Predatory borings in the inarticulate brachiopod Artiotreta from the Silurian of Oklahoma

A sample containing inarticulate acrotretid brachiopods, from the Silurian Clarita Formation of Oklahoma, was studied to determine the occurrence, nature and frequency of boring in the shells, and the possible identity of the boring organism. Specimens of Artiotreta parva Ireland, 1961 are abundant and specimens of Opsiconidion n. sp. and Acrotretella siluriana Ireland, 1961 are rare in the samples studied. All of the borings discovered are in A. parva except for one, which is in a specimen of O. n. sp. The boreholes are considered to be of predatory origin, and are similar in morphology to borings made by Recent gastropods. The small countersunk boreholes are equally frequent on pedicle and brachial valves, but preferentially located in particular regions of each valve. Boring frequency is high. The identity of the boring organism has not been determined, but is considered to be a soft bodied predator or an archaeo-gastropod.     

Hemibranchiate sphaeromatids (Crustacea: Isopoda) from Queensland, Australia, with a world-wide review of the genera discussed

All known Queensland species of the isopod family Sphaeromatidae, subfamily Sphaeromatinae (= hemibranchs), are discussed. The following new taxa are erected: Calcipila cornuta, gen. nov., sp. nov. ; Cymodoce tribullis, sp. nov. ; Cymodoce bipapilla, sp. nov. ; Paracilicaea aspera, sp. nov. ; Cilicaeopsis glebosa, sp. nov. ; Cilicaeopsis furculata, sp. nov. ; Cilicaea calcarifera, sp. nov. ; Zuzara curtispina, sp. nov. ; Zuzara digitata, sp. nov. ; and Clianella brucei, sp. nov. Exosphaeroma intermedium Baker is transferred to the genus Sphaeroma Latreille. The genus Dynoides Barnard is reviewed and its current synonymy is contested. With several new records, this brings the total number of sphaeromatid species known from Queensland to 49, 24 of which are in the subfamily Sphaeromatinae. A checklist of all sphaeromatid species occurring in Queensland waters is given. From the rest of Australia: Cymodoce tuberculata Haswell is given the replacement name Cymodoce haswelli, nom. nov. ; Cymodoce granulata Miers is made a junior synonym of Cerceis trispinosa (Haswell) (subfamily Dynameninae); Zuzara diadema Leach, Z. dicantha (Milne Edwards) and Z. Integra Haswell are made junior synonyms of Z. semipunctata Leach; Cilicaeopsis dakini Tattersall is tentatively transferred to the genus Paracilicaea Stebbing. The genera discussed are reviewed world-wide and among the non-Australian species: Exosphaeroma papillae Bayliff is transferred to the genus Sphaeroma; Sphaeroma irakiensis Ahmed is made a junior synonym of Sphaeroma annandalei annandalei Stebbing; Cymodoce richardsoniae Nobili is shown to be distinct from Cymodoce truncata Leach; Cymodoce eupyga Nobili is transferred to the genus Paracilicaea; Dynoides amblysinus Pillai, Dynoides castroi Loyola e Silva and Exosphaeroma globicaudum (Dana) are transferred to the genus Clianella Boone; Dynoides brasiliensis (Loyola e Silva; and Sphaeroma savignn Milne Edwards sensu Dana, 1853 are declared to be conspecific with Clianella castroi. The name Sorrentosphaera Verhoeff is made a junior synonym of Dynamene Leach (subfamily Dynameninae.     

Population structure, growth and distribution of Lingula anatina (Brachiopoda) in Queensland, Australia

Size-frequency data collected in large samples from five populations of Lingula anatina from North Queensland intertidal sandflats conformed to previously known brachiopod size-frequency distributions. Probability paper analysis of the samples and constituent sub-samples confirmed that all the distributions had a hidden poly-modality resulting from a long but defined breeding season. Two patterns of annual recruitment were revealed; the first is the periodic failure of the populations to gain recruits and the second is one of patchy distribution of settlement cohorts. These patterns introduce sampling bias into the derivation of lingulid size frequency curves unless compensated by more extensive sampling methods than have previously been considered adequate. The interpretation of year classes has enabled a growth curve to be derived. The populations inhabited predominantly sandy sub-strates and displayed aggregated distributions. Littoral distribution of the species is regarded as optimal rather than marginal.     

Population structure and dispersal of the saltmarsh mosquito Aedes vigilax in Queensland, Australia

Population genetics of the mosquito Aedes vigilax (Skuse) (Diptera: Culicidae), a major vector of arboviruses (e.g. Barmah Forest, Ross River), were investigated to obtain an indirect estimate of mosquito dispersal characteristics in typical habitats of Aedes vigilax in south-east Queensland: on the off-shore islands of Moreton Bay and on the mainland where disjunct breeding populations of Ae. vigilax are distributed along intertidal marsh. Six allozyme loci were assessed for genetic differentiation between samples from 11 localities. Significant larval variation between some breeding sites was attributed to site-specific selection. Nonsignificant genetic differentiation was found among collections of adult mosquitoes caught in light traps throughout the study area (exceeding 60x27 km), indicating widespread dispersal. As distances of < or = 9 km over water did not appear to act as effective barriers to Ae. vigilax dispersal, localized control activities applied to Ae. vigilax breeding sites are unlikely to be effective against the vagile adult population. Therefore, the contiguous shires programme of broad acre control is endorsed to prevent the spread of arboviruses carried by Ae. vigilax     

New species of Prosopodesmus Silvestri, 1910 (Diplopoda, Polydesmida, Haplodesmidae) from Queensland, Australia

Prosopodesmus cratersp. n., Prosopodesmus kirramasp. n. and Prosopodesmus monteithisp. n. are described from the Wet Tropics of north Queensland. The hothouse species Prosopodesmus panporus Blower & Rundle, 1980 is recorded from rainforest on Queensland's Cape York Peninsula, where it is likely to be native.     

Genetic structure and differentiation of four Lethenteron taxa from the Far East, deduced from allozyme analysis

Genetic structure and differentiation among four Lethenteron taxa, L. japonicum, L. kessleri, and two groups of L. reissneri, collected from Japan and the Far Eastern region of Russia, were investigated by electrophoretic analysis. Several complete-allele substitutions were found between all possible pairs of taxa in regions of sympatry, strongly suggesting the existence of reproductive isolation between them. Therefore, four Lethenteron taxa should be regarded as discrete species, respectively. In each taxon, the genetic variability within each population (H=0.062 – 0.127 for L. japonicum, H=0.062– 0.128 for L. kessleri, H=0.026 – 0.148 for the northern group of L. reissneri, and H = 0.015 – 0.102 for the southern group of L. reissneri) was considerable, suggesting large effective sizes for most populations. The sample of L. japonicum collected from Kyiya, the basin of Amur, was somewhat divergent from the other intraspecific samples. This may have resulted mainly because it does not migrate to the sea. In contrast L. kessleri has a fluvial life style, but the genetic differentiation between populations (G_ST=0.117, D = 0.000 – 0.061) was less than that for each group of L. reissneri (G_ST = 0.493, D=0.000 – 0.226 for the northern group and G_ST=0.660, D = 0.008 – 0.422 for the southern group), probably meaning more recent dispersal of L. kessleri than the two groups of L. reissneri. The parasitic and anadromous L. japonicum appeared to be closely related to L. kessleri (D=0.042 – 0.090) and the northern group of L. reissneri (D=0.163 – 0.355), which have nonparasitic and fluvial life styles, whereas the southern group of L. reissneri was greatly divergent from the other three Lethenteron species (D=0.559 – 0.926), suggesting that the former three species might be monophyletic.     

Genetic structure among and within peripheral and central populations of three endangered floodplain violets

Understanding the partitioning of genetic variance in peripheral and central populations may shed more light on the effects of genetic drift and gene flow on population genetic structure and, thereby, improve attempts to conserve genetic diversity. We analysed genetic structure of peripheral and central populations of three insect-pollinated violets (Viola elatior, Viola pumila, Viola stagnina) to evaluate to what extent these patterns can be explained by gene flow and genetic drift. Amplified fragment length polymorphism was used to analyse 930 individuals of 50 populations. Consistent with theoretical predictions, peripheral populations were smaller and more isolated, differentiation was stronger, and genetic diversity and gene flow lower in peripheral populations of V. pumila and V. stagnina. In V. elatior, probably historic fragmentation effects linked to its specific habitat type were superimposed on the plant geographic (peripheral-central) patterns, resulting in lower relative importance of gene flow in central populations. Genetic variation between regions (3-6%), among (30-37%) and within populations (60-64%) was significant. Peripheral populations lacked markers that were rare and localized in central populations. Loss of widespread markers in peripheral V. stagnina populations indicated genetic erosion. Autocorrelation within populations was statistically significant up to a distance of 10-20 m. Higher average genetic similarity in peripheral populations than in central ones indicated higher local gene flow, probably owing to management practices. Peripheral populations contributed significantly to genetic variation and contained unique markers, which made them valuable for the conservation of genetic diversity.     

Aboriginal fire regimes in Queensland, Australia: analysis of the explorers' record

ABSTRACT. The record of eighteenth and nineteenth century explorers' references to Aboriginal fire in Queensland was stratified according to fourteen vegetation typcs and season of fire. It was demonstrated that references to 'current' fire (i.e. flames or smoke) may not represent traditional Aboriginal activity and that many fires were lit to frighten or harm, to protect themselves from, or to signal to kinfolk the presence of the European intruders. Because of this interpretational difficulty the records to 'current' fire were treated separately from 'past' fire (i.e. burnt ground). The data were analysed as the number of observations per 100 km spent in each vegetation type for any one season to compensate for bias created by differing amounts of travel. The record suggests highest frequency of burning in grassland around the Gulf of Carpentaria, relatively high fire frequency of most coastal and subcoastal vegetation types and relatively infrequent burning of inland Queensland. The analysis indicates a propensity for winter and autumn fue relative to spring and summer fire in all vegetation types combined and in most individual vegetation types.     

A biogeographically mixed, Middle Permian brachiopod fauna from the Baoshan Block, western Yunnan, China

A small brachiopod fauna is described from the carbonate rocks of the basal Shazipo Formation of the Baoshan Block, western Yunnan, south-west China, including significant new ventral and dorsal internal morphological features of Cryptospirifer omeishanensis Huang. This fauna is regarded as Wordian (Middle Guadalupian, Middle Permian) because of the presence of Cryptospirifer omeishanensis Huang and associated fusulinids ( Neoschwagerina craticulifera Zone). Palaeobiogeographically, the brachiopod fauna is of considerable interest because of its admixed nature characterized by typical warm-water Cathaysian elements intermingled with temperate Peri-Gondwanan taxa. This in turn is interpreted to indicate that the Baoshan Block may have been situated in an intermediate palaeogeographical position between Gondwanaland to the south and Cathaysia to the north during the Mid Permian and, as such, it probably furnished an important 'stepping stone' for the dispersal of Mid Permian eastern Tethyan marine invertebrate taxa (e.g. Cryptospirifer ) to the western Tethys.     

Genetic variation at enzyme loci in the southernmost European populations of Atlantic salmon

Genetic variation was studied at 8 allozyme loci in six severely endangered wild Spanish populations of Salmo salar located at the southernmost geographical limit of European Atlantic salmon. Low levels of variation were detected and no significant deviations from Hardy–Weinberg equilibrium were found.     

Genetic structure of three populations of rhesus macaques (Macaca mulatta): Implications for genetic management

One of the prime concerns at zoos and at primate breeding facilities is to maintain genetic variability. This can be accomplished by avoiding inbreeding. It is relatively easy to assess genetic variability and the level of inbreeding by using pedigree information and genetic markers. In this study we used genetic markers controlled by 6 independent polymorphic loci (GPI, PGD, CA2, MPI, DIA1, Tf) to ascertain genetic variation in two captive and one wild population of rhesus monkeys. Two other loci ADA and NP were also examined and found to be monomorphic in the three populations. F-statistics and contingency chi-square analyses indicated that there was significant genetic differentiation among the populations. We also found that the mean heterozygosities were very similar in the three populations, in spite of the diverse breeding strategies. These data are important because rhesus monkeys are frequently used for biomedical research; and the genetic markers provide useful information for genetic management of captive colonies of nonhuman primates. © 1992 Wiley-Liss, Inc.     

Genetic structure of populations of Calomys laucha (muridae, sigmodontinae) from central Argentina

The genetic structure of populations of the Sigmodontinae rodent Calomys laucha was studied by means of allozyme electrophoresis. This highly opportunistic species is found preferably in periodically perturbed habitats of crop fields in central Argentina, where it can attain very high densities. A total of 17 enzymatic proteins assayed gave information on 25 loci; only four were monomorphic in the seven populations studied. Levels of genetic variability (H_o from 0.144 to 0.171; P_95% from 44% to 56%) were higher than mean values reported for mammals and rodents. These high levels of heterozygosity could be maintained by large populations that do not experience great fluctuations in size, or by a social structure consistent in many small breeding groups that are formed and dissappear every breeding season. Genetic differentiation at a macrogeographical scale (θ=0.018) was low but statistically significant, and showed no correlation with geographic distance between pairs of populations. The pattern of population differentiation found is compatible with a relatively recent range expansion.     

Frequency of cyanogenesis in tropical rainforests of far north Queensland, Australia

BACKGROUND AND AIMS: Plant cyanogenesis is the release of toxic cyanide from endogenous cyanide-containing compounds, typically cyanogenic glycosides. Despite a large body of phytochemical, taxonomic and ecological work on cyanogenic species, little is known of their frequency in natural plant communities. This study aimed to investigate the frequency of cyanogenesis in Australian tropical rainforests. Secondary aims were to quantify the cyanogenic glycoside content of tissues, to investigate intra-plant and intra-population variation in cyanogenic glycoside concentration and to appraise the potential chemotaxonomic significance of any findings in relation to the distribution of cyanogenesis in related taxa. METHODS: All species in six 200 m(2) plots at each of five sites across lowland, upland and highland tropical rainforest were screened for cyanogenesis using Feigl-Anger indicator papers. The concentrations of cyanogenic glycosides were accurately determined for all cyanogenic individuals. KEY RESULTS: Over 400 species from 87 plant families were screened. Overall, 18 species (4.5 %) were cyanogenic, accounting for 7.3 % of total stem basal area. Cyanogenesis has not previously been reported for 17 of the 18 species, 13 of which are endemic to Australia. Several species belong to plant families or orders in which cyanogenesis has been little reported, if at all (e.g. Elaeocarpaceae, Myrsinaceae, Araliaceae and Lamiaceae). A number of species contained concentrations of cyanogenic glycosides among the highest ever reported for mature leaves-up to 5.2 mg CN g(-1) d. wt, for example, in leaves of Elaeocarpus sericopetalus. There was significant variation in cyanogenic glycoside concentration within individuals; young leaves and reproductive tissues typically had higher cyanogen content. In addition, there was substantial variation in cyanogenic glycoside content within populations of single species. CONCLUSIONS: This study expands the limited knowledge of the frequency of cyanogenesis in natural plant communities, includes novel reports of cyanogenesis among a range of taxa and characterizes patterns in intra-plant and intra-population variation of cyanogensis.     

Genetic differentiation ofLethenteron reissneri populations,with reference to the existence of discrete taxonomic entities

Genetic divergence in the Far Eastern brook lamprey,Lethenteron reissneri, collected from Hokkaido and Honshu Islands, Japan, was investigated by electrophoretic analysis. Two local groups, northern and southern, were distinguishable by complete allele substitutions at 11 loci, resulting in high genetic differentiation (D=0.558–0.926). In addition, no genetic evidence of hybridization between the two groups was detected in three sympatric river populations, strongly suggesting their reproductive isolation, and separate specific status of the groups. In each local group, the genetic variability within and genetic differentiation between each population was considerable (H=0.034–0.147,Gst=0.508 for the northern group; H=0.024–0.105,Gst=0.629 for the southern group), suggesting large sizes for most populations, along with considerable isolation of each population from the others, resulting in lowered gene flow between them. Based on allele distribution and the cluster pattern on a UPGMA dendrogram, the northern and southern groups could be divided into two and three subgroups, respectively, which may have resulted mainly from isolation due to geographic barriers.     

Genetic structure and dispersal of Macrobrachium australiense (Decapoda: Palaemonidae) in western Queensland, Australia

SUMMARY 1. The freshwater prawn, Macrobrachium australiense (Decapoda: Palaemonidae), is an abundant species throughout the rivers of western Queensland, and it is thought to have effective dispersal capabilities. Given the very low topographical relief of the western Queensland landscape and the vast nature of episodic flooding, it was predicted that widespread dispersal in this species would occur within, and possibly between the four major catchments of the region: the Darling, Bulloo, Cooper and Diamantina. We analysed eight polymorphic allozyme systems and a fragment of the cytochrome c oxidase subunit 1 (COI) mitochondrial DNA (mtDNA) gene to determine the extent of recent and historical patterns of dispersal at nested spatial scales, within and between catchments.
2. Large and significant levels of allozyme and mtDNA differentiation were revealed among all catchments, indicating that dispersal of M. australiense does not occur across catchment boundaries, although this species is reportedly capable of overland movement. In contrast, no significant patterns of genetic differentiation were resolved between major subcatchments of the Darling and Cooper, or between sites within these subcatchments, indicating that populations of M. australiense are panmictic within catchments.
3. The MtDNA data resolved two divergent and reciprocally monophyletic clades, with the first representing the Darling catchment, and the second corresponding to the Bulloo, Cooper and Diamantina catchments. We postulate that extreme variation in historical climatic patterns and palaeohydrologic conditions played an important role in shaping the population structure of M. australiense throughout western Queensland during the Quaternary.     

Habitats of Culicoides spp. in an intertidal zone of southeast Queensland, Australia

The distribution of immature Culicoides Latreille (Diptera: Ceratopogonidae) in the intertidal zone was investigated at Redland Bay near Brisbane, southeast Queensland. The aims of this study were to determine the distribution of Culicoides immatures and to identify environmental factors influencing these distributions. Light trapping of adult midges indicated that C.subimmaculatus Lee & Reye, C.marmoratus (Skuse), C.longior Hagan & Reye, C.henryi Lee & Reye, C.cordiger Macfie, may have been breeding in the study site. Soil sampling on six transects traversing mangrove and salt-marsh revealed the breeding habitats from which immature stages of the first four species were obtained. The elevation, vegetation and soils of positive sites were recorded and analysed for each species of Culicoides. The distribution of intertidal vegetation (mangroves and salt-marsh plants) was compared to MacNae's (1966) system of mangrove zonation for eastern Australia. The distribution of immature Culicoides did not correspond with mangrove zones, but was related to the presence or absence of intertidal vegetation. C.subimmaculatus was closely associated with a particular substrate and the presence of burrowing crabs.