Parasites of freshwater fishes and the Great American Biotic Interchange: a bridge too far?

Abstract

We examine the extent to which adult helminths of freshwater fishes have been part of the Great American Biotic Interchange (GABI), by integrating information in published studies and new data from Panama with fish biogeography and Earth history of Middle America. The review illustrates the following: (1) the helminth fauna south of the Trans-Mexican Volcanic Belt, and especially south of the Isthmus of Tehuantepec, shows strong Neotropical affinities; (2) host-parasite associations follow principles of the 'biogeographic core fauna' in which host-lineage specificity is pronounced; (3) phylogenetic analysis of the widespread freshwater trematode family Allocreadiidae reveals a complex history of host-shifting and co-diversification involving mainly cyprinodontiforms and characids; (4) allocreadiids, monogeneans and spiruridan nematodes of Middle American cyprinodontiforms may provide clues to the evolutionary history of their hosts; and (5) phylogenetic analyses of cryptogonimid trematodes may reveal whether or how cichlids interacted with marine or brackish-water environments during their colonization history. The review shows that 'interchange' is limited and asymmetrical, but simple narratives of northward isthmian dispersal will likely prove inadequate to explain the historical biogeography of many host-parasite associations in tropical Middle America, particularly those involving poeciliids. Finally, our study highlights the urgent need for targeted survey work across Middle America, focused sampling in river drainages of Colombia and Venezuela, and deeper strategic sampling in other parts of South America, in order to develop and test robust hypotheses about fish-parasite associations in Middle America.

Incipient genetic divergence or cryptic speciation? Procamallanus (Nematoda) in freshwater fishes (Astyanax)

“…Individuals of Astyanax spp. are infected by a highly host-specific nematode, Procamallanus (Spirocamallanus) neocaballeroi across Mexico; this parasite species has only been found, as adult, parasitizing the intestine of some species of Astyanax in Middle America (Choudhury et al, 2017). The life cycle of P. (S.) neocaballeroi involves a copepod as intermediate host, and a fish as a definitive host, where the parasite matures and reproduces (Moravec & Vargas-Vázquez, 1996).…”

A new species of Wallinia Pearse, 1920 (Digenea: Allocreadiidae) collected from Astyanax fasciatus (Cuvier, 1819) and A. lacustris Lucena and Soares, 2016 (Characiformes: Characidae) in Brazil based on morphology and DNA sequences

“…Pérez-Ponce de León et al (2007 showed that the genus Wallinia represents bona fide allocreadiids and not macroderoidids. The current geographic distribution of most members of the genus Wallinia is largely restricted to Middle America, though W. valenciae was described as a parasite of G. valenciae in Lake Valencia, Venezuela (Pearse 1920 Choudhury et al 2017). Wallinia brasiliensis n. sp.…”

“…Phyllodistomum angulatum (Linstow, 1907) and Prosthenhystera obesa (Diesing, 1850) (AY222206) were used as the outgroup for rooting the tree. Previous phylogenetic analyses have demonstrated that callodistomids (e.g., P. obesa) and gorgoderids (e.g., P. angulatum) are sister taxa of Allocreadiidae and represent the best choice as outgroups for phylogenetic analyses (see Choudhury et al, 2017;Pérez-Ponce de León et al, 2015). Sequences were aligned using the MUSCLE software (Edgar 2004), implemented in the Geneious Server database, version 7.1.3, using default settings (Kearse et al 2012) with the extremes of the alignment trimmed.…”

A new species of Creptotrematina (Trematoda: Allocreadiidae) from characid fishes of Brazil: morphological and molecular data

“…Prosthenhystera obesa (Diiesing, 1850) (AY222206) was used as an outgroup for rooting the trees. Callodistomidae are the sister group of Allocreadiidae (Pérez-Ponce de León et al ., 2015; Choudhury et al ., 2017). The final alignment was 1002 bp long to the 28S rRNA gene and 491 bp to ITS2.…”