Diel Seasonality of a Shallow-Water Fish Assemblage in a Sandy Beach at Canto Grande, Santa Catarina, Brazil

• Published in: Journal of coastal research 2005-04 (Special Issue No. 42), p.343-347
• Main Authors: Barreiros, João P., Figna, Vicente, Hostim-Silva, Maurício, Santos, Ricardo S.
• Format: Article
• Language: English
• Subjects: Beaches; Biomass; Fish; Freshwater fishes; Marine ecology; Marine fishes; Night tables; PART V: Systematics, Biota, Technology, and Pollution; Predators; Salinity; Species diversity
• ISSN: 0749-0208; 1551-5036

A shallow-water fish assemblage, over a soft, sandy bottom, at Canto Grande, Santa Catarina, Brazil, was sampled at bimonthly intervals with a beach seine. Sampling was undertaken at 3 h intervals over 24 h on a bimonthly basis between April 1996 and February 1997. Each monthly set of samples was divided into day and night catches. A total of 67 species, belonging to 56 genera and 33 families, were collected. From these, ten occurred only in the day catches and 18 only at night. There was seasonal variation and day/night differences in the number of species (49/57), density of fishes (63.3/62.4 fish 1000 m⁻²). and biomass (316.3/626.9 g 1000 m⁻²). The highest values occurred in summer night samples (182.1 fish 1000 m⁻², 1893.0 g 1000 m⁻²). In terms of density both day and night catches were dominated by Lycengraulis grossidens while in terms of biomass day catches were dominated by Harengula clupeola and night catches by Trichiurus lepturus. Despite a slight tendency for greater night values, species diversity (H') and evenness (J') were not significantly different between the two periods. The largest change in the assemblage structure occurred between winter months (July and August) and the other seasons, especially due to the distribution of the main predators found Pomatomus saltator (winter and night) and Trichiurus lepturus (summer and night). Most of the species observed were either juvenile fish or small pelagic and strongly gregarious species. A comunidade de peixes de fundos móveis arenosos de Canto Grande, Santa Catarina, Brasil, foi estudada por amostragens bimensais com recurso a redes de praia. As amostragens realizaram-se durante períodos de 24 h com intervallos de 3 h, numa base bimensal entre Abril de 1996 e Fevereiro de 1997. Cada conjunto mensal de amostras foi dividido em capturas diurnas e nocturnas. Colectaram-se 67 espécies de peixes, correspondendo a 56 géneros e 33 famílias. De entre estas espécies, 10 ocorreram apenas de dia e 18 exclusivamente de noite. Verificou-se uma variação sazonal e diferênças dia/noite no número de espécies (49/57), densidade de peixes (63.3/62.4 peixes 1000 m⁻²) e biomassa (316.3/626.9 g 1000 m⁻²). Os valores mais elevados verificaram-se nas amostras nocturnas de Verão (182.1 peixes 1000m⁻², 1893.0 g 1000m⁻²). Em termos de densidade, tanto as amostras diurnas como as nocturnas foram dominadas por Lycengraulis grossidens enquanto que em termos de biomassa as amostras diurnas forma dominadas por Harengula cl