We examined monthly changes in crustacean zooplankton community composition during the initial colonisation period of a newly constructed pond (LWL pond), and in the littoral zone of an adjacent lake (Ramsey lake). In addition, four unconnected constructed ponds aged ≥20 years with established zooplankton communities were sampled and compared to the LWL pond. The species richness of both LWL pond and Ramsey lake increased over the ice-free season, although Ramsey lake always had more species. Almost half of all species sampled occurred in both pond and lake. None of the zooplankton communities in the ponds used in the spatial analysis resembled communities of the LWL pond or one another. Taken together, these results indicate a lack of dispersal limitation, which suggests that differing local habitat factors had a strong influence in structuring the zooplankton communities.

Acute respiratory infections (ARI) are still a major health problem in most developing countries. So far no study has evaluated the importance of childhood ARI in rural Senegal. We prospectively studied ARI, the percentage of pneumonia and related mortality, as well as the bacterial composition of nasopharyngeal flora using nasopharyngeal aspirates in 114 children, aged 2-59 months, presenting at Ndioum's pediatric ward. Excluded from the trial were those children that had had antimicrobial therapy in the previous 2 weeks. The Kirby-Bauer method was used to determine antibiotic resistance throughout the study. The percentage of ARI and pneumonia among the population tested was 24 per cent and 11 per cent respectively. Streptococcus pneumonia was often resistant to cotrimoxazole (31 per cent) but only 9 per cent were resistant to chloramphenicol and 14 per cent to penicillin. Haemophilus influenzae (HI) was uniformly sensitive to ampicillin, and only 4 per cent were resistant to chloramphenicol and 11 per cent to cotrimoxazole. We conclude that SP and HI resistance to cotrimoxazole is important and warrants larger clinical trials using chloramphenicol. Information campaigns and intense management of comorbidities are desirable in this type of population. Comorbidities (tuberculosis, malaria, HIV-AIDS, severe malnutrition) are determinant variables in many ARI cases and carry a high negative prognosis value.

Intraspecific hybridisation may result in hybrid offspring exhibiting superior (heterosis) or inferior (outbreeding depression) fitness relative to their parental populations. As both have been demonstrated in salmonids, consequences of interbreeding between divergent populations are relevant to their conservation. Atlantic salmon Salmo salar L. were extirpated from Lake Ontario by the late 19th Century due to anthropogenic causes. Multiple allopatric populations of hatchery‐reared Atlantic salmon are being stocked in an effort to re‐establish a self‐sustaining population. This study evaluated whether interbreeding between Sebago Lake (Maine) and LaHave River (Nova Scotia) individuals will result in heterosis or outbreeding depression in juveniles. This was accomplished through full‐factorial 2 × 2 mating crosses between the strains and comparing multiple fitness‐related traits between the cross types. Hybrid juveniles displayed no signs of outbreeding depression nor heterosis. Further studies on comparative fitness of backcross and F2 hybrids are recommended to assess potential consequences for this and similar restoration efforts.