Anurans as Intermediate and Paratenic Hosts of Helminth Infections in the Rainforest and Derived Savanna Biotopes of Southern Nigeria

Abstract

Anurans from the rainforest (Okomu National Park) and derived savanna (Agbede) locations in Nigeria were investigated for their role either as intermediate or paratenic hosts of helminth infections. A total of 269 anuran specimens (157 from the Okomu National Park and 112 from Agbede) were examined. Metacercariae of a strigeoid trematode, two nematode species, a proteocephalid cestode, and an acanthocephalan were recovered from infected hosts. Except for the strigeoid trematode, which was only recorded in the rainforest, there was no ecological dichotomy in the distribution of the larval parasites recorded. Tree frogs from the rainforest only served as second intermediate hosts for the strigeoid trematode. The two nematode larvae (type I and type II) found in the body cavity of the infected host are believed to use them as paratenic hosts. Tree frogs were the predominant intermediate hosts of the proteocephalid cestode larvae in the rainforest, while Ptychadena and Phrynobatrachus spp. served this function in the derived savanna. The occurrence of cystacanths in the anurans from both biotopes confirms their known role as paratenic host for acanthocephalans. Afrixalus dorsalis is a new host record for the ascaridoid nematode while the finding of the strigeoid trematode, the proteocephalid cestode larvae and acanthocephalan cystacanths in the anurans investigated represents new geographical records.

Parasitic infections of anurans from a freshwater creek community in Delta State, Niger Delta of Nigeria

“…in Nigeria is the lizard Agama agama reported by Adeoye and Ogunbanwo (2007). As already reported by Imasuen et al (2012b), the larval ascaridida found in this study, whether in the body cavity or in the stomach mucosa, most probably use the infected anurans as transport hosts.…”

Larval strigeoid trematodes in anurans from southern Nigeria

“…Examination of anurans from a monoculture plantation (Oil Palm) and those collected from a derived savannah location has revealed that anurans in these locations also habour strigeiod trematode larvae. Some of the larvae recovered were encysted like those reported by Imasuen et al (2012) while others were recovered unencysted in the body cavity and lungs, respectively. In this paper, we report the different strigeoid trematode larvae infecting anurans collected from a monoculture plantation located in a rainforest environment and a derived savannah location in southern Nigeria.…”

“…The anurans (tree frogs) examined for strigeoid trematode larvae at the Okomu National Park as reported by Imasuen et al (2012) are shown in Table 1. In this location, six tree frogs (Afrixalus dorsalis, Afrixalus cog.…”

“…In members of the genera Strigea and Alaria, an additional stage, the mesocercaria, may be interposed between the cercaria and the metacercaria and these species therefore have a four host life cycle (Stunkard, 1973). In a recent paper, Imasuen et al (2012) reported the occurrence of an unidentified encysted strigeoid metacercariae in the body cavity of several tree frogs from a protected forest habitat in southern Nigeria. Apart from the strigeoid trematode metacercariae, the authors also reported other larval helminths, which use amphibians either as intermediate or paratenic hosts (Imasuen et al, 2012).…”

“…In a recent paper, Imasuen et al (2012) reported the occurrence of an unidentified encysted strigeoid metacercariae in the body cavity of several tree frogs from a protected forest habitat in southern Nigeria. Apart from the strigeoid trematode metacercariae, the authors also reported other larval helminths, which use amphibians either as intermediate or paratenic hosts (Imasuen et al, 2012). Examination of anurans from a monoculture plantation (Oil Palm) and those collected from a derived savannah location has revealed that anurans in these locations also habour strigeiod trematode larvae.…”