Insights on the influence of phylogenetic on the relative growth using Atherinella brasiliensis as a tool / Introspecções sobre a influência da filogenética no crescimento relativo usando Atherinella brasiliensis como ferramenta

The length–weight relationship (LWR) is an important tool for ichthyology. It is very useful to demonstrate the environmental influence on growth. In this study we estimate the LWR of the Atherinella brasiliensis in the shallow areas of the São Francisco River estuary and compare the growth of this specie in different environments of the Brazilian coast. Specimens of Brazilian silverside (A. brasiliensis, n = 3483), between 2.1 and 13.6 cm in length, were caught in the shallow areas of the São Francisco River estuary between May 2017 and April 2018. The length-weight ratio of the species was represented by the equation y = 0.0047x3.0913. Frequency distribution indicates that the species is present in the studied area in all its ontogenetic stages and apparently reproduces throughout the year with constant input of recruits into the population. Von Bertalanffy’s growth model and longevity were adjusted to reach asymptotic length (L∞) of 14.7 cm, growth coefficient (K) of 0.91 year-1 and longevity (A95) of 3.25 years. The analysis of variance revealed differences for the maximum total length. However, the differences found between the present study and data available in the literature appear to be caused by environmental and methodological differences.

A relação peso-comprimento (LWR) é uma ferramenta importante para a ictiologia, muito utilizada para demonstrar a influência ambiental no crescimento. Neste estudo estimamos o LWR de Atherinella brasiliensis em áreas rasas do estuário do rio São Francisco e comparamos o crescimento desta espécie em diferentes ambientes do litoral brasileiro. Espécimes do peixe-rei (A. brasiliensis, n = 3483), entre 2,1 e 13,6 cm de comprimento, foram capturados nas áreas rasas do estuário do rio São Francisco entre maio de 2017 e abril de 2018. A relação peso-comprimento das espécies foi representada por a equação y = 0,0047x3,0913. A distribuição de frequência indica que a espécie está presente na área estudada em todos os seus estágios ontogenéticos e aparentemente se reproduz ao longo do ano com entrada constante de recrutas na população. Os modelos de crescimento e longevidade de Von Bertalanffy foram ajustados para atingir comprimento assintótico (L∞) de 14,7 cm, coeficiente de crescimento (K) de 0,91 ano-1 e longevidade (A95) de 3,25 anos. A análise de variância revelou diferenças para o comprimento total máximo. No entanto, as diferenças encontradas entre o presente estudo e os dados disponíveis na literatura parecem ser causadas por diferenças ambientais e metodológicas.

Insights on the influence of phylogenetic on the relative growth using Atherinella brasiliensis as a tool / Introspecções sobre a influência da filogenética no crescimento relativo usando Atherinella brasiliensis como ferramenta

The length–weight relationship (LWR) is an important tool for ichthyology. It is very useful to demonstrate the environmental influence on growth. In this study we estimate the LWR of the Atherinella brasiliensis in the shallow areas of the São Francisco River estuary and compare the growth of this specie in different environments of the Brazilian coast. Specimens of Brazilian silverside (A. brasiliensis, n = 3483), between 2.1 and 13.6 cm in length, were caught in the shallow areas of the São Francisco River estuary between May 2017 and April 2018. The length-weight ratio of the species was represented by the equation y = 0.0047x3.0913. Frequency distribution indicates that the species is present in the studied area in all its ontogenetic stages and apparently reproduces throughout the year with constant input of recruits into the population. Von Bertalanffys growth model and longevity were adjusted to reach asymptotic length (L∞) of 14.7 cm, growth coefficient (K) of 0.91 year-1 and longevity (A95) of 3.25 years. The analysis of variance revealed differences for the maximum total length. However, the differences found between the present study and data available in the literature appear to be caused by environmental and methodological differences.(AU)

A relação peso-comprimento (LWR) é uma ferramenta importante para a ictiologia, muito utilizada para demonstrar a influência ambiental no crescimento. Neste estudo estimamos o LWR de Atherinella brasiliensis em áreas rasas do estuário do rio São Francisco e comparamos o crescimento desta espécie em diferentes ambientes do litoral brasileiro. Espécimes do peixe-rei (A. brasiliensis, n = 3483), entre 2,1 e 13,6 cm de comprimento, foram capturados nas áreas rasas do estuário do rio São Francisco entre maio de 2017 e abril de 2018. A relação peso-comprimento das espécies foi representada por a equação y = 0,0047x3,0913. A distribuição de frequência indica que a espécie está presente na área estudada em todos os seus estágios ontogenéticos e aparentemente se reproduz ao longo do ano com entrada constante de recrutas na população. Os modelos de crescimento e longevidade de Von Bertalanffy foram ajustados para atingir comprimento assintótico (L∞) de 14,7 cm, coeficiente de crescimento (K) de 0,91 ano-1 e longevidade (A95) de 3,25 anos. A análise de variância revelou diferenças para o comprimento total máximo. No entanto, as diferenças encontradas entre o presente estudo e os dados disponíveis na literatura parecem ser causadas por diferenças ambientais e metodológicas.(AU)

A protocol for measuring spatial variables in soft-sediment tide pools

We present a protocol for measuring spatial variables in large (>50 m2) soft-sediment tide pool. Secondarily, we present the fish capture efficiency of a sampling protocol that based on such spatial variables to calculate relative abundances. The area of the pool is estimated by summing areas of basic geometric forms; the depth, by taken representative measurements of the depth variability of each pool's sector, previously determined according to its perimeter; and the volume, by considering the pool as a prism. These procedures were a trade-off between the acquisition of reliable estimates and the minimization of both the cost of operating and the time spent in field. The fish sampling protocol is based on two con secutive stages: 1) two people search for fishes under structures (e.g., rocks and litters) on the pool and capture them with hand seines; 2) these structures are removed and then a beach-seine is hauled over the whole pool. Our method is cheaper than others and fast to operate considering the time in low tides. The method to sample fish is quite efficient resulting in a capture efficiency of 89%.

A protocol for measuring spatial variables in soft-sediment tide pools

We present a protocol for measuring spatial variables in large (>50 m2) soft-sediment tide pool. Secondarily, we present the fish capture efficiency of a sampling protocol that based on such spatial variables to calculate relative abundances. The area of the pool is estimated by summing areas of basic geometric forms; the depth, by taken representative measurements of the depth variability of each pool's sector, previously determined according to its perimeter; and the volume, by considering the pool as a prism. These procedures were a trade-off between the acquisition of reliable estimates and the minimization of both the cost of operating and the time spent in field. The fish sampling protocol is based on two con secutive stages: 1) two people search for fishes under structures (e.g., rocks and litters) on the pool and capture them with hand seines; 2) these structures are removed and then a beach-seine is hauled over the whole pool. Our method is cheaper than others and fast to operate considering the time in low tides. The method to sample fish is quite efficient resulting in a capture efficiency of 89%.(AU)

ALIMENTAÇÃO DE JUVENIS DE TRÊS ESPÉCIES ÍCTICAS NA ZONA DE ARREBENTAÇÃO DE PRAIA GRANDE, SP

O objetivo deste trabalho foi estudar os hábitos alimentares de três espécies de peixes com hábitos de fundo que ocorrem na zona de arrebentação de uma praia urbana em Praia Grande (SP), em função de seus tamanhos, ocorrências diurnas e noturnas e sobreposição de suas dietas. Foram coletados 617 indivíduos no total, sendo 362 Menticirrhus littoralis; 194 Genidens barbus e 61 Polydacytilus virginicus, no período de 2013 a 2015. Os resultados dos conteúdos estomacais estudados foram representados através dos valores de IRI (Índice de Relativa Importância) mostrando os itens com maior importância para cada espécie. Para M. littoralis o bivalve Donax gemmula foi o item alimentar mais importante, para G. barbus escamas de Teleostei e para P. virginicus os crustáceos (Euphausiacea). A similaridade entre a alimentação das três espécies mostrou-se diferenciada com 44% de similaridade entre a alimentação de G. barbus e M. littoralis, 5% entre G. barbus e P.virginicus , 84% entre M. littoralis e P. virginicus. Portanto, as únicas espécies que apresentaram alguma similaridade entre os itens consumidos foram P. virginicus e M. littoralis. Para M. littoralis foram encontrados em todas as estações do ano: escamas ctenóides (Teleostei), Donax gemmula, Teleostei fragmentado (espécie não identificada), Euphausiacea, Megalopa de Brachyura, copépode, poliqueta, Mellita quinquiesperforata e larva de Diptera. O bagre G.barbus foi capturado apenas durante o inverno e outono, tendo como principais itens escamas ctenóides, escamas ciclóides, insetos, fragmento de vegetais, cristalino de Teleostei, Mellita quinquiesperforata, larva de Diptera. Para P. virginicus foram encontrados conteúdos em todas as estações, exceto no inverno, pois não foram capturados exemplares da espécie no inverno. Os itens encontrados foram escamas ctenóides, Donax gemmula, Decapoda, Euphausiacea, Megalopa de Brachyura, copépode, substrato e escamas cicloides.

This study aims the evalauation of the dietary habits of three fish species with bottom habits in the surf zone of an urban beach at Praia Grande (SP), considering their size, diurnal and nocturnal occurrences and overlapping of their diets. A total of 617 individuals were collected, 362 Menticirrhus littoralis, 194 Genidens barbus and 61 Polydacytilus virginicus, from 2013 to 2015. The results of the stomach contents were represented as IRI (Relative Importance Index) values showing the most important items for each species. The bivalve Donax gemmula was the most important food item to M. littoralis, Insects to G. barbus and Euphausiacea to P. virginicus. The similarity among the feeding of the three species was differentiated with 60% similarity for P. virginicus and G. barbus, 13% for M. littoralis and G. barbus and 22% for M. littoralis and P. virginicus. Therefore, two species had shown any similarity among the prey items (P. virginicus and G. barbus). At M. littoralis food items found in all seasons of the year were ctenoid scales (Teleostei), Donax gemmula, fragmented Teleostei (unidentified species), Euphausiacea, Megalopa of Brachyura, Copepod, Polychaete, Mellita quinquiesperforata and Diptera larvae. The catfish G. barbus was captured only during Winter and Autumn; main items were ctenoid scales, cycloid scales, insects, fragment of plants, Teleostei lens, Mellita quinquiesperforata, and Diptera larvae. For P. virginicus, food items contents were found in all seasons, except in Winter, when none specimens of this species were captured. The items found were ctenoid scales, Donax gemmula, Decapoda, Euphausiacea, Brachyuran megalopae, Copepod, substrate and cycloid scales.

Variação espaço-temporal da ictiofauna da zona de arrebentação da Praia do Cassino, Rio Grande do Sul, Brasil

This study analyzes the spatiotemporal variation of the ichthyofauna of the surf zone of Praia do Cassino, municipality of Rio Grande (state of Rio Grande do Sul, Brazil) from October 2005 to September 2006. Fishes were collected monthly and during daytime using a large beach seine net (30 m x 1.8 m, with 12 mm uniform mesh manufactured with monofilament nylon wire). Five hauls were conducted on each of three sampling sites: one near the jetties of Patos Lagoon and two located 5 km and 10 km south from the jetties, respectively. We caught 10,066 fishes, weighting 128,486 g, distributed in 37 species belonging to 18 families that are similar in species composition to the dominant fish fauna - Trachinotus marginatus (Cuvier, 1832), Atherinella brasiliensis (Quoy & Gaimard, 1825), Brevoortia pectinata (Jenyns, 1842), Mugil platanus (Gunther, 1880), Menticirrhus americanus (Linnaeus, 1758), Menticirrhus littoralis (Holbrook, 1847), and Oncopterus darwinii (Steindachner, 1874) - usually collected in the beaches of Rio Grande do Sul with a smaller net. The dominant size classes were between 50 and 100 mm TL and represent 43% of total catch. Based on CCA analysis we suggested that the ichthyofauna is primarily structured by seasonal variation in the physicochemical and environmental parameters and secondarily by the spatial difference between areas nearer ( approximately 10 km) or more distant (> approximately 10 km) from the Patos Lagoon's jetties. The composition and dominance of the fish community of the surf zone of Cassino Beach changed little in the latest 20 years, indicating a possible stability of the system.

Variação espaço-temporal da ictiofauna da zona de arrebentação da Praia do Cassino, Rio Grande do Sul, Brasil

This study analyzes the spatiotemporal variation of the ichthyofauna of the surf zone of Praia do Cassino, municipality of Rio Grande (state of Rio Grande do Sul, Brazil) from October 2005 to September 2006. Fishes were collected monthly and during daytime using a large beach seine net (30 m x 1.8 m, with 12 mm uniform mesh manufactured with monofilament nylon wire). Five hauls were conducted on each of three sampling sites: one near the jetties of Patos Lagoon and two located 5 km and 10 km south from the jetties, respectively. We caught 10,066 fishes, weighting 128,486 g, distributed in 37 species belonging to 18 families that are similar in species composition to the dominant fish fauna - Trachinotus marginatus (Cuvier, 1832), Atherinella brasiliensis (Quoy & Gaimard, 1825), Brevoortia pectinata (Jenyns, 1842), Mugil platanus (Gunther, 1880), Menticirrhus americanus (Linnaeus, 1758), Menticirrhus littoralis (Holbrook, 1847), and Oncopterus darwinii (Steindachner, 1874) - usually collected in the beaches of Rio Grande do Sul with a smaller net. The dominant size classes were between 50 and 100 mm TL and represent 43% of total catch. Based on CCA analysis we suggested that the ichthyofauna is primarily structured by seasonal variation in the physicochemical and environmental parameters and secondarily by the spatial difference between areas nearer ( approximately 10 km) or more distant (> approximately 10 km) from the Patos Lagoon's jetties. The composition and dominance of the fish community of the surf zone of Cassino Beach changed little in the latest 20 years, indicating a possible stability of the system.

Variação espaço-temporal da ictiofauna da zona de arrebentação da Praia do Cassino, Rio Grande do Sul, Brasil

This study analyzes the spatiotemporal variation of the ichthyofauna of the surf zone of Praia do Cassino, municipality of Rio Grande (state of Rio Grande do Sul, Brazil) from October 2005 to September 2006. Fishes were collected monthly and during daytime using a large beach seine net (30 m x 1.8 m, with 12 mm uniform mesh manufactured with monofilament nylon wire). Five hauls were conducted on each of three sampling sites: one near the jetties of Patos Lagoon and two located 5 km and 10 km south from the jetties, respectively. We caught 10,066 fishes, weighting 128,486 g, distributed in 37 species belonging to 18 families that are similar in species composition to the dominant fish fauna - Trachinotus marginatus (Cuvier, 1832), Atherinella brasiliensis (Quoy & Gaimard, 1825), Brevoortia pectinata (Jenyns, 1842), Mugil platanus (Gunther, 1880), Menticirrhus americanus (Linnaeus, 1758), Menticirrhus littoralis (Holbrook, 1847), and Oncopterus darwinii (Steindachner, 1874) - usually collected in the beaches of Rio Grande do Sul with a smaller net. The dominant size classes were between 50 and 100 mm TL and represent 43% of total catch. Based on CCA analysis we suggested that the ichthyofauna is primarily structured by seasonal variation in the physicochemical and environmental parameters and secondarily by the spatial difference between areas nearer ( approximately 10 km) or more distant (> approximately 10 km) from the Patos Lagoon's jetties. The composition and dominance of the fish community of the surf zone of Cassino Beach changed little in the latest 20 years, indicating a possible stability of the system.