Mode of nutrition of the larvae of the filarial nematode Brugia pahangi

Abstract

SUMMARY(1) Light-microscopic observations were made on B. pahangi larvae at various stages of development in stained serial sections of A. aegypti thoraces, and on 8-to 9-day 2nd-stage live, unstained larvae.(2) Six-day larvae situated in A. aegypti flight muscle, and isolated 8- to 9-day 2nd-stage larvae, were examined with the electron microscope.(3) Results showed that host-muscle mitochondria which appeared to be morphologically intact aggregated outside the larvae at the head and tail ends and were present from 6 days onwards in the oesophagus and in the midgut. Those in the oesophagus were unchanged; some of those in the midgut were intact, others showed varying degrees of disintegration suggestive of digestion. Host-muscle mitochondria are therefore likely to be a source of nutrients for B. pahangi larvae during the last third of their intramuscular developmental phase.Dr W. W. Macdonald, of the Liverpool School of Tropical Medicine, kindly supplied the infected mosquitoes, and offered valuable advice in the course of this work. Miss M. A. Johnson assisted with the care of the mosquitoes.We are particularly indebted to Mr David John for his patient work in preparing the filariae for electron-microscopic observation. Mrs J. Oliver assisted with some of the histological preparations.We are pleased to acknowledge the financial assistance of the Royal Society towards the purchase of the ultramicrotomes used in the course of this work.