Shark's sixth sense aid attacks from below

March 3, 2015 by Aaron Bryans, Science Network WA
Shark's sixth sense aid attacks from below
In addition to dorsal and ventral electrosensory pores, wobbegong and angel sharks posses a rare hyoid cluster that the scientists believe assists in predator detection. Credit: Richard Ling

Wobbegong (Orectolobus maculatus) and angel sharks (Squatina australis) have evolved unique electrosensory pores that aid attacks on unsuspecting prey from beneath, according to a recent study.

The study, involving UWA Oceans Institute researchers Channing Egeberg and Dr Ryan Kempster, compared and analysed the distribution and abundance of electrosensory pores in both spotted wobbegong and Australian angel sharks to determine their importance.

They found both feature large clusters of pores both dorsally and ventrally, aiding their benthic lifestyle and ambush hunting style.

"Both species will sit motionless on the seafloor and wait for unsuspecting prey to pass over their head, at which point they strike with incredible speed," Ms Egeberg says.

"We looked at their sensory biology to see if electroreception was being used to facilitate this type of hunting behaviour.

"We found that both species have independently evolved a similarly unique distribution of electrosensory pores, unlike any other , that would certainly assist in their ambush feeding strategy."

Most sharks possess electroreceptor clusters that are dependant on their method of hunting.

Electroreceptor cluster key to hunting

"The electrosensory system of sharks has evolved to operate efficiently under the environmental conditions of the particular habitat in which a species lives," Ms Egeberg says.

"Some sharks, like the Port Jackson, have as little as 150 electroreceptors, while some hammerheads can have more than 3,000."

However both wobbegong and angel sharks lack mandibular clusters which are thought to assist in directing their mouth towards prey.

"These differences likely reflect the different behaviors of each species, and so we can learn a lot about their feeding habits just by looking at the distribution and abundance of these electroreceptors," Ms Egeberg says.

In addition to dorsal and ventral electrosensory , wobbegong and angel sharks posses a rare hyoid cluster that the scientists believe assists in predator detection.

"Given the posterior position of these electroreceptors on the head, we believe this cluster may assist in the detection of predators rather than prey, and will be particularly useful to benthic species that spend long periods of time motionless on the seabed," Dr Kempster says.

"This is just a theory at the moment, but it could be tested further by blocking certain electroreceptor clusters and assessing a shark's behavioural response to prey or predator-mimicking stimulus."

Explore further: Knowledge of stingrays' sparked-up sex may help deter sharks

Related Stories

Many sharks colour blind, research confirms

September 19, 2012

(Phys.org)—New research which could help to deter and conserve sharks has confirmed that many of the ocean predators are probably completely colour blind. 

Baby sharks stay still to avoid being detected by predators

January 9, 2013

Baby sharks still developing in their egg cases can sense when predators are near, and keep very still to avoid being detected, according to research published January 9 in the open access journal PLOS ONE by Ryan Kempster ...

Sharks more abundant on healthy coral reefs

September 10, 2014

Sharks in no-fishing zones in the Great Barrier Reef (GBR) Marine Park are more abundant when the coral is healthy, according to a study published September 10, 2014 in the open-access journal PLOS ONE by Mario Espinoza from ...

Recommended for you

Scientists crack genetic code of cane toad

September 19, 2018

A group of scientists from UNSW Sydney, the University of Sydney, Deakin University, Portugal and Brazil have unlocked the DNA of the cane toad, a poisonous amphibian that is a threat to many native Australian species. The ...

Scientists examine variations in a cell's protein factory

September 19, 2018

You can think of a cell in your body like a miniature factory, creating a final product called proteins, which carry out various tasks and functions. In this cellular factory, genes control the series of sequential steps ...

Why some animals still have a penis bone

September 19, 2018

A team of researchers affiliated with several institutions in the U.K. has found a possible explanation for why some animals still have a penis bone—"prolonged intromission." In their paper published in Proceedings of the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.