Two Marine Species of Flabellula (Amoebida,Mayorellidae)*

SYNOPSIS. Two species of amoebae identified as Flabellula citata Schaeffer, 1926, and F. calkinsi (Hogue, 1914) were isolated from saltwater habitats on the Maine coast. Both species showed the locomotive form and behavior of the genus Flabellula emend. Bovee, 1965. Both showed a mitotic pattern distinct from that of the genus Vannella Bovee, 1965, supporting Bovee's subdivision of Schaeffer's genus Flabellula. Preparations of F. calkinsi had an unusually high proportion of cells with 2 or more nuclei. F. calkinsi is a voracious cannibal. Neither F. citata nor F. calkinsi formed cysts in culture. Both species could be cultivated on media made with highly dilute sea water, but neither survived in a medium equivalent to a freshwater medium.     

Development of 21 microsatellite loci for puma (Puma concolor) ecology and forensics

We developed 21 microsatellite (13 dinucleotide and 8 tetranucleotide) primers specifically for pumas (Puma concolor). The primers were tested across 243 individuals from California and Nevada, and displayed an average of 5.5 alleles per locus. Previously, domestic cat (Felis catus) primers have been adapted for puma genetic studies. Puma‐specific loci may reduce concerns associated with ascertainment bias, improve genetic structure resolution and provide additional tetranucleotide loci valuable for forensic applications. These puma‐specific microsatellites will aid studies involving parentage, kinship and population structure, along with forensic case applications including poaching and puma‐associated injuries to humans and domestic animals.     

The roles of dispersal limitation and environmental conditions in controlling caddisfly (Trichoptera) assemblages

1. Many recent studies have quantified the relative importance of environmental variables and dispersal limitations in shaping the structure of stream communities. However, the relative importance of these factors at different spatial extents has been seldom evaluated. 2. We analysed the distribution of caddisfly species in 89 Amazonian streams in relation to stream characteristics and spatial variables representing overland dispersal routes. The streams occur in three regions that differ in spatial extent and environmental characteristics. We analysed the data using partial redundancy analysis with two predictor data sets, one environmental and one spatial, to evaluate the variation in assemblage composition. We also separated caddisflies into ‘good’ and ‘poor’ dispersers to evaluate possible differences in the responses of these two groups. 3. The environmental component explained a higher proportion of variance in assemblage composition than did the spatial component. Spatial effects were evident only when data from all three regions were analysed together, although the exclusive spatial fraction was quite low. Good dispersers responded similarly to the community as a whole, while poor dispersers were related to environmental variables only in one region and also were not related to spatial variables. 4. Caddisflies were most affected by environmental factors. The large environmental effect and small spatial effect are in accord with the use of these stream insects as good indicators of site properties and disturbances in monitoring programmes.     

Ectoparasites of commensal rodents in Sulawesi Utara, Indonesia, with notes on species of medical importance

Ectoparasite records are presented for four species of commensal murid rodents (Rattus rattus palelae Miller & Hollister, R. argentiventer (Robinson & Kloss), R. exulans (Peale) and Mus musculus castaneus Waterhouse) in Sulawesi Utara, with particular reference to the potential for these arthropods to bite and transmit pathogens to humans. The flea, Xenopsylla cheopis (Rothschild), was most common on R.r. palelae and is capable of transmitting plague and other pathogens to humans although no current foci for these diseases are known in Sulawesi. Hoplopleura pacifica Ewing and Polyplax spinulosa (Burmeister) sucking lice parasitized all three Rattus species although H. pacifica was mainly associated with R. exulans and P. spinulosa with R.r. palelae. These lice do not bite humans but may be intramurid vectors of murine typhus and other zoonoses. The mites Laelaps echidnina Berlese and L. nuttalli Hirst were both collected; the latter was recorded from all four murid species, mainly R. exulans. The mite Ornithonyssus bacoti Hirst was rare. Only one chigger mite, Walchiella oudemansi (Walch), was retrieved from murids (from R. exulans) and a single Leptotrombidium deliense (Walch) chigger was taken from a human subject. Although L. deliense is a significant vector of scrub typhus, a disease known from Sulawesi, the L. deliense-R. argentiventer relationship frequently noted in the ecology of this rickettsial disease, was not evident in this survey. Other ectoparasites collected from murids were the ticks, Ixodes granulatus Supino (first record for Sulawesi), Haemaphysalis sp. and Dermacentor sp., the mites Myocoptes musculinus (Koch) and Listrophoroides cucullatus (Trouessart), acarids and a uropodid.(ABSTRACT TRUNCATED AT 250 WORDS)     

Incorporating Estimates of Group Size in Sightability Models for Wildlife

ABSTRACT Sightability models have been used to estimate population size of many wildlife species; however, a limitation of these models is an assumption that groups of animals observed and counted during aerial surveys are enumerated completely. Replacing these unknown counts with maximum observed counts, as is typically done, produces population size estimates that are negatively biased. This bias can be substantial depending on the degree of undercounting occurring. We first investigated a method-of-moments estimator of group sizes. We then defined a population size estimator using the method-of-moments estimator of group sizes in place of maximum counts in the traditional sightability models, thereby correcting for bias associated with undercounting group size. We also provide associated equations for calculating the variance of our estimator. This estimator is an improvement over existing sightability model techniques because it significantly reduces bias, and variance estimates provide near nominal confidence interval coverage. The data needed for this estimator can be easily collected and implemented by wildlife managers with a field crew of only 3 individuals and little additional flight or personnel time beyond the normal requirements for developing sightability models.     

Two New Species of Paramoeba from Maine*

SYNOPSIS Four clonal strains of amoebae isolated from salt-water habitats of the Maine coast show the characteristic Nebenkörper or paranucleus of the genus Paramoeba Schaudinn, 1896, this being the first report of free-living members of that genus from North America. The isolates are identified as 2 species, P. pemaquidensis n. sp. and P. aestuarina n. sp. In form and mitotic pattern, these 2 species resemble members of the family Mayorellidae.     

A revised classification of the Gymnamoebia (Protozoa: Sarcodina)

A revised classification of the naked amoebae is proposed on the basis of a synthesis of many kinds of information presently available for taxonomic purposes above the species level. These amoebae, constituting the subclass Gymnamoebia within the class Lobosea, superclass Rhizopoda, include not only strictly lobose amoebae but also those with more or less filose subpseudopodia produced from a broader hyaline lobe. The subclass is divided into the orders Amoebida, Schizopyrenida, and Pelobiontida, and suborders are recognized within the order Amoebida. Although the Gymnamoebia are undoubtedly heterogeneous and polyphyletic and the proposed classification is intended chiefly as a practical system with a logical basis, there are a few suggestions of natural relationships.     

Angle Meristem Origin and Development in Selaginella martensii

The origin and early development of angle meristems (AMs) inSelaginella martensii were studied using a high-resolution mouldand cast technique for scanning electron microscopy, in conjunctionwith light microscopy. Both dorsal and ventral AMs originatein the apical region shortly after the most recent bifurcationof the shoot apex. AMs appear to arise from a single superficialinitial cell, which subsequently undergoes an oblique anticlinaldivision to establish the apical cell of the AM. The AM apicalcell has a relatively short active life and divides laterallyusually only six to twelve times; most cells of the AM originatefrom repeated divisions of apical cell derivatives. Dorsal andventral AMs show similar developmental sequences, although theydiffer slightly in time of appearance. Ventral AMs originatedfirst, dorsal AMs appearing shortly thereafter. At a given branchpoint, the ventral AM is typically larger than the correspondingdorsal AM. Both dorsal and ventral AMs grow out as rhizophores(aerial roots), although ventral AM development greatly precedesdorsal AM development. It is possible that the apparent earlierdecrease in apical cell activity in dorsal AMs compared to ventralAMs could account for the lag in dorsal AM development as arhizophore at a given branch point. Selaginella martensii Spring, Lycophyta, angle meristem, apical cell, morphogenesis, mould and cast technique, replica technique, scanning electron microscopy