NOTE Thedinga et al.: Mark retention and growth of jet-injected marine fish 
633 
Bagge, 1963) and resulted in increased mortality in 
sablefish (McFarlane and Beamish, 1990), jet-in- 
jected marks did not affect flatfish and sablefish 
growth or survival. Marks, however, may not be re- 
tained as long under natural conditions where growth 
is faster: sablefish in their natural habitat average 
31-33 cm FL in spring (McFarlane and Beamish, 
1983) in contrast with 28 cm FL recorded at the end 
of our laboratory study in spring. 
Jet-injected marks did not affect fish histology. 
There was no evidence of lesions in skin or muscula- 
ture and no alterations in either the cells or the struc- 
ture of dyed tissues. Changes in liver hepatocytes 
occur when fish have been exposed to toxicants 
(Hinton et al., 1992) but test hepatocytes in our 
preparations were normal. 
Jet-injection of either alcian blue dye or fluores- 
cent orange acrylic paint is a good method for mass 
marking or individually marking juvenile marine fish 
and meets most criteria for an effective external 
marker (Kelly, 1967). The marks are effectively re- 
tained and nontoxic and nonirritating; they do not 
affect mortality, can be used rapidly, and are inex- 
pensive, readily visible, and permit numerous dif- 
ferent mark combinations (Thedinga et al., 1994). 
Their application requires minimal training and 
equipment. Most importantly, jet injection does not 
alter the growth or tissue structure of fish. A limita- 
tion of jet-injection marking is the nonpermanent 
nature of the mark (Thedinga and Johnson, 1995). 
As a moderate-lasting marking method of juvenile 
marine fish, it is superior to most available external 
marking methods. 
Acknowledgments 
We thank Mike Murphy and Scott Johnson for re- 
viewing the manuscript and Mark Carls for photo- 
graphing jet-injected sablefish and yellowfin sole. 
Literature cited 
Andersen, K. P., and O. Bagge. 
1963 . The benefit of plaice transplantation as estimated 
by tagging experiments. In International Commission for 
the Northwest Atlantic Fisheries, North Atlantic fish mark- 
ing symposium, Woods Hole, MA, May 1961, p. 164- 
171. Dartmouth, Nova Scotia, Spec. Publ. 4. 
Cane, A. 
1981 . Tests of some batch-marking techniques for rainbow 
trout ( Salmo gairdneri Richardson). Fish. Manage. 
12 ( 1 ): 1 — 8 . 
Dando, P. R., and R. Ling. 
1980 . Freeze-branding of flatfish: flounder, Platichthys 
flesus, and plaice, Pleuronectes platessa. J. Mar. Biol. 
Assoc. U.K. 60:741-748. 
Hart, P. J. B., and T. J. Pitcher. 
1969 . Field trials of fish marking using a jet inoculator. J. 
Fish Biol. 1:383-385. 
Herbinger, C. M., G. F. Newkirk, and S. T. Lanes. 
1990 . Individual marking of Atlantic salmon: evaluation of 
cold branding and jet injection of Alcian Blue in several 
fin locations. J. Fish Biol. 36:99-101. 
Hinton, D. E., P. C. Bauman, G. R. Gardner, W. E. 
Hawkins, J. D. Hendricks, R. A. Murchelano, and 
M. S. Okihiro. 
1992. Histopathologic biomarkers. In R. J. Huggett, R. A. 
Kimerie, P. M. Mehrle, and H. L. Bergman (eds.), 
Biomarkers: biochemical, physiological and histological 
markers of anthropogenic stress, p. 155-209. Lewis Pub- 
lishers, Boca Raton, FL. 
Kelly, W. H. 
1967 . Marking freshwater and a marine fish by injected 
dyes. Trans. Am. Fish. Soc. 96:163-175. 
Laufle, J. C., L. Johnson, and C. L. Monk. 
1990 . Tattoo-ink marking method for batch-identification 
offish. Am. Fish. Soc. Symp. 7:38-41. 
McFarlane, G. A., and R. J. Beamish. 
1983 . Preliminary observations on the juvenile biology of 
sablefish ( Anoplopoma fimbria) in waters off the west coast 
of Canada. In Proceedings of the International Sablefish 
Symposium, March 29-31, 1983, Anchorage, AK, p. 119- 
135. Alaska Sea Grant Rep. 83-8. 
1990 . Effect of an external tag on growth of sablefish 
( Anoplopoma fimbria), and consequences to mortality and 
age at maturity. Can. J. Fish. Aquat. Sci. 47:1551-1557. 
McFarlane, G. A., R. S. Wydoski, and E. D. Prince. 
1990 . Historical review of the development of external tags 
and marks. Am. Fish. Soc. Symp. 7:9-29. 
Moles, A., and B. L. Norcross. 
1995 . Sediment preference in juvenile Pacific flat- 
fish. Neth. J. Sea Res. 34:177-182. 
Pauley, G. B., and D. A. Troutt. 
1988 . Comparison of three methods of fluorescent dye ap- 
plication for marking juvenile steelhead. Trans. Am. Fish. 
Soc. 117:311-313. 
Riley, J. D. 
1966 . Liquid latex marking technique for small fish. J. 
Cons. Perm. Int. Explor. Mer 30:354-357. 
Rutecki, T. L., and T. R. Meyers. 
1992 . Mortality of juvenile sablefish captured by hand-jig- 
ging and traps. N. Am. J. Fish. Manage. 12:836-837. 
Thedinga, J. F., and S. W. Johnson. 
1995 . Retention of jet-injected marks on juvenile coho and 
sockeye salmon. Trans. Am. Fish. Soc. 124:782-785. 
Thedinga, J. F., M. L. Murphy, S. W. Johnson, J. M. 
Lorenz, and K V. Koski. 
1994 . Determination of salmonid smolt yield with rotary- 
screw traps in the Situk River, Alaska, to predict effects of 
glacial flooding. N. Am. J. Fish. Manage. 14:837-851. 
