Pain in the tentacles? ‘Marathon’ three-hour sex sessions leave squid so tired they can’t swim

Marathon three hour sex sessions leave squid  so exhausted they limp through the water for up to half an hour afterwards.

There is a reason for this – the long mating  sessions help the southern dumpling squid ensure their genes are passed  on.

The creatures also mate frequently throughout  their short lives.

Octopussy: The long mating sessions help the southern dumpling squid ensure their genes are passed on

Octopussy: The long mating sessions help the southern  dumpling squid ensure their genes are passed on

But it seems the mating sessions take their  toll. The squid are so exhausted after sex they have to hide in the sand to  escape predators.

Professor Amanda Franklin, of the  University  of Melbourne, said: ‘We found that after mating, both male  and female dumpling  squid took up to thirty minutes to recover to their  previous swimming  ability.

‘This suggested that the squid were suffering  from temporary muscle fatigue.

‘We predict that during this phase of muscle  fatigue, squid may hide in the sand to avoid predators until they have  recovered,’ say the researchers

‘Our results were a little surprising as the  degree of fatigue was similar in both genders even though mating looks more  strenuous for males.

‘We predict that during this phase of muscle  fatigue, squid may hide in the sand to avoid predators until they have  recovered.

‘The cost to them in doing this of course is  that they cannot forage for food or search for other mates at this  time

‘Dumpling squid live for less than a  year,  and may engage in the energetic activity of mating many times  within their  short breeding period.

‘This reproductive strategy may have  other  costs to individuals besides energy loss and we have investigated  this further  by assessing the effect of mating on female lifespan.

‘We’re hoping to report the results of this  experiment very soon.’

In order to pass on their genes, southern  dumpling squid engage in up to three hours of mating with each partner, but this  results in a reduced ability to swim for up to 30 minutes  afterwards.

Male dumpling squid appear to initiate mating  whenever the opportunity arises by grabbing the female from underneath and  holding her in place while they have sex.

And both male and females can change colour  from a sandy yellow to dark purple with green and orange highlights, as well as  producing a cloud of ink as a decoy to help them escape from  predators.

Dumpling squid can grow up to about 7cm long  and live for less than a year, but make up for their short life by mating  countless times in their short breeding period.

They are closely related to about ten bobtail  squid species around the world, including the waters around Hawaii and the South  China Sea.

Researchers were keen to understand the  impact of such an extensive mating ritual because the energy used in copulation  could reduce an animal’s survival by decreasing their ability to avoid predators  and hunt for food.

They collected dumpling squid from St  Leonards, south-eastern Australia, and tested their swimming endurance against a  constant current of water.

The squid were then allowed to mate and their  swimming ability was re-tested, with results showing it took them up to half an  hour to return to their normal ability.

The Biology Letters study says the squid  could have been suffering from temporary muscle fatigue and may hide from  predators in this time.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s