Daphnia parasites

Daphnia Parasites

Below are pictures of some parasites we commonly find infecting Daphnia in lakes in Southwest Michigan, near the Kellogg Biological Station. All pictures taken by Meghan Duffy, Alan Tessier, and Spencer Hall. More pictures will be added as they are taken. For more pictures of Daphnia parasites, consult Pieter Johnson's webpage. Dieter Ebert's page has a wealth of information about Daphnia parasites, but currently does not have pictures of infected Daphnia.

People wishing to use the images on this page for educational purposes may do so, provided that they reference the page. Anyone else should e-mail (mduffy2 at wisc.edu) first. Thank you!

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Bacteria
Fungi
Microsporidia

Bacteria:

Pasteuria ramosa
This is probably the best-studied of the Daphnia parasites, due to the research carried out in the lab of Dr. Dieter Ebert.

Above: Daphnia dentifera infected with Pasteuria.

Spirobacillus cienkowskii
This parasite is most commonly observed in Daphnia dentifera, and is also common in Daphnia pulicaria and D. retrocurva. We have also seen it in other Daphnia and many other zooplankton taxa (e.g., Ceriodaphnia, Diaphanosoma, Scapholebris). It is one of the most common parasites of D. dentifera in our lake populations.

Above: Daphnia dentifera infected with Spirobacillus (right); uninfected D. dentifera (left) shown for reference.

Above: Scanning electron micrographs of Spirobacillus; Below: Transmission electron micrographs of Spirobacillus.

Fungi:

Metschnikowia bicuspidata

We see this parasite most often in Daphnia dentifera and Daphnia retrocurva. Metschnikowia is one of the most common parasites of D. dentifera. It can also infect other species of Daphnia and other Cladocera.

Above: Uninfected and Metschnikowia-infected Daphnia dentifera; Below: Metschnikowia ascospores in the head of a D. dentifera.

Above: SEM of Metschnikowia ascospores

Brood parasites

We frequently see Daphnia infected with brood-parasitic fungi. The Daphnia dentifera on the left in the picture below is infected with a brood parasite; the animal on the right has a healthy egg for reference.

Other fungi

Above: D. dentifera infected with a fungus.

Microsporidia:

Gurleya

We most commonly see Gurleya in D. pulicaria, although it also infects other Daphnia species in our lake populations. Below: Gurleya-infected (on left in both pictures) and uninfected (on right in both picture) Daphnia pulicaria.

Larssonia

Above: Larssonia-infected (on left in both pictures) and uninfected (on right in both pictures) Daphnia dentifera.