Trematoda , Digenea , Didymozoidae , Wedlia retrorbitalis ( Yamaguti , 1970 ) and Wedlia submaxillaris ( Yamaguti , 1970 ) : First record in South America and the Atlantic Ocean

387 During a survey of the helminth parasites of scombrid fishes from Rio de Janeiro coast, Brazil, two didymozoid species Wedlia retrorbitalis (Yamaguti 1970) and Wedlia submaxillaris (Yamaguti 1970) were recovered from the retrorbital adipose tissue and maxillary region, respectively, of a Thunnus obesus (Lowe 1839) off Rio de Janeiro coast, Southern Atlantic Ocean. These species are reported from Rio de Janeiro coast, Brazil, representing the first record in South America. Thunnus obesus an epipelagic and mesopelagic species, is found worldwide in tropical and subtropical waters of the Atlantic, Indian and Pacific Oceans, but is absent from the Mediterranean Sea. This species is commonly known as Bigeye tuna or as Albacora-bandolim in Brazil and feed on a wide variety of fishes, crustaceans and cephalopods. It is a highly migratory species with a wide distribution and remarkable pelagic activity (Collete and Nauen, 1983). From January 2004 to April 2007, thirty five T. obesus (42 80 cm total body length; 1.2 8.0 kg) were examined. Fish were obtained from local fishermen from the coastal zone of the state of Rio de Janeiro, Cabo Frio, Brazil (22°52’46” S, 42°01’07” W). Fish were transported on ice to the laboratory of the Instituto de Estudos do Mar Almirante Paulo Moreira IEAPM, Arraial do Cabo, Rio de Janeiro state, to be examined for the presence of helminth parasites. Fish were identified according to Collette and Nauen (1983), and parasites studied in the Laboratório de Helmintos Parasitos de Peixes, Instituto Oswaldo Cruz Fiocruz, Rio de Janeiro. The didymozoid were released from dissected cysts and fixed with or without compression in AFA (alcohol 93 %, formalin 5 %, and acetic acid 2 %), stained in alcoholic-acid carmine, dehydrated in alcohol series, cleared in methyl salicilate and mounted in Canada balsam. Measurements are in micrometers, with the mean in parentheses when more than two. Photomicrographies were taken with a digital camera connected to a Nikon Eclipse E 800 microscope. Parasites were identified following Yamaguti Abstract: Two species of Didymozoidae originally described from Pacific Ocean, Wedlia retrorbitalis and Wedlia submaxillaris are reported for the first time in South America, Atlantic Ocean. W. retrorbitalis was found encysted in retrorbital adipose tissue and W. submaxillaris in the maxillary region of Thunnus obesus caught along the Rio de Janeiro coastline, extending their current geographical distribution. Original measurements and figures are presented. Márcia Cristina Nascimento Justo * and Anna Kohn

During a survey of the helminth parasites of scombrid fishes from Rio de Janeiro coast, Brazil, two didymozoid species Wedlia retrorbitalis (Yamaguti 1970) and Wedlia submaxillaris (Yamaguti 1970) were recovered from the retrorbital adipose tissue and maxillary region, respectively, of a Thunnus obesus (Lowe 1839) off Rio de Janeiro coast, Southern Atlantic Ocean.These species are reported from Rio de Janeiro coast, Brazil, representing the first record in South America.
Thunnus obesus an epipelagic and mesopelagic species, is found worldwide in tropical and subtropical waters of the Atlantic, Indian and Pacific Oceans, but is absent from the Mediterranean Sea.This species is commonly known as Bigeye tuna or as Albacora-bandolim in Brazil and feed on a wide variety of fishes, crustaceans and cephalopods.It is a highly migratory species with a wide distribution and remarkable pelagic activity (Collete and Nauen, 1983).
From January 2004 to April 2007, thirty five T. obesus (42 -80 cm total body length; 1.2 -8.0 kg) were examined.Fish were obtained from local fishermen from the coastal zone of the state of Rio de Janeiro, Cabo Frio, Brazil (22°52'46" S, 42°01'07" W).Fish were transported on ice to the laboratory of the Instituto de Estudos do Mar Almirante Paulo Moreira -IEAPM, Arraial do Cabo, Rio de Janeiro state, to be examined for the presence of helminth parasites.Fish were identified according to Collette and Nauen (1983), and parasites studied in the Laboratório de Helmintos Parasitos de Peixes, Instituto Oswaldo Cruz -Fiocruz, Rio de Janeiro.
The didymozoid were released from dissected cysts and fixed with or without compression in AFA (alcohol 93 %, formalin 5 %, and acetic acid 2 %), stained in alcoholic-acid carmine, dehydrated in alcohol series, cleared in methyl salicilate and mounted in Canada balsam.Measurements are in micrometers, with the mean in parentheses when more than two.Photomicrographies were taken with a digital camera connected to a Nikon Eclipse E 800 microscope.Parasites were identified following Yamaguti Abstract: Two species of Didymozoidae originally described from Pacific Ocean, Wedlia retrorbitalis and Wedlia submaxillaris are reported for the first time in South America, Atlantic Ocean.W. retrorbitalis was found encysted in retrorbital adipose tissue and W. submaxillaris in the maxillary region of Thunnus obesus caught along the Rio de Janeiro coastline, extending their current geographical distribution.Original measurements and figures are presented.
Wedlia retrorbitalis and W. submaxillaris present as generic characteristic the body divided into anterior and posterior regions in both sexes with male located in special cavity in female body.Males are smaller than females with strong sexual dimorphism.
Description and main measurements based on two males and two females.In this opportunity W. retrorbitalis is reported from the type host (T.obesus) for the first time since the original description.
W. submaxillaris, originally described from Pacific Ocean by Yamaguti (1970) was posteriorly reported by Pozdnyakov (1996) from T. obesus, T. albacares and Makaira mazara (Jordan & Snyder 1901) in the same ocean, by Dubina (1985) from M. mazara and by Nikolaeva and Dubina (1985) and Mordinova and Nikolaeva (1990) from Makaira nigricans Lacepède, 1802 from Indian Ocean.It is now redescribed for the first time in Brazil, representing the first record in South America, Atlantic Ocean.
The finding of these didymozoid species for the first time in the Atlantic Ocean, demonstrated its cosmopolitan distribution, matching the geographical distribution of its host, and showing that tuna fish migration in different oceans may facilitate infections by members of Didymozoidae.