RESUMO

Here we evaluated the potential for trace metal accumulation of two parasitic species, Hysterothylacium sp. (Nematoda) and Phyllodistomum sp. (Digenea), found parasitizing Hoplias malabaricus, a characiform fish also known as trahira, collected from two neotropical rivers, Jacaré-Pepira and Jacaré-Guaçú, in southeastern Brazil. Fish were collected between July 2017 and July 2019, totaling 90 fish specimens analyzed, 45 from each river. From fish, we take samples of three different tissues: muscle, intestine and liver. Along with the parasite samples taken from fish hosts, tissue samples were analyzed by an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) for obtaining the trace metal (Al, Cr, Mn, Fe, Ni, Cu, As, Cd e Pb) concentrations. All elements were found in statistically higher concentrations in the parasites, both nematodes and digeneans, than in the host tissues, but in comparison, was observed that Hysterothylacium sp. had higher concentrations than those obtained in Phyllodistomum sp. We also found that uninfected fish had statistically higher concentrations of metals than infected ones. And in those who are infected, the size of the parasitic infrapopulations correlated negatively with the concentrations of trace metals obtained in the hosts tissues, that is, the concentrations in fish showed a tendency to decrease as the parasitic infrapopulations increased, or vice versa. In addition, our results show that the influence of the parasitic infrapopulations on metal concentrations in the fish host is not affected in cases of mono-infection or co-infection.

Assuntos

RESUMO

A new myxozoan species, Henneguya sp., is described based on material from skin of Cyphocharax modestus. Mature myxospores are were elongate and ellipsoidal, measuring 21.4 ±â€¯1.2 (19.4-23.2) µm in total length, 5.1 ±â€¯0.3 (4.5-5.8) µm in width, 11.9 ±â€¯0.5 (10.9-12.7) µm in body length and 9.6 ±â€¯0.7 (8.4-10.5) µm in length of the caudal process. The polar capsules were elongated and had unequal sizes, with length of 5.1 ±â€¯0.4 (4.5-6.0) µm and 5.6 ±â€¯0.4 (4.9-6.3) µm for smaller and larger respectively and width of 1.8 ±â€¯0.2 (1.4-2.0) µm. The larger polar capsule had 8 turns in polar filament while the smaller polar capsule had 5 turns in polar filament. The macroscopic analysis revealed the presence of large nodules, which were located before and after the dorsal fin of the hosts. The histopathological analysis showed the development of nodules filled with plasmodia, surrounded by loose connective tissue, developed in the dermis of the skin. Many cysts containing countless spores, as well as free spores, were located in the dermis and hypodermis of the hosts, causing the disorganization of the connective tissue that is responsible for the support. This is the first record of a Henneguya species in C. modestus.

Assuntos

RESUMO

Current essay describes three new Monogenean species, namely, Cosmetocleithrum striatuli sp. nov., Jainus leporini sp. nov. and Rhabdosynochus guanduensis sp. nov., parasites on the gills of Trachelyopterus striatulus (Steindachner, 1877), Leporinus copelandii Steindachner, 1875 and Centropomus undecimalis (Bloch, 1792), respectively. Fish were collected from the Guandu river, State of Rio de Janeiro, Brazil between August 2005 and November 2008. Cosmetocleithrum striatuli sp. nov. differs from all other congeneric species by the shape of an accessory piece (more robust and resembling a crustacean claw or chela) and by the shape of its ventral and dorsal bars (not V-shaped and with expanded lateral ends directed to the rear). Jainus leporini sp. nov. differs from all other Jainus species by the male copulation organ (MCO), with a 2-ring coil, by the absence of medial projection on ventral bar and by a plate-like sclerotized structure associated to the vagina. Rhabdosynochus guanduensis sp. nov. differs from all other congeneric species by the morphology of the copulation complex and by a shell-shaped vagina.

RESUMO

The qualitative and quantitative analyses of diplostomid metacercariae in Geophagus brasiliensis (Quoy & Gaimard, 1824) of the Guandu river, Seropédica, Rio de Janeiro, Brazil, are provided. Between April 2006 and March 2007, 200 specimens of G. brasiliensis were collected and necropsied. Further, five morphotypes of diplostomid metacercariae were obtained, namely, Austrodiplostomum compactum, Diplostomum sp., Posthodiplostomum sp. 1, Posthodiplostomum sp. 2 and Neascus type 1. Whereas the metacercariae of Diplostomum sp., Posthodiplostomum sp. 1 and Posthodiplostomum sp. 2 were described, a new site of infection of A. compactum was registered and a new geographical report for Neascus type 1, responsible for the black-spot disease, has been added. Current investigation enhances the importance of G. brasiliensis as an intermediate host of diplostomid trematodes and the diversity of these larvae in the Guandu river.

O presente trabalho teve como objetivo o estudo qualitativo e quantitativo das metacercárias de diplostomídeos em Geophagus brasiliensis (Quoy & Gaimard, 1824) do rio Guandu, Seropédica, Rio de Janeiro, Brasil. Entre abril de 2006 e março de 2007, foram coletados e necropsiados 200 espécimes de G. brasiliensis, sendo obtidos cinco morfotipos de metacercárias de diplostomídeos: Austrodiplostomum compactum, Diplostomum sp.,  Posthodiplostomum sp. 1, Posthodiplostomum sp. 2 e Neascus tipo 1. No presente trabalho, foram descritas as metacercárias de Diplostomum sp., Posthodiplostomum sp. 1 e  Posthodiplostomum sp. 2, além de registrar novo sítio de infecção de A. compactum e aumentar o conhecimento da distribuição geográfica de Neascus tipo 1, causadora da doença dos pontos pretos. O presente trabalho aponta para a importância de G. brasiliensis como hospedeiro intermediário de trematódeos diplostomídeos e sobre a diversidade dessas larvas no rio Guandu.

RESUMO

Fifty specimens of acarGeophagus brasiliensis (Quoy and Gaimard, 1824) from Guandu River, (224832S, 433735W), Rio de Janeiro State, Brazil were studied for their metazoan parasites during December 2004 and November 2005. A total of nine species of metazoan parasites were collected. Posthodiplostomum macrocotyle Dubois, 1937 (metacercariae) found in the eyes, was the most prevalent species (88%) with the highest mean intensity value (12.4), followed by the metacercariae of Austrodiplostomum compactum (Lutz, 1928) and the hirudinean Glossiphoniidae gen. sp. showing prevalence of 14% and 10%, respectively. No parasite species showed significant correlation between the total body length of the host and their prevalence. Posthodiplostomum macrocotyle showed significant correlation between the total body length of the host and their abundance. The sex of the hosts influenced the abundance of P. macrocotyle, A. compactum and Glossiphoniidae gen. sp. being the females the most parasited. The parasite species richness showed a mean value of 1.240.69 (0-3). The parasite species showed an aggregated distribution pattern.

Foram estudados 50 acarás Geophagus brasiliensis (Quoy e Gaimard, 1824) provenientes do rio Guandu, coletados próximo barragem da Estação de Tratamento de àgua (ETA) (22º4832S, 43º3735O), no Estado do Rio de Janeiro, no período de dezembro de 2004 novembro de 2005. Nove espécies de metazoários parasitos foram coletadas. O digenético Posthodiplostomum macrocotyle Dubois, 1937 (metacercária) foi a espécie mais prevalente (88%) e com a maior intensidade média (12,4), sendo a maioria dos espécimes encontrados parasitando os olhos, seguida pela metacercária Austrodiplostomum compactum (Lutz, 1928) e pelo hirudíneo Glossiphoniidae gen. sp., que apresentaram prevalências de 14% e 10%, respectivamente. Nenhum parasito apresentou correlação significativa entre o comprimento total do corpo do hospedeiro e sua prevalência. Posthodiplostomum macrocotyle apresentou correlação significativa entre o comprimento total do corpo do hospedeiro e sua abundância. O sexo dos hospedeiros influenciou a abundância de P. macrocotyle, A. compactum e Glossiphoniidae gen. sp., sendo as fêmeas as mais parasitadas. A riqueza parasitária apresentou uma média de 1,24±0,69 (0-3). Os parasitos apresentaram um padrão de distribuição agregado.

RESUMO

One hundred specimens of tamboatá Hoplosternum littorale (Hancock, 1828) from Guandu River, (224832S, 43º3735W), Rio de Janeiro state, Brazil were studied as for their metazoan parasites during May 2004 and February 2005. A total of eight species of metazoan parasites were collected and identified. Kalipharynx sp. was the most prevalent species (61.0%), followed by Glossiphoniidae gen. sp. (20%) and the progenetic metacercariae of Herpetodiplostomum caimancola (Dollfus, 1935) (11%). No parasite species showed significant correlation between the total body length of the host and their abundance. The sex of the hosts influenced the abundance of Kalipharynx sp., being the males the most parasited. The mean parasite species richness showed low values (1.59 ± 1.09 (0-3)). The parasite species presented an aggregated distribution pattern.

Foram estudados 100 tamboatás Hoplosternum littorale (Hancock, 1828) provenientes do rio Guandu, coletados próximo à barragem da Estação de tratamento de água (ETA) (224832S, 43º3735O), no Estado do Rio de Janeiro, no período de maio de 2004 à fevereiro de 2005. Oito espécies de metazoários parasitos foram coletadas e identificadas. O digenético Kalipharynx sp. foi a espécie mais prevalente (61%), seguido pelo hirudíneo Glossiphoniidae gen. sp. (20%) e a metacercária progenética de Herpetodiplostomum caimancola (Dollfus, 1935) (11%). Nenhum parasito apresentou correlação significativa entre o comprimento total do corpo do hospedeiro e sua abundância. O sexo dos hospedeiros influenciou a abundância de Kalipharynx sp., sendo os machos os mais parasitados. A riqueza parasitária média apresentou valores baixos (1,59 + 1,09 (0-3)). Os parasitos apresentaram um padrão de distribuição agregado.