2.3 Tissue sample collection
Immediately after each behavioural trial, squid were euthanised with
AQUI-S (1:1000). The head was separated from the mantle, rinsed in
distilled water, and blotted dry. The skin, tentacles, beak, and buccal
mass were removed and the eyes and central nervous system (CNS,
containing the oesophagus running through the middle) were dissected and
snap frozen in liquid nitrogen within 4.18 ± 0.55 (mean ± SD) minutes
after euthanasia. Tissues were then transferred to
-80OC for storage. This study followed the animal
ethics guidelines at James Cook University (JCU animal ethics number
A2644).