Ocean acidification impairs shrimp’s ability to change sex
A team of researchers from the Stazione Zoologica Anton Dohrn have found that the Hippolyte inermis shrimp, when raised on marine algae grown in acidic water, do not undergo the necessary sex change that is pertinent to their reproductive cycle.
As published in PLOS ONE, H. inermis shrimp have two breeding seasons each year. Some males born in the spring rapidly develop into females with eggs in order to breed come fall. This sex change happens when male endocrine cells die as a result of the shrimp eating a bioactive compound produced by micro algae (Cocconeis scutellum parva) in the springtime.
To come to their conclusion, researchers fed shrimp algae grown in waters with a pH 8.2, which represents current ocean conditions, as well as algae grown in waters with a pH 7.7, which represents predicted ocean acidity by 2100.
The growth of algae correlated with the amount of carbon dioxide dissolved within the water. The team saw that four times more algal cells were grown in acidic water than the current ocean acidity, which appears to be good news — algae thrives in acidic oceans.
However, the H. inermis shrimp raised on algae grown at the normal pH were 63% female, whereas those that ate algae from more acidic waters were only 36% female, thus indicating that the algal compound necessary to trigger the sex change was either not produced or not effective.
If the oceans continue to acidify as a result of climate change, this species of shrimp, among other marine species, could see their breeding cycle damaged.
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Image Credit: Valerio Zupo, Friedrich Jüttner, Chingoileima Maibam, Emanuela Butera, Judith F. Blom