Some effects of alternating current electronarcosis and of rectified current electronarcosis on C.
carpio were investigated. In all instances recovery from narcosis was accompanied by convulsive spasms.
Haemorrhaging of the gills was also observed to occur. Carp do not appear to be suitable candidates for
electronarcosis.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. 
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

Barham, W.T.

Schoonbee, H.J.

Visser, J.G.J.

The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. 
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Some effects of alternating current electronarcosis and of rectified current electronarcosis on C.
carpio were investigated. In all instances recovery from narcosis was accompanied by convulsive spasms.
Haemorrhaging of the gills was also observed to occur. Carp do not appear to be suitable candidates for
electronarcosis.lmchunu2014mn201

UPSpace at the University of Pretoria

Onderstepoort J. vet. Res., 56, 215-218 (1989) RESEARCH COMMUNICATION SOME OBSERVATIONS ON THE NARCOTIZING ABILITY OF ELECTRIC CURRENTS ON THE COMMON CARP CYPRINUS CARPIO W. T . BARHAM\ H. J. SCHOONBEE2 and J. G. J. VISSER1 ABSTRACf BARHAM, W. T., SCHOONBEE, H. J. & VISSER, J. G: J., 1989. Some observations on the narcotizing ability of electric currents on the common carp Cyprmus carp to. Onderstepoort Journal of Veterinary Research. 56,215-218 (1989). Some effects of alternatins current electronarcosis and ?f rectified curr~nt electronan;:osis on C. carpio were investigated. In allmstances recovery from narcosis was accompamed by convuls1v~ spasms. Haemorrhaging of the gills was also observed to occur. Carp do not appear to be suitable candidates for electronarcosis. INTRODUCfiON The European common carp Cyprinus carpio is one of the most domesticated freshwater fish used in aquaculture today. Although the pond production of tilapia is still on the increase in countries such as Taiwan and Israel (Schoonbee, personal observa-tion, 1988) the common carp still remains an impor-tant table fish in the Mediterranean and northern European countries. Even in Israel where pond pro-duction of tilapia has increased significantly from 5 % of the total pond fish yield in 1967 to almost 27 % in 1987 (Sarig, 1987), the common carp still comprises more than 60 % of the total tonnage of pond fish produced. F?r thi_s reas~n r~search _on _its feeding and reproductwn bwlogy IS still contmumg (Viola & Arieli, 1983; Siwicki & Studnicka, 1986; Viola, Arieli & Zohar, 1988). C. carpio is known to survive water temperatures well below 10 oc but can also withstand warm water conditions exceeding 30 oc (Schoonbee, personal ob-servation, 1972). It has a tough leathery skin richly endowed with mucus cells and has been subjected to a number of blood physiological studies locally (Fer-reira, 1979, 1982; Smit, 1980). Barham Schoonbee & Visser (1987b, 1988, 1989) reported on the narcotizing effects of electric cur-rents on the tilapia Oreochromis mossambicus and came to the conclusion that alternating current was the method of choice for that species. The present study evaluates the use of both alternating and recti-fied currents on C. carpio as possible alternatives to chemical anaesthesia. MATERIALS AND METHODS The materials and methods were those used by Barham eta/. (1987a,b, 1988, 1989). Fish were elec-tronarcotized individually in a 60 em long 48 I ca-pacity aquarium. Water temperature was 20 oc un-less otherwise indicated. Alternating current electro-narcosis was induced at a potential of 60 Vrms, ex-cept in the voltage trials. Rectified current electronarcosis was induced at a potential of 100 Vp. Each group consisted of 8 fish. RESULTS The effects of alternating current electronarcosis The effects of voltage Although there was a significant difference (P = 0,01) in mean narcosis times between 15 Vrms and 1 Tilapia Research Unit, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, Republic of South Africa. 2 Department of Zoology, Rand Afrikaans University, P.O. Box 524, Johannesburg 2000, Republic of South Africa. Received 6 March 1989-Editor 215 30 Vrms and highly significant differences (P = 0,001) in the mean narcosis time at 15 Vrms and the mean times obtained at 60 Vrms and at 90 Vrms, the mean narcosis times at 30, 60 and 90 Vrms did not differ significantly from each other (T~ble 1, ~i~. 1). This pattern is reinforced by narcosis co~ffiCien~s which show clearly that1 with a m~an narcosis coeffi-cient value of 1,2 s em· , a potential of 15 Vrms was the least effective voltage. Furthermore an increase in the potential beyond 30 Vrms did not resul~ in a substantial improvement on 2,1 s cm·1• The higher voltage also resulted in longer opercular r~covery times than at the lowest voltage but once agam there were no significant differences in these times at the higher voltages. This pattern extended to recovery times. At all voltages the fish exhibited erratic opercular movements shortly after the current was switched off 200 ~ 150 0 0 ~ .!: .~ 100 1/) ·c;; 0 :! "' 50 z * 0 20 t t 40 60 80 100 Volts FIG. 1 The effect of alternating current electronarcosis at 3 dif-ferent potentials on mean narcosis time (± SE) 200 1/) -g 150 0 ~ en .!: ~ 100 1/) ·c;; 0 :! 2! 50 f f f o+-----~--~-----------r----~----~ 0 10 20 30 Temperature ° C FIG. 2 The effect of 100 Vp rectified current electron~rc<!sis at 3 different water temperatures on mean narcosis time (± SE) COMPARATIVE INFECTION RATES OF THEILERIA PAR VA LA WRENCEI IN SALIVARY GLANDS TABLE 1 The effects of alternating current electronarcosis at 3 different potentials on opercular recovery, narcosis and recovery times respectively Opercular Narcosis Length (em) Mass (g) recovery N a reo sis time ( s) ~ecovery time ( s) coefficient time (s) (s em·') n= 8 8 8 8 8 8 Minimum 30,7 470,7 31,7 34,8 0,0 1,1 > Maximum 34,3 618,4 43,7 44,2 11,0 1,4 ~ Range 3,6 147,7 12,0 9,4 11,0 0,3 Mean 32,5 563,3 37,6 40,1 4,2 1,2 Standard dev. 1,4 59,7 3,7 3,7 4,3 0,1 Standard err. 0,5 21,1 1,3 1,3 1,5 0,0 n= 8 8 8 8 8 8 Minimum 27,6 398,8 34,9 42,3 5,0 1,3 > Maximum 35,0 740,1 92,5 109,!2. 42,2 3,1 0 Range 7,4 341,3 57,6 66,9 37,2 1,8 <"> Mean 32,9 651,8 53,4 70,6 16,8 2,1 Standard dev. 2,3 109,6 19,9 22,0 13,3 0,6 Standard err. 0,8 38,7 7,0 7,8 4,7 0,2 n= 8 8 8 8 8 8 Minimum 31,0 505,4 40,1 52,9 8,4 1,7 > Maximum 35,5 651,1 75,0 94,7 57,0 2,7 ~ Range 4,5 145,7 34,9 41,8 48,6 1,0 Mean 32,8 597,1 52,5 72,5 18,6 2,2 Standard dev. 1,6 61 ,8 11,4 15,6 15,8 0,4 Standard err. 0,6 21,9 4,0 5,5 5,6 0,1 n = 8 8 8 8 8 8 Minimum 27,8 393,3 43,9 59,6 4,3 1,7 > Maximum 36,5 797,5 63,1 90,0 42,3 2,6 ~ Range 8,7 404,2 19,2 30,4 38,0 0,9 Mean 33,4 656,6 50,3 73,1 18,2 2,2 Standard dev. 2,4 112,4 5,9 10,0 14,3 0,3 Standard err. 0,8 39,7 2,1 3,5 5,1 0,1 TABLE 2 The effects of duration of current flow on opercular recovery, narcosis and recovery times respectively Opercular Narcosis Length(cm) Mass (g) recovery Narcosis time (s) Recovery time ( s) coefficient time (s) (s em·') n= 8 8 8 8 8 8 Minimum 32,2 535,7 31,4 40,5 2,4 1,1 "' Maximum 36,1 753,4 49,6 50,7 6,2 1,5 ~ Range 3,9 247,7 18,2 10,2 3,8 0,4 Mean 34,2 691,4 40,0 45,6 4,2 1,3 Standard dev. 1,4 73,5 6,1 4,0 1,5 0,1 Standard err. 0,5 26,0 2,2 1,4 0,5 0,1 n= 8 8 8 8 8 8 Minimum 31,0 205,4 40,1 52,9 8,4 1,7 "' Maximum 35,5 651,1 75,0 94,7 56,9 2,7 0 Range 4,5 145,7 34,9 41 ,8 48,5 1,0 <"> Mean 32,8 597,1 52,5 72,5 18,6 2,2 Standard dev. 1,6 61,8 11,4 15,6 15,8 0,4 Standard err. 0,6 21,9 4,0 5,5 5,6 0,1 n= 8 8 8 8 8 8 Minimum 45,5 1 322,5 48,5 80,0 21,9 1,6 "' Maximum 51,0 1 740,5 60,7 119,1 %,6 2,5 .,., Range 5,5 418,0 12,2 39,1 74,7 0,9 -~ Mean 47,6 1 507,6 55,3 96,0 47,1 2,0 Standard dev. 2,5 175,1 5,1 18,4 33,6 0,4 Standard err. 0,9 61,9 1,8 6,5 11,9 0,1 n= 8 8 8 8 8 8 Minimum 39,0 812,4 50,1 64,1 13,4 1,6 "' Maximum 46,5 1 365,7 70,6 114,8 36,9 2,5 ~ Range 7,5 553,3 20,5 50,7 23,5 0,9 Mean 43,4 1131,25 58,3 92,2 21,9 2,1 Standard dev. 3,7 247,4 8,8 21,7 10,3 0,3 Standard err. 1,3 87,5 2,8 7,7 3,6 0,1 216 E. F. BLOUIN & W. H. STOLTSZ TABLE 3 The effects of rectified current electronarcosis at 3 different water temperatures on opercular recovery, narcosis and recovery times respectively Opercular Narcosis Length (em) Mass (g) recovery Narcosis time (s) Recovery time ( s) coefficient time (s) (s em·') n= 8 8 8 8 8 8 Minimum 31,2 532,5 68,8 92,2 10,3 2,4 ~ Maximum 43,2 1 285,4 99,9 156,5 63,4 4,0 V) Range 12,0 752,9 31,1 64,3 53,1 1,6 ..... Mean 38,2 %1,3 83,7 122,5 25,0 3,2 Standard dev. 4,4 273,3 14,2 27,5 22,0 0,6 Standard err. 1,9 122,2 6,4 12,3 9,8 0,3 n= 8 8 8 8 8 8 Minimum 25,1 910,4 40,7 56,4 5,2 1,4 ~ Maximum 40,7 1 059,6 64,3 156,1 12,8 4,5 0 Range 15,6 149,2 23,6 99,7 7,6 3,1 N Mean 33,7 1 008,0 52,4 99,0 8,6 3,0 Standard dev. 5,0 51 ,5 8,5 39,7 2,4 1,2 Standard err. 2,0 21 ,0 3,5 16,2 1,0 0,5 n= 8 8 8 8 8 8 Minimum 31,5 539,1 30,1 44,4 12,7 1,2 u Maximum 59,2 1266,2 48,9 154,3 110,0 4,1 0 Range 27,7 727,1 18,8 109,9 97,3 2,9 ~ Mean 39,7 908,1 40,9 73,0 43,7 1,9 Standard dev. 8,8 238,5 5,9 34,3 35,7 0,9 Standard err_ 3,1 84,3 2,1 12,1 12,6 0,3 't' Values (df) 15/20 (14) NS NS 5,349 (P=0,001) NS 2,096 (P=0,05) NS 15/25 (14) NS NS 7,872 (P=0,001) 3,184 (P=0,01) NS 2,600 (P=0,02) 20/25 (14) NS NS 3,143 (P=0,01) NS 2,774 (P=0,02) 1,991 (P=0,1) df = degree of freedom; P = two-tailed probability; NS = not significant and rapid convulsive shudders of the body would commence a few seconds later_ These movements made it extremely difficult to determine when the fish were responding to stimuli. On a number of occasions haemorrhaging of the gills was observed, a phenomenon which occurred in all the tests underta-ken on carp. In this respect the common carp dif-fered completely in its response to electronarcosis from that exhibited by the freshwater bream 0. mos-sambicus, which recovered uneventfully. The effect of frequency A preliminary investigation showed that carp ex-hibited erratic opercular movements and convulsive shudders at frequencies ranging from 25 Hz to 500 Hz, which made it difficult to determine the exact time of first response to a stimulus. Since there were no significant differences in opercular recovery times, narcosis times and recovery times in tilapia narcotized at different frequencies (Barham et a/., 1988), the effect of frequency on carp was not inves-tigated further. The effect of duration of application The results of duration of application time are pre-sented in Table 2. Current application was not ex-tended beyond a period of 60 s because of severe convulsions. Although mean narcosis times in-creased with increasing application times up to and including 45 s there was a slight but insignificant decrease when the current flowed for 60 s. This trend was not reflected in the mean narcosis coeffi-cients which did not increase significantly when ap-plication times exceeded 30 s. This indicates that the mcreased narcosis times observed at 45 s and 60 s application times were due to the increased sizes of the fish. Opercular recovery times reflected the nar-cosis coefficient pattern. The narcosis times for cor-217 responding current flows were in all instances sub-stantially lower in the common carp than the times observed for 0. mossambicus. The effects of rectified current electronarcosis The effect of temperature Narcosis times declined with increasing water tem-peratures (Table 3, Fig. 2) but it was only the times at 15 oc and 25 oc that were significantly different (P=0,01). This trend was also evident in mean oper-cular recovery times. Mean recovery times did not continue this trend and fish subjected to narcosis at 20 oc recovered the quickest , followed by fish narco-tized at 15 °C, with those at 25 oc taking the longest time to recover. The narcosis coefficient decreased slightly as the temperature rose from 15 oc to 25 oc but decreased significantly at 25 oc (P = 0,02). Al-though carp exhibited a similar pattern to tilapia (Barham eta!., 1988) the narcosis times for corre-sponding temperatures were much lower in the com-mon carp. DISCUSSION Electronarcosis suggests itself as a cheap and ef-fective alternative to chemical anaesthesia and is free from the carcinogenic hazards often associated with chemical anaesthesia. Barham et a/. (1987b, 1988, 1989) have shown that the tilapia 0. mossam-bicus is an excellent candidate for electronarcosis, with an adequate period of narcosis and an unevent-ful recovery. The results obtained in this study clearly suggest that the common carp Cyprinus carpio is not a suit-able candidate for either alternating or rectified cur-rent electronarcosis. The narcosis times induced are, generally, of too short a duration for practical use and the occurrence of haemorrhaging is a further COMPARATIVEINFECTIONRATESOFTHEJLERJAPARVALAWRENCEJINSALIVARYGLANDS negative aspect. These findings contrast with the findings for the tilapia 0. mossambicus (Barham et al., 1988, 1989) which is an eminently suitable candi-date for electronarcosis. The reasons for the observed erratic movements of carp are not clear and will need further investiga-tion. Physiological resl?onses of carp to electronarco-sis will be reported on m another paper. ACKNOWLEDGEMENTS The financial support of the University of Zulu-land and the Rand Afrikaans University is gratefully acknowledged. REFERENCES BARHAM, W. T., SCHOONBEE, H. J. & VISSER, J. G. J., 1987a. The design and development of an alternating current electro-narcosis unit for use With freshwater fish. Publication series of the University of Zululand. Series B64, 20 pp. BARHAM. W. T., SCHOONBEE, H. J. & VISSER, J. G. J., 1987b. The use of electronarcosis as anaesthetic in the cichlid, Oreo-chromis mossambicus (Peters). I . General experimental proce-dures and the role of fish length on the narcotizing effects of electric currents. Onderstepoort Journal of Veterinary Research, 54,617-622. BARHAM, W. T., SCHOONBEE, H. J. & VISSER, J. G. J., 1988. The use of electronarcosis as anaesthetic in the cichlid, Oreo-chromis mossambicus (Peters). II. The effects of changing phy-sical and electrical parameters on the narcotizing ability of al-ternating current. Onderstepoort Journal of Veterinary Re-search, 55,205-215. BARHAM, W. T., SCHOONBEE, H. J. & VISSER, J. G. J., 1989. The use of electronarcosis as anaesthetic in the cichlid, Oreoch-romis mossambicus (Peters). III The effects of chan~ing fhysi-cal and electrical parameters on the narcotizing abihty o half-wave rectified current. Onderstepoort Journal of Veterinary Re-search, 56,67-71. FERREIRA, J. T., 1979. Bereiding en evaluering van benzocaine-hidrochloried as narkosemiddel vir varswatervis. M.Sc. disser-tation, Rand Afrikaans University. FERREIRA, J. T., 1982. Evaluering van benzocaine-hidrochloried as narkosemiddel vir varswatervis. Ph.D. thesis, Rand Afrikaans University. SARIG, S., 1987. Fisheries and fish culture in Israel. Bamidgeh 39 (4), 95- 108. SMIT, G. L., 1980. The effect of tricaine methane sulphonate and generally used anticoagulants on fish haematology. Ph.D. the-sis, University of the Witwatersrand. SIWICKI, A. & STUDNICKA, 1986. Ceruloplasma activity in carp (Cyprinus carpio L) Bamidgeh 38 (4) , 126--129. VIOLA. S. & ARIEL!, Y., 1983. Evaluation of different grains as basic ingredients in complete fish feeds for carp and tilapia in intensive culture. Bamidgeh 35 (2), 38-43. VIOLA, S., ARIEL!, Y., & ZOHAR, G., 1988. Unusual feedstuff (tapioca and lupin) as ingredients for carp and tilapia feeds in intensive culture. The Israel Journal of Aquaculture-Bamid-geh 40 (1), 29-34. Printed by the Government Printer, Private Bag X85, Pretoria, 0001 218 

Some observations on the narcotizing ability of electric currents on the common carp Cyprinus carpio

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Some observations on the narcotizing ability of electric currents on the common carp Cyprinus carpio

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