Female fish that avoid mating with related species also shun some of their own

Date:

March 6, 2015

Source:

University of Illinois at Urbana-Champaign

Summary:

A new study offers insight into a process that could lead one species to diverge into two, researchers report. The study found that female killifish that avoid mating with males of a closely related species also are less likely to mate with males of their own species -- if those males come from an unfamiliar population.

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How One Weird Fish Jumps on Land

Strong leaping skills help a bizarre hermaphrodite fish live out of water for weeks at a time, new research shows.

The mangrove rivulus is a small tropical killifish that's found in swamps from Florida to Brazil, measuring no bigger than 3 inches (75 millimeters) long. Its dull appearance hides the fact that the fish is sort of a freak; it can survive on land for as long as two months and it has a strange sex life.

All members of the species are hermaphrodites (though a few males have been found), and they are the only known vertebrate, or animal with a backbone, to reproduce by self-fertilizing. Researchers discovered in 2007 that the fish can live on land for up to 66 days straight, crowding inside the damp tunnels of rotting mangrove logs and even inside old beer cans and coconut shells, Reuters reported at the time.

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Gulf Killifish Show Defects from Crude Oil Exposure

Jacqueline Conciatore, National Science Foundation
Date: 22 May 2013 Time: 09:31 PM ET
This Research in Action article was provided to LiveScience in partnership with the National Science Foundation.

New research shows that a signal species of fish in the Gulf Coast was harmed by exposure to crude oil toxins nearly a year after the 2010 Deepwater Horizon oil rig disaster occurred.

Using wire minnow traps, the researchers — from Louisiana State University, Clemson University and the University of California, Davis — collected Gulf killifish (Fundulus grandis) from oil-contaminated Grande Terre, La., and from reference sites in Mississippi and Alabama — sites that were not contaminated — during four trips between May 2010 and August 2011.

Analyses of the Grande Terre fish revealed abnormal gene expression in their liver and gill tissues. Furthermore, embryos that were exposed in the lab to Grande Terre sediments failed to hatch or were smaller and showed "poor vigor." The embryos also suffered edema, or excessive fluid buildup, around the heart and in the yolk sac.


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