A new Davaineid Cestode-Raillietina (Pa-roniella) macropa sp. n., from a wallaby

Volume: 9Start Page: 602End Page: 61

Genetic differences between the two remaining wild populations of the endangered Indian rhinoceros (Rhinoceros unicornis)

The management of rare and endangered species in the wild and in captivity requires an understanding of the characterization of the genetic units within each species and their relationships to each other. The Indian rhinoceros (Rhinoceros unicornis) is an endangered species with a current population size of c. 2800 individuals. We analyzed 26 individuals of known origin kept in captivity and 21 wild ranging individuals of the two remnant large wild populations in Assam (India) and Nepal employing mitochondrial and microsatellite markers to determine whether the two geographically isolated populations show distinct patterns of genetic diversity, and whether the genetic diversity of the populations is influenced by past demographic bottlenecks. We identified 10 different mitochondrial D-loop haplotypes, of which 4 were specific to the Assam population (10 sequences examined) and 6 specific to the Nepal population (19 sequences). Similarly, the microsatellite analysis demonstrated a strong genetic differentiation between the Assam and Nepal populations and allowed to assign each individual to its origin with high confidence. Furthermore, our analyses revealed the occurrence of a bottleneck in the Assam population long before the reported bottleneck in 1908, and it revealed that the Nepal population is a recent (probably post-glacial) colonization. In summary, the extent of genetic divergence between the two remnant R. unicornis populations suggests separate conservation programs (even for captive individuals) as long as the persistence of the entire species is not severely threatened. The microsatellite markers can also be used to determine the origin of confiscated material such as horns

Strukturwandel der schweizerischen Lehrerbildung

So begann Johann Rudolph Steinmüller seine „Vorschläge eines Versuchs zur Errichtung einer Erziehungsanstalt angehender Landschullehrer im reformierten Theile des Kantons Säntis“, die er im Jahr 1800 dem Erziehungsrat des neu gegründeten Kantons Säntis vorlegte. Steinmüller formulierte drei Grundannahmen, die bis heute in der schweizerischen Lehrerbildung unbestritten sind: Erstens hielt er eine Ausbildung der Lehrkräfte für sinnvoll und notwendig: Lehrkräfte werden nicht ‚geboren‘, sondern müssen ausgebildet werden. Zweitens sollten Lehrkräfte in den zu unterrichtenden Fächern fachlich ausgebildet werden, und drittens sollte diese fachliche Ausbildung durch eine methodische ergänzt werden

Determinants of female and male reproductive success in a simultaneous hermaphrodite land snail

Classical sexual selection theory assumes that the reproductive success of females is limited by the resources available for egg production, while the reproductive success of males is determined by the number of mates (Bateman’s principle). It has been suggested that the optimal mating rates should also diverge between gender functions within individuals of simultaneous hermaphrodites. We assessed determinants of mating success and female and male reproductive success in individuals of the simultaneous hermaphrodite land snail Arianta arbustorum. We videorecorded the behaviour of individually tagged snails kept in groups of six animals over one reproductive period (58 days) and assigned the genotyped hatchlings to the female and male function of individual parents. We found considerable interindividual variation in the activity of snails, which is a combined measure of time spent crawling, feeding and digging. The snails mated between zero and three times. Mating success, which is equal to the female and male function in simultaneous hermaphrodites with reciprocal copulation, was mainly determined by the activity of an individual. We found that female reproductive success (number of hatchlings emerging from the eggs laid by the focal snail) was positively correlated with male reproductive success (number of hatchlings sired by the focal snail) and that both were determined by the individual’s activity. Furthermore, both female and male reproductive success of an individual were influenced positively by the snail’s degree of genetic heterozygosity and negatively by shell size. Our results challenge the trade-off assumption of sex allocation theory in simultaneous hermaphrodites