Five species of Enterogyrus were found from the stomach of three species of Cichlidae, C. rendalli, O. mossambicus and T. sparrmanii, collected from four localities across South Africa (Fig. 1, Table 1). Measurements of anchors and male copulatory organs of all species are given in the supplemantary Table 1. Enterogyrus malmbergi was indentified from new hosts O. mossambicus and T. sparrmanii and this finding represents the first report of this species in South Africa. Enterogyrus coronatus was found in C. rendalli and T. sparrmanii from three localities. A new host, T. sparrmanii, was reported to be parasitised by E. cichlidarum and E. multispiralis while E. mashegoi was found from its type host, O. mossambicus, from a new locality. Intensity of infections were generally low, with the highest being seven specimens of E. coronatus collected from C. rendalli (for more details see Table 1). Prevalence of the infection varied between species, hosts and sampled localities. The lowest prevalence of 10% was observed for E. coronatus from C. rendalli, while a prevalence of 100% was reported for E. coronatus and E. multispiralis from T. sparrmanii and E. coronatus from O. mossambicus.
In Africa, E. malmbergi was reported from Cameron only (Bilong Bilong, 1988). Additional records of the species from Mexico and China do not represent its natural distribution but they are related to the introduction of non native cichlids in those countries (Jiménez-Garcia et al. 2001; Zhang et al. 2019). Finding E. malmbergi from two new hosts in South Africa indicates that host specificity of Enterogyrus spp. might not be as strict as previously thought and only more intesive sampling of various host species of Cichlidae from different African countries will show the real picture of complete host-parasite interactions. The current knowledge regarding the distribution of the other two Enterogyrus species in Africa further supports this assumption. The first, E. coronatus, has been reported from three host species and three African countries, including South Africa (Pariselle et al. 1991; Mendlová et al. 2010; Madanire-Moyo and Avenant-Oldewage 2014). The present study increase the number of current known hosts for E. coronatus in Africa to five (and extra two more hosts, Coptodon zillii (Geavis, 1848) and O. niloticus, were reported in China (Zhang et al. 2019)). The discovery of this species from three distant localities within South Africa, clearly indicates that E. coronatus is widely distributed in the region and further reports from new hosts and new localities can be anticipated. Another species with an Africa wide distribution is E. cichlidarum. Apart from its original description from Israel (Paperna, 1963) and two records from, USA and Brazil (Noga and Flowers, 1995; Jeromino et al. 2010), it has been found in Egypt, Cameroon and South Africa (Billong Billong et al. 1996; Eisa et al. 2011; Olivier et al. 2011). The present report of a new host, T. sparrmanii, for E. cichlidarum increases the total number of hosts to seven.
Although only a the single specimen of E. cichlidarum was found in the present study, the spiral formula of 1–2–3 of the MCO as originally decribed by Paperna (1963) for this species, made its identification possible. The record of E. cichlidarum from O. niloticus in Cameroon (Bilong Bilong et al. 1989) certainty represents another species. However, the drawing of the original species description of E. cichlidarum is not of good quality, and thus warrants a redescribtion.
Enterogyrus mashegoi and E. multispiralis, two species recently described from Limpopo Province, South Africa (Luus-Powell et al, 2020), were also found during the present survey. Enterogyrus multispiralis was collected at the type locality but from a new host, T. sparrmanii while E. mashegoi was identified from its type host, O. mossambicus, but in a new locality, Mooi River, North West Province. However, the information on the distribution of these two species in the regions are still limited. The record here of E. mashegoi in a new locality and different river system, aproximately 650 km from the type locality, might be an indication that this species is widely distributes in southern Africa.
Not many studies on Enterogyrus spp. provide information about the prevalence and intensity of infection. Luus-Powell et al. (2020) presented cummulative indexes for two Enterogyrus species, E. mashegoi and E. multispiralis, with the highest intensity of infection being 17 specimens. In the present study, the highest number of Enterogyrus sp. per host, seven, was recorded for E. coronatus from C. rendalli from Doorndraai Dam, Limpopo Province. But generaly the intesity of infection for most of the Enterogyrus spp. were low, between 1 and 4.
The present study provides new information on host-parasite interaction by reporting several new hosts, new geographic and disctribution records for species of Enterogyrus. The present finding also clearly shows that even a small scale survey can contribute to the current knowledge of parasite diversity and distribution and there is still much to be discovered, especially in Africa.