Didymocystis lamotheargumedoi n. sp. (Digenea:Didymozoidae) a parasite of three species of scombrid fishes

Abstract

DIDYMOCYSTIS LAMOTHEARGUMEDOI N. SP. IS DESCRIBED FROM THE OPERCULUM AND PALATE OF THUNNUS ATLANTICUS (LESSON, 1831), PALATE OF THUNNUS ALBACARES (BONNATERRE, 1788), AND THE OPERCULUM OF KATSUWONUS PELAMIS (LINNAEUS, 1758) CAUGHT ON THE COAST OF RIO DE JANEIRO, BRAZIL. THE NEW SPECIES IS MOST SIMILAR TO D. ALALONGAE (YAMAGUTI, 1938), D. EXIGUUS (YAMAGUTI, 1970), AND D. OESOPHAGICOLA (YAMAGUTI, 1970), BASED ON THE VITELLINE AND OVARIAN BRANCHES LACKING RAMIFICATIONS. IT VARIOUSLY DIFFERS FROM THESE 3 SPECIES IN THE NUMBER OF OVARIAN AND VITELLINE BRANCHES, THE LENGTH OF THE VITELLINE BRANCHES, EGG SIZE, BODY SIZE AND SITE WITHIN THE HOST. IMMATURE FORMS ASSOCIATED WITH ADULTS ARE ALSO DESCRIBED.