Setocallosa—a new genus and species of land snail from Arnhem Land,Australia (Stylommatophora: Camaenidae)

The new, monotypic camaenid genus Setocallosa is described for the new species S. pathutchingsae from Arnhem Land, Top End of the Northern Territory. This camaenid is characterized by a combination of distinct morphological features, such as a small, weakly elevated shell with widely open umbilicus and thick callus on the parietal wall, a wide epiphallic flagellum, elongated penis and short bursa copulatrix with subglobose end. The relationships of Setocallosa with the other camaenid genera in the area are investigated by means of mtDNA, but its phylogenetic position remains ambiguous. S. pathutchingsae occurs in sympatry with Arnhemtrachia ramingining, but based on morphology the two camaenids can be readily differentiated.

http://zoobank.org/urn:lsid:zoobank.org:pub:1C50CF24-7FEE-446A-9724-A0A4E850B5AA     

Molecular phylogeny and taxonomic revision of the genera Baudinella Thiele, 1931, Retroterra Solem, 1985 and Molema Köhler, 2011 endemic to the coastal Kimberley,Western Australia (Gastropoda,Camaenidae)

Baudinella Thiele, 1931, Retroterra Solem, 1985 and Molema Köhler, 2011 are three genera of camaenid land snail endemic to coastal regions of the Western Australian Kimberley. Each of these genera has fairly distinct shells, but all exhibit a rather similar configuration of the reproductive system, which is characterized by lack of a penial sheath and presence of an elongated and coiled bursa copulatrix. By combining comparative morphology of shell and penial anatomy with analyses of the mitochondrial DNA fragments 16S rRNA (16S) and cytochrome c oxidase subunit 1 (COI), the phylogenetic relationships amongst representative species of these genera are addressed to test the monophyly of taxa and to identify new species. Our results show that all three genera are members of a single camaenid radiation. Five new species are described: two new species of Baudinella, B. magna n. sp. from the Institute and Montesquieu Archipelagos and B. margaritata n. sp. from Pitta Gorge in the Prince Regent Reserve, one new species of Molema, Molema tenuicostata n. sp., from near Talbot Bay, and two new species of Retroterra, R. dichroma, and R. nana, from the Prince Regent Reserve.     

Conserved shell disguises diversity in Mesodontrachia land snails from the Australian Monsoon Tropics (Gastropoda: Camaenidae)

We comprehensively revise the taxonomy of the camaenid genus Mesodontrachia Solem, 1985, which is endemic to the Victoria River District and East Kimberley in the north‐western Australian Monsoon Tropics based on comparative analyses of key morphological features and mitochondrial DNA sequences. We examined newly collected samples from several collection sites spread over nearly 20 000 km² of mostly inaccessible land, which represented all three currently known and three previously undescribed species. All species were initially identified as members of Mesodontrachia based on their similar, putatively typical shell. However, Mesodontrachia as so delimited was polyphyletic in a mitochondrial phylogeny with respect to several other camaenid genera from NW Australia. Contrary to the shell, we found considerable variation in the penial anatomy that was consistent with the mtDNA differentiation. To retain monophyletic taxa, we propose a revised taxonomy whereby Mesodontrachia is maintained as a monotypic taxon. In addition, four genera (Nodulabium, Ototrachia, Pseudomesodontrachia and Vincentrachia) and three species (P. gregoriana, O. compressa and N. solidum) are newly described. The shell of all these taxa is highly conserved and of little taxonomic utility. Shell similarity is attributed to a similar life style in a similar and harsh environment.     

Leptopalaemon gagadjui gen. nov., sp. nov., a new freshwater palaemonid shrimp from Arnhem land,and a re-evaluation of Palaemonetes holthuisi Strenth,with the designation of a new genus,Calathaemon

A new palaemonid shrimp, Leptopalaemon gagadjui, gen. nov., sp. nov., from the Arnhem Land plateau, Australia, is described and illustrated, and its systematic position discussed. The new genus most closely resembles Leptocarpus Holthuis, 1950, presently known only from India. Palaemonetes holthuisi Strenth is re-examined and excluded from the genus Palaemonetes. A new genus, Calathaemon, is designated for its accommodation.     

Small snails in a big place: a radiation in the semi‐arid rangelands in northern Australia (Eupulmonata,Camaenidae, Nanotrachia gen. nov.)

Continuing the revision of the Camaenidae in the Australian Monsoon Tropics, we employed comparative analyses of morphological features (with a focus on shell and penial anatomy) and genetic markers (with a focus on mitochondrial COI and 16S sequences) to address the systematic relationships of land snails from the Victoria River District, Northern Territory, and adjacent East Kimberley (Western Australia). These analyses revealed that the species under study represented the previously undescribed genus Nanotrachia. This genus differs from all other camaenid genera known from north‐western Australia most conspicuously by its small, flat, and ribbed shell. Six species are identified as members of the new genus, four of them new species ( Nanotrachia costulata sp. nov. , Nanotrachia carinata sp. nov. , Nanotrachia coronata sp. nov. , Nanotrachia levis sp. nov. ). Two further species have already been described previously but assigned to different genera. These species, Ordtrachia intermedia (as the type species of Nanotrachia) and Mouldingia orientalis, are here transferred to Nanotrachia. Like other camaenids from the Australian Monsoon Tropics, species of Nanotrachia are characterized by essentially allopatric distributions, regional endemism, and a patchy distribution across their range. © 2013 The Linnean Society of London     

Recent behavioural and population genetic divergence of an invasive ant in a novel environment

Aim Invasive species frequently exhibit high temporal and spatial variation in abundance. Although ecological aspects undoubtedly affect this variation, genetic factors may also play a part. The invasive unicolonial yellow crazy ant Anoplolepis gracilipes exhibits considerable variation in abundance throughout its extensive distribution in Australia’s Northern Territory, where it was first detected in the 1980s. First, we aimed to determine whether A. gracilipes variation in abundance was associated with behavioural and genetic differentiation of the population and to determine whether one or more introductions occurred. Second, we investigated whether the A. gracilipes population was genetically and behaviourally heterogeneous to determine whether population divergence has occurred since introduction. Location Tropical monsoonal savanna in Arnhem Land, Northern Territory, Australia. Methods Ant abundances were assessed at 13 sites throughout the study region. We used mitochondrial DNA sequences and microsatellite molecular markers to determine population genetic structure, which we correlated with abundance. Behavioural differentiation was assayed using aggression trials and analysed together with genetic data to investigate population divergence. Results Although we found considerable variation in abundance, we found no association between population structure and differences in abundance. Our analyses suggest that A. gracilipes ants in Arnhem Land resulted from a single introduction. The population is not homogeneous, however, as aggression scores varied over both genetic and geographic distance. We also found a positive relationship between genetic and geographic distance. Main conclusions The variation in abundance in the Arnhem Land population of A. gracilipes is clearly not owing to invasion by ants from different sources. The genetic and behavioural differentiation we observed is suggestive of incipient genetic and behavioural divergence, which may be expected over time when an invasive species enters in a new environment.     

A new species of Camaenidae (Gastropoda,Pulmonata) from Nusa Penida and Lombok Islands,Indonesia: novelty in a well-known fauna

A new species of camaenid land snail, Vulnus wallacei Páll-Gergely, Otani & Hosoda n. sp. is described from Nusa Penida and Lombok Islands, Indonesia. The new species is putatively classified into the genus Vulnus, which is only known so far from the Northern Maluku Islands. The genital anatomy, especially the presence of a well-developed penial sheath in V. wallacei, suggests a close relationship with Australian camaenids. However, the molecular phylogeny based on partial cytochrome c oxidase I, and 16S and 28S ribosomal RNA genes shows that the new species falls outside the cluster of all Australian Camaenidae.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:D28554D0-3578-4E95-8849-09EAFB7D30F7     

Land management affects grass biomass in the Eucalyptus tetrodonta savannas of monsoonal Australia

Abstract We surveyed herbaceous biomass across the range of Eucalyptus tetrodonta savannas in north‐western Australia. Sample sites (n = 211) were stratified within four broad geographical regions characterized by different mixes of land management regimes. Grasses dominated (87% mean) the herbaceous biomass. After controlling for climatic and edaphic gradients, herbaceous biomass was highest in the Greater Darwin region (2.2 t ha⁻¹) which is managed predominantly by Europeans, and least under semi‐traditional Aboriginal management in Arnhem Land region (1.1 t ha⁻¹). In the drier Gulf of Carpentaria and Kimberley regions, where a mix of Aboriginal, conservation and pastoral land uses occurs, fuel loads were higher than in Arnhem Land region but still considerably lower than around Darwin. Sarga was recorded in all regions except the Gulf of Carpentaria and had the highest biomass in Darwin (0.88 t ha⁻¹) and lowest biomass in the Kimberley (0.54 t ha⁻¹). The proportion of herbaceous biomass made up of perennial grasses was least in Darwin (17%) and greatest in the Gulf (77%) regions. We suggest that climate, soils and land management account for differences between the drier pastoral regions of the Gulf of Carpentaria and the Kimberley and the wet Greater Darwin region relative to the Arnhem Land region. The high frequency, and larger spatial scale, of fires in the Greater Darwin region relative to the Arnhem Land region underpins the contrasting trends in total herbaceous biomass and abundance of flammable annual grasses.     

Satsuma jinlunensis— a new species from Taiwan (Stylommatophora: Camaenidae)

A new species of camaenid land snail, Satsuma jinlunensis n. sp., from southeastern Taiwan is established. This species inhabits the lowland forests with a narrow geographical distribution insofar as we know. The species is characterised by having a sinistral shell, a rounded periphery, an oblique columellar lip joining the basal lip smoothly, an open umbilicus, a coiled flagellum, an absent or weakly developed penial caecum, a hemispherical verge internally, and a pedunculus of the bursa copulatrix expanded medially. The new species is distinguishable from congeners by a combination of its sinistral and conical shell, and coiling of the flagellum and part of the epiphallus. The characteristics of male genitalia and species biodiversity of terrestrial snails in southern Taiwan are discussed.

http://zoobank.org/urn:lsid:zoobank.org:pub:96F3118C-09B9-4ED4-AAB7-2DBEE978459F     

Musculature of the penial complex: A new criterion in unravelling the phylogeny of Hygrophila (Gastropoda: Pulmonata)

The taxonomy of freshwater pulmonates (Hygrophila) has been in a fluid state warranting the search for new morphological criteria that may show congruence with molecular phylogenetic data. We examined the muscle arrangement in the penial complex (penis and penis sheath) of most major groups of freshwater pulmonates to explore to which extent the copulatory musculature can serve as a source of phylogenetic information for Hygrophila. The penises of Acroloxus lacustris (Acroloxidae), Radix auricularia (Lymnaeidae), and Physella acuta (Physidae) posses inner and outer layers of circular muscles and an intermediate layer of longitudinal muscles. The inner and outer muscle layers in the penis of Biomphalaria glabrata consist of circular muscles, but this species has two intermediate longitudinal layers separated by a lacunar space, which is crossed by radial and transverse fibers. The muscular wall of the penis of Planorbella duryi is composed of transverse and longitudinal fibers, with circular muscles as the outer layer. In Planorbidae, the penial musculature consists of inner and outer layers of longitudinal muscles and an intermediate layer of radial muscles. The penis sheath shows more variation in muscle patterns: its muscular wall has two layers in A. lacustris, P. acuta, and P. duryi, three layers in R. auricularia and Planorbinae and four layers in B. glabrata. To trace the evolution of the penial musculature, we mapped the muscle characters on a molecular phylogeny constructed from the concatenated 18S and mtCOI data set. The most convincing synapomorphies were found for Planorbinae (inner and outer penis layers of longitudinal muscles, three-layered wall of the penis sheath). A larger clade coinciding with Planorbidae is defined by the presence of radial muscles and two longitudinal layers in the penis. The comparative analysis of the penial musculature appears to be a promising tool in unraveling the phylogeny of Hygrophila.     

External structures used during attachment and sperm transfer in tubificids (Annelida,Oligochaeta)

The genital region of seven species of Tubificidae has been studied by SEM (Scanning Electron Microscopy). The form and the position of penial and spermathecal chaetae, male and spermathecal pores and other special structures have been examined. Peristodrilus montanus shows a special system to hold the partner: the penial chaetae anchor in an elaborated structure of the body wall formed between the spermathecal pores, the `anchorage bridge'. Protuberodrilus tourenqui has a long glandular porophore with the male pores at the tip, allowing contact with the spermathecal pores which are located in deep, close to the mid-ventral line of the body. The grooved and strongly curved penial chaetae of Rhyacodrilus falciformis seem to be used both for attachment and for sperm transfer, entering into the lateral spermathecal pores. The embrace of the partners, as suggested by observations on Psammoryctides barbatus, Potamothrix bavaricus, Potamothrix hammoniensis and Potamothrix heuscheri, seems to be another important mechanism to fix contact between male and spermathecal pores and allow sperm transfer. The spermathecal chaetae could be interpreted as piercing chaetae with a chemical or mechanical stimulating role. Sensitive cilia near the penial chaetae seem to be used by the three rhyacodrilines studied to find the correct anchorage place. There is a great variety of structures which appear to be used for attachment and sperm transfer in tubificids, and consequently their role in the evolution of the whole family may be profound.     

Specific criteria in Grania (Oligochaeta,Enchytraeidae)

The structure of the penial bulb and male efferent duct system of Grania species may be used in addition to setal pattern and spermathecal shape to distinguish species. Six penial bulb types are distinguished: (1) a simple, small, glandular bulb surrounding the male pore; (2) a small, glandular bulb, with a large, associated, dorso-medial gland mass; (3) a small glandular bulb, medial to the male pore, with an elongate male bursa (the aglandular sac), the vas deferens exitting directly into the invaginated male pore; (4) a glandular bulb with an aglandular sac and a small, cuticular stylet embedded in the bulb, extending from the ectal end of the vas deferens; (5) a glandular bulb and an aglandular sac with a long stylet extending from the vas deferens, through the bulb into the sac; and (6) glandular bulb reduced or absent, with or without an aglandular sac; with a long stylet and other prominent modifications, usually muscular, of the vas deferens. The details of the male duct structure were consistent within specimens grouped on the basis of setal distribution and shape and detailed spermathecal structure. Diverse male duct patterns are found within the polytypic species G. macrochaeta and G. postclitellochaeta. The positions of the spermathecal and male pores in their respective segments are distinctive for some species.     

A new freshwater oligochaete species (Clitellata: Enchytraeidae) from Livingston Island,Antarctica

The new enchytraeid species Lumbricillus healyae sp. n. is described from freshwater streams, with well-oxygenated and poorly mineralised waters, situated in Byers Peninsula (Livingston Island, South Shetland Islands, Antarctica). Lumbricillus healyae sp. n. is morphologically close to L. antarcticus and L. incisus, and it is mainly distinguished by the structure of the spermatheca with a short, distinct ectal duct, the oval penial bulb (greatest diameter in the transverse body axis) associated with strong dorso-ventral muscular fibres, and a protrusible pseudopenis. A second undetermined Lumbricillus species is described from a small stream. Study specimens are not fully mature; however, the highly irregular form and size of the testis-sac lobes and the absence of a penial bulb encapsulated under a muscular layer are remarkable. It is probably related to a small group of Lumbricillus species reported from the Antarctic maritime region (L. colpites, L. griseus and L. aestum), characterised by the structure of the male duct, which ends in a simple pore surrounded by glands.

Allosyncarpia-dominated rain forest in monsoonal northern Australia

Following recent classifications of rain forest vegetation in northern Australia this paper examines the biogeo-graphical status and condition of a rain forest type endemic to that region, dominated by the sclerophyll Allosyncarpia ternata (Myrtaceae). These forests are restricted to the Arnhem Land region of the Northern Territory, which includes Kakadu National Park. They cover an area of 1138 km², or 41 % of all rain forest in northern and northwestern Australia. DCA of floristic data from 140 sites illustrates that Allosyncarpia forests occupy a range of sandstone-derived substrates, from moist valley sediments to steep, freely draining, rocky sites. DCA of floristic transect data illustrates that Allosyncarpia is by far the dominant canopy species over this topographic-moisture sequence, but especially on seasonally dry substrates where it provides over 80 % basal area and effectively the entire canopy. DCA of floristic quadrat data from a floristi-cally singular site illustrates major death of the fire-sensitive gymnosperm Callitris intratropica, and, to a lesser extent, Allosyncarpia itself, on the forest-savanna boundary. Biogeographical implications arising from the Gondwanic distributions of Allosyncarpia and its close relatives, Arillas-trum (New Caledonia), Eucalyptopsis (eastern Malesia), and an as yet undescribed taxon (eastern Australia), suggest that taxa ancestral to this group were extensive in the late Cretaceous. Their current restriction is in marked contrast to the success of their near relatives, the eucalypts. Given the tolerance of Allosyncarpia to a wide range of substrate moisture conditions in the present day, it is argued that fire regulates patch margins of this forest type. Although tolerant of light fires, canopy trees at patch margins are susceptible under a regime of frequent, intense late dry-season fires, such as are prevalent in Arnhem Land today. For effective conservation of fire-sensitive communities in this floristically significant region, greater attention must be given to management and monitoring of the fire regime.     

Three new species of the carnivorous snail genus Perrottetia Kobelt, 1905 from Thailand (Pulmonata,?Streptaxidae)

Three new species of the streptaxid snail genus Perrottetia are described from north and northeastern Thailand, Perrottetia aquilonaria sp. n., Perrottetia dermapyrrhosa sp. n. and Perrottetia phuphamanensis sp. n. Each species is endemic to a single or a few limestone mountain ranges. The species are characterized by the morphology of their genital organs, as well as by shell characters. Perrottetia aquilonaria sp. n. has a club shaped distal penis and large penial hooks are present and penial papillae cover almost the entire penial hook portion; adjacent areas possess low reticulated folds. Perrottetia dermapyrrhosa sp. n. has a long genital atrium and the penial sheath is about two-thirds of the penis length. Penial hooks are long, scattered and sunken into deep ovate hollows; vaginal hooks are present. Perrottetia phuphamanensis sp. n. has a rounded and protruded shell periphery. The aperture is subcircular, peristome is thick and the second parietal lamella is adjacent to the first parietal lamella; a basal lamella is the smaller than in the other Thai species.     

A peculiar new species in the genus Landouria Godwin-Austen, 1918 from China (Gastropoda: Heterobranchia: Stylommatophora: Camaenidae)

Landouria omphalostoma n. sp. is described from northern Yunnan, China. The new species is placed in the genus Landouria Godwin-Austen, 1918 based on the presence of tuberculated flagellum and swollen basal part in the bursa copulatrix, and on the absence of dart sacs and mucous glands. L. omphalostoma n. sp. is characterized by a horizontal aperture of the shell which is unique in the genus. This feature resembles those of only two other camaenid/bradybaenid taxa, species of the Chinese genus Pseudaspasita Möllendorff, 1902 and species of the Japanese genus Coelorus Pilsbry, 1900. This is the first verified record of the genus in China and the easternmost record of Landouria. This paper provides the taxonomic ground work for further studies of the repeated evolution of a horizontal aperture.     

Genetic and socio-cultural differentiation in the aborigines of Arnhem Land, Australia

Four tribes of Arnhem Land were surveyed for dermatoglyphics; based on pattern intensity indices, total ridge-counts, and a distance statistic combining the two, it was shown that the tribes can be arranged into western (Tiwi, Gunwinggu) and eastern (“Murngin” and Andilyaugwa) groups. This substantiates observations made on Arnhem Land by linguists and social anthropologists. From a survey of allele frequency traits of blood factors and P.T.C. tasting, distance statistics were computed between the four tribes. These confirmed the relative isolation of the extreme Arnhem Land tribes. Distance statistics were also computed between the four tribes and two Central Australian tribes, the Aranda and Wailbri. The Aranda and “Murngin” were relatively close together agreeing with theories that the Aranda are derived from a not too remote southwards migration from north Arnhem Land, as supported by linguistic data. Correlations between the biological, geographical and linguistic distances were positive, and generally agreed with the expectation that socio-cultural and linguistic barriers are important in regulating gene flow between populations. This study emphasizes the need to consider biological distances in association with ecological and socio-cultural factors.     

Aboriginal Resource Utilization and Fire Management Practice in Western Arnhem Land, Monsoonal Northern Australia: Notes for Prehistory, Lessons for the Future

This paper considers traditional resources and fire management practices of Aboriginal people living in a near-coastal region of western Arnhem Land, monsoonal northern Australia. The data illustrate that before the arrival of Europeans freshwater floodplains and riverine habitats provided the major proportion of food resources over much of the seasonal cycle. By contrast, the extensive lowland woodlands and open forests, the sparser vegetation of the Arnhem Land escarpment and plateau, and the generally small patches of rain forest (jungle), provided relatively few resources, although jungle yams were of critical importance through the relatively lean wet season. The paper then considers burning as a management tool through the seasonal cycle. In broad terms, burning commenced in the early dry season and was applied systematically and purposefully over the landscape. Burning in the late dry season was undertaken with care, and resumed in earnest with the onset of the first storms of the new wet season, particularly on floodplains. These general patterns of resource use and fire management are shown to have applied widely over much of near-coastal northern Australia. The implications of these data for prehistory and for contemporary land management practices in the region, are considered. It is suggested that pre-European patterns of fire management in the region are likely to have been practiced only over the past few thousand years, given the development of abundant food resources in the late Holocene. It is shown that traditional burning practice offers a generally useful, conservative model for living in and managing a highly fire-prone savanna environment.