intracerebroventricular ( icv ) administration of the opioid peptide , beta-endorphin ( 5.0 pg/g ) to goldfish , carassius auratus , significantly increased the cohesiveness and duration of shoaling ( 'bout ' length ) in shoals of five fish , as well as decreasing the latency of shoal formation in response to an external disturbance , while a higher dose of beta-endorphin ( 15 pg/g ) decreased shoaling .
C0205753
opioid peptide
C0014242
endorphin