$re = '/(\((.*?)\))/m';
$str = 'Chats (Felis catus)
Chiens (Canis lupus familiaris)
Chevaux (Equus ferus caballus)
Moutons (Ovis aries)
Bovins (Bos taurus taurus)
Porcs (Susscrofa domestica)
Chèvres (Capra aegagrus hircus)
Les lapins (Oryctolagus cuniculus)
Les canards (Anas platyrhyncos domesticus)
Les dindons (Meleagris gallopavo gallopavo)
Ânes (Equus asinus)
Mules (Equus asinus x Equus caballus)
Chien
Chat
Furet
Cheval
âne
vache
lama
mule
Porc
Cochon d\'Inde
Rat domestique
Hamster doré
Souris domestique
gerbille de Mongolie
Lapin domestique
Canard colvert
Poule
paon
Pigeon
tourterelle
colombe
Canari
Perruche
Poisson rouge
Carpe koï
axolotl
';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php