LEPTOMONAS CENAEI sp. nov., FROM THE DIGESTIVE TRACT OF CENAEUS CARNIFEX (HEMIPTERA), WITH SPECIAL REFERENCE TO THE METACYCLIC FORMS

Abstract

The life-history of Leptomonas cenaei sp. nov., parasitic in Cenaeus carnifex, is described. The lepto-monad is found in the digestive tract only, first in the mid-gut and later in the hind-gut and rectum. Only leptomonad forms are found in the first two localities, but in the rectum small leishmania-like bodies are developed by modification and division of leptomonads which have become adherent to the rectum walls. The small leishmanial elongate, grow flagella, and become motile. They then become free in the rectum and are found in the faecal droplet of the host in very large numbers. Soon after leaving the host their flagella become shorter and later disappear. It is shown that the flagella are retracted within the bodies of the organisms. These torpedo-shaped bodies are capable of extruding their flagella and becoming motile in saline after having been dried for 24 hours. It is suggested that they represent the infective form of the parasite.