Abuse and Misuse of the Term "Guild" in Ecological Studies

In its original definition, guild refers to a group of syntopic organisms using a given resource in a similar way, without regard to their taxonomic relationships. I contend that this term is abused by researchers that define guilds in a-priori manner (any group of syntopic, taxonomically related organisms, i.e., an assemblage), and misused by researchers that define guilds a-posteriori (subgroups within assemblages). I discuss the consequences of these practices and the relationship between guild structure and competition.