A study examines whether carp can disperse their eggs via the digestive system of ducks. Fish have colonized water bodies across the globe, but it remains unclear how fish eggs reach isolated areas. To determine whether fish eggs can survive gut passage after being ingested by a bird and dispersed through feces, Orsolya Vincze and colleagues fed live carp eggs to eight captive mallard ducks. The authors acquired the eggs from common carp and Prussian carp, which are both invasive species with wide geographic ranges. Ducks are known to play a key role in the dispersal of many aquatic and terrestrial plants. Each duck was fed approximately 500 common carp eggs and approximately 500 Prussian carp eggs. Six ducks passed live eggs in feces. However, only 0.2% of ingested eggs were recovered intact from fresh feces up to 24 hours after feeding. Of 18 eggs recovered, 12 eggs contained viable embryos, and one common carp and two Prussian carp hatched successfully. Passed eggs that did not hatch died of fungal infection. The findings suggest that avian gut passage may play an important role in the long-distance dispersal of fish. Furthermore, dispersal of a single Prussian carp egg could establish a new population, given Prussian carp's potential to reproduce asexually, according to the authors.
Article #20-04805: "Experimental evidence of dispersal of invasive cyprinid eggs inside migratory waterfowl," by Ádám Lovas-Kiss et al.
MEDIA CONTACT: Ádám Lovas-Kiss, Wetland Ecology Research Group, Centre for Ecological Research, Debrecen, HUNGARY; tel: 0036-303-589-501; email:
Proceedings of the National Academy of Sciences