Studies on the Life History ofEchinostoma ivaniosin. sp.

Abstract

The life cycle ofEchinostoma ivaniosin.sp., found in the rectum of domestic fowl (Gallus gallus domesticus) has been worked out in detail. The eggs hatch in 7–8 days in tap water at room temperature (24-28°C). Body of the miracidium covered with 18 epidermal plates arranged in four tiers of 6, 6, 4, 2 from the anterior to the posterior end. Miracidia develop into sporocysts in the snails,Lymnaea luteola f typica.There are two redial generations and the first cercariae are liberated 25–30 days post-infection with miracidia, or a little later. 37 collar spines of the cercaria are arranged in the pattern-5(3+2)+6+15(8+7)+6+5(3+2). Caudal finfold present, cuticle spinose, paraoesophageal gland cells present, penetration glands two pairs and excretory system with 18 pairs of flame cells in triplets. Metacercaria develops into adult in domestic fowl and the eggs are recovered from the faeces of the host, 12–14 days post-infection. The adult is compared with other 37-spined echinostomes whose life cycles are known or which show characteristic differences from the present species and the creation of a new species is justified.