Mating success of males with and without wing patch in Drosophila biarmipes.

Some males of D. biarmipes--synonym of D. rajasekari and D. raychaudhuri have a black patch on the wing. The patch extends from the apical margin of wing to the third longitudinal vein. Field and laboratory studies have been carried out in D. biarmipes to study role of male's wing patch in mating success. The field study shows that nature favors D. biarmipes males with patch. Although males without patch mated, males with patch have higher mating success suggesting the role of wing patch during courtship. Further, among mating males, males with patch had longer wings than males without patch. During courtship, males with patch oriented and mated faster; performed courtship acts such as tapping, scissoring, vibration, licking and twist dance more times than males without patch in both competitive and non-competitive situations. The results indicate that there is a casual relationship between the presence of wing patch, mating speed and success. Also there is a correlation between presence of wing patch, size of the flies and mating success.

Acute renal failure secondary to rhabdomyolysis following near-drowning in sea water.

We report here a rare case of acute renal failure following near-drowning in sea water. A 21-year old college student presented in acute renal failure 48 hours after a near-drowning event. Investigations revealed rhabdomyolysis to be the cause of renal failure.

Variability of morphological traits in Drosophila bipectinata complex.

Phenotypic or morphological differences among different populations and sexual dimorphism in certain metric traits were analysed in D. bipectinata complex. It was noticed that different populations of D. bipectinata species group harbour large amount of variation for these characters. In all the populations, morphometric characters such as lengths of femur, tibia and wing length, wing width, number of sternopleural bristles and bristles on epandrium varied significantly among populations. The study indicates that the morphological variations are due to the interplay of genetic and environmental endowments. Further, females had significantly larger values, for lengths of femur, tibia and wing length, wing width and sternopleural bristles.

Bottleneck effect on intra- and interspecific competition in Drosophila malerkotliana.

Intra and interspecific competition experiments involving control and bottleneck lines of monomorphic and polymorphic populations of D.malerkotliana with D.nasuta nasuta have been carried out. Productivity and population size were evaluated in these lines. The results show that control line had higher relative fitness and adaptedness (productivity and population size) under both intra and interspecific competition than their respective bottleneck lines and D.nasuta nasuta. This indicates that bottlenecks have an effect on competition in D.malerkotliana. The consequence of such competition studies using control and bottleneck lines of D.malerkotliana and D.nasuta nasuta is discussed.

Body size, mating success and advantage of large flies in Drosophila bipectinata species complex.

Mating success of large and small flies of Drosophila malerkotliana and D. bipectinata was studied using multiple, male and female choice methods. In multiple choice method the large male mated with large female and small male paired with small female. In female choice method, large male was successful in mating with female irrespective of its size while in male choice method, preferential mating occurred between large male and large female as well as small male and small female. The consequence of such non-random mating in the presence of male rivarly and preferential mating has been discussed.

Effect of bottlenecks on incipient sexual isolation, mating activity and fertility in Drosophila malerkotliana.

Effect of bottleneck sizes, on sexual isolation, mating speed and fertility were studied in D. malerkotliana established from natural population. After 10 generations of laboratory breeding, flies showed incipient sexual isolation between control line and some bottleneck lines and also between bottleneck lines. These findings do not fully agree with the general assumption that the establishment of bottlenecks accelerates speciation. The courtship latency and mating speed increases with increasing size of bottlenecks whereas copulation duration and fertility decreases with increasing bottleneck size. There was no sign of rebounding in fitness with in 10 generations as observed by Bryant et al. in house flies.

Lack of correlation between mating activity and EST-1 polymorphism in three natural and laboratory populations of Drosophila bipectinata.

Est-1 polymorphism and mating activity have been studied in three natural populations of D. bipectinata and after 10 generations of their maintenance in the laboratory. The results indicate that the enzyme Est-1 variation was not significant within natural populations within F10 generation and also between different natural populations and F10 generation indicating the role of balancing selection in the maintenance of enzyme polymorphism in both natural and laboratory conditions. On the other hand, there was variability in the mating activity within natural populations and within F10 generation and also between natural population and F10 generation. However, there was no correlation between Est-1 polymorphism and mating activity.

Correlative studies on mating speed and metric traits in Drosophila malerkotliana.

Relationship between mating speed, an important component of fitness, and morphological characters such as lengths of wing, femur, tibia and first tarsus have been analysed in D. malerkotliana. Flies mating first have longer wings and forelegs and mating flies have lower coefficient of variability in wing length than nonmating ones. Age seems to have no detectable effect on the relationship between these metric traits and mating speed.