More Like this

1. Impact of dispersant on early life stages of the water flea Daphnia magna and the eastern oyster Crassostrea virginica

   https://doi.org/10.1002/jat.3494  

   Salehi, Maryam ; Rodriguez, Rachel ; Boettcher, Anne ; Powers, Sean ; Geitner, Nick ; Ladner, David A. ; Rikard, Scott ; Whelton, Andrew J. ( December 2017 , Journal of Applied Toxicology)
2. Evaluating the potential role of predation by native fish regulating the abundance of invasive spiny water flea

   https://doi.org/10.1080/02705060.2023.2187470  

   Martin, Benjamin E. ; Mrnak, Joseph T. ; Vander Zanden, M. Jake ( July 2023 , Journal of Freshwater Ecology)
3. Immune defense mechanisms against a systemic bacterial infection in the cat flea (Ctenocephalides felis)

   https://doi.org/10.1016/j.jip.2022.107850  

   Muñoz, Melanie ; Lin, Nathan ; Lin, Rickie ; King, Brannen ; Brown, Lisa D. ( November 2022 , Journal of Invertebrate Pathology)
4. Rapid range expansion of an invasive predatory snail, Oxychilus alliarius (Miller 1822), and its impact on endemic Hawaiian land snails

   Curry, Patrick A. ; Yeung, Norine W. ; Hayes, Kenneth A. ; Meyer, Wallace M. ; Taylor, Andrew D. ; Cowie, Robert H. ( April 2016 , Biological invasions)

   The invasive predatory snail Oxychilus alliarius is established in many locations around the world including the Hawaiian Islands. Anecdotal evidence suggests that it negatively impacts indigenous snail species where it has been introduced, although such impacts have not been quantified. On the Hawaiian island of Oahu, we tested the hypothesis that indigenous snails, especially small ones (<3 mm in maximum dimension), would be less abundant where O. alliarius had established populations. Fifty-six sites at four locations were repeatedly surveyed for snails between July 2010 and April 2011. The composition of the snail fauna differed in relation to O. alliarius abundance, as well as location. Notably, the abundance of the native Succineidae was negatively related with that of O. alliarius. The abundance of the native Tornatellidinae was significantly related to O. alliarius abundance but this relationship differed among locations, negative at one site and positive at the other three; these snails do not appear to be negatively impacted by O. alliarius. We also monitored the rate of expansion of a newly introduced O. alliarius population along a transect through a bog on the summit of Oahu’s highest mountain, Mt. Kaala. The population’s range expanded linearly between 2008 and 2011 by approximately 300 m (mean c. 113 m/year). This is the first attempt to quantify the impacts of O. alliarius on threatened native island snail faunas. While the results are complex, its high abundance, rapid rate of population expansion and probable negative impacts on certain species caution vigilance in preventing its introduction and spread to as yet uninvaded islands and locations. 

   more » « less
5. Variation in Immune Defense Shapes Disease Outcomes in Laboratory and Wild Daphnia

   https://doi.org/10.1093/icb/icz079  

   Stewart Merrill, Tara E. ; Hall, Spencer R. ; Merrill, Loren ; Cáceres, Carla E. ( May 2019 , Integrative and Comparative Biology)

   Host susceptibility may be critical for the spread of infectious disease, and understanding its basis is a goal of ecological immunology. Here, we employed a series of mechanistic tests to evaluate four factors commonly assumed to influence host susceptibility: parasite exposure, barriers to infection, immune responses, and body size. We tested these factors in an aquatic host–parasite system (Daphnia dentifera and the fungal parasite, Metschnikowia bicuspidata) using both laboratory-reared and field-collected hosts. We found support for each factor as a driver of infection. Elevated parasite exposure, which occurs through consumption of infectious fungal spores, increased a host’s probability of infection. The host’s gut epithelium functioned as a barrier to infection, but in the opposite manner from which we predicted: thinner anterior gut epithelia were more resistant to infectious spores than thick epithelia. This relationship may be mediated by structural attributes associated with epithelial cell height. Fungal spores that breached the host’s gut barrier elicited an intensity-dependent hemocyte response that decreased the probability of infection for some Daphnia. Although larger body sizes were associated with increased levels of spore ingestion, larger hosts also had lower frequencies of parasite attack, less penetrable gut barriers, and stronger hemocyte responses. After investigating which mechanisms underlie host susceptibility, we asked: do these four factors contribute equally or asymmetrically to the outcome of infection? An information-theoretic approach revealed that host immune defenses (barriers and immune responses) played the strongest roles in mediating infection outcomes. These two immunological traits may be valuable metrics for linking host susceptibility to the spread of infectious disease.

    

   more » « less