1. Laboratory of Zoology, Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaounde I, Yaounde, Cameroon
2. Biology Department, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA
3. Laboratory of Parasitology and Ecology, University of Yaounde I, Yaounde, Cameroon
4. Department of Biology, Boston University, Boston, MA 02215, USA