ACANTHOCEPHALANS

 

Adult members are highly specialized, dioecious parasites of the intestines with no intestines of their own. The body is made up of two major parts: the praesoma and the metasoma. The praesoma contains the proboscis (cluster of hooks). The tube-shaped metasomais is a solid body mainly containing male or female sexual organs. (Mehlhorn, 2001).

Acanthocephala –

Taxonomy: Kingdom Animalia, Phylum Acanthocephala

Description: Consists of a small group of unsegmented, cylindrical, dioecious, endoparasitic worms without a digestive tract at anytime during in their development (Schmidt, 1992). The most obvious trait and distinguishing feature is the thorny retractable proboscis at the anterior end of the body (Olsen, 1986). Their size ranges from 0.92 to 2.4 mm long (Schmidt and Roberts, 1989). About 100 µm in length. Their eggs can withstand a temperature of -10 to 45 degrees Celsius and remain infectious for up to three years in the soil (Cheng, 1973).

Lifecycle: According to Schmidt and Roberts (1989), the life cycle of every species of 3 uses at least two hosts with the first being a crustacean, insect, or myriapod (ex. millipedes.) after it has ingested an egg. Once inside, the egg matures into a larva, or “acanthor”, that moves out of the host’s stomach into the body cavity to continue its maturation into a “cystacanth” when encysted (Schmidt, 1992). Once the first host is eaten by the definitive host the acanthocephala adults reproduce. Hosts include invertebrates, amphibians, fishes, birds, and mammals (Cheng, 1973).

Pathology: Unknown

Location and Lifestage in Frog: Acanthocephala are found in the intestines of their definitive hosts. The proboscis attaches to the intestinal mucosa and damages the soft tissue with each attachment and reattachment (Marquardt, Demaree, & Grieve, 2000).