Cephalopod ink

A number of other aquatic molluscs have similar responses to attack, including the gastropod clade known as sea hares.

The second response to a predator is to release pseudomorphs ("false bodies"), smaller clouds of ink with a greater mucus content, which allows them to hold their shape for longer.

[4] The spotty bobtail squid releases ropes of ink longer than itself and hides among them, possibly to be confused with floating seagrass leaves.

[6][10] Sepia officinalis ink forms a polydisperse suspension composed by spheric particles with a size between 80 and 150 nm (measured by TRPS and SEM).

Modern use of cephalopod ink is generally limited to cooking, primarily in Japan and the Mediterranean, where it is used as a food colouring and flavouring, for example in pasta and sauces, and calamares en su tinta.

For this purpose, it is generally obtainable from fishmongers, gourmet food suppliers, and is widely available in markets in Japan,[15](p 336) Italy and Spain.

It currently remains unclear however if any of the antitumor activity of squid ink can be obtained from oral consumption, and this is indicated as an area for future investigation.

Ventral view of the viscera of Chtenopteryx sicula , showing the specific location of the ink sac
Arròs negre owes its dark colour to squid ink
Squid ink pasta with truffles and pistachios