Anais da Academia Brasileira de Ciências ISSN: 0001-3765 [email protected] Academia Brasileira de Ciências Brasil ZAGO, ALINE C.; YAMADA, FÁBIO H.; FRANCESCHINI, LIDIANE; BONGIOVANI, MARCELA F.; YAMADA, PRISCILLA O.F.; DA SILVA, REINALDO J. A new species of Tereancistrum (Monogenea, Dactylogyridae) from the gills of three Leporinus species (Characiformes, Anostomidae) and a revised description of Tereancistrum parvus Anais da Academia Brasileira de Ciências, vol. 89, núm. 2, abril-junio, 2017, pp. 1121- 1131 Academia Brasileira de Ciências Rio de Janeiro, Brasil Available in: http://www.redalyc.org/articulo.oa?id=32751197030 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Anais da Academia Brasileira de Ciências (2017) 89(2): 1121-1131 (Annals of the Brazilian Academy of Sciences) Printed version ISSN 0001-3765 / Online version ISSN 1678-2690 http://dx.doi.org/10.1590/0001-3765201720160628 www.scielo.br/aabc A new species of Tereancistrum (Monogenea, Dactylogyridae) from the gills of three Leporinus species (Characiformes, Anostomidae) and a revised description of Tereancistrum parvus ALINE C. ZAGO, FÁBIO H. YAMADA, LIDIANE FRANCESCHINI, MARCELA F. BONGIOVANI, PRISCILLA O.F. YAMADA and REINALDO J. DA SILVA Universidade Estadual Paulista/Unesp, Instituto de Biociências, Câmpus de Botucatu, Rua Professor Doutor Antônio Celso Wagner Zanin, 250, 18618-689 Botucatu, SP, Brazil Manuscript received on September 27, 2016; accepted for publication on January 11, 2017 ABSTRACT The present study describes Tereancistrum flabellum n. sp. (Dactylogyridae, Ancyrocephalinae) from the gills of the anostomid fishesLeporinus 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 inSchizodon nasutus. Key words: Ancyrocephalinae, anostomid fish, gill ectoparasites, monogeneans, Neotropical region. INTRODUCTION Leporinus Agassiz, 1829 is the most diverse genus among anostomids, with 87 species, while The Anostomidae Günther, 1864 family includes the Schizodon Agassiz, 1829 genus is represented fish species that are widely distributed from by 14 species (Nelson 2006). Some larger members southern Central America to tropical and sub- of Leporinus and Schizodon are known for their temperate regions of South America (Nelson 2006). Many anostomid species are recognized by spawn migrations in the Paraná-Paraguay river their habit of feeding in an inclined position, and system and in the Amazon and Orinoco basins. constitute a significant part of the fish biomass in Because of their annual migrations, these species are different aquatic habitats (Garavello and Britski subjected to significant exploitation by commercial 2003). and subsistence fisheries as an important food source for the people of South America (Garavello Correspondence to: Aline Cristina Zago E-mail: [email protected] and Britski 2003). An Acad Bras Cienc (2017) 89 (2) 1122 ALINE C. ZAGO et al. Although monogeneans are common fish (Bloch, 1974), Leporinus amblyrhynchus Garavello parasites, despite the efforts of taxonomists and Britski, 1987 and Leporinus elongatus their diversity in the Neotropics remains largely Valenciennes, 1850. unknown (Cohen et al. 2013). Dactylogyridae The present study describes this new species Bychowsky, 1933 is the most abundant taxon and compares it with closely related species of the in South America, and included in this family is genus. We also present new data on the morphology Tereancistrum Kritsky, Thatcher and Kayton, 1980, of T. parvus and report its occurrence in S. nasutus which accommodates parasites of characiform for the first time. fishes in the Neotropical region (Thatcher 2006). The ZooBank Life Science Identifier Currently, eight species have been included (LSID) of this publication is: urn:lsid:zoobank. in this genus, seven of which have been described org:pub:05557665-9FC4-4237-8C8B- in Brazil: Tereancistrum kerri Kritsky, Thatcher 982278EF1948. and Kayton, 1980 (type species) from Brycon melanopterus (Cope, 1872) collected in the Januaca MATERIALS AND METHODS Lake, Amazonas state, Brazil; Tereancistrum ornatus Kritsky, Thatcher and Kayton, 1980 from Twenty-four specimens of L. amblyrhynchus, 22 of Prochilodus reticulatus Valenciennes, 1850 from L. elongatus, 40 of L. friderici, and 40 of S. nasutus Rio Cauca, Juanchito, Cali and Valle, Colombia; were collected from the Sapucaí-Mirim River, São Tereancistrum parvus Kritsky, Thatcher and Paulo state, Brazil (20°26’12.5”S, 47°53’18.59”W) Kayton, 1980 from Leporinus fasciatus (Bloch, between March 2012 and July 2013, while 116 1794) collected in the Amazon River Basin (Kritsky specimens of L. friderici were captured from et al. 1980); Tereancistrum toksonum Lizama, the Jurumirim Reservoir, São Paulo state, Brazil Takemoto and Pavanelli, 2004 and Tereancistrum (23°12’17’’S, 49°13’19’’W) between April 2011 curimba Lizama, Takemoto and Pavanelli, 2004 and July 2012. from Prochilodus lineatus (Valenciennes, 1847) The fishes were collected using a nylon from the Upper Paraná River floodplain, Brazil monofilament gillnet between 5:00 PM and 7:00 (Lizama et al. 2004); Tereancistrum arcuatus AM, totaling 14 hours of exposure. The capture Cohen, Kohn and Boeger, 2012 from Salminus of fish specimens from the Sapucaí-Mirim River brasiliensis (Cuvier, 1816) from the Paraná was authorized under a Permanent License for River, Brazil (Cohen et al. 2012); Tereancistrum the Collection of Zoological Material (SISBio pirassununguensis Cepeda, Ceccarelli and Luque, 13794-1), while collection from the Jurimirim 2012 from P. lineatus from the Mogi Guaçu River, Reservoir was authorized by the Department of the in the south east of Brazil (Cepeda et al. 2012); and Tereancistrum paranaensis Karling, Lopes, Development of Fishery and Inspection/DEFOP Takemoto and Pavanelli, 2014 from Schizodon (License #SP/538/88). All animal procedures borellii (Boulenger, 1900) from the Upper Paraná were performed in full compliance with the Ethics River floodplain, Brazil (Karling et al. 2014). Committee for Animal Experimentation (protocol During an investigation of helminth fauna of #120) of the Universidade Estadual Paulista fish from the Sapucaí-Mirim River and Jurumirim (São Paulo State University - UNESP). The fish Reservoir in the south east of Brazil, specimens specimens collected were individually stored in of an undescribed species of Tereancistrum were plastic bags and placed in a Styrofoam box with ice recovered from the gills of Leporinus friderici for immediate transportation to the laboratory. An Acad Bras Cienc (2017) 89 (2) A NEW SPECIES OF Tereancistrum 1123 The gills were removed and placed in vials Biociências (the Helminthological Collection containing hot water with a temperature of of the Institute of Biosciences) (CHIBB), of the around 60°C. After that, they were shaken, and Universidade Estadual Paulista (São Paulo State absolute ethanol was added (Thatcher 2006). The University - UNESP), in the municipality of monogeneans were collected and stored in 70% Botucatu, São Paulo state, Brazil. ethanol solution. Samples of these parasites were stained with Gömöri’s trichrome and mounted in RESULTS Canada balsam for analysis of internal organs. MORPHOLOGICAL DESCRIPTION Some specimens were mounted in Hoyer’s and Gray and Wess medium for the study of sclerotized Dactylogyridae Bychowsky, 1933 structures (Kritsky et al. 1986). Tereancistrum Kritsty, Thatcher and Kayton, 1980 Morphological and morphometric analysis Tereancistrum flabellumn. sp. of parasites was carried out using a computerized Diagnosis: Based on 13 specimens. Body system for image analysis with differential elongate, 336 (260–434; n=13) long; greatest width interference contrast (DIC) – LAS V3 (Leica 91 (64–124; n=13) near mid-length; tegument thin Application Suite V3; Leica Microsystems, Wetzlar, and smooth. Cephalic region with two bilateral Germany). The illustrations of the sclerotized incipient cephalic lobes; head organs well- structures were performed with the aid of a camera developed, cephalic glands indistinct. One pair lucida mounted on a Leica DMLS microscope of eyes; accessory granules sometimes present in with phase contrast optics. All measurements were the cephalic region and trunk. Pharynx spherical, presented in micrometers (μm) and expressed 21 (17–26; n=11) in diameter; esophagus short, as means, followed by the range and number bifurcating into two intestinal caeca; caeca confluent of specimens measured (n) in parentheses. The posterior to gonads. Haptor 60 (52–76; n=13) prevalence and mean intensity of infestation was long, 100 (84–118; n=13) wide. Ventral anchor 45 calculated in accordance with Bush et al. (1997). (41–49;