RHABDOCHONA (RHABDOCHONA) ACUMINATA (NEMATODA) IN FISHES (CHARACIFORMES, ACESTRORHYNCHIDAE) FROM THE TRÊS MARIAS RESERVOIR, UPPER SÃO FRANCISCO RIVER, BRAZIL

Rhabdochona (Rhabdochona) acuminata (Molin, 1860) (Rhabdochonidae) parasitizes the intestine of several species of fish and it has a broad geographical distribution. The present study is the first to report adult specimens of this helminth in Acestrorhynchus britskii Menezes, 1969 and Acestrorhynchus lacustris Lütken, 1875 (Acestrorhynchidae), collected in the Três Marias reservoir, upper São Francisco River, State of Minas Gerais, Brazil. At the same locality, Rhabdochona sp. larvae were found in sympatric populations of forage fishes, Tetragonopterus chalceus Spix & Agassiz, 1829 and Triportheus guentheri (Garman, 1890) which are potential prey to the piscivorous Acestrorhynchids and they are mentioned as possible intermediate or paratenic hosts of this parasite species. The parasite indices of R. acuminata were not influenced by either sex or total length of these piscivorous hosts.Rhabdochona (Rhabdochona) acuminata (Molin, 1860) (Rhabdochonidae) parasita o intestino de várias espécies de peixes e apresenta uma ampla distribuição geográfica. O presente estudo registra pela primeira vez a ocorrência de espécimes adultos deste helminto em Acestrorhynchus britskii Menezes, 1969 e Acestrorhynchus lacustris Lütken, 1875 (Acestrorhynchidae), coletados no Reservatório de Três Marias, Alto Rio São Francisco, Estado de Minas Gerais, Brasil. Nesta mesma localidade, larvas de Rhabdochona sp. foram encontradas em peixes forrageiros simpátricos, Tetragonopterus chalceus Spix & Agassiz, 1829 e Triportheus guentheri (Garman, 1890) potenciais presas dos acestrorhynchídeos piscívoros e relacionadas como possíveis hospedeiros intermediários ou paratênicos dessa espécie de parasito. Os índices parasitários de R. acuminata não foram influenciados pelo sexo e nem pelo comprimento total desses hospedeiros piscívoros

PROSTHENHYSTERA OBESA (DIESING, 1850) (DIGENEA, CALLODISTOMIDAE) DEL RÍO SÃO FRANCISCO, BRASIL: NUEVOS REGISTROS DE HOSPEDEROS Y SUS PARÁMETROS ECOLÓGICOS

Prosthenhystera obesa (Diesing, 1850) (Digenea, Callodistomidae), parasitizes the gall bladder of freshwater fish and was first found in Leporinus reinhardti Lütken, 1875 (Characiformes, Anostomidae) and Pimelodus pohli Ribeiro & Lucena, 2006 (Siluriformes, Pimelodidae). These omnivorous fish were collected in the upper São Francisco River, Minas Gerais, Brazil. prevalence (%) and mean abundance of P. obesa were 1.58% and 0.02 ± 0.127 in L. reinhardti, and 3.85% and 0.04 ± 0.196 in P. pohli, respectively. Prosthenhystera obesa has already been reported in a carnivorous characin Salminus franciscanus Lima & Britski, 2007 and in an omnivorous pimelodid Pimelodus maculatus Lacepède, 1803 both in the São Francisco River, but their ecological parameters are here presented for the first time together with the data for L. reinhardti and P. pohli, two new hosts in the Neotropical Region. The ecological descriptors of P. obesa were similar, i. e., they were low in all fish of the São Francisco River and also in most fish from different hydrographic basins in accordance to literature review. It is noteworthy that despite the considerable morphometric variability, pregnant adult specimens of P. obesa occurred mainly in characin fish, especially ichthyophagous, top carnivores.Prosthenhystera obesa (Diesing, 1850) (Digenea, Callodistomidae) parasita la vesícula biliar de los peces de agua dulce y se encontró por primera vez en Leporinus reinhardti Lütken, 1875 (Characiformes, Anostomidae) y en Pimelodus pohli Ribeiro & Lucena, 2006 (Siluriformes, Pimelodidae). Estos peces omnívoros se colectaron en la parte alta del río São Francisco, Minas Gerais, Brasil. La prevalencia (%) y abundancia media del parasitismo por P. obesa fue 1,58% y 0,02 ± 0,12 en L. reinhardti, y 3,85% y 0,04 ± 0,19 en P. pohli, respectivamente. Prosthenhystera obesa ya ha sido registrado en un carnívoro characido Salminus franciscanus Lima & Britski, 2007 y en un omnívoro pimelódido Pimelodus maculatus Lacepède, 1803, los dos del río São Francisco, pero sus parámetros ecológicos son presentados aquí por primera vez junto con los datos de L. reinhardti y P. pohli, dos nuevos hospederos de la región Neotropical. Los descriptores ecológicos de P. obesa fueron similares, en otras palabras, fueron bajos en todos los peces del río São Francisco y también en la mayoría de los peces de diferentes cuencas hidrográficas, de acuerdo con la revisión de la literatura. Se destaca que a pesar de la variabilidad morfométrica de P. obesa, los especímenes adultos con huevos se encuentran principalmente en los peces characidos, en particular en los ictiófagos, carnívoros superiores de la cadena alimentaria

A new species of Anacanthoroides and redescription of Apedunculata discoidea (Monogenoidea) parasitizing Prochilodus argenteus (Actinopterygii) from the São Francisco River, Brazil

Monteiro, Cassandra Moraes, Brasil-Sato, Marilia Carvalho (2014): A new species of Anacanthoroides and redescription of Apedunculata discoidea (Monogenoidea) parasitizing Prochilodus argenteus (Actinopterygii) from the São Francisco River, Brazil. Zootaxa 3784 (3): 259-266, DOI: 10.11646/zootaxa.3784.3.

Helminth fauna parasitizing Pimelodus pohli (Actinopterygii: Pimelodidae) from the upper São Francisco River, Brazil

The parasite fauna of catfish, Pimelodus pohli, from the São Francisco River Basin is presented. A total of 45 catfish from the upper São Francisco River (45°15′44″W 18°13′25″S), were examined from July 2009 to September 2011. Forty-three catfish (95.5%) were infected by at least one parasite species, with 885 parasite specimens being found, distributed across 17 species: Monogenea (Demidospermus uncusvalidus, Pavanelliella pavanellii, and Scleroductus sp.); Eucestoda (plerocercoids of Proteocephalidea); Digenea (metacercariae of Austrodiplostomum compactum, adults of Auriculostoma platense and Kalipharynx sp., and juvenile of Prosthenhystera obesa); Nematoda (larvae of Contracaecum sp., Hysterothylacium sp., Procamallanus pimelodus, Procamallanus sp., and unidentified of Cucullanidae, and adults of Cucullanus caballeroi, Philometra sp., and Procamallanus freitasi); and Acanthocephala (adults of Neoechinorhynchus pimelodi). Procamallanus freitasi and Scleroductus sp. were the taxa with the highest prevalence. Demidospermus uncusvalidus, P. freitasi, and Scleroductus sp. were the dominant species. The host's sex did not influence parasitic indexes; however, the total length of the catfish did appear to have some influence. The parasites, with except for P. obesa, were registered for the first time in P. pohli, as well as the occurrence of Kalipharynx sp. and C. caballeroi among pimelodid hosts from São Francisco River and South America

Parasite Community of Cichla kelberi (Perciformes, Cichlidae) in the Três Marias Reservoir, Minas Gerais, Brazil

A total of 112 specimens of yellow peacock bass, Cichla kelberi, were collected in the Três Marias Reservoir, upper São Francisco River, State of Minas Gerais, between 2004 and 2005. Twelve species of parasites were collected: two species of ectoparasites (the monogenetic Gussevia sp. and the copepod Ergasilus sp.); and ten species of endoparasites, including four species of adult endoparasites: the cestodes Proteocephalus macrophallus and P. microscopicus, and the nematodes: Capillostrongyloides sentinosa and Rhabdochona acuminata, and six species of larval endoparasites: the metacercariae of Austrodiplostomum compactum and the nematodes: Hysterothylacium sp., Contracaecum sp. Type 1, Procamallanus (Spirocamallanus) inopinatus, Spiroxys sp., and Goezia sp.. A significant positive correlation in the abundance of the two adult endoparasites species, P. macrophallus and P. microscopicus, may indicate that such associated species had the same ecological requirements. The positive correlations between the prevalence of the larval endoparasites, Hysterothylacium sp. and A. compactum, may indicate that there was opportunism for the two generalists species. Ergasilus sp., C. sentinosa, R. acuminata and Hysterothylacium sp. were recorded for the first time in C. kelberi, and this increased their list of known hosts. In addition, both proteocephalid species and C. sentinosa can extend their known biogeographical distribution to the Três Marias Reservoir

New species and reports of dactylogyrids (Monogenoidea) from Salminus franciscanus (Actinopterygii: Bryconidae) from the upper São Francisco River, Brazil

Monteiro, Cassandra Moraes, Cohen, Simone Chinicz, Brasil-Sato, Marilia Carvalho (2015): New species and reports of dactylogyrids (Monogenoidea) from Salminus franciscanus (Actinopterygii: Bryconidae) from the upper São Francisco River, Brazil. Zootaxa 3941 (1): 137-143, DOI: 10.11646/zootaxa.3941.1.

Digenea of Hoplias intermedius and Hoplias malabaricus (Actinopterygii, Erythrinidae) from upper São Francisco River, Brazil

A total of 103 specimens of Hoplias intermedius (Günther, 1864) and 86 specimens of H. malabaricus (Bloch, 1794) from the upper São Francisco River, State of Minas Gerais were collected between April 2011 and August 2013, and their parasitic fauna were investigated. Four species of Digenea were found: metacercariae of Austrodiplostomum sp., and Ithyoclinostomum sp.; and adult specimens of Phyllodistomum spatula Odhner, 1902, and Pseudosellacotyla lutzi (Freitas, 1941) Yamaguti, 1954. The prevalence of the metacercariae was higher than that of the adult digeneans of erythrinids from the upper São Francisco River as a result of piscivorous feeding habits of these adult erythrinids. The presence of metacercariae and adult digeneans indicate that they act as intermediate and definitive hosts, respectively, in their biological cycles. Hoplias intermedius is a new host for the four species of Digenea, and the São Francisco River basin is a new location for the known geographical distributions of P. spatula and P. lutzi

Digenea in the surubim Pseudoplatystoma corruscans (Spix and Agassiz, 1829) (Siluriformes: Pimelodidae) of the upper São Francisco River, State of Minas Gerais, Brazil

The specimens of surubim, Pseudoplatystoma corruscans (Spix and Agassiz, 1829), an important food fish with high commercial value in the Upper São Francisco River, were collected downstream from the Três Marias Dam, in the municipality of Três Marias, State of Minas Gerais, Brazil. Thirty-six individuals were examined and among the parasites, four species of Digenea were found: Witenbergia witenbergi Vaz, 1932 and Tylodelphys sp. (metacercarie), both with prevalence above 10%, followed by Acanthostomum gnerii (Szidat, 1958) and Acanthostomum sp.. The total length of the hosts did not influence the parasite prevalence. Witenbergia witenbergi occurred only in female hosts and the abundance of Tylodelphys sp. was higher in the males. These Digenea were recorded for the first time in P. corruscans, and their known geographic distribution has been expanded to the São Francisco Basin in Brazil