Observations on the Efficacy of Carbonic Acid as Anesthetic of Indian Major Carps

Central Institute of Freshwater Aquaculture (CIFA)
Dhauli, Kausalyagang, Bhubaneshwar

NETWORK OF AQUACULTURE CENTRES IN ASIA
BANGKOK, THAILAND

Hyperlinks to non-FAO Internet sites do not imply any official endorsement of or responsibility for the opinions, ideas, data or products presented at these locations, or guarantee the validity of the information provided. The sole purpose of links to non-FAO sites is to indicate further information available on related topics.

This electronic document has been scanned using optical character recognition (OCR) software. FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.

OBSERVATIONS ON THE EFFICACY OF CARBONIC ACID AS ANESTHETIC
FOR INDIAN MAJOR CARPS *

by

D. Kumer,¹ B. K. Mishra¹, R. K. Dey¹ & B. Biswas²

1. Freshwater Aquaculture Research & Training Centre (CIFRI), P. O. Kausalyagang, Via. Bhubaneswar - 751002 (Orissa) INDIA.

2. Assistant Director of Fisheries, Department of Fisheries, Governments of Orissa, P. O. Kausalyageng (Orissa), INDIA.

* Paper presented at All India Seminar on Fish Biology, P. G. Dept. of Zoology, Bihar University, Muzaffarpur; Bihar, India in November, 1981.

ABSTRACT

Various anaesthetics have been in use in culture fishery operations. The present communication describes the efficacy of carbonic acid as anaesthesis for Indian major carps. Different dose levels were tried and the results discussed. It was observed that at lower concentrations the fish were anaesthetized slowly and less deeply whereas at higher concentrations the effect was rapid with greater sedation. The duration for which the fish could be safely held in the anaesthetizing bath also varied according to the concentra tion of carbonic acid and size of the fish. For smaller fry, the safe dose range of carbonic acid was rather very narrow. No significent differences could be observed between the three species of Indian major carps in their response towards the carbonic acid anaesthesia.

INTRODUCTION

The use of anaesthetics in fishery research is fast gaining importance. Sedation of stock is rarely necessary in fish production operations, however, in experimental aquaculture studies which involve tagging, transport, stripping, sexing and other forma of handling, some degree of sedation to prevent the stress of handling and concomittant physical -rauma becomes essential.

A number of substances have been tested for their efficacy as anaesthesia for fish (Schoettger and Julin, 1967; Dhurve, 1970; Liard and Oswald, 1975; Dawson and Gilderhas, 1979; Lindsay and John, 1979). Several workers have also observed the effects of various anaesthetics on Indian major carps (Saha et al., 1955; Natarajan and Banganathan, 1960; Kewalramai and Gogote, 1968; Sreenivasan, 1962). Very little information is available in the efficacy of carbonic acid (Carbon dioxide) as anaesthetic for fish. The use of carbonic as an anaesthesia for fish was first suggested by Fish (1943) and later, Post (1979) has worked on its desative effect, advantages and limitations of use.

The increasing need for guidelines to be established in this field has necessitated this study with the purpose of testing the efficacy of carbonic acid as anaesthesia for Indian major carps.

MATERIALS AND METHODS:

Carbonic acid used for this study was prepared from solutions of sodium carbonate and concentrated sulphuric acid as described by Post, G. (1979). Stock solutions of sulphuric acid and sodium bicarbonate were prepared and added separately to the test vessels (10 lits. capacity glass jars) with deep tube well water in quantities needed to promote the desired concentrations of anaesthetic and stirred thoroughly.

Induced bred advanced fry of rohu (0.8 g) and sub-adult (13–15 g) of three species of Indian major carps Catla, Rohu and Mrigal were used as test fish. They were maintained in plastic pools and acclamatized to test waters for three days before use. They are then transferred in batches of 10 to the sedative bath. For recovery studies separate but same number of similar glass jars having 10 lit. of deep tube well water in each were kept and recovery studies conducted by transferring sedated fish into these jars.

The tests were designed firstly to see the time taken to achieve sedation by different dose levels and the corresponding revival time after 10 and 15 min. exposure in the case of fry and sub-adult fish respectively and secondly to see how long the fish could be safely held in the anaesthetic bath of different concentrations before irreversible sedation occurs. Stages of anaesthetization were determined by using characteristics defined by schoetter and Julin (1967). Loss of equilibrium meant stage 2.

RESULTS:

Tests with sub-adult fish

The results of various anaesthetic concentrations used for sub-adult fish are given in Table - I. All the three species of Indian major carps showed a total loss of equlibrium (Stages 2) within 5 min. and loss of reflex within 10.8 min. at anaesthetic concentrations between 500 and 650 ppm. without causing any mortality. At higher concentrations (700 ppm and above) and at 15 min. exposure mortality was encountered up to 33%. Partial loss of reflex was observed in rohu and mrigal within desired period of 15 min. at concentration level of 400 ppm and less, whereas catla showed total loss of reflex within 12.5 min. at 400 ppm.

Tests with fry

Heavy mortality (85–95%) was encountered when rohu fry (0.8 g) was exposed to 450 and 500 ppm. of carbonic acid for 10 minutes (Table II). At 400 ppm. time taken for loss of reflex was 7 min. with 90% survival. At 350 ppm for 10 min. exposure, fry partially lost reflex while at 300 ppm. loss of reflex was not encountered at all.

In case of sub-adult fish maximum exposure time limit with 100% revival possibility was 25 min., 30 min., and 250 min. at concentrations of 550, 500 and 450 ppm respectively. At 450 ppm fish started reviving inside the anaesthetic bath (table III).

DISCUSSION:

The dose levels of carbonic acid anaesthetia depended upon size of fish and period of exposure like other fish anaesthetics. The observations suggest wider safe limit (450 ppm-650 ppm) for sub-adult fish while very narrow and lower range of such limit for fry size class. With an increase of 50 ppm i. e. from 400 ppm to 450 ppm the fry could not withstand the exposure safely even for five mim. while on the lower side between 300 and 350 ppm only loss of equilibrium occured and the fry started reviving inside the bath. No marked difference was observed between the three species of Indian major carps towards their response to the xarbonic acid anaesthesia. Sub-adult fish could also be held in anaesthetic bath for lower periods (from 25 min. to 200 min. ) with 100% revival possibility at anaesthetic concentrations between 550 and 450 ppm. However, the fish started reviving inside the anaesthetic bath after few hrs. These results clearly indicate that carbonic acid can safely be used as anaesthesia for Indian major carps. On the basis of its effectiveness, safety, availability and cost as have been verified under the present set of experiments. Carbonic acid is recommended for its wide application as fish anaesthetic in fish culture practices.

REFERENCES:

Dawson V. K. and P. A. Gilderhaus, 1979. Ethylp-aminobengoate (Ben gocaine) : Efficacy as an Anaesthetic for Fivespecies of Freshwater Fish. U. S. Fish. Wildl. Serv. Invest. Fish Control 87 pp. 1–5

Dhurve, V. S. , 1970. Effects of anaesthetics on the behaviour of mullet fingerlings and the scope of using these indifferent fishery procedures. II. Effects of tertiary amyl alcohol, other, quinaldive, peraldehyde, pentobarbital sodium, phenobarbital sodium and MS - 222 Sandoz. Ind. J. Fish 13 (1) : 158–182.

Fish F. F. , 1943. The anaesthesia of fish by high carbon dioxide concentrations. Trans. An. Fish Soc. 72(1942). pp. 25–29.

Post, G. (1979). Carbonic Acid anaesthesia for aquatic organisms. Prog. Fish Cult. 41(3) : 142–144.

Kewalramani H. G. and Gegate M. G., 1968. Anesthetisation in fish-Tilapia and major carps. Proc. Indian Acad Sci 67B(5): 237-46.

Liard L. and Oswald R. L. O., 1975. A note on the use of bengocaine (ethyl-p-aminoben goate) as a fish anesthetic. J. Inst. Fish Manage., 6(4) : 92–94.

Lindsay G. Ross and John A. Geddes, 1979. Sedation of warm-water fish species in Aquaculture Research. Aquaculture 16 (1979) pp. 183–186.

Natarajan, M. V. and Ranganathan V., 1960. A note on the possibilities of utilizing quinaldive in transporting live fish-Curr. Sci. 29: pp 393.

Saha K. C., Sen D. P. and Banergea S. M., 1955. Use of sodium amytal in the transport of fry of Indian major carps. Ann. Biochem. 15(2) : 133.

Schoettger R. A. and A. M. Julin, 1967. Efficacy of MS-222 as an an esthetic on four salmonids. U.S. Fish. Wildl. Serv. Invest. Fish. Control 13–15 pp.

Sreenivasan A., 1962. Use of tranquilizing drugs and narcotics in reducing oxygen consumption by fish. Ind. J. Fish. 9A(2): 738-45.

Table-1. Response of Indian major carps to different dose levels of carbonic acid anaesthesia under 15 min. of exposure time.

+ Loss of reflex did not occur to 100% within 15 min. period.

Table 2 : Response of rohu (Labeo rohita) fry to different dose levels of carbonic acid anaesthesia un of exposure

* loss of reflex did not occur to 100% within 10 min. period.

Table 3: Dose level related to exposure time with 100% revival