical distribution given. The type material of two badly known species, A. grandis (Blanco) and A. gruzovi (Stepan'yants), has been re-examined, re-described and figured. A comparative table listing main features of known species of Antarctoscyphus is presented. Finally, a general survey of biogeographical distribution of the known species is given.     

Two new genera and five new species of the feather mite subfamily Proctophyllodinae (Astigmata: Proctophyllodidae) from suboscine birds in Brazil

Two new genera and five new species of feather mites of the family Proctophyllodidae are described from passerine birds from Brazil: Tyranniphyllodes pitangi gen. n., sp. n. from Pitangus sulphuratus (Tyrannidae); Atrichophyllodes delalandi gen. n., sp. n. from Corythopis delalandi (Tyrannidae); A. mentalis gen. n., sp. n. from Dysithamnus mentalis (Thamnophilidae); Anisophyllodes candango sp. n. from Elaenia chiriquensis (Tyrannidae); and Platyacarus sittasomi sp. n. from Sittasomus griseicapillus (Dendrocolaptidae). The discovery of these taxa might give data for a better understanding of the evolution of the family Proctophyllodidae in general and the dispersion of these mites on passerines in South America in paricular.     

Two new species of Clinocentrus Haliday (Hymenoptera: Braconidae) from Argentina,with notes on South American species

The Argentine species of the genus Clinocentrus Haliday are revised. Two new species are described, Clinocentrus mamull sp. nov. and Clinocentrus roigi sp. nov., which represent the southernmost records of the genus in South America. Additionally Clinocentrus nigripectus Enderlein is redescribed and a key to known South American species is provided.