There is now proof that birds do carry killifish eggs and distribute them to other waters.

     An article in Hakai Magazine, a coastal science and societies magazine, in 2019 details an fascinating study where swans ingested killifish eggs in a mix of corn and later the eggs were found still fully viable in the droppings of the birds. 

     According to the article “German naturalist Carl Christian Gmelin posited that ducks spread fish to distant waters by carrying fish eggs stuck to their beaks.”  and “British naturalist Alfred Russel Wallace wrote that freshwater fish eggs being carried by birds could be one of several means by which the same fish species wind up in distinct rivers.”

     Apparently two types of killifish eggs were tested in a study by Giliandro G. Silva, a doctoral student at the University of the Sinos Valley in Brazil.   Of five eggs found in the droppings of the swan, one hatched into a viable fry, essentially proving this is a way killifish distribution can be spread.

               Geo-historically, this study could lead to speciation over thousands of years.

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