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.
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.
ResumoO tambaqui é a principal espécie de peixe cultivado na Amazônia Ocidental. Porém durante o processo produtivo, práticas de manejo são necessárias para o monitoramento do crescimento e estado geral da sanidade dos animais. Para isso os animais devem ser anestesiados para maior segurança no trabalho. O eugenol, componente majoritário do óleo de cravo, tem sido bastante utilizado como anestésico alternativo para peixes por ser um produto natural e de baixo custo. Entretanto, estudos tratando de respostas metabólicas em peixes tropicais expostos a diferentes anestésicos são ainda necessários. Dentro desse intuito, o presente trabalho avaliou respostas metabólicas, detectadas por meio de alterações de parâmetros sanguíneos e plasmáticos do tambaqui, exposto ao eugenol em banhos anestésicos simulados. Respostas típicas ao estresse foram detectadas devido ao manuseio imposto aos peixes durante a realização dos banhos anestésicos. O eugenol não reduziu totalmente essas reações ao estresse. Por outro lado, esse anestésico não provocou estresse adicional em exposições curtas de 15 min em concentrações próximas a 20 mg L -1 . PalavRas-Chave: Colossoma macropomum, respostas fisiológicas, hematologia. Evaluation of tambaqui metabolic responses to eugenol in anesthetics bathsabstRaCt Tambaqui is the main farmed fish in the Western Amazon. However, in handling this fish has to be anesthetized for safety purposes, usually when evaluating growth and health conditions. Eugenol, the main component of clove oil, has been reported as an alternative fish anesthetic, because it is an inexpensive natural product. However, continued studies are necessary about the metabolic responses of tropical fish to anesthetics. The present work evaluated metabolic responses of tambaqui to eugenol in simulated anesthetic baths, measuring blood and plasma parameters. Typical metabolic stress responses to handling were detected, but they were not totally reduced by eugenol. On the other hand, the anesthetic dissolved in water did not provoke any extra charge of stress during short-term exposures in concentrations of about 20mg L -1 for 15 min.
The matrinxã fish is suitable for Amazonian aquaculture, exhibiting positive characteristics such as good growth and feed conversion ratio. However, it is a very active fish and must be anesthetized for handling. The present study evaluated the use of Ocimum gratissimum essential oil (EO) as anesthetic for juvenile matrinxãs. A first experiment assessed the induction time to anesthesia of 7 concentrations (20, 30, 40, 50, 60, 70 and 80 mg L-1 of O. gratissimum (EO). A second experiment investigated the physiological response to the anesthetic through analysis of tissue and blood parameters collected 0h (T0) and 24h after (T24) the experimental protocols that were applied to 4 groups: control, handling without O. gratissimum (EO) and handling with two EO levels. In the first experiment, fish were anesthetized within 10 min in the lowest EO concentration (20 mg L-1), and recovered within 2 min. As concentrations increased times to induction to anesthesia decreased from 10 min to 1 min (approximately). In the second experiment, plasma lactate, glucose and ammonia increased in the treatments involving handling and EO concentrations. After 24h, fish had recovered from the experimental procedures, and no mortality was observed in the next 30 days. Ocimum gratissimum was shown to be a suitable anesthetic for matrinxãs, and causes minimum stress to fish in the concentrations and exposure time applied.
Summary The aim of this study was to investigate the effects of a dietary Allium sativum (garlic) addition on growth, parasite infestation and blood parameters in Colossoma macropomum (tambaqui) using 12 net‐cages (1 m3). There were four treatments with three replicates each (15 fish per replicate). Tambaqui of 112.4 g mean weight were fed for 45 days with diets containing 0, 15, 30 and 45 g of fresh garlic kg−1 feed. Garlic did not affect the tambaqui survival, growth, feed conversion, body condition, plasma glucose levels, total plasma protein levels or red blood cells. Total leukocyte and lymphocyte numbers decreased in fish fed diets containing 45 g garlic kg−1 feed, but neutrophils decreased in fish fed diets containing 15, 30 and 45 g garlic kg−1 diet, while the number of immature leukocytes increased in fish fed 30 g and 45 g garlic kg−1diet. Gills in fish fed 30 and 45 g kg−1 diet had lower infestation (52% and 63%, respectively) of Anacanthorus spathulatus (Monogenea) compared to controls. The application of garlic in diets improved the response of leukocytes and enhanced the resistance to infections by monogeneans.
Aspects of digestion in juvenile silver catfish Rhamdia quelen fed with four levels of protein (20, 27, 34 and 41%) were studied. The studied traits were digestive enzymes (nonspecific proteases, trypsin, chymotrypsin, amylase and lipase) and weight gain. The experiment lasted 60 days; 160 juvenile catfish with initial body weight of 32 grams were transferred to the experimental system of 500L tanks with recirculated and thermostatized water. The average weight of silver catfish increased with dietary protein and 41% of crude protein (CP) was accepted as the best one. Gastric protease activity increases with the CP level. The intestinal alkaline protease reached the peak at 27% CP and the highest activities were observed in the anterior section of the gut (AS). The trypsin peak was observed at 34% CP in the AS and medium section of the gut (MS). Amylase and lipase activities were inverse to the dietary CP and the highest values were observed in AS. In conclusion, the digestive enzymes of catfishes are responsive to the dietary protein level. The dietary CP required for highest weight gain of juvenile silver catfish is 41%.Keywords: digestive enzymes, nutrition, fish, Rhamdia quelen RESUMO Foram estudados aspectos digestivos de juvenis de jundiá Rhamdia quelen alimentados com quatro níveis de proteína (20, 27, 34 e 41 %). As características estudadas foram enzimas digestivas (proteases
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.