Fish ID from Nova Scotia

Joel from Nova Scotia caught some small fish and asked us what species they were.  image (1) image

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Any guesses before I answer Joel?


OK Joel, thanks for the question.  This species is known as the mummichog.  It’s a member of the topminnow or killifish family.  It’s scientific name is Fundulus heteroclitus.  They are small fish usually less than 5 inches and can show up with gorgeous white and yellow spots over a green, tan body. The females are typically larger, paler, and drabber.  The males can have vivid coloration especially in the breeding season.

Mummichog live in shallow marsh habitats. They are extremely abundant in these marsh areas of the western Atlantic.  They are very hardy and can survive in difficult conditions with high temperatures, pollution, or low oxygen levels.  They will eat just about anything that can fit in their mouth, dead or alive.  Being small, they are a very important prey species to fish, birds, turtles, and crabs.

Their eggs are very sticky and attach to the bottom in shallow areas, particularly with marsh vegetation.

Developing fish eggs

Because the mummichog is quite vigorous and are tough survivors, they are very important test organisms for scientists.  Scientists learn a lot about the effects of pollution from the mummichog.  One of my colleagues is learning how higher levels of CO2 from global pollution might affect how ‘ear bones’ grow and develop in fish.  These ear bones are critical for balance and swimming for fishes.  Can you imagine if fish couldn’t swim anymore?




About rw

A marine biologist in the middle of the western Atlantic

Posted on July 16, 2014, in Fishery Species. Bookmark the permalink. 1 Comment.

  1. Reblogged this on Fin Flapper and commented:
    Great ID work! Killifish are a very interesting family. A challenge to keep in captivity, and often quite beautiful!

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