Population Structure of the Lower Keys Marsh Rabbit as Determined by Mitochondrial DNA Analysis

ABSTRACT We used nucleotide sequence data from a mitochondrial DNA fragment to characterize variation within the endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri). We observed 5 unique mitochondrial haplotypes across different sampling sites in the Lower Florida Keys, USA. Based on the frequency of these haplotypes at different geographic locations and relationships among haplotypes, we observed 2 distinct clades or groups of sampling sites (western and eastern clades). These 2 groups showed low levels of gene flow. Regardless of their origin, marsh rabbits from the Lower Florida Keys can be separated into 2 genetically distinct management units, which should be considered prior to implementation of translocations as a means of offsetting recent population declines.     

Analysis of a Repeat-Containing Family of Giardia lamblia Variant-Specific Surface Protein Genes: Diversity Through Gene Duplication and Divergence

ABSTRACT. Giardia lamblia trophozoites express on their surfaces one of a set of cysteine-rich antigenically variant proteins, called variant-specific surface proteins, which comprise the majority of proteins detected by surface labeling. While these VSP proteins may be immunodominant proteins important in the host immune response to G. lamblia , the ability to switch expression from one VSP to another may provide a means for the trophozoites to avoid the host immune response. The first VSP characterized, VSPA6 (from the A6 clone of the WB isolate, originally termed CRP170), contains 18–23 copies of a 65 amino acid repeat. We have now used the repeat as a probe to isolate from a WBA6 genomic library two genes related to vspA6 (called vspA6-S1, vspA6-S2). Sequence analysis of the vspA6-S1 gene revealed nearly two complete copies of the 195 bp repeat and substantial nucleotide and translated amino acid similarity in the coding regions 5'and 3'to the repeats. The vspA6-S2 gene, while still related, showed greater divergence from vspA6 than vspA6-S1 in the nonrepeat coding region and contained nearly four copies of a 201 bp repeat that was 75% identical to the 195 bp vspA6 repeat. These results suggest that gene duplication followed by divergence has played a key role in the generation of the vsp gene repertoire.     

Kin Recognition and Incest Avoidance in Toads

Toads, like many amphibians, display breeding site fidelity.Individuals that return to natal ponds to breed are likely toencounter siblings as potential mates. We examined the geneticstructure of Bufo americanus breeding populations at five localitieswithin a 1 km radius. Mitochondrial DNA (mtDNA) haplotypes significantlydiffered among the breeding populations, but haplotype distributionsdid not differ from year to year within breeding sites. Natalphilopatry may account for these results. Although incest isthus possible, siblings rarely mate. Comparing haplotypes oftoads captured while mating, we found only 2 of 86 pairs thatcould possibly be siblings. We suggest that toads might recognizeand actively avoid close kin as mates. Advertisement vocalizationsgiven by males serve as potential cues by which females mightrecognize their kin. We recorded calls of males, in the field,and later obtained rank estimates of their relationships toone another by DNA fingerprinting of the nuclear genome. Theresemblance of males' calls was positively correlated with thesimilarity of their fingerprints. Significant differences incall characteristics were also found among breeding populations.Temporal parameters, rather than frequency components, encodekinship information. Recently developed techniques in moleculargenetics facilitate studies of the heritability of behavioraltraits in natural populations.     

Matabelea fuhrmanni (Cestoda, Cyclophyllidea, Paruterinidae): redescription, synonymy and systematic position

Matabelea fuhrmanni (Southwell. 1925) comb. n. [syns Lateriporus fuhrmanni Southwell. 1925: Culcitella fuhrmanni (Southwell) Baer in Fuhrmann, 1932; Matabelea aetodex Mettrick. 1963. new synonym] is redescribed on the basis of the type-specimens of L. fuhrmanni and M. aetodex plus additional specimens from African birds of prey. Matabelea Mettrick. 1963 is regarded as a monotypic genus of the family Paruterinidac and not of the family Dilepididae. where it was originally placed. The host range of M. fuhrmanni includes the African falconiform birds Cireaetus cinereus. Melierus metabates and Aquila rapax (Accipitridac) plus Falco biarmicus (Falconidae).     

The impact of predation by the powerful owl,Ninox strenua,on a population of the greater glider,Petauroides volans

Powerful owls were frequently observed during a study of the ecology of a community of arboreal marsupials in south-eastern New South Wales. For about 17 months the population of greater gliders in the 100 ha study area appeared to remain ‘stable’ at more than 80 individuals. In the following 46 months, the population declined to about one-tenth of its previous level. The forest in the study area was unlogged and remained undisturbed during this period. The frequency of sightings of powerful owls holding captured greater gliders, and of observations on the ground of tails and bodies belonging to greater gliders, and the unaccountable disappearance of 9 out of 11 individually marked greater gliders in the study area, suggest that the observed decline in the population of greater gliders was due to predation by the powerful owl. Powerful owls were not detected in the study area during the first 12 months or the last 21 months of the study. It is suggested that powerful owls forage by concentrating their activities in pockets of their large home range until they reduce the populations of their preferred prey below limits where it becomes difficult to catch the remaining animals. If preferred prey are available elsewhere, powerful owls probably move their centres of foraging activity to these pockets and harvest them before moving on to the next pocket of their range.     

Do caterpillars disperse their damage?: larval foraging behaviour of two specialist herbivores,Euphydryas phaeton (Nymphalidae) and Pieris rapae (Pieridae)

Abstract. 1. To examine ecological and evolutionary aspects of caterpillar foraging behaviour, this study focused on observation of the individual foraging behaviour of two lepidopteran species, Pieris rapae L. and Euphydryas phaeton (Drury), on their respective host plants.
2. Periodic observations over the course of a day showed that the larvae move considerable distances, forage on the upper surfaces of leaves, and often immediately leave areas from which they have fed, leaving a pattern of dispersed herbivory.
3. Differences in foraging behaviour were not found between the two species, even though one species is aposematic and the other is cryptically coloured, but there were significant differences in the foraging patterns of P.rapae on the two host plants, broccoli and radish.