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The genus Catadiscus Cohn, 1904 has a total of 16 known species that infect the intestinal tract of reptiles, amphibians, and mollusks. However, Catadiscus has never been found in teleosts. The annual fish Austrolebias prognathus (Amato, 1986) and A. cheradophilus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete, 1965) were collected from temporary ponds in the southeast of Uruguay. The specimens found in the intestinal tract of these hosts were morphologically identified as Catadiscus uruguayensis Freitas & Lent, 1939, which until now were only known to infect amphibians. This work represents the first report of the genus Catadiscus infecting and developing in a fish host., Centro de Estudios Parasitológicos y de Vectores

Este trabajo describe y analiza una experiencia de investigación y extensión con los trabajadores de la Intergremial Marítima de Uruguay, quienes cuestionaban la sustentabilidad del modelo de explotación pesquero industrial. Se emplearon técnicas cualitativas y cuantitativas de relevamiento y análisis de información y participación activa entre actores sociales (investigación participativa). Considerando el complejo pesquero como productivo, se describen los vínculos de los sindicatos con el equipo universitario interdisciplinario y, desde una perspectiva extensionista, la producción conjunta de conocimiento, la apropiación del mismo por los actores y el planteo de propuestas alternativas al modelo de explotación cuestionado. Se compatibilizaron los tiempos de investigación con las urgencias de los actores sociales que demandaron la intervención. A través de la identificación de problemas críticos, el proceso de extensión permitió establecer propuestas de cambio al modelo de explotación y el desafío de construir agenda de investigación a partir de la actividad de extensión. O objetivo deste trabalho foi descrever e analisar uma experiência de pesquisa e extensão com os trabalhadores da Intergremial Marítima do Uruguai, que questionavam a sustentabilidade do modelo de exploração da pesca industrial. Técnicas qualitativas e quantitativas foram utilizadas para levantar e analisar informações e a participação ativa entre os atores sociais (pesquisa participativa). Considerando o complexo pesqueiro produtivo, descrevem-se os vínculos dos sindicatos com a equipe interdisciplinar universitária e, numa perspectiva de extensão, a produção conjunta do conhecimento, a apropriação dele pelos atores e a formulação de propostas alternativas ao modelo de exploração questionado. Os tempos de pesquisa foram conciliados com as urgências dos atores sociais que exigiam a intervenção. A partir da identificação de problemas críticos, o processo de extensão possibilitou o estabelecimento de propostas de mudanças no modelo de exploração e o desafio de construir uma agenda de pesquisa baseada na atividade extensionista. The objective of this work was describing and analyzing a research and extension experience with the workers of the Intergremial Marítima of Uruguay, who questioned the sustainability of the industrial fishing exploitation model. Qualitative and quantitative techniques were used for data collection and analysis, including active participation among social actors (participatory research). Considering the fishing complex as a productive complex, the bonds of the syndicate with the interdisciplinary university team are described from an extensive perspective. This includes, the co–production of knowledge, the appropriation of it by the actors and the alternative proposals to the exploitation model that has been questioned. The research time was reconciled with the urgencies of the social actors who demanded the intervention. From identifying critical issues, the extension process allowed us to establish proposals for changes to the exploitation model and the challenge of building a research agenda from the extension activity.

Silversides are renowned for their phenotypic plasticity with different populations coexisting as incipient species. The New World silverside Odontesthes argentinensis is an estuarine-resident fish with known populations inhabiting the Rio de la Plata estuary as well as coastal lagoons of Brazil, Uruguay and Argentina, where it constitutes an important resource for artisanal fisheries. Using classical morphometric analysis, we study six morphological variables to determine if there are differences between the New World silversides collected from two Uruguayan Atlantic coastal lagoons (Garzon and Rocha Lagoons), which communicate periodically with the ocean. In collaboration with artisanal fishermen, silversides were measured in fresh condition. After removing the size and allometric effect on the variables, Canonical Discriminant Analysis (DA) was applied to compare the morphometry of individuals collected in the two lagoons. Results supported the existence of two groups with values greater than 80% of accurate classification. The morphometric variables that contributed the most to this result were eye diameter, breadth of mouth, length from mouth tip to anal fin and length of pectoral fin. The first two morphometric variables are related to sensory perception and feeding, which could be indicators of an ecological segregation, conditioned by the characteristics of the environment, considering that the two coastal lagoons differ in their abiotic characteristics, most importantly in their hydrodynamic conditions. This work represents the first study of differences between two estuarine coastal lagoon populations of O. argentinensis.

The present study analyses the seasonal (summer: January, February, March; autumn: April, May, June; winter: July, August, September and spring: October, November, December) and annual (2006, 2007 and 2011) length-weight relationships and condition factors of Micropogonias furnieri and Cynoscion guatucupa from Río de la Plata and the Uruguayan ocean coast from data collected throught monthly landings by the Uruguayan coastal fleet in the Montevideo port (Uruguay). A total of 9,146 individuals of M. furnieri ranging from 15 to 69 cm total length (L T); and 5,285 individuals of C. guatucupa, ranging from 21 to 54 cm L T were analyzed. For both species, the allometry coefficients showed that growth in the majority of seasons were negative (b < 3), except for M. furnieri in spring 2006 (isometric, b = 3) and during summer 2011 (positive, b > 3). For M. furnieri, no significant differences among slopes were found between 2006 and 2007 whereas 2011 showed significant differences compared to 2006 and 2007. For C. guatucupa no significant differences among slopes were found between 2007 and 2011, whereas 2006 showed significant differences with other years. The highest values for the condition factor in M. furnieri were recorded in summer 2006, and during the summer and autumn 2007 and for C. guatucupa in winter 2006 and autumn 2007. Significant seasonal and annual differences for condition factors were found for both species. This work provides the first reference regarding condition factor for both sciaenid species in the study area. RESUMEN En este trabajo se analizaron las relaciones longitud-peso y el factor de condición de Micropogonias furnieri y Cynoscion guatucupa en diferentes épocas [verano; otoño; invierno, primavera y años (2006, 2007 y 2011)] a partir de muestreos mensuales de desembarques de la flota costera uruguaya que operó en el Río de la Plata y costa oceánica uruguaya. Fueron analizados 9.146 individuos de M. furnieri (entre 15-69 cm de longitud total) y 5.285 individuos de C. guatucupa, (entre 21-54 cm de longitud total). Para ambas especies, el coeficiente de alometría fue negativo (b < 3), excepto para M. furnieri en primavera de 2006 (isométrico, b = 3) y durante verano de 2011 (positivo, b > 3). Para M. furnieri, las pendientes no mostraron diferencias significativas entre el 2006 y 2007, mientras que el 2011 presentó diferencias significativas con ambos años. Para C. guatucupa no se encontraron diferencias significativas entre el 2007 y 2011, pero si cuando ambos años fueron comparados con el 2006. Los mayores valores del factor de condición fueron obtenidos en verano de 2006 y durante el verano y otoño del 2007 para M. furnieri, mientras que para C. guatucupa fueron en invierno 2006 y otoño 2007. Para ambas especies el factor de condición mostró diferencias significativas estacionales y anuales. Este trabajo presenta la primera referencia del factor de condición para estas especies de Sciaenidos en el área de estudio.

Specimens of Rioraja agassizi were collected at Guarujá pier, São Paulo State, Brazil, from March 2005 to March 2006. A total of 275 males were captured. Based on the analysis of the clasper length, gonad weight, clasper gland length, alar thorns and lobule diameter, the size-at-maturity was estimated to be 32 cm. There were 1049 females in the record. Size-at-maturity was calculated in 40 cm. Sexual resting females were observed. Gonadosomatic and hepatosomatic indexes varied significantly in both sexes throughout the year. However, ovulation, egg-laying and presence of sperm in the seminal vesicle were observed all year round. For this reason, an annual cycle with at least one peak in the sexual activity is proposed for this species. BIOLOGÍAREPRODUCTIVADE RIORAJAAGASSIZI (MÜLLERAND HENLE, 1841) (CHONDRICHTHYES: RAJIDAE), ENEL SUDESTEBRASILEÑO, ATLÁNTICO SUDOCCIDENTAL. –Se colectaron especímenes de Rioraja agassizi en el puerto de Guarujá, Estado de San Pablo, Brasil, desde marzo de 2005 hasta marzo de 2006. Se capturó un número total de 275 machos. De acuerdo con el análisis de la longitud del clasper y de la glándula del clasper, el peso de las gónadas, el diámetro de los lóbulos y el número de espinas alares, el tamaño de primera madurez sexual fue estimado en 32 cm. Se capturó un número de 1049 hembras. El tamaño de primera madurez sexual fue calculado en 40 cm. Se observó reposo sexual en hembras de esta especie. Los índices gonadosomáticos y hepatosomáticos variaron significativamente en ambos sexos a lo largo del año. Sin embargo, la ovulación y la deposición de cápsulas ovígeras sucedieron continuamente durante todo el año, así como la presencia de esperma en la vesícula seminal en ejemplares adultos. Por este motivo, se propone para esta especie, un ciclo reproductivo anual, con por lo menos un pico en la actividad sexual.

The diet of the South American Tern (Sterna hirundinacea) and its seasonal variation during the 2005 and 2006 non-reproductive seasons in the Uruguayan Atlantic coast was analyzed. Diet was assessed by the analysis of pellets collected in the Rocha lagoon sandbar, a major tern roosting area in Uruguay, aiming to analyze the hypothesis that terns feed mainly on the Argentine Anchovy (Engraulis anchoita) during the wintering period. A total of 844 pellets were collected, 442 in 2005 and 402 in 2006. Diet was composed of fish (88 %), insects (9 %) and crustaceans (3 %). The main fish species consumed was the Argentine Anchovy (77.7 %), followed by Marini's Anchovy (Anchoa marinii) (7.9 %) and the Striped Weakfish (Cynoscion guatucupa) (3.6 %). Insects and crustaceans were the main items in two of the groups of pellets collected during the study period. Despite this temporal variation in the diet, the Argentine Anchovy was the main prey item consumed during both seasons. These results support the hypothesis that South American Terns strongly depend on anchovies as trophic resource. En este trabajo se analizó la dieta del Gaviotín Sudamericano (Sterna hirundinacea) y su variación estacional durante las temporadas no reproductivas de 2005 y 2006 en la costa atlántica uruguaya. La dieta fue estudiada por medio del análisis de bolos colectados en la barra de la laguna de Rocha, una importante zona de descanso para la especie en Uruguay, con el propósito de analizar la hipótesis de que el gaviotín se alimenta principalmente de Anchoíta Argentina (Engraulis anchoita) durante el período de invernada. Un total de 844 bolos fueron colectados, 442 en 2005 y 402 en 2006. La dieta estuvo compuesta por peces (88 %), insectos (9 %) y crustáceos (3 %). La principal presa consumida fue la Anchoíta Argentina (77.7 %), seguida de la Anchoa (Anchoa marinii) (7.9 %) y la Pescadilla de Red (Cynoscion guatucupa) (3.6 %). Los insectos y los crustáceos fueron el ítem principal en dos de las muestras (grupos de bolos) colectadas durante el período de estudio. A pesar de esta variación temporal en la dieta la Anchoíta Argentina fue la presa principal durante las dos temporadas de estudio. Este resultado apoya la hipótesis planteada de que la anchoíta es el principal recurso alimenticio del Gaviotín Sudamericano.

This study analyses the seasonal fisheries and sexual proportion of the narrownose smooth-hound Mustelus schmitti from the Uruguayan oceanic coast. The maximum catches took place during the fall. Of a total of 2105 individuals, 1483 were males and 622 females, being females larger than males. Females were dominant at maximum depths of 50 m (inner shelf), whereas males occupied major depths of 50 m (outer shelf). The great proportion of mature females on the inner shelf during spring and summer, and mature males in summer are related to the mating, ovulation and delivery time as previously proposed for this shark in this area. The length in which 50% of the females were retained was below or on the length of sexual maturity of the narrownose smooth-hound, indicating that these are more affected by the fishing activity. Nevertheless, an important fraction of the population that distributes on the inner and outer shelf during the time of parturition, ovulation and mating would be protected in spring and summer by the establishment of fishing bans of the fishes Cynoscion guatucupa and Merluccius hubbsi

Specimens of Atlantoraja cyclophora were collected monthly from commercial fishing landings at Guarujá, São Paulo State, Brazil, from March 2005 to April 2006 at depths between 10 and 146 m. Males ranged from 13.3 to 58.5 cm TL (n = 396). Both the smallest mature male and the largest immature male were 47.0 cm long. Males’ size-at-50% maturity was calculated to be 46.3 cm. Females ranged from 11.5 to 68.0 cm (n = 401). The smallest mature and the largest immature female were 51.6 and 53.0 cm long respectively. For the females, size-at-50% maturity was calculated to be 53.2 cm. In the males the hepatosomatic and gonadosomatic indices varied between 0.48 (August) and 3.54 (November) and between 0.15 (November) and 1.45 (June) respectively, with no significant variation for the fourteen-month period. In the females the hepatosomatic and gonadosomatic indices varied from 1.55 and 6.30 3.54 (both for April 2006) and from 0.08 (December) to 4.41 (October) respectively, with no significant difference among months. Egg-bearing females were found in all months with proportions varying from 0.03 (March) to 0.67 (April). Both males and females undergo an annual cycle, with slight seasonal variations in reproductive activity and a peak in the proportion of egg bearing females between April and July. Jedinke raže okatice, Atlantoraja cyclophora prikupljene su mjesečno iz gospodarskih lovina u Guarujá u, država São Paulo, Brazil, od ožujka 2005. do travnja 2006. na dubinama od 10 do 146 metara. Duljina mužjaka kolebala je od 13.3 do 58.5 cm TL (n=396). Najmanji spolno zreli mužjak i najveća spolno nezrela ženka bili su dugi 47.0 centimetara. Izračunata dužina mužjaka pri stadiju 50% zrelosti populacije je iznosila 46.3 cm. Dužina ženki se kretala u rasponu od 11.5 do 68.0 cm (n=401). Najmanja spolno zrela i najveća nezrela ženka su bile dugačke 51.6 cm, odnosno 53.0 cm. Izračunata dužina ženki pri stadiju 50% zrelosti populacije je iznosila 53.2 cm.Kod mužjaka su hepatosomatski i gonadosomatski indeks kolebali od 0.48 (kolovoz) i 3.54 (studeni) i između 0.15 (studeni) i 1.45 (lipanj) bez značajnih kolebanja tijekom razdoblja od četrnaest mjeseci. Kod ženki su hepatosomatski i gonadosomatski indeks kolebali od 1.55 do 3.54 (oba u travnju 2006.) i između 0.08 (prosinac) i 4.41 (listopad), bez značajnijih mjesečnih kolebanja. Ženke s jajima su bile nazočne tijekom svih mjeseci u razmjerima koji su kolebali od 0.03 (ožujak) do 0.67 (travanj). I mužjaci i ženke prolaze kroz svoj godišnji ciklus, sa neznatnim sezonskim kolebanjima u reproduktivnoj aktivnosti i maksimumom u proporciji ženki s jajima između travnja i srpnja.

Specimens of Rioraja agassizi were collected monthly off Santos, Southeast Brazil, between latitudes 23°37’S and 27°40’S,from March, 2005 to March, 2006. A total number of 278 males and 1023 females were captured. Observed depth range was 10-120 m, being the species absent above 120 m. Sex ratio significantly favored females. The entire length range of R. agassizi was observed. Females ranged in length from 16.0 to 59.4 cm and males from 13.0 to 47.2 cm. Mean female length was significantly higher than that of males. For grouped length distributions, asymmetry patterns were observed in both sexes. Length-width functions were sexually dimorphic. Males with lengths < 24.5 cm were relatively wider than females. Length-total weight curves were significantly different than length-gutted weight ones, in both sexes. Females were heavier than males for a given TL class. The angular coefficient b was significantly 3 (positive allometry). The monthly variation of the condition factor showed significant differences in both sexes. Espécimes de Rioraja agassizi foram mensalmente coletados em águas ao largo de Santos, sudeste do Brasil entre as latitudes 23°37’S e 27°40’S, desde março de 2005 até março de 2006. Um total de 278 machos e 1023 fêmeas foi capturado. A amplitude de profundidade de ocorrência foi 10-120 m, estando a espécie ausente em profundidades >120 m. A razão sexual favoreceu as fêmeas. A amplitude completa de comprimentos de R. agassizi esteve representada e oscilou nas fêmeas entre 16.0-59.4 cm comprimento e nos machos entre 13.0-47.2 cm. O tamanho médio das fêmeas foi significativamente maior do que dos machos. A distribuição de freqüência de comprimentos por amostras agrupadas foi assimétrica em ambos os sexos. As curvas da relação comprimento-largura foram sexualmente dimórficas. As fêmeas foram mais largas que os machos em todas as classes de comprimento maiores do que 25 cm. As curvas comprimento-peso total foram significativamente diferentes das curvas comprimento-peso eviscerado em ambos os sexos. As fêmeas foram mais pesadas do que os machos para uma determinada classe de comprimento. O coeficiente angular b foi 3). O fator de condição variou significativamente ao longo do ano em ambos os sexos.