20

Nov

Grunters can be flippers

Grunters are a widespread group of fishes in freshwater, estuarine and marine habitats mostly found in tropical Australia, Papua New Guinea and the tropical Pacific islands. Last year coal grunters (attire: black body, gold flecks) were observed moving and flipping objects in search of prey. Obviously sequels rarely live up to the hype of the original, so in this case scientists have enlisted two fresh heroes for the full bill.

Coal grunters cruising loosely in a shoal (Photo: B. C. Ebner)

Hot off the press, juveniles of the silver grunter (dressed in horizontal stripes) and the barred grunter (sporting vertical bands) display dexterity rarely seen in freshwater fishes. Several individuals of these species were observed in north Queensland rolling, shifting and lifting stones, leaves and wood to get at prey that hides on the underside of these objects during the day.

A juvenile silver grunter. (Photos: B. C. Ebner)
A group of barred grunter juveniles.

 

 

 

 

 

 

 

 

Scientist Stuart Welsh, whilst visiting TropWATER recently from the West Virginia Cooperative Fish and Wildlife Research Unit, declared that ‘These recent findings of grunters flipping stuff bares similarity to the feeding biology of logperches in streams of the USA’. Dr Welsh was out here teaching Ebner some snorkel based fish observation skills. To access the GIF files of this behaviour go check out the links in the respective papers:

Ebner, B. C., Donaldson, J. A., & Starrs, D. (2019). Juvenile silver grunter Mesopristes argenteus shift benthic objects to access food. Journal of Fish Biology 95, 974–978.

Ebner, B. C., Donaldson, J. D., & Starrs, D. (2019). Barred grunters shift objects to access benthic macroinvertebrates in a crater lake. Food Webs e00119 (5 pages)

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