Schooling behavior of Mugil curema (Perciformes: Mugilidae) in an estuary in southeastern Brazil

Abstract

Schools of mullets, Mugilidae, are abundant in estuaries and shallow marine waters. We report on the schooling behavior of juvenile white mullet, Mugil curema, in the estuary of the Canto da Paciência stream, in Ubatuba, southeastern Brazil. Schools of small fish (15 to 35 mm TL) were composed of a larger number of individuals (up to a hundred individuals), and were found feeding mainly in shallow nearshore waters, whereas schools of larger fish (40 to 100 mm TL) were observed only in deeper waters. Three patterns of swimming were observed for the schools: stationary feeding, slow movement while searching for food, and rapid displacement. The variations observed in school structure and behavior seem to be related to the balance between predation risk and increasing food intake.Cardumes de mugilídeos são abundantes em ambientes estuarinos e de águas marinhas rasas. No presente trabalho registramos o comportamento de formação de cardume por juvenis de parati, Mugil curema, no estuário do Riacho do Canto da Paciência, em Ubatuba, sudeste do Brasil. Cardumes de peixes pequenos (15 a 35 mm CT) eram compostos por maior número de indivíduos (até uma centena) e observados se alimentando em águas marginais rasas, enquanto peixes maiores (40 a 100 mm CT) foram observados somente em áreas de maior profundidade. Três padrões de movimentação do cardume foram observados: forrageando estacionário, deslocamento lento procurando alimento e deslocamento rápido. As variações observadas na estrutura e comportamento dos cardumes parecem estar relacionadas com um balanço entre o risco de predação e a otimização do forrageamento.

Prey consumed by Guiana dolphin Sotalia guianensis (Cetacea, Delphinidae) and franciscana dolphin Pontoporia blainvillei (Cetacea, Pontoporiidae) in an estuarine environment in southern Brazil

“…For the Guiana dolphins, the two fish species with highest IRI values are species of large size and high energy value (M. curema and M. furnieri) (CurCho et al, 2009) that show variations in abundance of adult individuals inside estuarine regions (CaStro & petrere, 2001;CarvaLho et al, 2007).…”

Experimental assessment of the effects of a Neotropical nocturnal piscivore on juvenile native and invasive fishes

“…Although the invasive C. piquiti and the native A. altiparanae were the smallest prey available, the former was the most consumed prey whereas the latter was much less predated. Prey shoaling generally reduces predation success, since the ability of the predator to distinguish, pursue and attack an individual prey often declines with numerous and aggregated shoals (Shaw, 1978;Carvalho et al, 2007). Previous studies have also shown that most fish predators reduce its efficiency in high complexity environments by providing more prey refuges and reducing prey encounter rates with predators (e.g.…”

Schooling Fish Under Attack Are Not All Equal: Some Lead, Others Follow

“…These hypotheses were tested in schools of 10 juvenile golden grey mullet ( Liza aurata ). This school size is biologically relevant for many species of nearshore and freshwater fish [9], [27], [28] including mugilids in coastal areas [29], [30].…”