Document Vj7jDQ6LwKdGNJjdpOvq4eEyj

ARaac-oio^ \\ { SUMMARY OF HISTOPATHOLOGICAL EXAMINATIONS OF FATHEAD MINNOW (Pimephales promelas) EXPOSED TO 78.02 FOR 30 DAYS. RESEARCH REPORT SUBMITTED TO 3M COMPANY ST. PAUL, MINNESOTA REPORT #BW-78-ll-352 SUBMITTED BY E G & G, Bionomics Aquatic Toxicology Laboratory 790 Main Street Wareham, Massachusetts December/ 1973 001505 INTRODUCTION An "egg and fry test" was conducted between June 3 and July 6, 1978 (Bionomics Report &BW-78-8-263, August, 1978) to assess the sub-lethal effects of 14C-78.02 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 14C-78.02, histopathological examinations of exposed fish were also per formed. The results of these examinations are reported here. MATERIALS AND METHODS Upon termination of the egg and fry study, five fish from each replicate of the high 14C-78.02 concentration (1.9 mg/fc, measured) were preserved in 10% buffered formalin and sent to the Environmental Pathology Laboratories, Inc., Carolina, Rhode Island. Control fish were also examined. xThe fish were examined for gross lesions, and sagital sections were prepared by a pathologist. Fish were placed with identi fying numbers into processing cassetts, 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 parrafin. All blocks were sectioned at 6 microns: one 001506 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 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 vThe only tissue changes observed in fish in the study were fatty change of the liver of fish from both groups and autolysis of several parts of the digestive tract of fish from the control. The condition of the livers was consistent with that seen in healthy fathead minnows. In several fish it was obvious that only the deep portion of the 001507 3 affected organs were autolysed while the more superficial areas were well preserved. This autolysis appears to be the result of poor generation of fixative. Based on these data, it is concluded that 30 days exposure to a measured 14078.02 concentration of 1.9 mg/Jl did not cause any significant, demonstrable, tissue changes in 30 day old fathead minnow fry. \ 001508 O SUBMITTED BY: E G & G, Bionomics Aquatic Toxicology Laboratory 790 Main Street Wareham, Massachusetts December, 1978 PREPARED BY: Stephen J. Ells . ... Aquatic Toxicologist \ I APPROVED BY: George A. Cary 001509 Table 1 -- Histopathological examination of fathead minnow (Pimephales promelas) exposed 30 days to 1.9 mg/ l measured 78.02 and control water. Fish # Sex Organ Condition Missing Tissue 1.9 mg/ % 78 .02 1 male 2 male 3 female 4 unknown 5 female 6 male 7 male 8 male 9 unknown 10 female Control 1 2 unknown unknown 3 unknown 4 female s fatty change in liverall fatty change in liver 11 fatty change in liver II fatty change in liver II normal fatty change in liver II fatty change in liver II fatty change in liver II normal fatty change in liver I none none ear, thymus gonad ear nares spleen none gonad thymus, spleen fatty change in liver II bacterial gill disease fatty change in liver II autolysis in pharynx, stomach, intestine, and pancreas fatty change in liver II autolysis in pharynx fatty change in liver II autolysis in intestine gonad gonad gonad, nares spleen 001510 Table 1 (continued) Fish Sex Organ Condition Missing Tissue Control 5 6 7 8 9 10 unknown male female unknown unknown unknown fatty change in liver II autolysis in pharynx, intestine, and pancreas fatty change in liver I autolysis in pharynx, stomach, and intestine fatty change in liver II autolysis in pharynx, stomach, and intestine fatty change in liver I autolysis in pharynx, stomach, and intestine fatty change in liver II autolysis in pharynx, stomach, intestine, and pancreas autolysis in pharynx, stomach, and intestine nares, spleen gonad none nares spleen, nares and gonad nares, gonad spleen, gonad a Lesions graded as follows: I = minimal II = moderate III = marked IV = severe ! 001511