ABSTRACT A large number of fish species use the mangrove mainly due to food availability and protection against predators. The knowledge of temporal and spatial dynamics of ichthyofauna allows us to identify patterns of occupation of this ecosystem and to support the assessment and preservation of local biodiversity. In this sense, samplings were conducted in 1988 at five areas of the Itacorubi River estuary, Santa Catarina Island. A total of 3,883 specimens were collected, distributed in 21 families and 41 species with the predominance of Cetengraulis edentulus, Mugil liza, Mugil curema, Genidens genidens, Mugil gaimardianus, Eucinostomus gula, Micropogonias furnieri, Pomatomus saltatrix and Sphoeroides testudineus. On average, abundances differed between seasons and sampled areas. Differences were detected between the fish faunas of fall and winter compared to summer and spring and between sampling sites. This study identified a fish assemblage in the mangrove of the Itacorubi River with a similar structure to other estuaries of southern Brazil.

ABSTRACT This study aimed to describe the growth parameters of Anchoa tricolor in a subtropical estuary. From August 2010 to July 2011, 10.009 specimens of the anchovy Anchoa tricolor, mean total length 4.2 cm (±1.45), were captured in the intertidal region of the Estuarine Complex of Paranaguá (25º 15’ - 25° 35’ S and 48° 20’ - 48° 45’ W). Species´s weight/length relationship for grouped genders was described as follow: W = 0.0000591.Lt3.282 (length in centimeters; weight in grams) showing a positive allometric growth pattern (b>3; P=0.000). Significant differences concerning weight/length relationship for males, females and unsexed individuals were identified. Parameters of the length to age growth curve were estimated by adjusting a von Bertalanffy growth equation from aged individuals from a length-frequency distribution: L∞ = 10.06 (1-e-17715(t + 0.205)) (length in centimeters, age in years). The age to attain 95% of the asymptotic length ( A95 ; longevity sensu Taylor) was estimated at 1.7 years. Size frequency distributions indicate that A. tricolor uses the estuarine area as reproductive and growing grounds, especially during the first year of the life cycle, where the species represent a key element for ecosystem functioning due to relatively high abundance and energy transference from plankton to top predators.

ABSTRACT Within the Brazilian province, rocky reefs and submerged outcrops are among the most important habitats for reef fishes, providing suitable habitats for the development of reef fish communities and consequently sheltering a high ecological diversity. Rocky reef fish assemblages were sampled in seven coastal islands in South Brazil by strip transects of 40 m2 by the underwater visual census to obtain density (fish 40 m-2) and biomass (g 40 m-2). Fish species were also categorized according to trophic category and geographical distribution. In total, 526 strip transects were performed, covering an area of 21,040 m2, providing 19,377 fish, distributed among 73 species of 34 families. Itacolomis Island presented the highest density, followed by Veado Island. Regarding biomass, Itacolomis Island and Pedra da Baleia were the most representative rocky reefs. Mobile invertebrate predator was the trophic category with the highest density and biomass. A total of 60% of the species occur in the Western Atlantic, 20% are Transatlantic and 9.6% are endemic to the Brazilian Province. Our results indicate that despite the similarity in the taxonomic composition among islands, the observed differences in densities and biomass, highlight singular assemblage structures, whether by environmental and/or anthropogenic factors, and dominated by few species, both in density and biomass.

RESUMO A garoupa e o badejo-verdadeiro são predadores oportunistas de grande porte, com estratégia de emboscada, comumente encontrados em recifes tropicais do Atlântico Sul. A dieta das duas espécies foi investigada, avaliando influências ontogenéticas, espaciais e temporais, assim como a sobreposição no uso de recursos entre estes dois predadores co-orrentes no Banco dos Abrolhos, Brasil. Decápodes e peixes foram os principais itens alimentares de Epinephelus morio, enquanto que os peixes foram as principais presas de Mycteroperca bonaci. Ambas as dietas foram significativamente influenciadas pelo tamanho corporal e habitat, mas apenas indivíduos menores de E. morio alimentaram-se quase que exclusivamente de crustáceos. Como as duas espécies utilizam muitas presas semelhantes, a coexistencia parece ser facilitada pelo fato de E. morio se alimentar principalmente de crustáceos, particularmente do caranguejo Cronius ruber, enquanto que o badejo-verdadeiro consome relativamente poucos crustáceos e grande quantidade de peixes. Predadores como as espécies estudadas podem causar efeitos indiretos na comunidade e influenciar uma grande variedade de processos ecológicos, como conexões entre predadores de topo e intermediários e predadores intermediários e seus recursos.

ABSTRACT Red and black groupers are large-bodied opportunistic ambush predators commonly found in Southwestern Atlantic tropical reefs. We investigated the diet of both species in order to detail ontogenetic, spatial and temporal trends, and to assess the extent of overlap in resource use between these two sympatric predators on the Abrolhos Bank, Brazil. Decapods and fishes were the main food items of Epinephelus morio while fishes were the main prey of Mycteroperca bonaci. Both diets were significantly influenced by body size and habitat, but only smaller individuals of E. morio feed almost exclusively on crustaceans. While the two groupers rely on many of the same prey types, coexistence may be facilitated by E. morio feeding more heavily on crustaceans, particularly the blackpoint sculling crab Cronius ruber, while black grouper take comparatively few crustaceans but lots of fish prey. Predators like red and black groupers could trigger indirect effects in the community and influence a large range of ecological processes, such as linkages between top and intermediate predators, and intermediate predators and their resources.

ABSTRACT Specimens of Brazilian silverside (Atherinella brasiliensis, n=9672) with a length range of 1.5 to 14.2 cm were captured in the intertidal areas of the Estuarine Complex of Paranaguá, Brazil, between August 2010 and July 2011. The species’ weight-length relationship was represented by the equation W=0.00533 L3.136 with a slightly positive allometry (b>3) and could be divided into two growth stanzas: W = W1 + W2; Stanza 1: W1= SW. (0.005239 L3.152); Stanza 2: W2= (1 - SW). (0.000699 L3.913); Switch-Function: SW = [1 + e1.204 (L - 11.66)]-1. The breakpoint between the first and second stanza (11.66 cm) matches published values for the estimated size at first maturity of adult females. Frequency distributions indicate that the species is present in the shallow areas of the Estuarine Complex of Paranaguá during all phases of its ontogenetic development, with the recruitment of juveniles taking place between October and November. Modal displacement was monitored throughout 12 months. The von Bertalanffy growth model and longevity was estimated as follow: asymptotic length (L∞) of 17.5 cm, growth coefficient (K) of 0.89 (year-1) and longevity (A95) of 3.33 years. We present some considerations with regard to the general methodology for adjusting weight-length relationships.

The relative efficiency of two square-mesh codend designs with the same circumference (~2 m) but different mesh sizes and materials (32 mm polyethylene-PE and 30 mm polyamide-PA) was tested in an artisanal shrimp trawl fishery in Paraná, southern Brazil. The two square-mesh codends were hauled alternately with a 26 mm diamond-shaped mesh codend (control) in a twin gear configuration. Although not significant, the mean numbers of total bycatch were reduced by 16.6 and 10.0% with the 32 and 30 mm square-mesh codends, respectively. The results indicate significant improvement in size selectivity for some species (Xiphopenaeus kroyeri and Stellifer rastrifer). The operational changes tested can be a suitable technical solution for reducing the capture of immature organisms in the shrimp trawl fishery in Paraná, Brazil.

La eficiencia relativa de dos diseños de copos con malla cuadrada con la misma circunferencia (~2 m) pero diferentes tamaños de malla y materiales (32 mm de polietileno-PE y 30 mm de poliamida PA) ha sido evaluada en una pesquería de arrastre artesanal de camarón en Paraná, sur de Brasil. Los dos copos de malla cuadrada fueron arrastrados alternativamente con un copo de malla de 26 mm en forma de diamante (control) en una configuración de doble arrastre. Aunque no es significativo, el número medio de la captura incidental total se redujo en 16,6 y 10,0% en los copos de malla cuadrada de 32 y 30 mm, respectivamente. Los resultados indican que se logra una significativa mejora en la selectividad por tamaño medio de algunas especies (Xiphopenaeus kroyeri y Stellifer rastrifer). Los cambios operacionales evaluados pueden representar una solución técnica adecuada para reducir las capturas de organismos inmaduros en la pesquería de arrastre de camarón en Paraná, Brasil.

Diel and tidal variations of fish assemblages were assessed at Pontal beach, southern Brazil, using a seine net. Species richness was greater at night, whereas fish number, weight, and richness (cornmunity indicators) were all influenced by the tidal state. Samples from rising tides were more representative, probably due to onshore fish movements for feeding purposes. However, lower catches were associated with high tides, mainly through net avoidance, indicating that sampling in these conditions is not highly informative. Clupeoids exhibited greater variation in a 24 h period, and the night occurrence of A. tricolor and daylight shoaling of Harengula clupeola, Anchoa parva and Sardinella brasiliensis suggested distinct strategies for avoiding daylight predators. In some species, this behaviour may have been induced by the bottom morphology and tidal state, facilitating nearshore grouping. In addition to being caught at night, the occurrences of Menticirrhus littoralis, Pomadasys corvinaefórmis, Umbrina coroides and Hyporhamphus unifasciatus indicated a spatial niche partition according to tidal state. Although not evaluated properly, temporal fluctuations could reflect species recruitment patterns. Seasonal fluctuations have to be considered when analysing short-term changes in the cornmunity as such fluctuations are synchronized with the natural history of the species, making it difficult to interpret short-term variations in isolation.

Se utilizó una red de arrastre para evaluar la variación diaria y mareal del ensamble de peces en la playa de Pontal, sur de Brasil. Se encontró la mayor riqueza de especies durante la noche mientras que la abundancia, peso y riqueza (indicadores de la comunidad) fueron influenciados por la marea. Las muestras de marea creciente fueron las más representativas debido probablemente a los movimientos costeros con fines alimentarios; sin embargo, las menores capturas estuvieron asociadas a pleamares debido a la evasion a la red, indicando que los muéstreos en estas condiciones son poco informativos. Los clupeidos fueron los peces que más variaron durante un periodo de 24 h; la ocurrencia nocturna de A. tricolor y el agrupamiento matutino de Harengula clupeola, Anchoa parva and Sardinella brasiliensis sugieren distintas estrategias en la evasion de los depredadores diurnos. La morfología del fondo asociada con la marea, puede haber influenciado el comportamiento de algunas especies, facilitándoles el agrupamiento costero. Además de haber sido capturadas por la noche, la ocurrencia de Menticirrhus littoralis, Pomadasys corvinaefórmis, Umbrina coroides and Hyporhamphus unifasciatus indicó la repartición espacial del nicho según el estado de la marea. Aunque no evaluadas correctamente, las fluctuaciones temporales pueden reflejar los patrones específicos de reclutamiento; la estacionalidad debe ser incluida cuando se estudian desplazamientos de corto plazo en la comunidad debido a su sincronización con la historia natural de las especies, haciendo que las variaciones de corto plazo sean difíciles de interpretar por sí solas.

Os peixes de uma planície de maré da praia Balneário de Pontal do Sul, Paraná, foram coletados, na preamar diurna e na baixa-mar diurna e noturna das marés de sizígia e de quadratura, visando caracterizar as mudanças temporais entre agosto de 1998 e julho de 1999. As coletas totalizaram 64.265 peixes de 133 espécies. Foram observadas diferenças significativas na captura média em número de espécies e de peixes, peso total e nos índices de riqueza, diversidade (H' peso) e eqüitatividade entre os meses de coleta. A dissimilaridade da ictiofauna foi maior entre os meses de agosto, setembro e outubro em comparação com o período de novembro a janeiro. A ação combinada da temperatura da água, salinidade e intensidade do vento, influenciaram mais sobre a estrutura da assembléia de peixes.

Annual variation in the fish assemblage characteristics on a tidal flat was studied in coastal Paraná, in southern Brazil. Fish were collected between August 1998 and July 1999, during the diurnal high tide and diurnal and nocturnal low tide of the syzygial (full moon) and quadrature (waning moon) tides, to characterize temporal change in assemblage composition. A total of 64,265 fish in 133 species were collected. The average number of species and individuals, biomass, species richness, diversity (mass) and equitability varied significantly over time . The dissimilarity of the assemblage was greatest in August, September and October in contrast with the period from November to January, with the lowest dissimilarity. The combined action of water temperature, salinity and wind intensity had a great influence over the structure of the fish assemblage.

Abundance and diversity of the fish fauna in the shallow infralittoral region of Atami Beach, Paraná, Brazil, were studied through monthly collections between July 1998 and June 1999. A total of 7553 fishes from 70 species and 26 families, mainly juvenile forms, was captured in the area. The mean captures in number of species, number of fish and biomass were larger from the end of spring to the middle of autumn; seasonal tendency in richness, diversity (number) and equitability indices were not observed. The largest mean dissimilarity in the composition of the ichthyofauna occurred between June and May in comparison to the period between July and October. The species that contributed most to this dissimilarity were Selene setapinnis (Mitchill, 1815), Conodon nobilis (Linnaeus, 1758) and Stellifer rastrifer (Jordan, 1889). Three great groups reflecting patterns of temporal occurrence of the most abundant species were identified.

The present study seeks to elucidatc reproduetive aspects of Sphoeroides testudineus (Linnaeus, 1758), Tetraodontidae. Monthly collections were accomplished for one year (November/98-October/99), in the gamboa do Baguaçu, Bay of Paranaguá with a Fyke net. The macroscopic analysis of the gonad stages allowed us to estimate the sexual proportion as 1:1 during the whole period, except in the months of May and October, when the proportions of two females for one male and two males for one female were observed respectively. The analysis of the relative frequency of the monthly gonad stages and the Curve of Maturation aided in the determination of the reproduetive period, that oceurred from September to January. Microscopic analyses of the female gonads allowed us to characterize four develo-pment phases of the ovarian follicle, six stages of ovarian development and the type of spawn, which was parceled. The first maturation for females was estimated to be betwecn 10-11 cm of length.

Fishes were sampled by beach seine during the day and night at the high and low sygygy tides, on a sandy beach at the southeast coast of Brazil. The quantitative results appear to indicate a larger concentration of fish in the surf zone of this beach, in low tides at the start and end of the day. Only eight from the 17 most abundant taxa, appeared to have been influenced singly or in combination by the factors of the moon, day, night and tide.

Neste trabalho são analisados os padrões sazonais de desova da sardinha-verdadeira, Sardinella brasiliensis, e da anchoita, Engraulis anchoita, baseado em dados coletados em águas costeiras de Ubatuba (SP), entre 1985 e 1988. Ambas as espécies habitam a costa sudeste do Brasil A primeira efetua desova durante a noite (21:00 - 23:00 h) na região costeira durante o fim da primavera e o verão, enquanto que a segunda desova durante todo o ano, principalmente na região costeira durante o verão e na região nerítica durante o inverno. A desova da anchoita foi observada ao longo de todo o dia, porém com mais intensidade à noite. No verão, ocorre uma forte estratificação vertical das massas d'água. A desova da sardinha-verdadeira ocorre na camada superficial de mistura, enquanto que a da anchoita ocorre abaixo da termoclina, nas águas frias da "Água Central do Atlântico Sul" (ACAS), que ocupam as camadas do fundo durante o verão. Entretanto, ovos e larvas de ambas as espécies foram encontrados tanto na camada superior, de água tropical, como na camada inferior, de água fria, embora predominantemente acima da termoclina.

The Brazilian sardine (Sardinella brasiliensis) and anchoita (Engrautis anchoita) inhabit the southeastern Brazilian Bight. The former spawns at night (21:00-03:00) in coastal region during late-spring and summer, meanwhile, the latter spawns all year-around, mainly in coastal region during summer and in neritic region during winter. The spawning time of E. anchoita was observed all day long, but more intensively at night. During summer there occurs a strong vertical stratification of water masses. The spawning of S. brasiliensis occurs in surface mixed layer, while that of E. anchoita occurs beneath the thermocline inside the cool South Atlantic Central Water which occupies the bottom layer during late spring and summer. However, the sardine and anchovy egss and larvae were found inside both the upper tropical and lower cold water masses, but predominantly above thermocline in this region