EFFECTS OF HANDLING ON ENDOCRINOLOGY AND REPRODUCTIVE
PEFORMANCE OF THE FATHEAD MINNOW
M.D. Kahl, K.M. Jensen, J.J. Korge, G.T. Ankley-2001
Journal of Fish Biology, 59(3): 515-523
Abstract:
Anaesthesia with MS-222 followed by
intra-peritoneal (ip) injection (with a 10% ethanol in corn oil
carrier) of fathead minnow either as one or three (weekly)
treatments did not affect survival, behaviour or secondary
sexual characteristics of the fish. Fecundity of the
fish, as indicated by fertility and hatching success,
was also unaffected. Gonadal condition (relative gonad
mass, histopathology) was not altered in either sex.
Male and female plasma sex steroids (ß-oestradiol, testosterone,
11-ketotestosterone) and male vitellogenin concentrations
were not significantly affected by the treatments.
Females subjected to either ip treatment regime had
significantly higher plasma vitellogenin
concentrations than control females. However, based
on previous data, this difference did not appear
to be treatment-related. Overall, exposure of fathead
minnows to chemicals via the ip route should not confound
the interpretation of toxicity tests with potential
endocrine disrupting chemicals.
(U.S. Environmental Protection Agency, National
Health and Environmental Effects Research Laboratory, Mid-Continent Ecology
Division, 6201 Congdon Boulevard, Duluth, MN, 55804, U.S.A., Tel.: +1 218
529 5147; fax: +1 218 529 5003; email:ankley.gerald@epa.gov)