Acute, chronic and reproductive toxicity of complex cyanobacterial blooms in Daphnia magna and the role of microcystins

AbstractThe microsporidian parasite Hamiltosporidium tvaerminnensis can infect Daphnia magna both horizontally (through environmental spores) and vertically (through parthenogenetic and sexually produced eggs). The spores of H. tvaerminnensis come in three distinguishable morphologies, which are thought to have different roles in the transmission of the parasite. In this study, we examined the role of the two most common spore morphologies (i.e. oval-shaped spores and pear-shaped spores) in horizontal transmission of H. tvaerminnensis. To this end, we infected hosts with solutions consisting of either mostly oval- or mostly pear-shaped spores, and quantified infection rates, parasite-induced host mortality and mean number of parasite spores produced per host. We found that spore morphology by itself did not influence infection rates and parasite-induced host mortality. Instead, host clone and parasite isolate interacted with spore morphology in shaping infection outcome and mortality. Thus, there appear to be strong genotype-by-genotype (G × G) interactions in this system. While there is no dispute that H. tvaerminnensis can transmit both vertically and horizontally, our findings do not support theoretical predictions that different spore morphologies hold different roles in horizontal transmission of H. tvaerminnensis.

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In vivo exposure to codeine induces reproductive toxicity: role of HER2 and p53/Bcl-2 signaling pathway

Heliyon ◽

10.1016/j.heliyon.2020.e05589 ◽

2020 ◽

Vol 6 (11) ◽

pp. e05589

Author(s):

A.F. Ajayi ◽

R.E. Akhigbe

Keyword(s):

Signaling Pathway ◽

Reproductive Toxicity

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Role of curcumin on chloroquine phosphate-induced reproductive toxicity

Drug and Chemical Toxicology ◽

10.3109/01480545.2011.589846 ◽

2012 ◽

Vol 35 (2) ◽

pp. 184-191 ◽

Cited By ~ 3

Author(s):

Ketaki R. Desai ◽

Jignasa J. Dattani ◽

Dhrupad K. Rajput ◽

Nilofar Moid ◽

Hyacinth N. Highland ◽

...

Keyword(s):

Reproductive Toxicity

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The role of fish in cyanobacterial blooms in Australia

Marine and Freshwater Research ◽

10.1071/mf9940905 ◽

1994 ◽

Vol 45 (5) ◽

pp. 905 ◽

Cited By ~ 15

Author(s):

PC Gehrke ◽

JH Harris

Keyword(s):

Freshwater Fish ◽

Trophic Interactions ◽

Cyanobacterial Blooms ◽

Native Fish ◽

Fish Stocks ◽

Natural Predator ◽

Fish Grazing ◽

Zooplankton Communities ◽

Alternative Solutions

Potential pathways for interaction between fish and cyanobacteria include fish grazing directly on cyanobacteria, fish preying on grazers of cyanobacteria, fish supplying nutrients through excretion, fish providing nutrients by resuspending sediments, and fish altering the availability of nutrients and light by damaging macrophytes. The dominant interactions in Australia are likely to be through pathways that increase the availability of nutrients at the bottom of the food web. Carp probably contribute to these pathways more than do other species by excreting nutrients, resuspending sediments and damaging macrophytes. Further research, on both alien and native fish species, is needed to quantify these processes. Grazing of cyanobacteria by fish is probably trivial because freshwater fish in Australia lack mechanisms to process cyanobacterial cells effectively. Trophic interactions between planktivorous fish, zooplankton and cyanobacteria require closer study to assess the potential for preventing cyanobacterial blooms by manipulating natural predator communities in Australia. However, the need to protect and strengthen native fish stocks precludes removal of native fish to reduce predation pressure on zooplankton communities. Alternative solutions that combine control of nutrients entering waterways and removal of carp have a higher likelihood of success.

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