Complex sentence: A European Food Safety Authority (EFSA) 2005 publication stated that the largest of decapod crustaceans have complex behaviour, some degree of awareness, a pain system and considerable learning abilities.
Split into simpler sentences: A European Food Safety Authority (EFSA) publication stated that the largest of decapod crustaceans have complex behaviour and appear to have some degree of awareness. They also have a pain system and considerable learning abilities.