The effect of stocking density and repeated handling on the growth of juvenile mulloway, Argyrosomus japonicus (Temminck & Schlegel 1843)

The effect of stocking density on the growth of mulloway, Argyrosomus japonicus, was tested with 17 g fish stocked at 4.08, 8.16, or 16.32 kg m⁻³ in 50 l aquaria. Weight checks were carried out every 2 weeks to track performance. Each density treatment was also compared to a nonhandled control group to establish if handling during weight checks influenced the growth of mulloway. Mulloway performed poorly at the lowest density and, under the current experiment conditions, growth did not appear to be negatively affected by regular handling.     

Presence–absence surveys of prey and their use in predicting leopard (Panthera pardus) densities: a case study from Armenia

It is important to predict how many individuals of a predator species can survive in a given area on the basis of prey sufficiency and to compare predictive estimates with actual numbers to understand whether or not key threats are related to prey availability. Rugged terrain and low detection probabilities do not allow for the use of traditional prey count techniques in mountain areas. We used presence–absence occupancy modeling and camera‐trapping to estimate the abundance and densities of prey species and regression analysis to predict leopard (Panthera pardus) densities from estimated prey biomass in the mountains of the Nuvadi area, Meghri Ridge, southern Armenia. The prey densities were 12.94 ± 2.18 individuals km^?2 for the bezoar goat (Capra aegagrus), 6.88 ± 1.56 for the wild boar (Sus scrofa) and 0.44 ± 0.20 for the roe deer (Capreolus capreolus). The detection probability of the prey was a strong function of the activity patterns, and was highest in diurnal bezoar goats (0.59 ± 0.09). Based on robust regression, the estimated total ungulate prey biomass (720.37 ± 142.72 kg km^?2) can support a leopard density of 7. 18 ± 3.06 individuals 100 km^?2. The actual leopard density is only 0.34 individuals 100 km^?2 (i.e. one subadult male recorded over the 296.9 km²), estimated from tracking and camera‐trapping. The most plausible explanation for this discrepancy between predicted and actual leopard density is that poaching and disturbance caused by livestock breeding, plant gathering, deforestation and human‐induced wild fires are affecting the leopard population in Armenia.     

RAPD analysis of interspecific relationships in presumably apomictic Cotoneaster species

A few of the approximately 300 Cotoneaster species described are diploid but the majority appear to be polyploid. The occurrence of apomixis inpolyploid Cotoneaster species has been reported but never proven with genetic markers. We have used 76 polymorphic RAPD markers to investigate the breeding system and phenetic grouping of some critical taxa, including a total of 19 plant accessions representing 13 mostly European species in the series Cotoneaster. Three to four individual plants, raised from seed from the same original plant, were analyzed for each of three accessions to investigate the possible occurrence of apomictic seed set. Absolutely congruent RAPD profiles were encountered among seedlings from one accession, whereas we found one or two marker differences among seedlings from the other two accessions. Genetic similarities among the different accessions were analyzed with a UPGMA-derived dendrogram. The most deviant taxon was the Chinese C. albokermesinus. A group withC. soczavianus and C. tomentosus was rather isolated from the remainder, as was also C. kullensis. Among the remaining taxa, two well supported clusters were found: (1) C. antoninae and C. uralensis, and (2) C. integerrimus and C. raboutensis, whereas the other five species (C. canescens, C. niger, C. scandinavicus, C. juranus, C. cambricus) formed a poorly supported cluster with no clear substructuring. A principal coordinate analysis yielded results that were in good correspondence with the dendrogram. Again C. albokermesinus appears to be totally isolated from the other species. In addition, two well-defined and rather isolated groups were found: (1) C. tomentosus and C. soczavianus, and (2) C. antoninae and C. uralensis, with the remainder comprising a loosely defined group. This revised version was published online in July 2006 with corrections to the Cover Date.