No abstract

Many chemicals have been used as anaesthetics in fish farms and fish biology laboratories to keep the fish immobilized during handling procedures and to prevent accidents and animal stress. In Brazil, tricaine methane sulfonate (MS 222), quinaldine sulfate, benzocaine, and phenoxyethanol are the most common fish anaesthetics used to prevent fish stress during handling, but many side effects such as body and gill irritations, corneal damage and general risks of intoxication have been reported. Clove oil is a natural product proposed as an alternative fish anaesthetic by many researchers and it has been used in many countries with great economic advantages and no apparent toxic properties. In this work, we assessed the suitability of clove oil to anaesthetize matrinxã. Sixty-three juveniles of matrinxã were exposed to seven anaesthetic batches of clove oil (pharmaceutical grade) namely 18, 20, 30, 40, 50, 60, and 70 mg/L. The times to reach total loss of equilibrium and to recover the upright position were measured. Clove oil concentration about 40 mg/L was enough to anaesthetize the fish in approximately one minute and the recovery time was independent in regard to anaesthetic concentration.

No abstract

Fish transport is one of the most stressful procedures in aquaculture facilities. The present work evaluated the stress response of matrinxã to transportation procedures, and the use of clove oil as an alternative to reduce the stress response to transport in matrinxã (Brycon cephalus). Clove oil solutions were tested in concentrations of 0, 1, 5 and 10 mg/L during matrinxã transportation in plastic bags, supplied with water and oxygen as the usual field procedures in Brazil. Clove oil reduced some of the physiological stress responses (plasma cortisol, glucose and ions) that we measured. The high energetic cost to matrinxã cope with the transport stress was clear by the decrease of liver glycogen after transport. Our results suggest that clove oil (5 mg/l) can mitigate the stress response in matrinxã subjected to transport. KEY WORDSmatrinxã Brycon cephalus, transport, stress, clove oil.Efeito do óleo de cravo na resposta de estresse do matrinxã (Brycon cephalus) submetido ao transporte. RESUMO O transporte de peixes vivos é certamente um dos principais estímulos adversos à homeostase dos peixes nas condições de criação em cativeiro. O presente trabalho mensurou o estresse do matrinxã (Brycon PALAVRAS-CHAVEmatrinxã Brycon cephalus, transporte, estresse, óleo de cravo.

The adaptation of digestive proteases, amylase and lipase was studied in tambaqui fed with 350, 253, 301 and 205 g kg )1 of crude protein, and 49, 81, 113 and 145 g kg )1 of lipid, in isocaloric diets. Digestive protease increased when dietary protein increased in stomach, where the highest specific activity was observed. Unspecific protease activity in intestine was very low. Lipase was observed throughout the gastrointestinal tract, and higher activities were observed in the stomach. However, pyloric caecum and the anterior and posterior intestines were the responsive sections to the dietary lipid. Amylase was detected throughout the gastrointestinal tract, but pyloric caecum was the most relevant amylase producer. Positive correlations were observed between anterior intestine lipase versus dietary lipid and pyloric caecum amylase versus dietary protein. Tambaqui is responsive to the food composition adapting the main digestive enzymes to the best profile. KEY WORDS

No abstract

No abstract

No abstract