Nematode Parasites of Anurans from Three Cocoa Farms in Ondo State, Nigeria

Abstract

The research was designed to investigate the parasitic fauna of Anurans from cocoa farms in Ondo state. Amphibians are one of the most threatened groups of vertebrates. Many reasons are attributed to the decline of amphibian species such as global warming, habitat destruction and modification, others include: exploitation, pesticide use, introduced species, ultraviolet-B radiation (UV-B), pollution, parasites and diseases. A total of 31 frogs from 4 genera, Hemisus, Ptychadena, Rana and Xenopus and 7 toads from 1 genus, Sclerophrys were examined. 9 frogs were collected from Oluwateru farm at Iwoye Village; 7 frogs were collected from Folorunso farm at Ako-Igbatoro and 15 frogs from Obodulu farm in Idanre. 5 toads were collected from Oluwateru farm at Iwoye Village and 2 toads from Obodulu farm in Idanre. In all cases collection was done between 20:00 hrs and 05:00 hrs. Collected specimens were transported in sealed but ventilated containers to the laboratory where identification was done to species level. The frogs were anaesthetized until death in absolute chloroform soaked in cotton wool placed inside kill-jar for 3 minutes in the laboratory.  The gastrointestinal tracts were cut open and the contents of the various sections were put into separate Petri dishes containing normal saline.  The skin and the bladder were observed directly under a dissecting microscope for the presence of cysts and monogeneans. The parasites were fixed and preserved in 70% alcohol following standard procedure. Parasites recovered from the gastrointestinal tracts of the anurans include Cosmocerca ornata, Deising, 1861, Cosmocerca cummutata, Diesing, 1851 Paracosmocerca mucronata, Kung and Wu, 1945, Ampliceacum africanum, Taylor, 1924, Gendria liberrei Bain and Philipon, 1969 and Chenospirura asturi Hsu, 1957 Others were Procamallus brevis Kung, 1948 and Camallanus dimitrovi   Durette- Desset and Batcharov, 1974. Some of the parasites are zoonotic while a few others are established parasites of African fishes and water Birds raising probable public health concerns from the findings. Further works aimed at unravelling the biodiversity of hosts and parasites in the lush ecosystem of Ondo state, as well as identification of organisms involved in the life cycle are noted.