%0 Journal Article
%T Efficacy of 2-Phenoxyethanol as an Anaesthetic for Adult Redline Torpedo Fish, Sahyadria denisonii (Day 1865)
%A Anna Mercy Thoranam Varkey
%A Sajan Sajeevan
%J International Journal of Zoology
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/315029
%X Efficacy of 2-phenoxyethanol for redline torpedo fish exposed to five concentrations (200, 300, 400, 500, and 600£¿¦̀lL£¿1) was evaluated. The time periods necessary for each characteristic stage of induction and recovery were recorded. Results indicated that the induction time of the fish exposed to five anaesthetic concentrations significantly decreased with increasing concentration but recovery time was independent of concentration. Concentration of 500£¿¦̀lL£¿1 (induction time: 173 ¡À 7 and recovery time: 129 ¡À 41 seconds) was determined as the minimum effective concentration that induces anaesthesia in less than 3 minutes. 1. Introduction Anaesthesia is an effective method to minimize stress or physical damage caused during handling, transport, grading, weighing, and induction of spawning [1]. L. G. Ross and B. Ross [2] defined anaesthesia as a state caused by an applied external agent resulting in a loss of sensation through depression of the nervous system. The use of anaesthetics is primarily for the purpose of holding fish immobile while the animal is being handled for experiments. When choosing an anaesthetic, a number of considerations should be taken into account such as its efficacy, cost, availability, ease of use, and side effects on fish, humans, and the environment [3, 4]. Presently, there are many anaesthetics available for aquatic animals, including MS-222, benzocaine, quinaldine, chlorobutanol, 2-phenoxyethanol, eugenol, and metomidate [3]. 2-Phenoxyethanol is relatively inexpensive and remains viable in long-term exposure [5] and is also easily available compared to other anaesthetics. Deacon et al. [6] recommended 2-phenoxyethanol as a highly suitable anaesthetic for repeatedly exposed fishes. Over the last three decades, studies have evaluated the anaesthetic efficacy of 2-phenoxyethanol in various fish species [7¨C14]. According to Topic Popovic et al. [15], it is necessary to have a better understanding of safety margins, induction, and recovery times for many fish species in order to achieve optimal application. Sahyadria denisonii (or Puntius denisonii), an ornamental fish popularly known as redline torpedo fish or Miss Kerala, is endemic to the rivers flowing through the Western Ghats hotspots of India. The species is much sought after in the international ornamental fish trade and is listed as ¡°Endangered¡± in the IUCN Red List of Threatened Species [16]. Captive breeding is considered to be one of the solutions for ensuring sustainability and conserving wild populations of this endangered species [17]. In fisheries, various
%U http://www.hindawi.com/journals/ijz/2014/315029/