摘要:

Three oceanic sandy beaches, covering a full range of dissipative‐reflective categories were sampled at southern Chile (ca. 39'S) during the summer of 1990. The purpose of this study was to analyse the abundance, species richness and zonation schemes of the macroinfauna in relation to physical characteristics (e.g. texture, slope) of that sites. In addition, we also sampled an estuarine protected beach located nearby. Furthermore, we analysed the body sizes of the crustacean species to assess between‐ and within‐size variability. Principal component analysis showed that gravel percentage, mean grain size and slope were the most important variables accounting for by the spatial variability in the physical characteristics of the studied beaches. Maximum species richness (6) and abundances occurred at a dissipative and at an intermediate type of beach, respectively. Almost no macroinfaunal organisms were collected at the reflective beach of Matías. Kite diagrams and cluster analysis showed that the macroinfauna can be classified in four faunistical zones, each of one characterized by a particular species or duple of species. That zonation schemes are compared with other studies. Finally, body size comparisons detected that sizes of some species differed between and within beaches.

ISSN:0165-0521    

DOI:10.1080/01650529109360853

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A new species ofBiomphalariafound in Andean swamps close to Isluga, Tarapaca Region, north of Chile, is described. The study of its anatomy, particularly of those structures which have been assigned taxonomic and phylogenetic value, allows both its comparison and evaluation to establish relationships and differences with other species of the High Andes plateau.

ISSN:0165-0521    

DOI:10.1080/01650529109360854

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The systematic position of‐the molluscCastalia orinocensisMorrison, 1943, is clarified by comparing it with the holotype ofCastalia multisulcataHupé, 1857. The latter was suggested to be lost, but was refound in the collection of the Natural History Museum in Paris. The differences between the two species are described, andC. orinocensisis revalidated by this means.

ISSN:0165-0521    

DOI:10.1080/01650529109360855

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

After the examination of the types ofMygalarachne brevipesAusserer, 1871, andSericopelma rubronitensAusserer, 1875, we declareM. brevipes, a juvenile female, as a species “incertae sedis” since the specimen doesn't present sufficient characteristics which allow a secure identification of the genera and species.

ISSN:0165-0521    

DOI:10.1080/01650529109360856

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Spectacled bear(Tremarctos ornatus)predatory behavior on cattle was studied in the Venezuelan Andes from February 1986 to November 1988. Only 12 of the 140 localities surveyed reported spectacled bear predation. Sixteen recent claims of predation were investigated, and predation by spectacled bear confirmed. Herding practices used in the Venezuelan Andes may increase the probability of predation and the subsequent persecution and killing of bears.

ISSN:0165-0521    

DOI:10.1080/01650529109360857

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Sphiggurus vestitus pruinosus, a porcupine from western Venezuela, has a karyotype with a diploid number (2n) of 42, and a fundamental number (FN) of 76. The autosomes consist of 34 metacentric and submetacentric, 2 subacrocentric, and 4 acrocentric chromosomes. The X‐chromosome is submetacentric, and the Y‐chromosome is acrocentric. This karyotype is identical in gross morphology to that of the North American porcupine,Erethizon dorsatum, but differs markedly from the 2n=74 and FN=82 karyotype of the Panamanian porcupine,Coendou rothschildi. These findings are unexpected considering thatSphiggurusandCoendouresemble morphologically more to each other than either of them toErethizon, and are most parsimoniously explained by retaining the hypothesis of a closer cladistic relationship betweenSphiggurusandCoendouand by proposing the 2n‐74 and FN=82 karyotype to be autapomorphic. The karyological information is complemented with observations on cranial and external characters. The results support recognition ofSphiggurusandCoendouas separate genera.

ISSN:0165-0521    

DOI:10.1080/01650529109360858

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Psocoptera were collected from soil (by Kempson extraction) and from tree trunks (by arboreal photoeclectors) at two contrasting sites near Manaus, Brazil, for one year. The predominant soil taxa were Epipsocetae, especiallyIsthmopsocus, and a number of minor constituents are probably casual litter‐frequenters. Tree trunks yielded several taxa absent from soil. Soil in a secondary forest site yielded about four times as many psocids as a primary forest site and psocids were more abundant in the dry season than in the rainy season. Arboreal photoeclectors collected more psocids in the primary forest, but catches at both sites were larger in the dry season than in the rainy season. About 81 per cent of the psocids were immature stages.

ISSN:0165-0521    

DOI:10.1080/01650529109360859

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The maraDolichotis patagonumis a cursorial rodent typical of savannas, steppes and grasslands. In the Monte of Argentina, where the typical vegetation is an open scrub with a ground layer of scarce herbs and unvegetated spaces of sandy soil, difference in mara abundance between protected and grazed areas suggest a preference for open areas. The main purpose of this paper is to assess howD. patagonumuses the habitat, especially with reference to the vegetation structure. The abundance of mara feces was considered as a measure of its spatial activity and was correlated with cover of three vegetational strata in two study sites: one in Ñacuñán Ecological Reserve and another in a contiguous grazed area. Significant correlationas were obtained with percent bare ground (positive) and percent shrub cover (negative). It is concluded that the mara preferencially selects habitats with large representation of bare ground. This results in its increased presence in grazed areas. In contrast, mara abundance is markedly lower in areas with large accumulations of shrubs and herbs. Adequate management of grazed as well as of protected areas is recommended to enhance the conservation status of this species.

ISSN:0165-0521    

DOI:10.1080/01650529109360860

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0165-0521    

DOI:10.1080/01650529109360852

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor