Please register and log-in to create and edit pages

User Tools

    Please register and log-in to create and edit pages

Site Tools


Main Menu

Main menu
Click categories to expand

Other categories


Also see

Importance Ratingsplugin-autotooltip__plain plugin-autotooltip_bigImportance ratings

In a departure from the usual Wiki format, Wikenigma assigns 'Importance Ratings' to some pages.

The idea is to separate articles which are considered (by the editors) to cover exceptionally important unknown issues from those which (although also u…

Newsplugin-autotooltip__plain plugin-autotooltip_bigNews

[ newest at the top ]

• Jan 2021 : A milestone of 600 unknown articles has been reached.

• Oct 2020 : A milestone of 500 unknown articles has been reached.

• Aug 2020 : Currently (beta) testing the new 'WYSIWYG' (What You See Is What You Get

Contactsplugin-autotooltip__plain plugin-autotooltip_bigContacts

Use this form to send a message to Wikenigma . . . [ * note: all fields must be completed ]

Legalplugin-autotooltip__plain plugin-autotooltip_bigLegal

Content in general

Please note that in common with other publicly editable wikis, this website is not responsible for content posted by the public. Nevertheless, the ongoing editing process should be able to remove unsuitable content in a reasonable time. If you…

Donate/Sponsorplugin-autotooltip__plain plugin-autotooltip_bigDonate to Wikenigma . . .

The best way to donate is by adding new original content !

That can either be by contributing to an existing article, or by creating a new page with an as-yet-unlisted 'Known Unknown'.

Any registered user can create content.

Registerplugin-autotooltip__plain plugin-autotooltip_bigRegistration

At present, only registered users can create and edit articles.

If you'd like to register as a contributor, please request a password.

When filling in the form, make sure you supply a valid e-mail address, as the login password will be sent to that addre…


Wikenigma supports:


Utilities
A-Z listingplugin-autotooltip__plain plugin-autotooltip_bigA-Z listing

This is an alphabetical index of all content pages.

rss / xml feed
sitemap file

Wikenigma - an Encyclopaedia of Unknowns Wikenigma - an Encyclopaedia of the Unknown Science

Tonic Immobility

“Tonic Immobility (TI) is a reversible coma-like stasis inherent to a variety of terrestrial and aquatic taxa, including elasmobranchs [sharks] yet virtually nothing is known about its underlying neurological and physiological processes in any taxa.”

Source: The stress physiology of extended duration tonic immobility in the juvenile lemon shark, Negaprion brevirostris Journal of Experimental Marine Biology and Ecology Volume 409, Issues 1–2

The prevalence of Tonic Immobility in sharks is so well known that it's routinely used by marine researchers (instead of anaesthetics) for safely immobilising them. The animals are simply upturned (i.e. on their back) for a few tens of seconds and the animal goes flaccid, entering a coma-like state. It can also be induced in some species of shark simply by placing two hands on the animal's snout under the eyes.

Similar states can be induced (by various methods) in a very wide variety of animals, including reptiles, birds and mammals.

It's believed that TI has some relation to the fear response (especially in mammals) - and could have evolved as some form of protection mechanism - i.e. 'playing dead'


    Share this page :

X

Dear reader : Do you have any suggestions for the site's content?

Ideas for new topics, and suggested additions / corrections for old ones, are always welcome.

If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !


Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.

( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)

Show another (random) page

DOKUWIKI IMPLEMENTATION DESIGN BY UNIV.ORG.UK MARCH 2021