SOME DIGENEA PARASITES OF TUNNY FROM THE COAST OF RIO DE JANEIRO STATE ,

Rhipidocotyle pentagonum (Ozaki, 1924) is reported for the first time in South America parasitizing Auxis thazard and in a new host Katsuwonus pelamis. Tergestia laticollis (Rudolphi, 1819) is reported for the first time in South America and in Thunnus albacares, representing a new host record. Copiatestes filiferus (Leuckart, in Sars, 1885) is recorded for the first time in Brazil and in Thunnus albacares, another new host record. Tetrochetus coryphaenae (Yamaguti, 1934) is presented for the first time in Brazil parasitizing Thunnus albacares.


INTRODUCTION
Tuna and tuna-like species occur in the Atlantic, Indian, and Pacific Oceans and in the Mediterranean Sea and represent a significant food source.As Brazil, has a large canned-fish industry, these species are very important economically.At the same time, very litlle is known about the helminth parasites of these fish.In this paper we present data on the Digenea parasites of three different tuna species from the coast of the State of Rio de Janeiro.Four species are reported for the first time in Brazil, with three new host records.

MATERIAL AND METHODS
One hundred eighty-eight specimens belonging to three different tuna species were examined.The fishes were obtained by industrial tuna fisheries and carried in large containers to the laboratory.The trematodes collected were fixed in AFA (ethanol, formalin, acetic acid) under slight coverslip pressure; wholemounts were stained in an alcoholic acid carmine, cleared in beechwood creosote, and mounted in Canada balsam.Measurements, in micrometres unless otherwise stated, are quoted as the ranges with the means in parentheses.Drawings were made using a drawing tube.Material studied is deposited in the Helminthological Collection of the Instituto Oswaldo Cruz (CHIOC) in Rio de Janeiro.
This species was originally described from Scomberomorus nipponicus from Japan, and has been reported in different hosts and localities.
It has been found in different species including: Thunnus thynnus from the Mediterranean by Eckmann (1932) and from the Pacific Ocean by Yamaguti (1938a); Auxis thazard and Euthynnus affinis from the Gulf of Bengal by Madhavi (1974), and E. lineatus from Mexico by Castillo-Sánches et al. (1997).
For the first time in South America we report this species parazitizing A. thazard and in a new host Katsuwonus pelamis.The specimens taken from A. thazard are in agreement with those reported by Ozaki (1928), Eckmann (1932), andYamaguti (1938a), while specimens from K. pelamis presented smaller eggs than those previously reported.
Voucher specimens deposited: CHIOC n. 34.550 a-j Measurements based on 10 specimens.Body 1.57-2.67mm (2.06 mm) in length by 0.41-0.79mm (0.55 mm) in width; anterior sucker 105-195 (134)  Bucephalus sp. (Fig. 3) We recovered only one immature specimen from the stomach of Katsuwonus pelamis (Linnaeus, 1758) out of the 92 fish examined.The anterior sucker with 19 short tentacles and the general morphology are very similar to those of Bucephalus confusus (Velasquez, 1959), but considering the immaturity of the specimen, more material would be necessary in order to confirm this observation. Voucher

Accacoeliidae (Odhner, 1911) Looss, 1912
Tetrochetus coryphaenae Yamaguti, 1934 (Fig. 4) Oliva (1984) reported this species in the type host, Coryphaena hippurus from Chile, with one original figure, but without measurements or detailed description.It has been also reported as occurring in other hosts and localities in the Pacific, Atlantic, and Indian Oceans.In this paper, T. coryphaenae is reported for the first time in Brazil in Thunnus albacares (Bonaterre, 1788).It was already reported for this trematode by Korataeva (1976) from the Pacific Ocean.
Host: Thunnus albacares (Bonaterre, 1788) Site: stomach Intensity of infection: 2 out of 89 fish examined were parasitized by a single mature and 2 immature specimens respectively.
Our specimen basically agrees with the original description, but presents a wider body (0.60 mm instead of 0.29 mm) and larger eggs (32-35 x 21-23 instead of 26-33 x 16-19).

Fellodistomidae Nicoll, 1913
Tergestia laticollis (Rudolphi, 1819) Stossich, 1899 (Fig. 5) In South America the genus Tergestia Stossich, 1899, has been recorded only in Brazil where it comprises four species.These are, in the State of Rio de Janeiro: T. Pauca, proposed by Freitas & Kohn (1965) and cited by Wallet & Kohn (1987); T. pectinata (Linton, 1905), cited by Takemoto et al. (1995Takemoto et al. ( , 1996)); and T. priacanthi (MacCallum, 1917), described by Fábio (1981); and in the State of Santa Catarina: T. selenei Amato, 1982.Tergestia laticollis was originally described from the Mediterranean Sea in Trachurus trachurus and has been reported from the Pacific and Atlantic Oceans in different hosts.Regarding tunna, this trematode was already reported from Puerto Rico in Euthynnus alletteratus by Siddiqi &Cable (1960), andin Florida (after Yamaguti, 1971).We found one specimen which is in agreement with those reported previously.This species is being reported for the first time in South America and in Thunnus albacares, representing a new host record.
This species was described in detail by Gibson & Bray (1977).The single mature specimen collected in this study is similar to those reported by Gibson (1976) from Acantholatris monodactylus (= Euthynnus pelamys) from Tristan da Cunha, South Atlantic Ocean, with slightly smaller eggs (22.5-35 x 25-27.5 instead of 35-44 x 18-27).This trematode is reported for the first time in Brazil and in Thunnus albacares, representing a new host record.
Site: intestine Intensity of infection: 1 out of the 92 specimens of K. pelamis examined harbored 1 mature trematode, and 1 out of 89 specimens of T. albacares examined were parasitized by 2 immature trematodes.