Comparing cestode infections and their consequences for host fitness in two sexual branchiopods: alien Artemia franciscana and native A. salina from mixed-populations
- Subject Areas
- Biodiversity, Ecology, Parasitology, Zoology
- Cestodes, sexual Artemia, syntopic populations, invasive species, host impact, coevolution, Mediterranean salterns
- © 2015 Redón et al.
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2015. Comparing cestode infections and their consequences for host fitness in two sexual branchiopods: alien Artemia franciscana and native A. salina from mixed-populations. PeerJ PrePrints 3:e975v1 https://doi.org/10.7287/peerj.preprints.975v1
The American brine shrimp Artemia franciscana is invasive in the Mediterranean region where it has displaced native species (the sexual A. salina, and the clonal A. parthenogenetica) from many salt pond complexes. Artemia populations are parasitized by numerous avian cestodes whose effects have been studied in native species. We present a study from the Ebro Delta salterns (NE Spain), in a salt pond where both A. franciscana and native A. salina populations coexist, providing a unique opportunity to compare the parasite loads of the two sexual species in syntopy. The native species had consistently higher infection parameters, largely because the dominant cestode in A. salina adults and juveniles (Flamingolepis liguloides) was much rarer in A. franciscana. The most abundant cestodes in the alien species were Eurycestus avoceti (in adults) and Flamingolepis flamingo (in juveniles). The abundance of E. avoceti and F. liguloides was higher in the A. franciscana population syntopic with A. salina than in a monospecific population sampled at the same time in another pond where the native brine shrimp was absent, possibly because the native shrimp provides a better reservoir for parasite circulation. Infection by cestodes caused red colouration in adult and juvenile A. salina, and also led to castration in a high proportion of adult females. Both these effects were significantly stronger in the native host than in A. franciscana with the same parasite loads. However, for the first time, significant castration effects (for E. avoceti and F. liguloides) and colour change (for six cestode species) were observed in infected A. franciscana. Avian cestodes are likely to help A. franciscana outcompete native species. At the same time, they are likely to reduce the production of A. franciscana cysts in areas where they are harvested commercially.
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Proportion of juvenile brine shrimps in each sample examined at pond CX (A) and pond 4 (B)
Proportions are shown for both Artemia species when present.
Brine shrimp Artemia individuals of different colouration
Examples highlighted with arrows from left to right are: light-red, dark-red, and not-red.
General aspect of adult brine shrimp females with different reproductive status. infected by larval cestodes (indicated by arrows)
(A) ovigerous, (B) castrated. Females are infected by larval cestodes (indicated by arrows).
Temporal dynamics of cestode infection in adult A. franciscana from pond CX and proportion of this species in the community, through an annual cycle (January 2009-January 2010)
Bars show 95% confidence intervals.
Comparative data on total cestode prevalence in both sexual Artemia spp
Data for the native A. salina (AS) and the invader A. franciscana (AF) when coexisting (mixed-populations, present study) and from monospecific populations or those with small numbers of diploid A. parthenogenetica (PD). When many data are available (e.g. for several months, years), the mean value of total prevalence and the range (in parentheses) are given.