Jose Maria Orensanz, better known as 'Lobo' since his childhood, made different scientific contributions on the taxonomy of marine or estuarine annelids, as well as in ecology and artisanal fisheries of several benthic invertebrate groups. Lobo's contributions in fisheries were described elsewhere; in this eulogy, we make a brief review about some salient features of his life and about his efforts in the study of polychaetes. In particular, Lobo's 37 publications on benthic ecology or poychaete taxonomy are detailed, and in those dealing with polychaetes he dealt with 18 mostly benthic families and made 3 papers on pelagic species; he proposed 9 genera and described 29 species. Three annexes are included listing his publications, the taxa he proposed or described, and the taxa named after him including a genus and 18 species.