Geographic range, distribution patterns and interactions of Monogenea Van Beneden 1858, with species of native host freshwater fishes from Brazil / Distribuição geográfica, padrões de distribuição e interações de Monogenea Van Beneden 1858, com espécies de peixes hospedeiros nativos de água doce do Brasil

Abstract This paper investigated information on monogenean species using 312 scientific papers, to search for infection and geographic distribution patterns in native freshwater fish from Brazil. We used 1,698 samples of 296 fish species of 28 families distributed into Characiformes, Siluriformes, Cichliformes, Gymnotiformes, Perciformes, Mugiliformes, Osteoglossiformes and Clupeiformes, in addition to four hybrid fish. Among the hosts of the different orders and families, the greatest numbers of parasite-host associations were found for species of the families Serrasalmidae, Characidae, Loricariidae, Curimatidae and Anostomidae. The 578 species of monogeneans used in parasite-host interactions were distributed in 86 genera of six five families (Dactylogyridae, Gyrodactylidae, Diplectanidae, Microcotylidae, Ancylodiscoididae and Ancyrocephalidae), but with great predominance of Dactylogyridae species. There was variation in prevalence, intensity and abundance levels of monogeneans species among host fish species, as well as in infection sites that occurred predominantly in external organs. Positive correlations of prevalence, intensity and abundance with body length of hosts were observed. There was geographic distribution pattern of monogeneans limited mostly to two hydrographic basins those being the Amazon River and Paraná River. Just approximately 6% of potential monogeneans have been explored thus far, showing a clear need for further studies on this interesting group of parasites.

Resumo Este estudo investigou informações sobre espécies de monogenéticos, usando 312 artigos científicos para buscar padrões de infecção e distribuição geográfica em peixes nativos de água doce do Brasil. Foram utilizadas 1.698 amostras de 296 espécies de peixes de 28 famílias, distribuídas em Characiformes, Siluriformes, Cichliformes, Gymnotiformes, Perciformes, Mugiliformes, Osteoglossiformes e Clupeiformes, além de quatro peixes híbridos. Entre os hospedeiros das diferentes ordens e famílias, os maiores números de associações parasito-hospedeiro foram encontrados para espécies das famílias Serrasalmidae, Characidae, Loricariidae, Curimatidae e Anostomidae. As 578 espécies de monogenéticos, utilizadas nas interações parasito-hospedeiro, foram distribuídas em 86 gêneros de seis famílias (Dactylogyridae, Gyrodactylidae, Diplectanidae, Microcotylidae, Ancylodiscoididae e Ancyrocephalidae), mas com grande predominância de espécie de Dactylogyridae. Houve variação nos níveis de prevalência, intensidade e abundância das espécies de monogenéticos entre as espécies de peixes hospedeiros, bem como nos locais de infecção que ocorreram predominantemente em órgãos externos. Correlações positivas de prevalência, intensidade e abundância com o comprimento corporal dos hospedeiros foram observadas. Houve padrão de distribuição geográfica dos monogenéticos limitados principalmente a duas bacias hidrográficas, sendo elas o Rio Amazonas e Rio Paraná. Apenas aproximadamente 6% dos potenciais monogenéticos são conhecidos até agora, mostrando uma clara necessidade de mais estudos sobre esse interessante grupo de parasitos.

Record of the rare Caribbean mud eel, Pythonichthys sanguineus (Heterenchelyidae, Anguilliformes), in the region of the Amazon Reef / Registro da rara enguia de lama do Caribe, Pythonichthys sanguineus (Heterenchelyidae, Anguilliformes) na região dos Recifes da Amazônia

As they spend most of their time buried in the substrate and are not a fishery resource, heterenchelyids are seldom seen. These eels are characterized by their greatly reduced eyes, which are covered by semi-transparent skin, the absence of a pectoral fin or lateral line, and no pores on the head or body. Pythonichthys sanguineus is a particularly poorly-known species, with only eight scientific records from Cuba, Puerto Rico, Colombia, Venezuela, Guyana, and Suriname. The present study is based on six adult specimens of P. sanguineus captured by vessels of the shrimp trawling fleet along the northern Brazilian coast, in the vicinity of the Amazon Reef. We provide meristic, morphometric and DNA barcoding data. These findings provide insights into the distribution of the species off the northern Brazilian coast and contribute to the discussion about the southern limit of the Greater Caribbean fauna. (AU)

Heterenchelídeos passam a maior parte do tempo enterrados no substrato e raramente são vistos, não representando recursos pesqueiros importantes. Essas enguias são caracterizadas por seus olhos muito reduzidos e cobertos por pele semi-transparente, ausência de nadadeiras peitorais ou linha lateral, e ausência de poros na cabeça ou no corpo. Pythonichthys sanguineus é uma espécie particularmente pouco conhecida, com apenas oito registros em coleção zoológica para Cuba, Porto Rico, Colômbia, Venezuela, Guiana e Suriname. O presente estudo é baseado em seis espécimes adultos de P. sanguineus capturados pela frota industrial de arrasto de camarão-rosa na costa norte do Brasil, ao largo dos Recifes da Amazônia. Apresentamos dados merísticos, morfométricos e de DNA barcoding dos exemplares examinados. O registro fornece informações importantes sobre a distribuição da espécie na costa norte do Brasil, e contribui para a discussão sobre o limite sul da fauna do Grande Caribe.(AU)

Influence of strategic points in the dispersion of Aedes aegypti in infested areas / Influência de pontos estratégicos na dispersão de Aedes aegypti em áreas infestadas

ABSTRACT OBJECTIVE: To evaluate whether sites with large amount of potential breeding sites for immature forms of Aedes aegypti, called strategic points, influence in the active vector's dispersion into properties in their surroundings. METHODS: We selected four areas in the municipality of Campinas, three of them with strategic points classified as high, moderate, and low risk according to infestation and a control area, without strategic points. Between October 2015 and September 2016, we monthly installed oviposition traps and evaluated the infestation by Ae. aegypti in all properties of each selected area. To verify if there was vector dispersion from each strategic point, based on its location, we investigated the formation of clusters with excess of eggs or larvae or pupae containers, using the Gi spatial statistics. RESULTS: The amount of eggs collected in the ovitraps and the number of positive containers for Ae. aegypti did not show clusters of high values concerning its distance from the strategic point. Both presented random distribution not spatially associated with the positioning of strategic points in the area. CONCLUSIONS: Strategic points are not confirmed as responsible for the vector's dispersion for properties in their surroundings. We highlight the importance of reviewing the current strategy of the vector control program in Brazil, seeking a balance from the technical, operational, and economic point of view, without disregarding the role of strategic points as major producers of mosquitoes and their importance in the dissemination of arboviruses in periods of transmission.

RESUMO OBJETIVO: Avaliar se locais com grande quantidade de potenciais criadouros de formas imaturas de Aedes aegypti, denominados pontos estratégicos, influenciam a dispersão ativa do vetor aos imóveis no seu entorno. MÉTODOS: Foram selecionadas quatro áreas no município de Campinas, três delas com pontos estratégicos classificados como alto, médio e baixo risco segundo a infestação e uma área controle, sem ponto estratégico. Entre outubro de 2015 e setembro de 2016, instalaram-se mensalmente armadilhas de oviposição e avaliou-se a infestação por Ae. aegypti em todos os imóveis de cada área selecionada. Para verificar se houve dispersão do vetor a partir de cada ponto estratégico, com base em sua localização, investigou-se a formação de aglomerados com excesso de ovos ou de recipientes com larvas ou pupas, utilizando a estatística espacial Gi. RESULTADOS: o número de ovos coletados nas ovitrampas e o número de recipientes positivos para Ae. aegypti não apresentaram aglomerados de altos valores relativos à sua distância do ponto estratégico. Ambos apresentaram distribuição aleatória não associada espacialmente com o posicionamento dos pontos estratégicos na área. CONCLUSÕES: Pontos estratégicos não se confirmaram como responsáveis pela dispersão do vetor para os imóveis no seu entorno. Destaca-se a importância de rever a estratégia atual do programa de controle de vetores do Brasil, buscando um equilíbrio do ponto de vista técnico, operacional e econômico, sem desconsiderar o papel dos pontos estratégicos como grandes produtores de mosquitos e sua importância na disseminação de arboviroses em momentos de transmissão.

Distribución y abundancia del pez león Pterois volitans (Scorpaeniformes: Scorpaenidae) y especies nativas asociadas en el Parque Marino Cayos de San Felipe, Cuba / Distribution and abundance of the lionfish Pterois volitans (Scorpaeniformes: Scorpaenidae) and associated native species in Parque Marino Cayos de San Felipe, Cuba

ResumenEl primer avistamiento del pez león en el Parque Nacional "Cayos de San Felipe" en el 2009 podría amenazar la diversidad de sus ecosistemas marinos y la capacidad de brindar servicios. Para analizar la incidencia de la invasión del pez león en el área, se realizó un muestreo anual entre 2013 y 2015. La abundancia y la talla del pez león se estudió en manglares a través de censos visuales en diez transectos de 30x2 m/estación y en arrecifes (15 y 25 m de profundidad) con estéreo video en seis transectos de 50x2 m/estación. En arrecifes también se estimó incidencia de posibles competidores y depredadores nativos. En los tres años de estudio, la densidad promedio del pez león varió entre 0.0-1.3 indiv./100 m2 por estación de muestreo y no fue significativamente diferente entre hábitats (mangle - 0.6 indiv./100 m2, arrecifes a 15 m - 0.4 indiv./100 m2 y arrecifes a 25 m - 0.3 indiv./100 m2). La densidad de pez león fue igual o menor que la de competidores e igual o mayor que la de depredadores en ambas profundidades. La densidad del pez león en manglares y arrecifes a 25 m se mantuvo temporalmente estable, mientras que en arrecifes a 15 m disminuyó. Se observó que el incremento temporal de la abundancia de competidores y la densidad de depredadores no cambió durante el monitoreo. La talla del pez león varió entre 5 y 39 cm, siendo su promedio en manglares (12.6 cm) menor que en arrecifes (25.2 cm) y no mostró variaciones entre años. La talla de pez león en arrecifes fue más alta que la de competidores y menor que la de depredadores. Los resultados mostraron que en el parque: 1) los manglares son zonas de cría del pez león, 2) la incidencia del pez león en arrecifes no es tan alta como en otras áreas de Cuba y el Caribe y 3) la abundancia del pez león en arrecifes tendió a disminuir en el tiempo sin intervención de acciones extractivas o presencia de abundancia alta de meros nativos de tallas grandes. Considerando los resultados, se hacen recomendaciones para continuar el monitoreo e investigar los efectos del pez león y los factores que estan regulando su incidencia en el parque.

Abstract:The first lionfish sighting at the National Park "Cayos de San Felipe" was in 2009 and could be a threat to its marine ecosystem diversity and their capacity to generate services. To analyze the incidence of the lionfish invasion in the area, an annual sampling was conducted between 2013 and 2015. Lionfish abundance and size was investigated on mangroves through visual census on ten transects of 30x2 m/station, and on coral reefs (15 and 25 m deep) with stereo video on six transects of 50x2 m/station. Additionally, incidence of potential native competitors and predators on coral reefs were also estimated. Over the three years, the average density of lionfish varied between 0.0-1.3 indiv./100 m2 per sample stations and it was not significantly different among habitats (mangroves with 0.6 indiv./100 m2, reefs at 15 m - 0.4 indiv./100 m2 and reef at 25 m with 0.3 indiv./100 m2). Lionfish's density was equal to or lower than competitors' density, and was equal to or higher than predator's density in both depths. While lionfish density on mangroves and on reefs at 25 m remained temporally stable, it decreased on reefs at 15 m. Temporary increase in the competitor's density was observed and the predator´s density did not change during the monitored time. Lionfish size varied between 5 and 39 cm; the average fish size from mangroves (12.6 cm) was consistently lower than from reefs (25.2 cm) and showed no variations among years. Lionfish size in reefs was higher than competitor's size and lower than that of predator. Results showed that in the park: 1) mangroves represent lionfish nursery areas; 2) incidence of reef lionfish was not as high as in other areas of Cuba and the Caribbean; and 3) lionfish abundance in reefs tended to decrease over the years, without the intervention of extractive activities or high abundance of large size native groupers. In this sense, recommendations are made to continue monitoring and to investigate lionfish effects and factors that are regulating its incidence in the park. Rev. Biol. Trop. 65 (1): 117-125. Epub 2017 March 01.

Distribution of the deep-sea genus Bathypterois (Pisces: Ipnopidae) in the Eastern Central Pacific / Distribución del género de profundidad Bathypterois (Pisces: Ipnopidae) en el Pacífico Centro Oriental

Abstract:The genus Bathypterois (tripod fish) comprises 19 species of deep-sea fishes distributed worldwide. The biology and distribution of the species of this genus are relatively poorly known throughout the Eastern Central Pacific (ECP). This work aims to update the geographic and bathymetric distribution of species of Bathypterois throughout the ECP. To describe the influence of depth, temperature and dissolved oxygen concentrations (DO) on latitudinal and depth distribution of members of the genus throughout the Mexican Pacific, 51 specimens of B.atricolor (12 trawls) and 112 of B. ventralis (18 trawls), collected during TALUD project, were analyzed. Bathypterois atricolor had broader environmental niches (depth: 0.47, temperature: 0.46, DO: 0.39), and inhabits deeper and colder sites (Electivity positives: > 1 000 m, < 3.2 °C, 1.0-1.62 mL/L) than B. ventralis, which had narrow environmental niches (depth: 0.34, temperature: 0.32, DO: 0.28), with high affinity to warmer sites and lower DO concentrations (Electivity positives: 778-1 400 m, 3.3-5.8 °C, < 1.0 mL/L). Both species used different environmental strata (niche overlap; depth: 0.34, temperature: 0.32, DO: 0.28). The adaptation of B. atricolor to live in a broad range of DO concentrations explains its almost circumglobal distribution, while B. ventralis lives almost permanently in the Oxygen Minimum Zone (< 0.05 mL/L), so the DO could be a limiting factor, reducing its potential geographic and bathymetric distributions. None of these species had been previously recorded in the central Gulf of California, and B. ventralis had not been recorded along the West coast of Baja California. This study confirms that both species have a continuous distribution within the ECP, our new records extended the known northernmost range for B. atricolor by 886 km (from 22°46' N to 30°45' N) and for B. ventralis by 645 km (from 21°18' N to 27°07' N). Rev. Biol. Trop. 65 (1): 89-101. Epub 2017 March 01.

ResumenEl género Bathypterois (peces trípode) está conformado por 19 especies de peces de profundidad, distribuidas alrededor del mundo. La biología y distribución de las especies de este género son relativamente poco conocidas a lo largo del Pacífico Centro Oriental (POT). Este trabajo tiene el objetivo de actualizar la distribución geográfica y batimétrica de las especies del género Bathypterois a lo largo del POT. Para describir la influencia de la profundidad, temperatura y concentraciones de oxígeno disuelto (OD) sobre la distribución latitudinal y batimétrica de miembros del género Bathypterois en el Pacífico Mexicano, se analizaron 51 especímenes de B.atricolor (12 arrastres) y 112 B. ventralis (18 arrastres), recolectados durante el proyecto TALUD. Bathypterois atricolor presentó nichos ambientales más amplios (profundidad: 0.47, temperatura: 0.46, OD: 0.39) y habita sitios más profundos y fríos (Electividad positiva: > 1 000 m, < 3.2 °C, 1.0 - 1.62 mL/L) en comparación con B. ventralis, que tiene nichos ambientales reducidos (profundidad: 0.34, temperatura: 0.32, OD: 0.28), con alta afinidad por sitios más cálidos y bajas concentraciones de OD (Electividad positiva: 778-1 400 m, 3.3-5.8 °C, < 1.0 mL/L). Estas especies utilizaron distintos estratos ambientales (traslape de nicho; profundidad: 0.34, temperatura: 0.32, OD: 0.28). La adaptación de B. atricolor para vivir en un amplio intervalo de concentraciones de OD explica su distribución casi circunglobal, mientras que B. ventralis vive casi permanentemente en la Zona de Mínimo Oxígeno (< 0.05 mL/L), por lo que el OD puede ser un factor limitante, reduciendo su posible distribución geográfica y batimétrica. Ninguna de estas especies había sido registrada anteriormente en el centro del Golfo de California, así como B. ventralis no había sido reportada a lo largo de la costa occidental de Baja California. Este estudio confirma que ambas especies tienen una distribución continua dentro del POT, nuestros nuevos registros extienden la distribución más norteña conocida para B. atricolor en 886 km (de 22°46' N a 30°45' N) y en 645 km para B. ventralis (de 21°18' N a 27°07' N).

Distribución y abundancia espacial y temporal de Stomolophus meleagris (Rhizostomae: Stomolophidae) en un sistema lagunar del sur del Golfo de México / Spatial and temporal abundance and distribution of Stomolophus meleagris (Rhizostomae: Stomolophidae) in a lagoon system Southern Gulf of Mexico

ResumenLas escifomedusas se alimentan principalmente de crustáceos microscópicos, huevos y larvas de peces, moluscos y de otras medusas. La distribución y abundancia de la escifomedusa tiene una importancia económica y ecológica ya que son depredadores que influyen en la dinámica poblacional de otras pesquerías. El presente trabajo se realizó de septiembre 2013 hasta agosto 2014 en el sistema lagunar Arrastradero-Redonda, Tabasco, con el objetivo de aportar información sobre la distribución y abundancia espacial y temporal de la escifomedusa Stomolophus meleagris y su relación con los parámetros ambientales. Para su realización se efectuaron recorridos mensuales durante un ciclo anual y se recolectaron muestras biológicas; realizándose tres arrastres en cada una de las estaciones, en una área de 1 km2, con una duración de 5 a 10 min con un chinchorro playero de monofilamento de 20 m de longitud por 3 m de altura y luz de malla de 1.5 cm, con esos datos se realizó el análisis de eficiencia pesquera, (CPUE con Org./Unidad de superficie evaluada) y se determinó la relación con los parámetros ambientales. Se estableció que la mayor abundancia se presentó de la estación 1 a la 3 con 7 a 19 Org/km2 en los meses de abril hasta agosto 2014 y su menor abundancia se observó en las estaciones 6 a 10 con un promedio de 1 Org./km2 desde octubre 2013 a marzo 2014. El análisis de correlación múltiple por pasos indicó que existe una fuerte asociación entre la CPUE y algunas variables ambientales estudiadas, observándose el 70.9 % de la variabilidad de los datos. La salinidad fue la variable más influyente explicando el 64.3 % de la variabilidad, seguida por la temperatura con un 3.6 % mientras el oxígeno disuelto explica solo el 2.9 % de variabilidad, principalmente debido a que en la zona confluyen una serie de factores geológicos, oceanográficos y biológicos favorables para la proliferación de esta especie debido al aporte de agua marina de la barra de Tupilco. Sin embargo falta realizar mayores investigaciones que permita cuantificar este recurso y establecer zonas de explotación comercial y realizar estudios sobre el aspecto biológico, principalmente hábitos reproductivos y alimenticios; que aporten información necesaria para diseñar planes adecuados sobre su posible uso de manera adecuada. Así mismo con los datos obtenidos en el presente trabajo podamos determinar el potencial pesquero de este recurso en el estado de Tabasco.

Abstract:The scyphomedusae feed mainly on microscopic crustaceans, eggs and fish larvae, molluscs and some other jellyfishes. The distribution and abundance of the scyphomedusae has an economic and ecological impact as they are predators that have an influence on the population dynamics of other fisheries. This investigation took place in the lagoon system 'ArrastraderoRedonda', Tabasco, from September 2013 to August 2014, with the purpose to provide information on the distribution, and spatial and temporal abundance of Stomolophus meleagris; along with its relation to environmental parameters. A total of 10 stations were defined and biological samples were taken on a monthly basis during this annual cycle. For this purpose, three pulls with a beach seine monofilament (20 m long by 3 m height, mesh opening 1.5 cm, 5 to 10 minutes) per station were made within a 1 km2 area. Information obtained was used to calculate the fishing efficiency analysis (CPUE con org./Evaluated Area Unit) and to determine the relationship with the environmental parameters. Our results showed that the abundance in the stations 1 to 3 was from 7 to 19 org./km2 from April to August 2014; less organisms were observed in stations 6 to 10 (an average of 1 org./ km2) from October 2013 to March 2014. The multiple correlation steps analysis indicated that there is a strong association between the CPUE and some environmental investigated variables, and a 70.9 % variability of the data was observed. The salinity resulted the most important variable because it determined a 64.3 % of variation; it was followed by the temperature with a 3.6 %; meanwhile, dissolved oxygen explained only the 2.9 %, this was mainly because within the area there are several geological, oceanographic and biological factors that favor the distribution of this species due to seawater contribution through the Tupilco bar. With the provided data with this investigation we were able to determine the fishery potential of this resource for Tabasco state. However, additional research is required to allow an extended quantification of this resource, to determine the commercial exploitation areas, and drive studies about reproductive and feeding habits, that may provide the necessary information to establish plans for sustainable use. Rev. Biol. Trop. 65 (1): 167-179. Epub 2017 March 01.

Evaluación de análisis de endemicidad y PAE para identificar trazos generalizados, a partir de las serpientes del estado de Hidalgo, México / Evaluation of PAE and endemicity analysis for identifying generalized tracks using snakes in Hidalgo, Mexico

Resumen:Uno de los conceptos centrales en la Panbiogeografía es el trazo generalizado, el cual representa una biota ancestral que se ha fragmentado por eventos geológicos y puede recuperarse a través de distintos métodos, que incluyen el análisis de simplicidad de endemismos (PAE) y el análisis de endemicidad (AE). El PAE es un método frecuentemente utilizado para la identificación de trazos generalizados, mientras que el AE fue diseñado para encontrar áreas de endemismo, pero recientemente se ha usado también para identificar trazos generalizados. En este trabajo se evaluaron ambos métodos para la identificación de los trazos generalizados a partir de los datos de 84 serpientes distribuidas en el estado de Hidalgo, México. Con el PAE se obtuvo un trazo generalizado formado por tres trazos individuales (Agkistrodon taylori, Crotalus totonacus y Pliocercus elapoides), que corresponden a sinapomorfías que apoyan al clado principal. La prueba de robustez estadística mostró un soporte del 89 %, mientras que con el AE se identificaron dos áreas de endemismo con valores del índice de endemicidad de 2.71-2.96 y 2.84- 3.09 respectivamente, las cuales fueron transformadas a trazos generalizados; el primero formado por tres trazos individuales (Micrurus bernadi, Rhadinaea marcellae y R. quinquelineata) y el segundo formado por dos trazos individuales (Geophis mutitorques y Thamnophis sumichrasti). Estos trazos generalizados pueden considerarse un solo patrón de distribución, dada la cercanía geográfica y su topología. Al compararse los métodos se observó que ambos son útiles para la identificación de trazos generalizados, y aunque son independientes, se sugiere su uso de manera complementaria. Sin embargo, para una correcta aplicación e interpretación de los resultados, es necesario considerar las bases teóricas de cada método, así como la correcta elección del tamaño de las unidades de estudio. En el caso particular del AE si se utilizan tamaños de celda pequeños éstos pueden resultar ideales para la búsqueda de patrones biogeográficos a través de límites geopolíticos y esta información puede favorecer la realización de pro- puestas de conservación a nivel estatal que consideren a las especies con distribuciones restringidas, pues la pérdida de éstas representaría la extinción de linajes únicos.

Abstract:One of the most important concepts in Panbiogeography is the generalized track, which represents an ancestral biota fragmented by geological events that can be recovered through several methods, including Parsimony analysis of endemicity (PAE) and endemicity analysis (EA). PAE has been frequently used to identify generalized tracks, while EA is primarily designed to find areas of endemicity, but has been recently proposed for identifying generalized tracks as well. In this study we evaluated these methods to find generalized tracks using the distribution of the 84 snake species of Hidalgo. PAE found one generalized track from three individual tracks (Agkistrodon taylori, Crotalus totonacus and Pliocercus elapoides), supported by 89 % of Bootstrap, and EA identified two generalized tracks, with endemicity index values of 2.71-2.96 and 2.84-3.09, respectively. Those areas were transformed to generalized tracks. The first generalized track was retrieved from three individual tracks (Micrurus bernadi, Rhadinaea marcellae and R. quinquelineata), and the second was recovered from two individual tracks (Geophis mutitorques and Thamnophis sumichrasti). These generalized tracks can be considered a unique distribution pattern, because they resembled each other and agreed in shape. When comparing both methods, we noted that both are useful for identifying generalized tracks, and although they can be used independently, we suggest their complementary use. Nevertheless, to obtain accurate results, it is useful to consider theoretical bases of both methods, along with an appropriate choice of the size of the area. Results using small-grid size in EA are ideal for searching biogeographical patterns within geopolitical limits. Furthermore, they can be used for conservation proposals at state level where endemic species become irreplaceable, and where losing them would imply the extinction of unique lineages. Rev. Biol. Trop. 64 (4): 1611-1624. Epub 2016 December 01.

Population structure and reproduction of a migratory fish Leporinus piau (Characiformes: Anostomidae) in a semiarid tropical reservoir, Brazil / Estructura poblacional y reproducción del pez migratorio Leporinus piau (Characiformes: Anostomidae) en una represa tropical semiárida, Brasil

Abstract:Migratory fishes have been seriously impacted by the building of reservoirs and because of the negative effects of these projects such as the interruption of migratory routes, reduction or elimination of spawning/ feeding areas, and initial development can influence the population structure the migratory fishes, resulting in reduction in abundance. Leporinus piau is migratory fish widely distributed in the watersheds of the Brazilian semiarid and it is of importance for artisanal and sport fishing. The goal of the study was to evaluate the population structure and reproductive dynamics of the migratory species Leporinus piau in the Pau dos Ferros Reservoir, which is located in the semiarid region of Brazil. The CPUE, length structure, length-weight relation-ship, length at first maturity, sex ratio, gonad development and IGS were analyzed. Collections were performed quarterly between February 2011 and November 2012 using gillnets. The captured fish were counted; the standard length (cm) and total weight (g) were measured, and dissected to determine the sex and gonad maturity stage. The rainfall and reservoir water levels were recorded, and their correlations with the reproductive period and CPUE were analyzed. A total 549 individuals were captured. The average CPUE varied between 0.0259 individuals/m2*h (May/2011) and 0.0008 individuals/m2*h (August/2012), and significant differences were observed; however, significant correlations were not observed between rainfall and reservoir levels. The standard length varied between 5.9 cm and 20.7 cm, and the weight varied between 4.16 g and 271.5 g. A histogram analysis revealed that the 5-10 cm standard length class was the most abundant for juveniles and that the 10-15 cm class was the most abundant for adult females and males. The weight-length relationship was best fit by the equation log10Wt = -1.57711 + 3.00707 Log10 Ls, and the species presented isometric growth. The estimated length at first maturity was 12.76 cm. A total of 148 males and 82 females were collected (1.81:1, M:F), and these values were significantly different. The highest GSI was observed in February 2011 for both females (10.69) and males (5.72), and the GSI was significantly and positively correlated with rainfall. We concluded that the L. piau population is established in the reservoir and found that its reproduction period occurred during the rainy season between February and May. Rev. Biol. Trop. 64 (4): 1369-1381. Epub 2016 December 01.

Resumen:Los peces migratorios se han visto gravemente afectados por la construcción de embalses y los efectos negativos de estos proyectos, tales como la interrupción de rutas migratorias, reducción o eliminación de desove / áreas de alimentación. El desarrollo inicial puede influir en la estructura de la población de los peces migratorios, lo que resulta en la reducción en la abundancia de los mismos. El Leporinus piau es un pez migratorio que se encuentra ampliamente distribuido en las cuencas del semiárido brasileño y es de importancia para la pesca deportiva y artesanal. El objetivo del estudio fue evaluar la estructura de la población y la dinámica de reproducción de la especie migratoria Leporinus piau en el embalse Pau dos Ferros, región semiárida de Brasil. La relación estructura de tallas y talla-peso de la CPU la talla de la primera la madurez, proporción de sexos, el desarrollo gonadal y el IGS se analizaron. Con redes de enmalle se llevaron a cabo recolecciones trimestralmente entre febrero 2011 y noviembre 2012. Se contaron los peces capturados; se midieron la longitud estándar (cm) y peso total (g), y se disectaron para determinar el estadio del sexo y la madurez de las gónadas. Los niveles de agua de lluvia y los embalses se registraron y se analizaron sus correlaciones con el período reproductivo y la CPUE. Un total de 549 individuos fueron capturados. La CPUE promedio varió entre 0.0259 individuos/m2 * h (mayo/ 2011) y 0.0008 individuos/m2 * h (Agosto/2012), y se observaron diferencias significativas; sin embargo, ninguna correlación significativa se observo entre los niveles de lluvia y el nivel de la represa. La longitud estándar varió entre 5.9 y 20.7 cm, y el peso entre 4.16 y 271.5 g. Un análisis de histogramas, reveló que la clase estándar de 5-10 cm de longitud fue la más abundante de los jóvenes y que la clase 10-15 cm fue la más abundante de las hembras y machos adultos. La relación peso-talla se ajusta más adecuadamente a la ecuación log10Wt = -1.57711 + 3.00707 Log10 Ls, donde la especie presenta un crecimiento isométrico. La medida estimada de la primera madurez fue 12.76 cm. Se recogieron un total de 148 machos y 82 hembras (1.81: 1, M: F), y estos valores fueron significativamente diferentes. El más alto GSI se observó en febrero 2011, tanto para las mujeres (10.69) como para hombres (5.72), y el GSI fue significativa y positivamente correlacionado con la precipitación. Se llegó a la conclusión de que la población L. piau está establecida en la represa y encontramos que su periodo de reproducción se produjo durante la época de lluvias entre febrero y mayo.

Variación espacio-temporal de la ictiofauna del Parque marino Xel-Há, Caribe mexicano y su relación con parámetros fisicoquímicos / Spatio-temporal variation of the ichthyofauna in Xel-Ha, Mexican Caribbean Marine Park and its relationship to physico-chemical parameters

Resumen:Xel-Há es un parque ecoturístico marino donde no se permite ningún tipo de extracción de flora o fauna. Una de las principales atracciones turísticas en este parque son los peces de arrecife, no existiendo trabajos publicados sobre la comunidad íctica para este sitio. En este estudio se analizó la variación espacio-temporal de la comunidad íctica en diferentes zonas del parque marino Xel-Há. Para ello, se realizaron censos visuales durante un año en 21 transectos fijos de 100x5 m, distribuidos en cinco zonas del parque: "Bocana", "Centro", "Brazo Norte", "Cueva" y "Río", que incluyen la bocana del mar, canales de manglares y un sitio con aportes de agua dulce. Para caracterizar la comunidad de peces, se estimaron los descriptores ecológicos: riqueza de especies, diversidad, abundancia y densidad a partir del promedio de los censos y se compararon entre zonas y tres temporadas (lluvias, "nortes" y secas). El grado de similitud entre zonas y temporadas se evaluó mediante un análisis de escalamiento multidimensional no métrico. El reemplazo en la composición de especies entre temporadas fue determinado con la presencia-ausencia de peces. Además, se aplicó un análisis de componentes principales para evaluar si las variables fisicoquímicas como temperatura, salinidad y concentración de oxígeno disuelto influyen en la variación de las comunidades de peces. Se registró un total de 22 641 individuos que correspondieron a 63 especies, siendo "nortes", la temporada donde se presentó la mayor abundancia (7 991 organismos). Las especies mejor representadas basados en su abundancia total y frecuencia de aparición fueron: Haemulon sciurus, H. flavolineatum, Lutjanus griseus, Acanthurus coeruleus, Abudefduf saxatilis y Gerres cinereus. La diversidad incrementó de lluvias a secas y comparando entre zonas la riqueza de especies y diversidad fue menor en "Río". Entre temporadas, el 54 % de las especies fueron residentes durante todo el año; se observaron cuatro especies exclusivas para lluvias y tres para secas. La diversidad fue el único descriptor que permitió observar variación entre temporadas. El oxígeno disuelto fue la variable que más influyó en la variación de la comunidad de peces entre zonas. El parque Xel-Há, alberga cerca del 20 % de la biodiversidad de peces reportada para el Caribe mexicano y la predominancia de juveniles de varias especies confirma su importancia como sitio de crianza.

Abstract:Xel-Ha is a private marine park where the extraction of flora and fauna is not allowed. Here, reef fish are one of the main touristic attractions, but there are no published surveys focused on fish community in this site. In this study we analyzed the spatio-temporal variation of the fish community in different areas of the marine park Xel-Há. Abundance and richness were estimated during one-year period (2012-2013); visual censuses using fixed transects of 100x5 m each distributed in 21 transects along five sites were established in different zones: "Bocana", "Center", "North branch", "Cave" and "River", including the inlet mouth to the sea, brackish mangrove channels and a zone with freshwater influence. To characterize the fish community, we used species richness, abundance, diversity, and density compared among zones and climatic seasons (rain, "norths" and dry). The similarity among zones and seasons was estimated using a multidimensional scaling analysis. The replacement on the species composition among seasons and sites was realized based on the presence-absence of fish. The influence of physicochemical variables such as temperature, salinity and dissolve oxygen concentration in the fish community was estimated by a principal component analysis. A total of 22 641 individuals were recorded corresponding to sixty-three species over the year. Abundance was higher during the windy season (locally named "norths") with 7 991 organisms. The most representative species according with abundance and frequency of occurrence were: Haemulon sciurus, H. flavolineatum, Lutjanus griseus, Acanthurus coeruleus, Abudefduf saxatilis, and Gerres cinereus. Diversity increased from the rainy to the dry season; species richness and diversity was lower in "River" than other sites in Xel-Ha. Most species (54 %) species were residents through the year. Four non-shared species were observed during the rainy season and three in dry season. Dissolved oxygen was the most influential variable on the fish community composition among zones. Xel-Ha houses nearly 20 % of fish biodiversity reported for the mexican Caribbean, and the predominance of juveniles of several species confirms its role as a nursery area. Rev. Biol. Trop. 64 (4): 1353-1367. Epub 2016 December 01.

Distribution of the members of the Pipiens Assemblage in the sympatric area from Argentina: which is where and when?

Given their medical and veterinary relevance, the members of the Pipiens Assemblage are a worldwide target of ecological research. The distribution of Culex pipiens s.s. and Cx. quinquefasciatus converge in Buenos Aires, Argentina, where hybrids have been detected. Each member of the assemblage exhibits a distinct eco-physiological behaviour that can affect its efficiency in pathogen transmission. Our aim was to identify the environmental drivers for the spatio-temporal distribution of each member, focusing on latitudinal and urbanisation gradients. Immatures of mosquitoes were surveyed in artificial containers found within 11 public cemeteries, raised up to the adult stage and identified by their male genitalia. The distribution of each member was associated with the environment in a Generalized Linear Model. The variable accounting for most of the heterogeneity was latitude; Cx. quinquefasciatus was collected more frequently at northern cemeteries, whereas Cx. pipiens and hybrids were more likely at the southern extreme. The urbanisation gradient was also associated with the occurrence of Cx. quinquefasciatus and hybrids at the high and low end, respectively. Other relevant variables were cemetery total area, the proportion with graves and the presence of plastic flowers in the containers. The spatial distribution of the members of the Pipiens Assemblage within the sympatric region in South America is driven by environmental features. The information presented herein provides essential baseline data for surveillance programs and control activities.

Egg-guarding behavior of the treehopper Ennya chrysura (Hemiptera: Membracidae): female aggregations, egg parasitism, and a possible substrate-borne alarm signal

AbstractTreehoppers are known for their substrate-borne communication and some of them also for their subsocial behavior. Following a more general study of the natural history and substrate-borne signal repertoire of the treehopper Ennya chrysura, the objective of this paper was to explore in greater depth the signals and other behaviors associated specifically to egg-guarding. Theese were studied both in natural and laboratory conditions between July, 2000 and March, 2004. The spatial distribution of egg guarding females was studied in the natural population; recording equipment and playback experiments were used in the laboratory and then analyzed digitally. Under natural conditions (San Antonio de Escazú, Costa Rica), female E. chrysura guard their egg masses and egg-guarding was associated with lower parasitism of the eggs from the wasps Gonatocerus anomocerus and Schizophragma sp. (Mymaridae). Females tended to place their eggs close to other egg-guarding females and they produced substrate-borne vibrations when disturbed. An aggregated pattern under natural conditions was confirmed by calculating dispersion indices from egg-clutch data obtained from 66 leaves in the field. The disturbance signal was characterized from laboratory recordings of substrate-borne vibrations of 10 egg-guarding females. Experiments conducted in the laboratory with 18 egg-guarding females showed that those which were previously exposed to the disturbance signal of another female moved slightly or vibrated more during playbacks and that they reacted more quickly and exhibited more deffensive behaviors in response to a tactile stimulus. The signals produced while defending against egg parasites may therefore function as an alarm and favor aggregating behavior of egg-guarding females. Rev. Biol. Trop. 64 (3): 1209-1222. Epub 2016 September 01.

ResumenDespués de un estudio más general sobre la historia natural y la comunicación por vibraciones de sustrato del membrácido Ennya chrysura, este artículo explora con mayor profundidad los comportamientos específicamente relacionados con el cuido de los huevos. En condiciones naturales (San Antonio de Escazú, Costa Rica), las hembras de E. chrysura con frecuencia protegen sus masas de huevos, y el cuido está asociado con un menor porcentaje de parasitismo causado por las avispas parasitoides de huevos Gonatocerus anomocerus and Schizophragma sp. (Mymaridae). Las hembras tendían a poner sus huevos en la cercanía de otras hembras con huevos, y producían vibraciones de sustrato en respuesta a disturbios. Se confirmó un patrón agregado bajo condiciones naturales, calculando índices de dispersión a partir del número de masas de huevos en 66 hojas. La señal fue descrita a partir de grabaciones hechas en el laboratorio con 10 hembras que protegían sus huevos. Los experimentos conducidos con 18 hembras mostraron que aquellas que fueron expuestas a la señal de disturbio de otra hembra, se movieron ligaramente o vibraron más durante el experimento, y reaccionaron a un estímulo táctil más rápidamente y con un mayor número de comportamientos defensivos. Las señales producidas durante la defensa de huevos podrían entonces funcionar como alarma, y favorecer la agrupación con otras hembras que también protegen sus huevos.

Feeding ecology of three juvenile mojarras (Gerreidae) in a tropical estuary of northeastern Brazil

Distributions and feeding ecology of mojarra species from shallow water of a tropical estuary in Northeastern Brazil were observed aiming to investigate differences in distribution and resource partitioning among juveniles of three species of mojarras. Fishes were collected with a beach seine across four sites along a salinity gradient from January to December of 2011. Highest abundances were recorded during the rainy season in the upper and middle estuary. Microcrustaceans, mainly copepods, were the preferential prey items of all mojarras, irrespective of size or hydrological season, suggesting these areas may be important nursery habitats. Juveniles of mojarra used two important mechanisms for exploitation of resources: (1) spatial segregation along the salinity and temperature gradient, such as abundance of Eucinostomus melanopterus increased from downstream to upstream estuary, while Eugerres brasilianus displayed an opposite pattern; (2) differences related to the volumetric proportion of the main prey items, with indications that E. melanopterus and Diapterus rhombeus fed predominantly on Calanoida and Cyclopoida, while the diet of E. brasilianus was dominated by items of infauna. Such strategies were important for resource partitioning, favouring the coexistence of these three species in the estuary.

A distribuição e a ecologia alimentar de gerreídeos capturados em águas rasas de um estuário tropical no nordeste do Brasil foram abordados com o objetivo de investigar diferenças na distribuição e partição de recursos entre três espécies de gerreídeos juvenis. Arrastos de praia foram realizados ao longo de quatro locais ao longo do gradiente de salinidade entre janeiro e dezembro de 2011. Maiores abundâncias foram registradas durante a estação chuvosa na zona superior e média do estuário. Microcrustáceos, principalmente copépodos, foram as principais presas para as três espécies, independente do tamanho ou do período hidrológico, sugerindo que essas áreas são importantes para o recrutamento. Gerreídeos juvenis usaram dois importantes mecanismos para exploração dos recursos: (1) segregação espacial no uso dos habitats ao longo do gradiente de salinidade e temperatura, com a abundância de Eucinostomus melanopterus aumentando em direção a parte inferior para porção superior do estuário, enquanto Eugerres brasilianus apresentou um padrão oposto; e (2) diferenças relacionadas com a proporção volumétrica das principais presas ingeridas, com indicações que E. melanopterus e Diapterus rhombeus alimentaram-se principalmente de Calanoida e Cyclpoida, enquanto a dieta de E. brasilianus foi dominada por itens da infauna. Tais estratégias foram importantes para partição dos recursos, favorecendo a coexistência dessas três espécies no estuário.

Characterisation of Culex quinquefasciatus (Diptera: Culicidae) larval habitats at ground level and temporal fluctuations of larval abundance in Córdoba, Argentina

The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches) were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.

Longitudinal use of feeding resources and distribution of fish trophic guilds in a coastal Atlantic stream, southern Brazil

This study described the use of food resources and the distribution of fish trophic guilds along the longitudinal gradient of a coastal Atlantic stream, southern Brazil. Allochthonous resources (terrestrial insects) predominated in the headwaters, whereas autochthonous food items (algae, fish) and detritus predominated in the mouth section. Detritivorous, aquaticinvertivorous, and terrestrial- and aquatic-insectivorous species occurred throughout the gradient, while omnivorous and piscivorous in the headwaters and middle stretches, respectively, and herbivorous in the middle and mouth. Detritivores and aquatic-insectivores were significantly more specialized than the other guilds, however, there was no evidence of a longitudinal increase in trophic specialization. Density and biomass of aquatic-invertivores and aquatic-insectivores decreased, whereas that of detritivores increased longitudinally. The distribution of trophic guilds was significantly associated with the stream section, where aquatic and terrestrial insectivorous were more frequent in rocky and flowed stretches from the headwater and detritivores in deeper environments with finer particles of substrate from the mouth. This suggests that fish assemblages in coastal streams with a steep longitudinal gradient may follow patterns in the use of food resources according with the food availability along the river, as predicted by the River Continuum Concept.

Este estudo descreve o uso dos recursos alimentares e a distribuição das guildas tróficas de peixes ao longo do gradiente longitudinal de um riacho da encosta Atlântica, Sul do Brasil. Recursos alóctones (insetos terrestres) foram consumidos com maior frequência na cabeceira, entretanto, recursos de origem autóctone (algas, peixes) e detritos foram mais frequentemente registrados na foz. Espécies detritívoras, invertívoras aquáticas, insetívoras terrestres e aquáticas ocorreram ao longo de todo gradiente, enquanto que as onívoras e piscívoras na cabeceira e meio, respectivamente, e herbívoras no meio e foz. Detritívoras e insetívoras aquáticas foram significativamente mais especializadas em relação às demais guildas; entretanto, não houve nenhuma evidência de aumento longitudinal da especialização trófica. A densidade e a biomassa de invertívoras e insetívoras aquáticas diminuíram, enquanto que das detritívoras aumentaram no sentido cabeceira-foz. A distribuição das guildas tróficas foi significativamente associada com a secção do riacho, onde insetívoras aquáticas e terrestres foram mais frequentes em trechos rochosos e de elevado fluxo da cabeceira, enquanto que detritívoras em ambientes mais profundos com partículas finas de substrato da foz. Tais resultados sugerem que assembleias de peixes de riachos tropicais de encosta, os quais apresentam acentuado gradiente longitudinal, podem seguir padrões de uso dos recursos alimentares de acordo com a disponibilidade alimentar ao longo do rio, como previstos no Conceito de Continuidade de Rios.

Phylogeography of Hypostomus strigaticeps (Siluriformes: Loricariidae) inferred by mitochondrial DNA reveals its distribution in the upper Paraná River basin

In this study, phylogenetic and phylogeographic analyses of populations identified as Hypostomus strigaticeps from the upper Paraná River basin were conducted in order to test whether these different populations comprises cryptic species or structured populations and to assess their genetic variability. The sequences of the mitochondrial DNA ATP sintetase (subunits 6/8) of 27 specimens from 10 populations (one from Mogi-Guaçu River, five from Paranapanema River, three from Tietê River and one from Peixe River) were analyzed. The phylogeographic analysis showed the existence of eight haplotypes (A-H), and despite the ancestral haplotype includes only individuals from the Tietê River basin, the distribution of H. strigaticeps was not restricted to this basin. Haplotypes A, B and F were the most frequent. Haplotypes D, E, F, G, and H were present in the sub-basin of Paranapanema, two (A and B) were present in the sub-basin of the Tietê River, one (C) was exclusively distributed in the sub-basin of the Peixe River, and one (B) was also present in the sub-basin of the Grande River. The phylogenetic analysis showed that the populations of H. strigaticeps indeed form a monophyletic unit comprising two lineages: TG, with representatives from the Tietê, Mogi-Guaçu and Peixe Rivers; and PP, with specimens from the Paranapanema River. The observed degree of genetic divergence within the TG and PP lineages was 0.1% and 0.2%, respectively, whereas the genetic divergence between the two lineages themselves was approximately 1%. The results of the phylogenetic analysis do not support the hypothesis of existence of crypt species and the phylogeographic analysis confirm the presence of H. strigaticeps in other sub-basins of the upper Paraná River: Grande, Peixe, and Paranapanema sub-basins.

Neste estudo, foram conduzidas análises filogenéticas e filogeográficas de populações identificadas como Hypostomus strigaticeps na bacia do alto rio Paraná a fim de testar se essas populações compreendem espécies crípticas ou populações estruturadas e avaliar a variabilidade genética das mesmas. Foram analisadas sequências do DNA mitocondrial ATP sintetase (subunidades 6/8) de 27 espécimes de 10 populações (uma do rio Mogi-Guaçu, cinco do rio Paranapanema, três do rio Tietê e uma do rio do Peixe). A análise filogeográfica mostrou a existência de oito haplótipos (A-H), e apesar do haplótipo ancestral incluir apenas indivíduos da bacia do rio Tietê, a distribuição de H. strigaticeps não se restringe a esta bacia. Os haplótipos A, B e F foram os mais frequentes. D, E, F, G e H estão presentes na sub-bacia do rio Paranapanema, dois (A e B) estão presentes na sub-bacia do rio Tietê, um (C) está exclusivamente distribuído na sub-bacia do rio do Peixe, e um (B) também está presente na sub-bacia do rio Grande. A análise filogenética mostrou que as populações de H. strigaticeps realmente formam uma unidade monofilética que compreende duas linhagens: TG, com representantes do rio Tietê, rio Mogi-Guaçu e rio do Peixe, e PP, com espécimes do rio Paranapanema. O grau de divergência genética observada nas linhagens de TG e PP foram de 0,1% e 0,2%, respectivamente, enquanto que a divergência genética entre as duas linhagens foi de aproximadamente 1%. Os resultados da análise filogenética não suportam a hipótese da existência de espécies crípticas e a análise filogeográfica confirma a presença de H. strigaticeps em outras sub-bacias do alto rio Paraná: sub-bacias do rio Grande, rio do Peixe e rio Paranapanema.

Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwater

Juvenile freshwater dourados (Salminus brasiliensis Cuvier) were stocked in two batches of different size (61 and 133 individuals) with a time lag of 41 days in the headwaters of the Sinos River. A subsample of 25 fish was radio-tagged. Released juveniles displayed a density dependent dispersal pattern. During the first ten days mean covered distance of tagged batch 1 individuals (low density) was approximately 24 m d-1, while batch 2 individuals (high density) moved 296 m d-1. Activity of batch 1 fish increased after the release of batch 2 and remained high (459 m d-1) until 90 days. Activity of batch 2 fish during this period was in same range. After this period, activity levels of both batches decreased to about 60 m d-1. Increased movements in higher density condition are seen as a result of interspecific competition. The mean covered distances per day remained high until stocked individuals become established in their new habitat.

Dois lotes de 61 e 133 dourados (Salminus brasiliensis Cuvier) juvenis foram introduzidos nas cabeceiras do rio dos Sinos. O intervalo entre as solturas foi de 41 dias. Uma subamostra de 25 peixes foi marcada com radiotransmissores. A dispersão dos indivíduos após soltura mostrou um padrão dependente da densidade. Durante os primeiros dez dias a distância média dos indivíduos do lote 1 (densidade baixa) foi de 24 m d-1, enquanto os indivíduos do lote 2 (densidade alta) percorreram em média 296 m d-1. A atividade dos peixes do lote 1 aumentou depois da soltura do lote 2 e permaneceu alta (459 m d-1) durante 90 dias. A atividade dos indivíduos do lote 2 ficou no mesmo nível durante este período. Depois os movimentos de ambos os lotes diminuíram até uma média de 60 m d-1. O nível alto de movimentos na situação de maior densidade é visto como resultado da competição intraespecífica. As médias das distâncias percorridas por dia permanecem altas até os indivíduos introduzidos estabelecerem-se nos seus habitats novos.