Márcia Cristina Nascimento Justo

First record in South America of Koellikerioides internogastricus (Digenea, Didymozoidae) with new host record and pathological alterations

The study of different species of tunas has revealed high numbers of cysts of Koellikerioides internogastricus Yamaguti, 1970, parasitizing Thunnus atlanticus (Lesson), Thunnus albacares (Bonnaterre) and Thunnus obesus (Lowe), caught along the Rio de Janeiro coastline, Atlantic Ocean, Brazil. This parasite was isolated from mucosa and submucosa of the stomach of the three tuna species studied. We report K. internogastricus for the first time on the Brazilian coast, representing the first record of this species in South America and in T. atlanticus, a new host. The pathological alterations induced by K. internogastricus in the stomach of T. albacares, T. atlanticus and T. obesus are also described for the first time. Original measurements and figures are presented.

Juvenile didymozoids of the types, Torticaecum and Neotorticaecum (Didymozoidae: Digenea), from new marine fish hosts (Pisces: Teleostei) in the neotropical region of Brazil

From December 2006 to March 2008, 60 specimens of Paralichthys isosceles and 25 specimens of P. patagonicus were investigated for helminths. One hundred and sixty-nine digeneans were recovered and parasites were identified as juvenile didymozoids of two types. Torticaecum and Neotorticaecum were found in 48 of the 60 P. isosceles (80%) and 10 of the 25 P. patagonicus (40%). Torticaecum and Neotorticaecum are reported for the first time in fish in South America (Brazil), found in the Atlantic Ocean. Morphometrics and illustrations are presented.

First record in South America of Didymosulcus palati and Didymosulcus philobranchiarca (Digenea, Didymozoidae) with new hosts records and pathological alterations

Two species of Didymozoidae, Didymosulcus palati (Yamaguti 1970) and Didymosulcus philobranchiarca (Yamaguti 1970) were reported for the first time in South America, Atlantic Ocean, parasitizing three different tuna species from the coast of Rio de Janeiro, Brazil: Thunnus atlanticus (Lesson), Thunnus albacares (Bonnaterre) and Thunnus obesus (Lowe). Pairs of D. philobranchiarca were found on gill arches of T. albacares and T. obesus, in longitudinal rows of yellow cysts located inside grooves in the hard denticle palate (new site) of the three hosts species studied, and as disperse groups of cysts in the operculum (new site) and gill arches of T. atlanticus (new host record). D. palati occurred as disperse groups of encysted worm pairs in the gill arches of T. albacares and T. obesus and in gill arches and operculum of T. atlanticus (new host record). The pathological alterations induced by D. philobranchiarca in the palate of T. atlanticus are described for the first time. Original measurements and figures are presented.

A new genus and species of the Didymozoidae (Digenea) from the skipjack tuna Katsuwonus pelamis (L.) (Scombridae)

A new genus and species of didymozoid digenean is described from the skipjack tuna Katsuwonus pelamis (Linnaeus) in the Southwest Atlantic Ocean off Brazil. Pozdnyakovia gibsoni n. g., n. sp. is placed in the Gonapodasmiinae Ishii, 1935. The new genus differs from other genera in the morphology of the posterior regions of the fused pair; this consists of an unlobed, rounded mass fused only dorsally and with a large, elliptical ventral aperture opening into a longitudinal deep cavity from which emerge the two elongate anterior regions. It also differs in the form of the testes, which form two sets of three to four branches in each partner.

Histopathology and autoecology of Didymocylindrus simplex (Digenea: Didymozoidae), parasite of Katsuwonus pelamis (Scombridae) in the Southwestern Atlantic Ocean, off South America

Pathological alterations and autoecology of Didymocylindrus simplex in Katsuwonus pelamis (Linnaeus, 1758) in the Southwestern Atlantic Ocean off of South America are presented. This is the first record of the species in the region; the specimens are described. The pathologic changes observed most often were infiltration of lymphocytes and slight fibrosis of the connective tissue surrounding the parasite. The typical aggregated distribution pattern was observed for Didymocylindrus simplex Ishii, 1935. Statistical analysis demonstrated no correlation between the abundance and prevalence of parasites with the total length of the host. The sex of the host does not influence the prevalence and intensity of infection.

Annakohniella travassosi n. gen., n. sp. (Digenea: Cryptogonimidae) Parasite of Rhaphiodon vulpinus (Pisces: Cynodontidae) from Brazil

A new genus of the family Cryptogonimidae is described from a freshwater fish from the north of Brazil. Annakohniella n. gen. is most closely related to Timoniella Rebeq, 1960 mainly by possessing testes contiguous at the posterior extremity and preovarian seminal receptacle. The new genus differs from Timoniella by having a deeply lobed ovary, a very large seminal receptacle, and the ovary widely separated from the testes by uterine coils. Among the genera with an ovary that is slightly to highly lobed, Annakohniella n. gen. is most closely related to Adlardia Miller, Bray, Goiran, Justine & Cribb, 2009, mainly by the space between ovary and testes filled with uterine loops and by the presence of a well-developed seminal receptacle, immediately anterior to ovary. Annakohniella n. gen. differs from Adlardia by having a tegument strongly armed with spines, a long prepharynx, a smaller oral∶ventral sucker width ratio, ovary in mid hindbody, tandem testes contiguous in the posterior extremity of body, presence of a gonotyl, ceca ending blind in posterior extremity of body, and absence of uterine coils posterior to testes.

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

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.

Digenea parasites of Acestrorhynchus falcirostris (Osteichthyes, Acestrorhynchidae) in the state of Amazonas, Brazil

This study presents the helminthofauna of digenean parasites of Acestrorhynchus falcirostris in the state of Amazonas (Brazil). Eight species belonging to four families were recovered: Metacercariae of Austrodiplostomum compactum (Diplostomidae) and Clinostomum marginatum (Clinostomidae) and mature specimens of Bellumcorpus majus, Prosorhynchoides carvajali, Rhipidocotyle santanaensis (Bucephalidae); Prosthenhystera obesa (Callodistomidae); Genarchella genarchella (Derogenidae) and Phyllodistomum spatula (Gorgoderidae). Examining specimens belonging to the genus Bellumcorpus collected from A. falcirostris, were observed a great variation in the size and shape of testes, which also could be observed in the type specimens of Bellumcorpus majus and B. schubarti. Considering the similar morphology and morphometric characteristics of both species, in this paper B. schubarti is considered synonym of B. majus. Acestrorhynchus falcirostris is a new host records for all these species of digenean, except to A. compactum and C. marginatum. Prosorhynchoides carvajali is referred for the first time in Brazil.

Seasonality of parasitic helminths of Leporinus macrocephalus and their parasitism rates in farming systems in the Amazon

The objective of the present study was to analyze the seasonality of parasitic helminths of Leporinus macrocephalus from fish farms in the municipality of Cruzeiro do Sul, Acre, Brazil, and their parasitism rates. Between June 2014 and March 2015, 200 specimens were sampled from two fish farms: one with a semi-intensive system and the other with an extensive system (100 fish from each farm: 50 during the dry season and 50 during the rainy season). Fifteen species of parasites were found, with seasonal variations of some according to the farming system. In the semi-intensive fish farm, there was greater prevalence of infection during the dry season. Also, Urocleidoides paradoxus, Procamallanus (Spirocamallanus) inopinatus, Goezia leporini and Rhabdochona (Rhabdochona) acuminata presented differences in their parasitism rates between the seasons. In the extensive fish farm, no variation in the prevalence of infection was observed between the seasons and two species Tereancistrum parvus and G. leporini demonstrated differences only regarding the mean intensity of infection. The data presented here may help fish farmers to understand the parasite dynamics of L. macrocephalus in farming systems during the dry and rainy seasons in the state of Acre.

Parasitism by Monogenoidea in Piaractus mesopotamicus (Characiformes, Characidae) cultivated in Paraná River (Brazil)

This study investigated the occurrence, prevalence, mean abundance and mean intensity of monogenoidean parasites in Piaractus mesopotamicus farmed in cages in the reservoir of the Itaipu Hydroelectric Power Station, Paraná River, Brazil. The parasite distribution pattern and the correlation of prevalence and abundance with the total length of hosts were also investigated. Four monogenoidean species were collected: Anacanthorus penilabiatus, A. toledoensis, Mymarothecium ianwhitingtoni and M. viatorum. All the parasites collected in P. mesopotamicus showed the typical aggregated distribution pattern, and the abundance and the prevalence did not shown any correlation with the total length of hosts.