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Fishes of the order Siluriformes, known as catfishes, have a global distribution with more than 3,600 valid species of which 2,087 occur in the Neotropical region. Despite being highly diverse, abundant, and of economic importance as food and ornamental fishes, knowledge about the diversity and distribution of their helminth parasites is fragmentary and scarce. Eight species of catfishes (Pterodoras granulosus, Trachydoras paraguayensis, Pimelodella avanhandavae, Loricariichthys platymetopon, Pterygoplichthys ambrosettii, Rhinelepis aspera, Hemisorubim platyrhynchos, and Sorubim lima) from the Aguapeí River, Upper Paraná River basin, municipality of Castilho, São Paulo State, Brazil, were surveyed for helminth parasites. Collected fishes were weighed, measured, and examined for helminth parasites following standard methodology. Fifty helminth parasite taxa (23 monogeneans, 13 digeneans, 11 nematodes, and three cestodes) were found from a total of 405 fishes screened. The helminth taxon that showed the highest mean intensity of infection and mean abundance was the nematode Rondonia rondoni from P. granulosus, followed by the nematode Parasynodontisia petterae from R. aspera. The ecological analyses were carried out at the component community level and at the infracommunity level. Trachydoras paraguayensis had the richest helminth component community. Pterygoplichthys ambrosettii had the most diverse helminth component community and R. aspera had the lowest. Both hosts are loricariids and have similar diet. However, the high parasite diversity of P. ambrosettii is due to the number of dactylogyrids species found (10), which are directly transmitted, whereas only three dactylogyrid species were found in R. aspera. At infracommunity level, the nematode species R. rondoni and P. petterae dominated the parasite communities. This study presents 38 new host records, contributing considerably to increase the diffuse knowledge of helminth parasites of Neotropical siluriforms., Graphical abstract Image 1, Highlights • Fifty helminth parasite taxa were recovered from 405 catfishes surveyed. • Monogenea was the most diverse group, representing 46% of the helminth taxa found. • Thirty-eight new host records are presented.

Heteropriapulus Kritsky, 2007 (Monogenea: Dactylogyridae), which originally included only two species from the gills of loricariid catfishes, is reviewed and six newly described species from loricariids in the Paraná River basin in Brazil are added. Diagnosis of the genus is amended and a key to the species identification is provided. Heteropriapulus anchoradiatus n. sp. from Pterygoplichthys ambrosettii (Holmberg) (Hypostominae) differs from its congeners by having a long sclerotized vagina, ventral anchors with short shaft and conspicuous superficial root, and a conspicuous and robust postero-medial process on the dorsal bar; H. bitomus n. sp. from the same fish host differs by the presence of two pairs of sclerotized patches associated with the ventral anchors; H. falxus n. sp. from Hypostomus strigaticeps (Regan) (Hypostominae) and Hypostomus ancistroides (Ihering) (Hypostominae) is unique by the shape of the accessory piece composed of two strongly sclerotized subunits; H. microcleithrus n. sp. from P. ambrosettii differs by presenting the smallest length of the dorsal bar and unique shape of the longer subunit of the accessory piece resembling the ‘hammer and sickle’ shape; H. pterygoplichthyi n. sp. from the same host presents unique shape of the longer subunit of the accessory piece of the cirrus, which is represented by ‘two sickles’ jointed by the base; and H. semitortus n. sp. from Rhinelepis aspera Spix & Agassiz (Rhinelepinae) can be distinguished by the accessory piece composed of a single straight unit and a cirrus tube with the highest number of spiral rings at the proximal end (2½). First molecular data for this genus (partial sequences of the 28S rRNA gene) are provided including the type species H. heterotylus (Jogunoori, Kritsky & Venkatanarasaiah, 2004).

We studied the relationship between the morphology of the reproductive system and the reproductive strategies of six neotropical catfishes using macroscopic and microscopic analyses. The reproductive system of the examined Siluriformes showed diversified characteristics, but permitted their being grouped according to three reproductive strategies: pelagic spawning, demersal spawning, and internally fertilizing. The pelagic spawners Pseudoplatystoma corruscans and Conorhynchos conirostris have testes that are characterized by filiform lobes, absence of testicular secretion, full-grown oocytes of small diameter, thin zona radiata, and cuboidal follicular cells. Pimelodus maculatus is morphologically distinct from the other two pelagic spawners catfishes due to the presence of testicular secretion. The demersal spawners Lophiosilurus alexandri and Rhinelepis aspera possess homogeneous testicular secretion, large mature oocytes, and columnar follicular cells. The most specialized reproductive system was observed in the internally fertilizing Trachelyopterus galeatus, which possesses a seminal vesicle accessory to the testes, spermatozoa with elongated nuclei that form spermatozeugmata, and a secretory ovarian lamellar epithelium that is associated with sperm storage. The reproductive system observed in Neotropical catfishes showed a relationship associated with the type of fertilization and the reproductive strategies of the six species studied.

Paranaella luquei is a monogenean from family Microcotylidae, which was found parasitizing the gills of Steindachnerina brevipinna (Eigenmann & Eigenmann, 1889), collected in two different tributaries of Paranapanema River, Paraná, Brazil. This parasite was the first species of Microcotylidae described parasitizing freshwater fishes (Hypostomus sp., Hypostomus regani (Ihering) and Rhinelepis aspera Spix & Agassiz (Loricariidae) in the country.

In an allozyme electrophoresis survey of 15 hypostomine species from the Itaipu Hydroelectric Reservoir, 25 loci from 14 enzyme systems were scored. Allozyme data allowed recording diagnostic genetic markers for all species analyzed and for some species groups within Hypostomus, a taxon which is taxonomically still unresolved in the Upper Rio Parana basin. The mean expected heterozygosity of the species was considerably variable and hypotheses to tentatively explain this variation are discussed. A cladogram based upon the allelic frequencies of the species analyzed was produced by the continuous maximum likelihood method: Rhinelepis aspera and M. parananus were separated from the species of Hypostominae by a long branch length. Pterygoplichthys anisitsi was the sister of all the representatives of the genus Hypostomus. Within Hypostomus, two main clades were produced: in the first, H. cochliodon was the sister of the species comprising the H. plecostomus group, and in the second, the tree showed the following relationships: (H. albopunctatus (H. regani + Hypostomus sp. 3) + (H. margaritifer (H. microstomus (Hypostomus sp. 1 (H. ternetzi + Hypostomus sp. 2))))). Hypostomus ternetzi and Hypostomus sp. 2 are referred to here as representatives of the H. ternetzi group.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:07:46Z No. of bitstreams: 1 S1516-35982011000600001.pdf: 245950 bytes, checksum: 1757f2e75e91c81f2b85975dbb64745f (MD5) Made available in DSpace on 2013-08-22T19:07:46Z (GMT). No. of bitstreams: 1 S1516-35982011000600001.pdf: 245950 bytes, checksum: 1757f2e75e91c81f2b85975dbb64745f (MD5) Previous issue date: 2011-06-01 Made available in DSpace on 2013-09-30T20:12:26Z (GMT). No. of bitstreams: 2 S1516-35982011000600001.pdf: 245950 bytes, checksum: 1757f2e75e91c81f2b85975dbb64745f (MD5) S1516-35982011000600001.pdf.txt: 21914 bytes, checksum: e919ce777e43720e6ea60a4b98a45659 (MD5) Previous issue date: 2011-06-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:18:20Z No. of bitstreams: 2 S1516-35982011000600001.pdf: 245950 bytes, checksum: 1757f2e75e91c81f2b85975dbb64745f (MD5) S1516-35982011000600001.pdf.txt: 21914 bytes, checksum: e919ce777e43720e6ea60a4b98a45659 (MD5) Made available in DSpace on 2014-05-20T15:18:20Z (GMT). No. of bitstreams: 2 S1516-35982011000600001.pdf: 245950 bytes, checksum: 1757f2e75e91c81f2b85975dbb64745f (MD5) S1516-35982011000600001.pdf.txt: 21914 bytes, checksum: e919ce777e43720e6ea60a4b98a45659 (MD5) Previous issue date: 2011-06-01 Um experimento foi realizado com o objetivo de estimar a concentração espermática das espécies dourado (Salminus brasiliensis), curimba (Prochilodus lineatus), jundiá (Rhamdia quelen), cascudo-preto (Rhinelepis aspera) e tilápia-do-nilo (Oreochromis niloticus) pelo método de espermatócrito. Utilizaram-se 19, 58, 51, 43 e 85 reprodutores de dourado, curimba, jundiá, cascudo-preto e tilápia-do-nilo, respectivamente. Com exceção da tilápia-do-nilo, os reprodutores foram submetidos ao processo de indução hormonal e posteriormente submetidos a coleta de sêmen. Foram comparadas as técnicas de mensuração da concentração espermática do sêmen por contagem em câmara hematimétrica de Neubauer e por espermatócrito. Os resultados obtidos foram submetidos à análise de regressão a 5% de probabilidade. As concentrações espermáticas mensuradas por ambas as técnicas apresentaram relação linear, para curimbas, jundiás e tilápias-do-nilo, com equações y = 6,6624 × 10(9) + 3,68553 × 10(8)x; y = 2,153 × 10(9) + 4,426 × 10(8)x e y = -9,0897 × 10(8) + 6,0167 × 10(8), respectivamente. O método de espermatócrito pode ser utilizado para estimar a concentração espermática do sêmen de curimbas, jundiás e tilápias-do-nilo. The objective of this experiment was estimate sperm concentration of dourado (Salminus brasiliensis), curimba (Prochilodus lineatus), jundiá (Rhamdia quelen), cascudo-preto (Rhinelepis aspera) and Nile tilapia (Oreochromis niloticus) by the method of spermatocrit. It was used 19, 58, 51, 43 and 85 brood fish of dourado, curimba, jundia, cascudo-preto and Nile tilapia, respectively. Except for the Nile tilapia, the fishes were subjected to the hormonal induction process and then submitted to the semen collection. The measurement techniques of the sperm concentration by sperm count in Neubauer chamber (CSPZ) and by spermatocrit (ESPMT) were compared. The results were submitted to the regression analysis at 5% of probability. It was observed that the variables CSPZ and ESPMT presented linear relationship to the curimba, jundia and Nile tilapia with equations y = 6.6624 × 10(9) + 368553 × 10(8)x; y = 2.153 × 10(9) + 4.426 × 10(8)x and y = -9.0897 × 10(8) + 6.0167 × 10(8), respectively. The method of spermatocrit can be used to estimate the sperm concentration of curimba, jundiá and Nile tilapia. Universidade Estadual Paulista Júlio de Mesquita Filho Centro de Aqüicultura Universidade Estadual do Oeste do Paraná (UNIOESTE) Centro de Engenharias e Ciências Exatas Universidade Federal de Uberlândia (UFU) Departamento de Zoologia Universidade Estadual Paulista Júlio de Mesquita Filho Centro de Aqüicultura

Utilization of the fish ladder installed at the Engenheiro Sergio Motta Dam (also known as Porto Primavera) on the Paraná River, Southern Brazil, by long-distance migrating potamodromous species (sampling Protocol I), and ascending and descending movements (Protocol II) were evaluated. Three pools along the fish ladder (designated as lower, middle, and upper) were sampled monthly between December, 2004 and March, 2005 to determine the abundance of species in the ladder. The ascending and descending movements of the species in the ladder were also analyzed in the same period. In the samples for both protocols, 37 species representing 17 families and 5 orders (Characiformes, Siluriformes, Perciformes, Gymnotiformes, and Myliobatiformes) were recorded. Characiformes were represented by 21 species. Long- distance migratory species (11 species) predominated in the ladder (60% of the total number of individuals), with high abundance of Rhinelepis aspera (5645 individuals). For protocol I, mean abundance varied greatly among the months and pools, with lowest values in December and March for all pools, and highest in January for the lower pool due to high capture of R. aspera. Fish abundance declined from the lower to the upper pool, especially for R. aspera and Rhaphiodon vulpinus. For Protocol II, 17 species were recorded ascending the ladder, where Astyanax altiparanae and Leporinus friderici were the most abundant species (684 and 111 individuals, respectively). However, 18 species showed descending movements, with high captures of Metynnis maculatus and A. altiparanae (339 and 319 individuals, respectively). Twelve species (52%) moved in both directions, and among the seven migratory species sampled, four were recorded ascending and descending, and three species only ascending the ladder. The fish ladder appears to selectively favor species with high swimming capabilities. A discussion is presented on the requirements for future research on attraction to the fish ladder entrance, downstream movements, fish utilization of the ladder, and impacts on spawning and rearing habitat both upstream and downstream of the dam. A utilização da escada para peixes instalada na barragem Engenheiro Sergio Motta (também conhecida como Porto Primavera) no rio Paraná, no sudeste do Brasil, por espécies potamódromas de longa distância (protocolo I) e os movimentos ascendentes e descendentes (protocolo II) foram avaliados. Três tanques ao longo da escada para peixes (denominados como foz, meio e tomada) foram amostrados mensalmente entre dezembro de 2004 a março de 2005 para avaliar a abundância de espécies na escada. Os movimentos ascendentes e descendentes das espécies na escada foram analisados no mesmo período. Nas amostragens relativas aos protocolo I e II, foram capturadas 37 espécies representando 17 famílias e cinco ordens (Characiformes, Siluriformes, Perciformes, Gymnotiformes e Myliobatiformes). Os Characiformes foram representados por 21 espécies. Espécies migradoras de longa distância (11 espécies) predominaram (60% do total), com maior abundância de Rhinelepis aspera (5645 indivíduos). A abundância média variou entre os meses e tanques para o protocolo I, com menores valores em dezembro e março para todos os tanques, e maiores em janeiro no tanque foz, devido a maior captura de R. aspera. A abundância de peixes diminuiu do tanque foz para o tanque tomada, especialmente para R. aspera e Rhaphiodon vulpinus. Nas capturas relativas ao protocolo II, foram capturadas 17 espécies ascendendo a escada: Astyanax altiparanae e Leporinus friderici foram as mais abundantes (com 684 e 111 indivíduos, respectivamente). Entretanto, 18 espécies apresentaram movimentos descendentes, com elevadas capturas de Metynnis maculatus e A. altiparanae (339 e 319 indivíduos, respectivamente). Doze espécies apresentaram movimentos ascendentes e descendentes na escada, e das sete espécies migradoras amostradas, quatro apresentaram movimentos para cima e para baixo, e três espécies somente subiram. Esta escada para peixes parece favorecer seletivamente espécies com elevada capacidade de natação. As necessidades de pesquisas futuras para elucidar sobre a atratividade da escada, movimentos descendentes, utilização da escada pelos peixes e os impactos sobre as áreas de reprodução e criadouros, ambos a montante e jusante da barragem, são discutidos.