Further studies on the occurrence of freshwater Microturbellaria in the British Isles

Five new British records of freshwater Microturbellaria are illustrated: Gieysztoria infundibuliformis, Castrada lanceola, Castrada neocomensis, Castrada viridis and Strongylostoma elongatum. These species together with a new species, Macrostomum johni described by Young (1972), are woven into the fabric of the existing key for the group (Young, 1970). All six species were recorded from the littoral zone of lakes in Caernarvonshire, N. Wales. The times of the recordings are indicated.     

Concentration of monoamines in the brain of minks differing in their reaction to man

Content of dopamine in the striatum; of serotonin, 5-hydroxyindolacetic acid and noradrenaline in the hypothalamus, striatum and midbrain was studied in three groups of minks from population of an animal farm, differing by their reaction to humans (cowardly, calm, aggressive). The reaction to humans was estimated by a system of marks at the attempt to catch the mink with a mitten. Aggressive animals had a lowered level of serotonin in the hypothalamus and striatum, a lesser content of serotonin metabolite--5-hydroxyindolacetic acid in the striatum. Minks of different groups did not differ by noradrenaline content, but dopamine level in the striatum of cowardly minks was higher than in calm and aggressive animals. Conclusion is made that polymorphism of behaviour corresponds to polymorphism of the state of monoaminergic systems.     

EM chromosome mapping using surface-spread polytene chromosomes

Electron micrographs as well as light micrographs of individual surface-spread polytene (SSP) chromosomes indicate more detailed banding patterns than standard squash preparations do. For EM preparations of SSP chromosomes a simple technique is described, avoiding thin-sectioning of chromosomes.