ABSTRACT The Guatemalan Caribbean has a deepwater fishing area close to the shore around the Cayman Trench. This study reports the first record of the bluntnose sixgill shark (Hexanchus griseus) from this fishing area. Fishery-independent surveys using longlines at ~430-465 m depth, ~11 km northeast of El Quetzalito fishing village, were conducted in 2022 and 2023. Two bluntnose sixgill sharks were captured during these surveys. The sharks were females with total lengths of 300 and 310 cm, with morphological characteristics consistent with this species. These are the first confirmed records of bluntnose sixgill sharks in the western Caribbean Sea. Expanding coastal fisheries to deeper waters presents an emerging threat to deep-sea chondrichthyans in the region. Therefore, periodic fisheries monitoring is needed to estimate their vulnerability to fishing pressure.

Abstract This paper describes the fishing profile and the temporal variation in the commercial landings of elasmobranchs in a global hotspot for their conservation and investigates the variables that influenced the landings. Census data on commercial catches were obtained between April 2008 and October 2010 from nine landing sites in Bragança (Pará, northern Brazil). Five vessel types, four fishing gears, and eight fishing techniques engaged with elasmobranch capture were identified. A total of 2,357 landings were recorded, with a total production of 354 t. The highest yields were recorded in 2009, with sharks being harvested mostly by small and medium-sized vessels, and batoids, by small vessels and canoes. Drifting nets and longlines played a prominent role in elasmobranch fisheries. The results show that the landings were influenced by days at sea, which is common in tropical fisheries. The elasmobranch data series is discontinuous as statistics are absent for most fishing sites albeit imperative for proper management, as well as relevant for decision-makers focusing on their conservation. 200 201 Pará, Pará (Pará Brazil. Brazil . Brazil) types gears identified 2357 2 357 2,35 35 t 2009 mediumsized medium sized batoids canoes fisheries sea management decisionmakers decision makers 20 235 2,3 3 23 2,

ABSTRACT The southern rays bream (Brama australis) is a highly migratory, epi-mesopelagic species supporting an important artisanal fishery off central-southern Chile. Despite its importance, several questions exist about this species's demography and migratory routes. The first step in understanding the migratory behavior of B. australis is to test the feasibility of a conventional tagging program, a standard mark-recapture method, to infer migration in fish. Between February 2020 and December 2021, conventional tagging was conducted during 21 fishing trips on board artisanal vessels off Lebu harbor (Biobío Region, Chile) using gillnets, longlines, and handlines. Three thousand nine hundred forty-six individuals of B. australis between 30 and 55 cm fork length were tagged using external T-anchor bar labels (commonly known as “spaghetti”). Approximately 100 and 200 fish were tagged per fishing trip using longlines and gillnets, respectively. The size distribution of the tagged individuals was consistent with those retained in the catch, with 90% of tagged fish being longer than the fork length at 50% maturity. Eight tags have been recovered off the coast of Lebu up to May 2022. With times at liberty between 50 and 537 days. These preliminary recaptures are also analyzed in the context of the conceptual model for demography and migration proposed for this species in Chile. The main conclusion of this research is that a conventional tagging program is feasible for B. australis in Chile.

ABSTRACT There are very little data on Central America and the Western Caribbean elasmobranch populations. Here we present the first results of standardized fisheries-independent monitoring of sharks and rays in Panama’s Bocas del Toro Archipelago over four consecutive years. Using baited remote underwater videos (BRUVs), underwater visual census (UVC), and scientific longline, we provide baseline data on the composition, relative abundance, distribution, and demographics of seven shark species and six rays observed during the study. Observations differed among methods and habitats, with BRUVs (n = 148) more effective for assessing shark diversity and abundance and UVC (n = 108) more effective for assessing ray abundance. Nurse sharks (Ginglymostoma cirratum) and southern stingrays (Hypanus americanus) were the most commonly observed species overall (frequency of occurrence = 30.4 and 18.9%, respectively). Depth, temperature, and protected area status significantly affected the relative abundance of sharks and rays based on UVC and BRUV data. The use of scientific longlines (n = 55) highlighted the lagoon habitat as a potential nursery site for blacktip sharks (Carcharhinus limbatus), with juvenile (average total length = 113 cm) individuals representing 58% of longline captures. The results provide a current baseline for elasmobranch communities that can further aid in the conservation and management of these species nationally and regionally.

Resumo: O rio Madeira é o mais extenso afluente do rio Amazonas e possui a maior biodiversidade de peixes do mundo. Em sua margem direita, o rio Madeira recebe o rio Jamari, no qual foi construída a primeira usina hidrelétrica (UHE) do estado de Rondônia, a UHE Samuel. Além desta, outros barramentos foram construídos no rio Jamari e em seus afluentes, contudo são raras as informações disponíveis na literatura científica sobre a diversidade ictiofaunística desta bacia. O objetivo deste trabalho foi providenciar um inventário ictiofaunístico na região da bacia do rio Jamari, no estado de Rondônia, onde foram implantadas três pequenas centrais hidrelétricas (PCHs). A ictiofauna foi amostrada em 16 expedições entre os meses de agosto de 2015 e dezembro de 2018. Foram utilizadas redes de espera e arrasto com malhas de diversos tamanhos, além de espinhéis e tarrafas em diferentes períodos do dia. Adicionalmente, 81 lotes de espécies do INPA da área de influência da UHE Samuel foram reanalisados. Os peixes foram identificados de acordo com a literatura especializada, bem como em consultas com especialistas de diversos grupos taxonômicos. Exemplares testemunho das espécies foram catalogados e depositados na coleção ictiológica do Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura da Universidade Estadual de Maringá. Foram registradas 230 espécies, destas, 22 são possíveis espécies novas, 117 são acrescentadas à bacia do rio Jamari e 28 à bacia do rio Madeira. A continuação dos estudos neste trecho da bacia do rio Jamari é fundamental para análises de impacto local devido à presença de barramentos. Além disso, a adição de possíveis novas espécies à bacia do rio Madeira aponta lacunas no conhecimento da ictiofauna Neotropical.

Abstract: The Madeira River is the most extensive tributary of the Amazon River and has the largest diversity of fishes in the world. On its right bank, the Madeira River receives the Jamari River, in which the first hydroelectric power plant (HPP) in State of Rondônia, Samuel HPP, was built. Besides this, other dams were built in the Jamari River and its tributaries, however, the available information in the scientific literature about the ichthyofaunistic diversity of this basin is rare. This work aims to provide an ichthyofaunistic inventory in a region of the Jamari river basin, in the State of Rondônia, where three small hydropower plants (SHPs) were implemented. The ichthyofauna was sampled in 16 expeditions between August 2015 and December 2018. Gill nets and seine nets were used with different meshes, as well as longlines and cast nets at different times of the day. Additionally, 81 INPA lots of species from the Samuel HPP area of influence were reanalyzed. Fish were identified according to the specialized literature, as well as in consultations with experts of various taxonomic groups. Voucher specimens of the species were cataloged and deposited in the ichthyological collection of the Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura (Nupélia) of the Universidade Estadual de Maringá. A total of 230 species were recorded, of which 22 were putative new species, 117 were added to the Jamari River basin and 28 to the Madeira River basin. The continuation of the studies in this section of the Jamari river basin is fundamental for analysis of local impact due to the presence of dams. Moreover, the addition of putative new species to the Madeira River basin indicates gaps in the knowledge of Neotropical ichthyofauna.

Resumo A determinação do período de parto e identificação de áreas de berçário são fundamentais para o manejo e conservação da espécie. Através da combinação de abundância mensal, comprimentos e tempo de desenvolvimento de embriões nós inferimos sobre a época de parto do tubarão galha preta, Carcharhinus limbatus, no Sudoeste Atlântico. Espécimes de C. limbatus foram capturados entre 2002 e 2008 por frotas artesanais de três locais diferentes ao longo da costa brasileira usando redes de emalhar (largura de malha variando entre 30 e 120 mm entre nós opostos e operando de 9 a 120 m de profundidade), linhas de mão (19 a 140 m de profundidade) e espinhel (6 a 90 m de profundidade). Através de análise comparativa de dados de desembarque pesqueiro, verificamos picos de captura de neonatos (< 90 cm) em períodos específicos do ano em diferentes localidades e, combinando com a previsão de nascimento de embriões, propomos que C. limbatus apresenta um período de parto bem definido no final da primavera e início do verão no Sudoeste do Atlântico. Além disto, nós indicamos prováveis áreas de berçário ao longo da costa brasileira. Estas informações serão cruciais para avaliações de estoque da espécie e poderão servir de base para determinação de medidas de manejo de pescarias.

Abstract The determination of the period of parturition and identification of nursery areas are fundamental for the management and conservation of a fishing resource. Through combination of monthly abundance, length measurements, and development time of embryos we inferred about parturition time of the Blacktip sharks, Carcharhinus limbatus, from Southwestern Atlantic. Specimens of C. limbatus were caught from 2002 and 2008 by artisanal fleets from three different locations along the Brazilian coast using gillnets (mesh width ranging between 30 and 120 mm between opposite knots and operating from 9 to 120 m in depth), handlines (19 to 140 m depth) and longlines (6 to 90 m depth). Through a comparative analysis of fisheries landing data collected, we have verified neonatal (< 90 cm) catch peaks at specific times of the year in different locations and, matching with birth prediction of embryos, propose that C. limbatuspresents a well-defined parturition time in late spring-early summer in Southwestern Atlantic. Moreover, we indicate supposed nursery grounds for the species along the Brazilian coast. This information will be crucial for stock assessments of the species and may serve as a basis for determining fisheries management measures.

ABSTRACT Longlines bearing “hook timers” (HTs) and alternating circle (15/0 and 17/0) and “J” (10/0) hooks were employed off the coast of Brazil to measure differences in fishing mortality associated with hook type and on-hook time between capture and boarding. A total of 431 HTs were activated, revealing a clear pattern of the increased mortality rate of fishes associated with increased on-hook time. Swordfish had high mortality rates, unlike blue sharks, which had low mortality rates regardless of hook type and the location in which the hook was transfixed. The six species of tunas and billfishes examined in this study showed a strong association between hooking location and the animal's release condition, with reduced mortality associated with individuals hooked externally. Results suggest that knowledge of factors affecting the survival of pelagic fishes caught in longline fisheries may enable the development and adoption of fishing methods to reduce mortality of longline bycatch.

Interactions between the longline toothfish (Dissostichus eleginoides) fisheries and cetaceans in the Southern Ocean have been registered over three decades. Two species primarily involved in these interactions are the sperm whale (Physeter macrocephalus) and the orca (Orcinus orca). Both species have been registered depredating on the longlines and fisheries have been substantially affected by the noticeable decrease on the catch. In this review, we summarized current knowledge about these interactions occurring south of 47°S in the industrial fleet. At present, interactions occur predominantly with the orca and in a lower extent with the sperm whale, after the modification of the fishing gear that diminished the depredation of the sperm whale. To date, many alternatives have been tested to repel cetaceans, including physical modifications of the fishing gear, acoustic devices, and changes in the fishing practices by the vessels, yet none seem effective. In the future, not one solution but a complex mix of actions must be coordinated effectively between the fishing operators, researchers, fishery engineers and State Public Institutions in order to diminish these interactions.

Interacciones entre la pesquería de palangre del bacalao de profundidad (Dissostichus eleginoides) y cetáceos en el Océano Austral se han registrado desde hace más de tres décadas. Las dos especies de cetáceos que se han visto mayormente involucradas son el cachalote (Physeter macrocephalus) y la orca (Orcinus orca). Ambas especies han sido observadas depredando sobre las líneas de palangre y las pesquerías de bacalao se han visto sustancialmente afectadas por la notoria disminución de las capturas. En este trabajo, resumimos el conocimiento que se tiene de las interacciones al sur de los 47°S en buques pesqueros industriales. Actualmente, las interacciones ocurren principalmente con la orca y en un menor grado con el cachalote, luego de la modificación del arte de pesca que ha disminuido la depredación de este último. A la fecha, distintas alternativas para disminuir esta interacción han sido probadas, incluyendo modificaciones físicas del arte de pesca, dispositivos acústicos y cambios en las prácticas pesqueras, sin embargo, no existe una solución a este problema. A futuro, un conjunto de acciones deberían ser coordinadas efectivamente entre los operadores pesqueros, investigadores, ingenieros pesqueros e instituciones públicas del estado, a través de un programa colaborativo con el objetivo de disminuir estas interacciones.

Atividades de pesca e perfuração exploratória disputam espaços em regiões oceânicas da costa brasileira. A agregação de peixes ao redor das plataformas atrai as embarcações para sua proximidade, fazendo com que adentrem a área de segurança de 500 metros, atividade considerada ilegal. Com o objetivo de identificar a frota que frequenta uma área de exclusão e a existência de relação sazonal nessa interação, foi realizado um estudo durante duas campanhas exploratórias, em períodos distintos, pela plataforma "Ocean Star" na bacia marítima do Espírito Santo. Os resultados indicaram uma elevada incidência de embarcações artesanais na área proibida e um comportamento não cooperativo por parte da tripulação. O método estatístico Análise Fatorial de Correspondência identificou embarcações que utilizavam o espinhel pelágico para pescaria de dourado (Coryphaena hippurus), registradas no Estado do Espírito Santo e com comprimento superiores a 11 m, pertencentes à campanha realizada no verão. A pescaria de Scombridae, com embarcações menores do que 11 m e não registradas no Espírito Santo, foram identificadas na campanha realizada no outono-inverno. Em conclusão, pode-se afirmar que as frotas foram distintas em cada campanha exploratória, mas para comprovar o real motivo dessa aproximação da plataforma são necessárias mais pesquisas sobre o assunto.

Fishing and oil drilling compete for space in some regions off the Brazilian coast. Fish congregate around drilling platforms, which attracts fishing vessels that may illegally breach the 500 m safety perimeter. The objective of this study was to identify the fleets that frequent the safety zone of a platform and their behavior and to determine if there was a seasonal relationship in this interaction, during two exploration campaigns, in different periods, carried out on the "Ocean Star" platform in the Espírito Santo Basin. The results indicated a high incidence of artisanal fishing vessels inside the prohibited area, and of uncooperative behavior on the part of the boat crews. The statistical method of Factorial Correspondence Analysis distinguished vessels that were using pelagic longlines to fish for dolphinfish, registered in the state of Espírito Santo and longer than 11 m, which operated during the summer campaign. Vessels fishing for scombrids, which were less than 11 m long and registered outside Espírito Santo, were prominent in the autumn-winter campaign. In conclusion, the data showed that the fleets involved in each exploratory campaign were different, but to determine the real reason why the boats insist on frequenting the area close to the platform further study is necessary.

The estimated age (around 45 years) from vertebral growth band counts for the largest Sphyrna mokarran caught in the Gulf of California and Central Mexican Pacific in the last decades, locates it as the oldest elasmobranch reported to date in Mexican Pacific waters. The specimen studied was a mature female of approximately 550 kg of total weight and 424 cm of total length, caught by artisanal fishermen using longlines south of the archipelago of Islas Marías on November 11th 2010. The distance between growth bands showed fast growth during the first 10 years. Growth bands after the age of 38 were only visible in the corpus calcareum, though difficult to separate and count. The age estimated in the present study was similar to the maximum age reported for the species in the Atlantic Ocean and Gulf of Mexico, confirming the species as long lived.

La edad estimada (alrededor de 45 años) a partir del conteo de las bandas de crecimiento vertebrales del ejemplar de Sphyrna mokarran más grande capturado en el Golfo de California y Pacífico Central Mexicano en las últimas décadas, lo sitúan como el elasmobranquio de mayor edad reportado en aguas del Pacífico mexicano. El organismo estudiado fue una hembra madura de aproximadamente 550 kg de peso total y 424 cm de longitud total, capturada por pescadores artesanales con palangre, al sur del archipiélago de las Islas Marías el 11 de noviembre de 2010. La distancia entre las bandas de crecimiento mostró un rápido crecimiento durante los primeros 10 años de vida. Después de los 38 años de edad las bandas fueron sólo visibles en el cuerpo calcáreo, siendo difíciles de separar y contar. La edad estimada en el presente estudios fue similar a la edad máxima reportada para la especie en el Océano Atlántico y el Golfo de México, confirmando a la especie como longeva.

En el Caribe colombiano existe una flota de embarcaciones artesanales denominadas ''pargueras'', consideradas las más desarrolladas de la región; no obstante, las operaciones de pesca se realizan manualmente, lo que implica mayor esfuerzo físico y restricción de las zonas de pesca, haciendo de esta una actividad poco productiva; en este sentido, la incorporación de maquinaría a la flota ''parguera'' artesanal, contribuye a mejorar la eficiencia. En consecuencia, se diseñaron, se calcularon, se construyeron y se instalaron en una embarcación dos máquinas hidráulicas: un tambor, para calado e izado de una red y un cobra-líneas, para virar palangres y nasas. Se realizó un seguimiento de las operaciones de pesca de la embarcación con las innovaciones y la flota tradicional, para comparar tiempos y movimientos, y a partir de las capturas desembarcadas, se realizó un análisis económico comparativo. Los resultados indicaron que la unidad con las máquinas disminuyó los tiempos de calado e izado de las artes de pesca y, consecuentemente, la tripulación evidenció reducción del esfuerzo físico. El incremento de las capturas demostró que las utilidades de la embarcación innovada triplicaron a las tradicionales (229% más); sin embargo, se identificaron actos inseguros, que obligan implementar normas de seguridad, para evitar accidentes. En conclusión, la mecanización de la flota facilitó las operaciones de pesca, mejoró la posición ergonómica, aumentó el tiempo efectivo de pesca, incrementó las capturas y permitió acceder a otros caladeros para disminuir la presión que soportan los tradicionales.

In the Colombian Caribbean a fleet of artisanal vessels called ''pargueras'' is considered the most developed in the region. However, fishing operations are done manually which involves physical effort and restricted fishing areas, making this an unproductive activity, in this sense, incorporating machinery to the fleet ''parguera'' helps to improve efficiency. Consequently, in an artisanal boat two hydraulic machines were designed, calculated, constructed and installed: A net drum for setting and hauling gillnets and a hauler for longlines and traps. Fishing operations of the vessel with the innovations and traditional fleet were monitored, to compare times and movements and a comparative economic analysis from landed catches was carried out. The results indicated that the vessel using innovations decreased the time setting and hauling of fishing gear and consequently the crew evidenced a reduction of physical effort. The increase in catches showed that the profits of the innovated vessel tripled the traditional ones (more than 229%), however, unsafe acts were identified that require implementing security standard protocols to prevent accidents. In conclusion, the mechanization of the ''pargueras'' fleet facilitated fishing operations, improved ergonomic position, increased effective fishing time and catches and allowed access to other fishing grounds to reduce the pressure on the traditional ones.

An experiment using longlines to evaluate the effects of hook type and depth of longline on the catches of sharks and other pelagic species was carried out close to Mazatlan, Mexico. We compared the J-style hooks, tuna hook, tuna 18° offset hook, and circle hook at three depth strata: S1 (0-55 m), S2 (55-85 m) y S3 (85-99 m). From the total capture, the circle hook had significantly higher catch rate than J-style hook and tuna hook. The main species caught with circle hook were blue marlin (Makaira nigricans) and striped marlin (Tetrapturus audax). The highest biomass of blue shark (Prionace glauca), blue marlin, sailfish (Istiophorus platypterus) and striped marlin was found in the shallow stratum (0-55 m) than in the deep stratum (85-99 m). By hook type, the higher capture of blue marlin was with circle hook and tuna hook at shallow depths (0-55 m)

Para evaluar el efecto del tipo de anzuelo y la profundidad de colocación del palangre sobre la captura de tiburones y otras especies pelágicas, se realizó un experimento cerca de Mazatlán, México. Se compararon los anzuelos recto plano 8/0, atunero plano 8/0, atunero inclinado 8/0 (18° de inclinación) y circular plano, en tres estratos de profundidad: S1 (0-55 m), S2 (55-85 m) y S3 (85-99 m). De la captura total, el anzuelo circular mostró significativamente mayor tasa de captura de marlin azul (Makaira nigricans) y marlin rayado (Tetrapturus audax), comparado con el anzuelo recto y el anzuelo atunero plano. En el estrato de profundidad más somero de los anzuelos (0-55 m) se presentó una mayor tasa de captura y peso de tiburón azul (Prionace glauca), marlin azul, pez vela (Istiophorus platypterus) y marlin rayado comparado con el estrato más profundo (85-99 m). La mayor tasa de captura y peso de marlin azul se presentó con los anzuelos circular y atunero plano en la profundidad más somera del palangre (0-55 m)

Desde 1994, o pacu Piaractus mesopotamicus, é a principal espécie nas capturas comerciais e esportivas no Pantanal sul-matogrossense, e seu rendimento máximo sustentável já foi ultrapassado. Sua captura só é permitida por anzóis, para as duas pescarias acima, visto que as artes de emalhe são proibidas na região. O objetivo deste estudo foi o de determinar a seletividade para diferentes tamanhos de anzóis usados na captura do pacu e verificar a partir de qual tamanho de anzol somente os adultos são capturados. Para tal, foram realizadas pescarias nos rios Miranda, Aquidauana e Vermelho, nos meses de janeiro, março e abril de 2002. Seis espinhéis contendo 8 tamanhos diferentes de anzóis foram empregados. A abertura do anzol foi adotada para expressar sua seletividade. Diferentes anzóis capturaram indivíduos de mesmo comprimento, e suas medianas foram similares, evidenciando a grande sobreposição dos tamanhos capturados. As regressões entre ln[c2 (l)/c1 (l)] e l não foram significativas. O teste de Kolmogorov-Smirnov também não detectou diferenças significativas nos tamanhos dos peixes capturados por diferentes anzóis. Várias hipóteses são levantadas para explicar a ausência de seletividade dessa amplitude de tamanhos de anzóis para a espécie. O recrutamento para a pesca, porém ocorre aos 28 cm de comprimento total, quando os indivíduos ainda estão imaturos.

The Pacu Piaractus mesopotamicus is the most captured fish species in the Pantanal, Mato Grosso do Sul State, and since 1994, its maximum sustainable yield had already been exceeded. Its capture is carried out only by hooks, as mesh gears are forbidden either for professional or for recreational fishing. The aim of this study was to determine selectivity for different hook sizes used in P. mesopotamicus fishing and to verify which sizes capture only adults. Data were collected in the rivers Miranda, Aquidauana, and Vermelho, in January, March, and April 2002. Six longlines with eight hook sizes were used and we adopted the hook opening as a measure related to selectivity. Different hooks captured individuals of the same length and their medians were similar, evidencing the great overlap among sizes. Regression results showed no significant relationship between ln[c2 (l)/c1 (l)] and total length of captured individuals. In addition, the Kolmogorov-Smirnov test also did not detect significant differences in the size of captured fish. Several hypotheses, such as the selectivity models, shape of selection curves, scarcity of large fishes, and behavior are used in order to explain the absence of hook selectivity for this species. Size of recruitment for this gear was 28 cm of total length, when individuals are still immature.

O Canal da Piracema é considerado o maior sistema de transposição para peixes no mundo, com 10 km de extensão. A sua construção foi controversa, pois viabilizou a conexão entre duas províncias ictiofaunísticas distintas. Este trabalho buscou avaliar a ictiofauna presente no Canal da Piracema, a abundância e distribuição das espécies migradoras de longa distância ao longo deste sistema de transposição (indicação de seletividade). O Canal da Piracema mostrou-se difícil de ser amostrado, devido a sua elevada heterogeneidade ambiental: lagos artificiais, escadas e canais semi-naturais, sendo utilizados diversos aparelhos de pesca, adequados aos diversos biótopos (litoral não estruturado e estruturado, amostrados com redes de arrasto e pesca elétrica; lêntico, amostrado com redes de espera e espinhel (mais profundo); e águas rápidas, amostradas com tarrafas). A ictiofauna presente seguiu o padrão para a América do Sul e rio Paraná, com amplo domínio de Characiformes e Siluriformes, sendo Characidae, Anostomidae, Pimelodidade e Loricariidae as famílias mais representativas. Ao todo foram capturadas 116 espécies sendo que 17 eram migradoras de longas distâncias. Nas regiões litorâneas estruturadas e não estruturadas do Canal da Piracema, as capturas se restringiram às espécies de pequeno porte, sendo as mais representativas Bryconamericus exodon e Apareiodon affinis.Nas áreas lênticas houve predomínio de Hypostomus spp., seguidos de Iheringichthys labrosus. Nas áreas lênticas profundas a espécie mais capturada foi Hoplias aff. malabaricus. Nas áreas de águas rápidas houve maior captura de espécies migradoras de longa distância, sendo Prochilodus lineatus e Leporinus elongatus as mais capturadas. A redução acentuada, no sentido de jusante a montante, inclusive das migradoras, indica que o Canal da Piracema está sendo seletivo. Então, a busca de informações dos vários tipos de sistemas de transposição existentes ao longo do Canal da Piracema é fundamental para permitir a movimentação ascendente de peixes. Se isto for alcançado, este polêmico mecanismo de transposição tem potencial para contribuir para a conservação dos estoques de peixes no reservatório de Itaipu e segmento a montante, devido a presença de áreas de desova e crescimento necessários para as espécies migradoras.

The Canal da Piracema is the longest (nearly 10 km) fish pass system in the world. The construction of this fish pass was somehow controversial, because it connected two distinct ichthyofaunistic provinces. This study evaluated the ichthyofauna present in the Canal da Piracema and the abundance and distribution of long-distance migratory fish species along this fish pass system (evaluated possible selectivity). The Canal da Piracema was shown to be difficult to sample because of its environmental heterogeneity: artificial ponds, ladders and nature-like fish pass. To solve this problem, we used several fishing gears, adequate for the several biotopes present (unstructured and structured littoral were sampled with seining nets and electrofishing; lentic were sampled with gillnets and longlines (deeper areas); and rapid water areas were sampled with cast nets). The ichthyofauna of the Canal da Piracema followed the pattern for South America and the Paraná River, with a predominance of Characiformes and Siluriformes. The most representative families were Characidae, Anostomidae, Pimelodidae and Loricariidae. We captured 116 species (17 were long-distance migratory) during the period studied. Small-sized species were predominant in unstructured and structured littoral areas, especially Bryconamericus exodon and Apareiodon affinis.The most abundant species was Hypostomus spp. in lentic areas, followed by Iheringichthys labrosus. Hoplias aff. malabaricus predominated in deeper lentic areas. Long-distance migratory species were abundant in rapid waters; they were Prochilodus lineatus and Leporinus elongatus. The sharp reduction in the number of species, including migratory ones, is an indication that the Canal da Piracema is selecting the species that ascend it. Therefore, the search for information on the efficiency of the various fish passes present in the Canal da Piracema is fundamental, to facilitate upward movements of fish. If this is reached, this polemic fish pass has the potential to contribute to the conservation of fish stocks in Itaipu Reservoir and upstream stretches, because of the presence of spawning and development (nurseries) areas for migratory species.

A longline exploratory fishing around Robinson Crusoe island, belonging to the Juan Fernandez Archipelago, was conducted between November 1996 and March 1997. The experience was developed by setting horizontal and vertical longlines at stations over four radial transects, between 50 and 1000 m depth, using unbalanced hooks numbers 5, 6, 7 and 9. Main resources caught during these activities were: deep water eel (Bassanago nielseni), breca (Cheilodactylus gayi), Juan Fernandez rockfish (Scorpaena fernandeziana), croaker (Helicolenus lengerichi), Juan Fernandez corvina (Umbrina reedi), Juan Fernandez mackerel (Pseudocaranx chilensis), moray (Gymnotorax porphyreus), codling (Mora moro), Juan Fernandez dogfish (Squalus mitsukurii), robin fish (Pterygotrigla picta) and alfonsino (Beryx splendens). Even though the catch with these gears was not conspicuously abundant, it was possible to identify the deep water fauna around these islands. The species with higher yields were the breca and Juan Fernandez dogfish, between 50 and 200 m, and codling, between 400 and 600 m. Between 600 and 1000 m no fishes were recorded

La pesca exploratoria con espineles se efectuó en torno a la isla Robinson Crusoe del archipiélago de Juan Fernández, entre noviembre de 1996 y marzo de 1997. Esta experiencia fue desarrollada mediante el calado de espineles horizontales y verticales en estaciones posicionadas sobre 4 transectas orientadas radialmente a las islas, entre 50 y 1000 m de profundidad. En dicha experiencia se trabajó principalmente con anzuelos desbalanceados números 5, 6, 7 y 9. Los principales recursos capturados en estas actividades correspondieron a: anguila de profundidad (Bassanago nielseni), breca (Cheilodactylus gayi), cabrilla de Juan Fernández (Scorpaena fernandeziana), chancharro (Helicolenus lengerichi), corvina de Juan Fernández (Umbrina reedi), jurel de Juan Fernández (Pseudocaranx chilensis), morena (Gymnotorax porphyreus), ribaldo (Mora moro), tollo de Juan Fernández (Squalus mitsukurii), pez mariposa (Pterygotrigla picta) y alfonsino (Beryx splendens). Si bien las capturas obtenidas con estos aparejos no fueron especialmente abundantes, permitieron determinar la fauna íctica de aguas profundas en torno a estas islas. Las especies que presentaron los rendimientos más altos fueron la breca y tollo de Juan Fernández, entre 50 y 200 m, y el ribaldo, entre 400 y 600 m. Entre 600 y 1000 m no se registró captura de peces