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<br />Effect of Extended Galvanonarcosis on Behavior of Rainbow Trout,
<br />Salmo gairdneri, and Channel Catfish, lctalurus punctatusl
<br />
<br />KEVIN D. CURRY
<br />
<br />Department 01 Forestry and Natural Resources, Purdue University,
<br />West Lafayette, Ind. 47907, USA
<br />
<br />AND BOYD KYNARD2
<br />
<br />Arizona Cooperative Fishery Unit, University 01 Arizona, Tucson, Ariz. 85721, USA
<br />
<br />CURRY, K. D., AND B. KYNARD. 1978. Effect of extended galvanonarcosis on behavior of
<br />rainbow trout, Salmo gairdneri, and channel catfish, Ictalurus punctatus. J. Fish.
<br />Res. Board Can. 35: 1297-1302.
<br />
<br />, Yea~ling rainbow trout, Sal~no gaird1leri,. an..l~ c1!J:lnn~1 catfis~, letalurus punctatu.l',
<br />wele subJccted to 0.5- and 3-h perIods of narcosIs u~ contlOuous dIrect current. Galvano-
<br />narcosis treatments decreased the immediate individual and group activity in both species
<br />of fish. Twenty-four hours after treatment, all fish except trout narcotized for 3 h recovered
<br />to levels of individual and group activity equivalent to those of untreated fish. Photo-
<br />negative response was strong in both fish species and was not influenced by galvanonarcosis
<br />trcatments. Trout narcotized with dircct current were more vulnerable to predation than
<br />untreated fish; susceptability increased .with increasing treatment periods. The potential
<br />of extended galvanonarcosis as a fish immobilization technique is strong.
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<br />Key words: galvanonarcosis, behavior, extended narcosis, direct current, rainbow trout,
<br />channel catfish, photonegative, activity, prey vulnerability, immobilization
<br />
<br />CURRY, K. D., AND B. KYNARD. 1978. Effect of extended galvanonarcosis on behavior of
<br />rainbow trout, Salmo gairdncri, and channel catfish, fctalurus punctatus. J. Fish.
<br />Res. Board Can. 35: 1297-1302.
<br />
<br />Nous avons soumis des truites arc-err-ciel, Salmo gairdneri, et des barbues de riviere,
<br />lctalurus puctatus, d'un an a des narcoses produites par un courant direct appliquc durant
<br />des pcriodes de 0.5 et 3 h. Chez les deux espcces, la galvanonarcose rcduit I'activite
<br />immediate individuelle et de groupe. Vingt-qllatre heures aprcs Ie traitement, tous les
<br />poissons, sauf les truites soumises a une narcose de 3 h, se retablissent et ont des niveaux
<br />d'activite individllclIe et de groupe equivalents a ceux des poissons non traites. Les deux
<br />esp'cces exhibent un phototropisme fortement negatif qui n'est pas affecte par la glavano-
<br />narcose. Les truites soumises a une narcose par courant direct sont plus vulncrables a la
<br />predation que les poissons non traitcs; la sensibilitc augmente en fonction de la longueur
<br />des traitements. Une galvanonarcose prolongee comme moyen d'immobiliser les poissons
<br />offre de grandes possibilites.
<br />
<br />Received June 27, 1977
<br />Acceptc June IS, 1978
<br />
<br />INVESTIGATIONS of the effects of immobilizing fish with
<br />electricity have concentratcd on short-term treatments
<br />similar to electroshocking. Past reports have shown that
<br />fish have a lower incidence of injury when immobilized
<br />with direct current instead of alternating current (Taylor
<br />et aI. 1957) and continue to grow normally after elec-
<br />trical treatment (Maxfield et at. 197]; Ellis 1974).
<br />The field intensities used in electroshocking immobi-
<br />
<br />!Journal Paper No. 6758, Agricultural Experiment Station,
<br />Purdue University, West Lafayette. Ind. 47907, USA.
<br />'Present address: Massachussetts Cooperative Fishery
<br />Research unit, University of Massachusetts, Amherst, Mass.
<br />01002, USA.
<br />
<br />Printed in Canada (14899)
<br />lmprimc au Canada (J4899)
<br />
<br />Re~u Ie 27 juin 1977
<br />Acceptc Ie IS juin 1978
<br />
<br />lize fish by inducing tetanus. Vibert (1967) demon-
<br />strated that fish go through definite phases during im-
<br />mobilization that are directly related to the intensity of
<br />the electrical field. Galvanonarcosis, the state of muscu-
<br />lar relaxation produced by constant direct current, oc-
<br />curred at a much lower field intensity than tetanus. If
<br />fish are held in a container where the length of the
<br />electric field is held constant, then the electric field
<br />could be adjusted so that the fish are immobilized in
<br />relaxed narcosis instead of tetanus.
<br />There has been little investigation of the potential of
<br />using low intensity electric fields for ex.tended immobi-
<br />lization of fish. Preliminary studies have shown that
<br />rainbow trout (Salmo gairdneri) can be immobilized up
<br />to 3 h with no significant effect on growth or photo-
<br />negative behavior (Kynard and Lonsdale 1975). The
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<br />1297
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