Diversity of host-parasite meta-communities
We investigated the patterns of host-parasite interaction of African
cichlid fishes and their gill parasites belonging toCichlidogyrus , a proposed model system for macroevolutionary
research (Pariselle et al. 2003; Vanhove et al. 2016). The
size of this species network (9901 infections, 473 interactions) is
comparable to widely used host-parasite datasets in terms of species
richness, e.g. the Global Mammal Parasite Database (GMPD) (Nunn &
Altizer 2005), the Sevillata interaction network (Dallas & Presley
2014), and other fish-parasite (Lima Jr et al. 2012; Bellayet al. 2015) and plant-arthropod systems (López-Carreteroet al. 2014; de Araújo et al. 2020; Oliveira et al.2020; de Araújo & Maia 2021). Additionally, the dataset here offers the
opportunity to investigate the effects of evolutionary mechanisms,
especially adaptive radiation events, on species interactions. This
system is also the first to encompass closely related parasite species
infecting hosts that are a model system for speciation research
(Seehausen 2006). Therefore, the cichlid-Cichlidogyrus dataset
could be a valuable asset for studies on network ecology and ecological
parasitology.
Some of the host-parasite meta-communities inferred from this network
(Fig. 2b, c) could be of particular interest for future studies due to
their sample size and species richness. Cichlid-Cichlidogyrusinteractions are diverse regarding their meta-community structures
(Appendix S1.2). For instance, only one recorded monogenean species
infects deepwater cichlids from the tribe Bathybatini (Kmentová et
al. 2016) (not in Fig. 2c as less than 10 species) whereas 27 host
species in the LV community share multiple parasite species (Fig.
2b, Appendix S1.2). Some communities show a reversed specialisation
asymmetry (Appendix S1.2) with the host communities being more diverse
than their parasites unlike most host-parasite (Vázquez et al.2005) or mutualistic (Thébault & Fontaine 2008) networks possibly due
to the young age of the host radiation (see Appendix S1.2). Furthermore,
anthropogenic introductions have expanded the realised host repertoire
of some meta-communities (Appendix S1.2) albeit with little changes to
their network structure (Fig. 3). The diversity of meta-communities
could lay the ground for future comparative studies, e.g. on the
communities from the East African lakes mirroring the research conducted
on cichlids from the same region (e.g. Duponchelle et al. 2008).