Development of Sporocysts of the Turtle Lung Fluke, Heronimus chelydrae MacCallum (Trematoda: Heronimidae)

Although the turtle lung fluke, H eronimus chelydrae, has been known for more than half a century, its life cycle has remained enigmatic. MacCallum (1902) was the first to describe this trematode, examples of which he recovered from the lungs and bronchi of a snapping turtle, Chelydra serpentina, collected in Ontario, Canada. Barker and Parsons (1914) in a preliminary report described the same worm under the name Aorchis extensus. Their specimens were from the lungs of a painted turtle, Chrysemys marginata, from lakes in Minnesota and from the Mississippi River at Fairport, Iowa. A fuller description of the parasite by these authors was published in 191 7. Ward (1917) established the family Heronimidae including therein the genera Heronimus and Aorchis, but suggested that Heronimus chelydrae and Aorchis extensus might prove to be identical, or at least might be congeneric. In Ward and Whipple\u27s Fresh Water Biology (1918), Ward, however, differentiated between the two genera on the basis of extent of the vitellaria and the presence or absence of the seminal receptacle. It remained for Stunkard (1919) who compared MacCallum\u27s and Barker and Parsons\u27 specimens with additional worms he had collected, to demonstrate that Heronimus chelydrae and Aorchis extensus are identical, and that the correct name for the parasite should remain Heronimus chelydrae MacCallum 1902. Stunkard, who found the adult worms in six different species of turtles, provided additional details of morphology, supplementing the observations of Mac Callum. No information, however, was presented relative to the life cycle