Explosive networking: The role of adaptive host radiations and ecological opportunity in a species‐rich host–parasite assembly

Abstract

Many species‐rich ecological communities emerge from adaptive radiation events. Yet the effects of adaptive radiation on community assembly remain poorly understood. Here, we explore the well‐documented radiations of African cichlid fishes and their interactions with the flatworm gill parasites Cichlidogyrus spp., including 10,529 reported infections and 477 different host–parasite combinations collected through a survey of peer‐reviewed literature. We assess how evolutionary, ecological, and morphological parameters determine host–parasite meta‐communities affected by adaptive radiation events through network metrics, host repertoire measures, and network link prediction. The hosts' evolutionary history mostly determined host repertoires of the parasites. Ecological and evolutionary parameters predicted host–parasite interactions. Generally, ecological opportunity and fitting have shaped cichlid‐Cichlidogyrus meta‐communities suggesting an invasive potential for hosts used in aquaculture. Meta‐communities affected by adaptive radiations are increasingly specialised with higher environmental stability. These trends should be verified across other systems to infer generalities in the evolution of species‐rich host–parasite networks.

A global review of problematic and pathogenic parasites of farmed tilapia

“…The gill‐infecting dactylogyrids of tilapia belong to Cichlidogyrus and Scutogyrus , and are characterised by a haptor bearing two pairs of anchors (whereas there is only one pair in gyrodactylids), a V‐shaped ventral transversal bar (in contrast to the ventral bar of members of Gyrodactylus , which possesses a membrane), a dorsal transversal bar with two auricles (in contrast to the simple dorsal bar in Gyrodactylus ) and seven pairs of marginal hooks (compared to 8 in Gyrodactylus ; Figure 9c–e, g). Cruz‐Laufer et al 289 identified that numerous gill‐infecting species have been co‐introduced outside continental Africa and are reported in the peer‐reviewed literature from Latin America, Asia, Australia or Madagascar. Five of these have been mentioned as co‐introduced in at least 15 publications.…”

“…tiberianus Paperna, 1960, which normally infect coptodonine tilapia occur on other tilapia and cichlids in their introduced range. These changes in host range can occur wherever tilapias are translocated, because ecological opportunity and host phylogenetic history determine the host range 289,344 . Introduced populations can be free of gill monogeneans, such as O .…”

“…These changes in host range can occur wherever tilapias are translocated, because ecological opportunity and host phylogenetic history determine the host range. 289,344 Introduced populations can be free of gill monogeneans, such as O. mossambicus in New Caledonia, because of genetic bottlenecks, salinity changes, single introduction events or treatment of translocated stock. 345 Tilapia-infecting monogeneans may become the most widespread tropical freshwater fish parasites, given the ubiquity of tilapia and the prevalence of their monogeneans.…”

All Quiet on the Western Front? The evolutionary history of monogeneans (Dactylogyridae:Cichlidogyrus, Onchobdella) infecting a West and Central African tribe of cichlid fishes (Chromidotilapiini)

“…intra-host speciation) and expansion of host repertoires (e.g. host switches) [8]; this fluctuation is also considered a likely occurrence in monogenean flatworms [6, 10]. However, identifying patterns for intra-host speciation or host switching in the absence of DNA sequence data poses a major challenge.…”

“…African cichlids are well-known for their spectacular adaptive radiations [108,114,118], and their role as model for evolutionary research [114]. The cichlid- Cichlidogyrus species network is the most extensively described host-parasite network from a species-rich host radiation [10]. A recent meta-analysis counted 477 different host-parasite combinations in this study system [10].…”