In this Act, except subsections (4) and (5), "animal" means a vertebrate other than man.
Nothing in this Act applies to an animal while it is in its foetal or embryonic form.
The appropriate national authority may by regulations for all or any of the purposes of this Act—
extend the definition of "animal" so as to include invertebrates of any description;
make provision in lieu of subsection (2) as respects any invertebrates included in the definition of "animal";
amend subsection (2) to extend the application of this Act to an animal from such earlier stage of its development as may be specified in the regulations.
The power under subsection (3)(a) or (c) may only be exercised if the appropriate national authority is satisfied, on the basis of scientific evidence, that animals of the kind concerned are capable of experiencing pain or suffering.
In this section, "vertebrate" means any animal of the Sub-phylum Vertebrata of the Phylum Chordata and "invertebrate" means any animal not of that Sub-phylum.