Biology

Fish-catching praying mantis surprises scientists

Fish-catching praying mantis s...
The fish-eating praying mantis chows down on its catch
The fish-eating praying mantis chows down on its catch
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The praying mantis paid daily visits to a plant-pot water feature, where it would perch on the leaves of water lilies and water cabbage plants floating on the surface
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The praying mantis paid daily visits to a plant-pot water feature, where it would perch on the leaves of water lilies and water cabbage plants floating on the surface
The water garden, with the praying mantis visible at right
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The water garden, with the praying mantis visible at right
The fish-eating praying mantis chows down on its catch
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The fish-eating praying mantis chows down on its catch

Praying mantises may not actually pray, but they do prey heavily on their fellow insects, along with other small land animals. Now, however, for the first time, scientists have documented a praying mantis catching and eating fish.

Measuring 5.6 cm in length (2.2 inches), the male Hierodula tenuidentata mantis was observed last March in a rooftop garden located in Karnataka, India.

Over five consecutive days, it paid daily visits to a plant-pot water feature in that garden, where it would perch on the leaves of water lilies and water cabbage plants floating on the surface. It proceeded to reach down into the water, grabbing and eating at least two guppies every day, for a total of nine fish over the five-day period.

For one thing, such behaviour is interesting simply because of its novelty.

The praying mantis paid daily visits to a plant-pot water feature, where it would perch on the leaves of water lilies and water cabbage plants floating on the surface
The praying mantis paid daily visits to a plant-pot water feature, where it would perch on the leaves of water lilies and water cabbage plants floating on the surface

Praying mantises have previously been claimed to catch small creatures such as birds, lizards, frogs, newts, mice, snakes and turtles. Not all of these attacks have been scientifically validated, however, or they were induced by people in a controlled setting. By contrast, this is reportedly the first scientific report of a fishing mantis, and of one that did so without any human intervention.

More notably, the observation confirms the theory that a single invertebrate species can impact a whole ecosystem, as the praying mantis was eating guppies that in turn fed on aquatic insects. It additionally shows that mantises have unexpectedly good night vision, as all of the catches took place either at sunset or late at night.

What's more, the fact that the insect kept returning to the same spot over multiple days may indicate that mantises possess sophisticated cognitive skills, including the ability to learn from their experiences.

The research was carried out by Roberto Battiston of Italy's Musei del Canal di Brenta, Rajesh Puttaswamaiah of Bat Conservation India Trust, and Indian environmental conservationist Nayak Manjunath. It is described in a paper that was recently published in the Journal of Orthoptera Research.

Source: Pensoft Publishers via EurekAlert

3 comments
Wombat56
Considering that they're cold blooded and don't expend much energy by running about, I'm surprised that a mantis would need so much food in a comparatively short period.
Lamar Havard
I’ve seen this myself...these ‘scientists’ must not get out much.
Towerman
never seen it myself, interesting ! Always wondered what these little alien insects thinking when staring back at me.