Metacercariae of Austrodiplostomum compactum (Trematoda, Diplostomidae) in non-native fish species in Brazil: a possible explanation for the high rate of parasitic infection.

Metacercariae of Diplostomidae are widely distributed in America and may cause diplostomiasis, an ocular disease in fishes. The aim of this study is to report the occurrence of metacercariae of Austrodiplostomum compactum in Plagioscion squamosissimus (non-native fish species) from Nova Avanhandava Reservoir, Tietê River, Brazil and an explanation for the high infection rates with this parasite in the Paraná River Basin is proposed. Eyes of 70 hosts were examined, the metacercariae were preserved and identified. The prevalence (P), mean intensity of infection (MII) ± standard deviation, mean abundance (MA) ± standard deviation, were calculated and a bibliographic review was performed. There was no difference in parasitism between male and female hosts. The values of P = 80%, MII = 21.55 ± 3.25 and MA = 17.24 ± 2.91 were high, as in most studies in areas where P. squamosissimus were introduced, while these values were low in areas of natural occurrence. This may be explained by the genetic susceptibility of the host to the parasite. The entire population of P. squamosissimus from the Upper Paraná has been founded by a few specimens, resulting in very low genetic variability. Consequently, the population may be highly susceptible to A. compactum.

Urotrema macrotestis and Urotrema scabridum (Digenea: Urotrematidae) parasitizing bats (Mammalia: Chiroptera) in Brazil.

Urotrema scabridum Braun 1900 and Urotrema macrotestis Mané-Garzón and Telias 1965 are reported from the small intestine of Eumops glaucinus (Wagner, 1843). The species were differentiated by the body width, the size and position of acetabulum, the size of testis, the caecal termination, and the distribution of vitellarium. The present study expands the distribution and the hosts of both species in Minas Gerais State and reports U. macrotestis parasitizing bats for the first time.

Parasitic communities of Hoplosternum littorale (Hancock, 1828) as indicators of environmental impact.

The parasites are indicative of several biological aspects of their hosts, including their diet, migration, recruitment and phylogeny, but they can also be direct indicators of the environmental quality. Hoplosternum littorale is a fish that has a high commercial value in some South American countries. The fishes were collected from January to July 2012, in two locations of the Peixe River in the municipality of Anhembi, State of São Paulo, Brazil, which had different environmental and limnological characteristics (river mouth and Lagoa Cabeça de Boi). An amount of 30 fish specimens were captured in each location for the analysis of their parasitic fauna. Nine species of metazoan parasites were collected. Both Brillouin`s diversity index and Margalef`s richness index were greater in the Lagoa Cabeça de Boi. The ratio of heteroxenous and monoxenous parasite species richness (SH/SM) was higher in the Lagoa Cabeça de Boi. The results of the physicochemical analysis of the water showed that the mouth of the Peixe River can be considered an area that suffers more from anthropogenic actions than the Lagoa da Cabeça de Boi. Proteocephalus sp., Gyrodactylus sp., Scleroductus sp. and Capillaria (Neocapillaria) pterophylli are being registered for the first time in this host.

Parasite infracommunities of Leporinus friderici: A comparison of three tributaries of the Jurumirim Reservoir in southeastern Brazil

ABSTRACT The degradation and homogenization of natural habitats is considered a major cause of biotic homogenization. Many studies have been undertaken on the effects of dams on aquatic wildlife, in particular fish assemblages. But how do dams affect the parasitic fauna of such fish? The aim of the present study was to examine parasitic similarity, comparing the diversity and structure of parasite communities of Leporinus friderici (Characiformes, Anostomidae) in three upstream tributaries under the influence of the Jurumirim Dam on the Upper Paranapanema River in southeastern Brazil. The present study did not find any significant differences in parasite communities among populations of L. friderici in the three upstream tributaries. This result highlights that dams promote and facilitate the dispersal of organisms between localities, and therefore the spatial homogenization of parasite communities. Overall, the results suggest that fish parasite assemblages can provide suitable data for evaluating biotic homogenization caused by dams.

A new species of Tereancistrum (Monogenea, Dactylogyridae) from the gills of three Leporinus species (Characiformes, Anostomidae) and a revised description of Tereancistrum parvus

ABSTRACT The present study describes Tereancistrum flabellum n. sp. (Dactylogyridae, Ancyrocephalinae) from the gills of the anostomid fishes Leporinus friderici, Leporinus amblyrhynchus and Leporinus elongatus from two freshwater ecosystems in the south east of Brazil. This new species is mainly characterized by the morphology of the copulatory complex (such as the MCO base formed by two fan-shaped structures, and accessory piece flattened, curved, rigid and channeled), a dorsal anchor with a well-developed superficial and inconspicuous deep root, and the shape of the accessory anchor sclerite with small spathulate termination. Tereancistrum flabellum n. sp. is the first record of a dactylogyrid from L. amblyrhynchus. The description of Tereancistrum parvus is also emended to correct and complement previous descriptions and the species is reported for the first time in Schizodon nasutus.

Parasite infracommunities of Leporinus friderici : A comparison of three tributaries of the Jurumirim Reservoir in southeastern Brazil.

The degradation and homogenization of natural habitats is considered a major cause of biotic homogenization. Many studies have been undertaken on the effects of dams on aquatic wildlife, in particular fish assemblages. But how do dams affect the parasitic fauna of such fish? The aim of the present study was to examine parasitic similarity, comparing the diversity and structure of parasite communities of Leporinus friderici (Characiformes, Anostomidae) in three upstream tributaries under the influence of the Jurumirim Dam on the Upper Paranapanema River in southeastern Brazil. The present study did not find any significant differences in parasite communities among populations of L. friderici in the three upstream tributaries. This result highlights that dams promote and facilitate the dispersal of organisms between localities, and therefore the spatial homogenization of parasite communities. Overall, the results suggest that fish parasite assemblages can provide suitable data for evaluating biotic homogenization caused by dams.

A new species of Tereancistrum (Monogenea, Dactylogyridae) from the gills of three Leporinus species (Characiformes, Anostomidae) and a revised description of Tereancistrum parvus.

The present study describes Tereancistrum flabellum n. sp. (Dactylogyridae, Ancyrocephalinae) from the gills of the anostomid fishes Leporinus friderici, Leporinus amblyrhynchus and Leporinus elongatus from two freshwater ecosystems in the south east of Brazil. This new species is mainly characterized by the morphology of the copulatory complex (such as the MCO base formed by two fan-shaped structures, and accessory piece flattened, curved, rigid and channeled), a dorsal anchor with a well-developed superficial and inconspicuous deep root, and the shape of the accessory anchor sclerite with small spathulate termination. Tereancistrum flabellum n. sp. is the first record of a dactylogyrid from L. amblyrhynchus. The description of Tereancistrum parvus is also emended to correct and complement previous descriptions and the species is reported for the first time in Schizodon nasutus.

Parasitic communities of Hoplosternum littorale (Hancock, 1828) as indicators of environmental impact

ABSTRACT The parasites are indicative of several biological aspects of their hosts, including their diet, migration, recruitment and phylogeny, but they can also be direct indicators of the environmental quality. Hoplosternum littorale is a fish that has a high commercial value in some South American countries. The fishes were collected from January to July 2012, in two locations of the Peixe River in the municipality of Anhembi, State of São Paulo, Brazil, which had different environmental and limnological characteristics (river mouth and Lagoa Cabeça de Boi). An amount of 30 fish specimens were captured in each location for the analysis of their parasitic fauna. Nine species of metazoan parasites were collected. Both Brillouin`s diversity index and Margalef`s richness index were greater in the Lagoa Cabeça de Boi. The ratio of heteroxenous and monoxenous parasite species richness (SH/SM) was higher in the Lagoa Cabeça de Boi. The results of the physicochemical analysis of the water showed that the mouth of the Peixe River can be considered an area that suffers more from anthropogenic actions than the Lagoa da Cabeça de Boi. Proteocephalus sp., Gyrodactylus sp., Scleroductus sp. and Capillaria (Neocapillaria) pterophylli are being registered for the first time in this host.

First report of Strongyloides sp. (Nematoda, Strongyloididae) in Leopardus tigrinus (Carnivora: Felidae) in the municipality of Botucatu, State of São Paulo, Brazil / Primeiro relato de Strongyloides sp. (Nematoda, Strongyloididae) em Leopardus tigrinus (Carnivora: Felidae) do município de Botucatu, Estado de São Paulo, Brasil

The present study reports the first case of infection by Strongyloides sp. in Leopardus tigrinus in the municipality of Botucatu, State of São Paulo, Brazil. Feces of the infected L. tigrinus specimen were cultivated in sterilized equine feces and a cat (Felis catus domesticus) was experimentally infected with three thousand infective L3 subcutaneous route, in order to identify the Strongyloides species involved in the parasitism. Parthenogenetic females recovered from the experimental animals were analyzed but comparison between the biometric data found and the data in the literature did not enable identification of the species. This is the first report on the occurrence of Strongyloides sp. in L. tigrinus.

O presente estudo reporta o primeiro caso de infecção por Strongyloides sp. em Leopardus tigrinus no município de Botucatu, Estado de São Paulo, Brasil. Fezes do exemplar parasitado de L. tigrinus foram cultivadas em fezes eqüinas esterilizadas e foi realizada infecção experimental em gato (Felis catus domesticus) com três mil larvas L3 infectantes por via subcutânea, para a identificação da espécie de Strongyloides envolvida no parasitismo. As fêmeas partenogenéticas obtidas do animal experimental foram analisadas porém a comparação dos dados biométricos encontrados com os dados da literatura não permitiu a identificação da espécie. Este é o primeiro relato sobre a ocorrência de Strongyloides sp. Em L. tigrinus.