Document Gx0kXpkoX5ZjJ47j2Oaoz6Dq
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AR726-0359
SUMMARY OF HISTOPATHOLOGICAL
EXAMINATIONS OF FATHEAD MINNOW
(Pimephales promelas) EXPOSED TO 78.01 FOR 30 DAYS.
FM-3922
RESEARCH REPORT SUBMITTED TO 3 COMPANY
ST. PAUL, MINNESOTA
REPORT #BW-78-9-300
susMrTTED BY
AquatEicGTo&xiG,coBloigoynomLiacbsoratory
Wareh7a9m0, MaMianssaScthrueseettts
September, 1978
:
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INTRODUCTION
An "egg and fry test" was conducted between March 31 and May 4, 1978 (Bionomics Report #BW-78-6-195, June, 1978) to assess the sub-lethal effects of 76.01 on fathead minnows (pimephales promelas). Effects on egg hatchability and on survival and growth of fry were measured. To further investigate possible effects due to exposure to 78.01, histopathological examinations of exposed fish were also performed. The results of these examinations are reported here.
MATERIALS AND METHODS
Upon termination of the gg and fry study, five fish from
each replicate of the high 78.01 concentration (20 ug/s,
nominal) vere preserved in 10% buffered formalin and sent,
*
to the Environmental Pathology Laboratories, Inc. Carolina,
Rhode Island. Control fish from a similar ongoing study
were also examined.
.
The fish were examined for gross lesions, and sagital sections were prepared by a pathologist. Fish were placed with identifying nunbers into processing cassettes, dehydrated, cleared and infiltrated on an Auto-technicon tissue processor using the method of the Armed Forces Institute of Pathology. The fish were then placed in a vacuum oven and subsequently embedded in paraffin. All blocks were sectioned at 6 microns: one
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2
slide was prepared from each block and stained with hematoxylin
and eosin. Special staining procedures such as PAS, Trichrome
and Acid Fast were used occasionally when requested by the pathologist. All blocks were sealed with paraffin and stored.
Slides were labeled, boxed and delivered with all work sheets to the pathologist for examination. Two slides were prepared
from each fish. Tissues processed and examined included but were not limited to; gill, thymus, liver, spleen, heart, gonad, kidney, foregut, hindgut, olfactory mucosa (nares), brain, ear,
skin, muscle, pancreas and pharyngeal mucosa.
RESULTS
B
A summary of the examination of each fish is reported in
*
Table 1. Only those tissues which were missing or contained
demonstrable change are listed.
The only tissue changes observed were hyperplasia of gill
lamellar epithilium and fatty change of the liver. These
changes were judged to be minimal and consistent with changes
seen routinely in healthy fish. Autolipis of gill tissue
vas observed in several fish. This change was probably due
to the poor penetration of the buffered formalin to the pos-
terior dorsal portion of the gill space.
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3 Based on these data, it is concluded that 30 days exposure to a nominal 78.03 concentration of 100 mg/t did not cause any significant, demonstrable, tissue changes in 30 day old fathead minnow fry.
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Table 1 -- Histopathological examination of fathead minnow (Pimephales promelas) exposed 30 days to 20 ug/t nominal 78.01 and control water.
-_--
20 ug/? 78.01
F-_i--sh 1 2 3 4
5 6
7 8 9
10
sex
coonrdgitainon eR
MTiissssiueng Tissue
"?
Normal
Ear, thymus
Uka
Normal
nSaprleeesn, gonad,
Ukn
Normal
Stphlyemeuns, gonad,
Ukn
Normal
Sgopnlaede,n, `nhaeraerst,
F
Normal
Spleen, nares
F
Normal
Stphlyemesn, nares,
F
Normal
Spleen, heart
r
Normal
nSaprleeesn, heart,
F
Normal
Spleen
F
G(ielplithHeylpieurmp)lasIia Stphlyemeuns, heart,
Control
:
1
Ukn
(cLhiavnegre-faItty
Gtohnyamdu,s nares,
G(ielpli-thhiylpieurmp)las1 ia
2
kn
Lcihvaenrg-efaTtty
Spleen, nares
gonad,
E
F
G(ielpli-thhiylpieurmp)lasIia Thymus
4
F
Normal
Spleen, nares
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Table 1 (cont.)
Fish #
Sex
_--
Control
5
ud
6
r
7
Ukn
8
Ukn
9
F
-
10
Ukn
-
b"Female. cUnknown. Jesions are minimal. Male
Conodrigtainon
MTiissssiueng
Normal Lchiavnegre-faTtty cLhiavnegre-faItty
Lihvaengre-faItty Lchiavnegre-faItty G(ielplithheylpieurmp)lasTia Normal
Shpelaeretn, thymus Spleen, heart gSopnlaede,n, "htehayrmtu|,s nares nSaprleese,n, thgyomnauds, Spleen, nares
Gonad, thymus
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SUBMITTED BY: PREPARED BY:
APPROVED BY:
EG&G, Bionomics
Aquatic Toxicology Laboratory
Wareh7a9m0,MaMianssaScthrueseettts
September, 1978
Stephen J. Ells
i Zrcorogior
George A. Cary
z
_
:Director, Aquatic-f&iology
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