الفهرس 
Experimental animalsOnly 14 pages are availabe for public view
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Abstract
The two a n n e l i d s p e c i e s ea,rthworm, A l l o l o b o p h o r a c a l i g i n o s a and l e e c h B a r b r o n i a s s i u t i h a v e b e e n c h o s e n a s t h e p a r t i c u l a r s u b j e c t o f t h e p r e s e n t i n v e s t i g a t i o n b e c a u s e t h e i r a b u n d a n c e i n s p e c i f i c a r e a s s u c h t h a t a d e q u a t e c o l l e c t i o n s c o u l d be made. A l s o t h e i r i m p o r t a n c e a s f u n c t i o n a l u n i t s among b o t h t e r r e s t - r i a l and a q u a t i c ecosystems,,as t h e y r e p r e s e n t an e s s e n t i a l f o o d i t e m f o r many o r g a n i s m s . Thus t h i s i n v e s t i g a t i o n may s t a n d a s a t r i a l t o a s s e s s t h e r o l e o f some e c o l o g i c a l p a r a m e - t e r s v i z : T e m p e r a t u r e , PH and h a r d n e s s on t h e t o x i c i t y o f t h r e e heavy m e t a l s c o p p e r , m e r c u r y and z i n c t o s u c h i m p o r t a n t o r g a n i s m s . On t h e o t h e r h a n d , i n o r d e r t o a c c o m p l i s h t h e b r o a d l i n e s o f t h e p r e s e n t p r o g r a m i t c a n be c o n c l u d e d t h a t : - The c u l t u r e o f t h e c o l l e c t e d e a r t h w o r m and l e e c h i n t h e l a b - o r a t o r y was c a r r i e d o u t u s i n g l a r g e s i z e d p o t s i n c a s e o f t h e e a r t h w o r m and g l a s s a q u a r i a i n c a s e o f t h e l e e c h s p e c i m e n s . - S o i l m o i s t u r e , pH, e l e c t r i c a l c o n d u c t i v i t y , c a r b o n a t e and c h l o r i d e s , t o t a l n i t r o g e n , c a l c i u m and magnesium and heavy m e t a l s ( c o p p e r and z i n c ) were m e a s u r e d s e a s o n a l y i n t h e s o i l s a m p l e s . However, t h e pH, e l e c t r i c a l c o n d u c t i v i t y , h a r d n e s s and heavy m e t a l s ( c o p p e r cadmium, l e a d and z i n c ) w e r e m e a s u r e d i n t h e c a n a l w a t e r (leeche; h a b i t a t ) . - T e s t s o l u t i o n s of copper (Cu SOq .7H20), m e r c u r i c c h l o r i d e (Hg C12) and z i n c s u l p h a t e (Zn SO4 .5 H 20 ) we r e p r e p a r e d a s s t o c k s o l u t i o n s of 1000 mg/l f o r e a c h . F r e s h d i l u t i o n s p r e - pared f o r e a c h e x p e r i m e n t and were made up i n canna1 w a t e r c o l l e c t e d f r e s h l y . - The t o x i c i t y t e s t s were p e r f o r m e d i n a b l a s t i c c o n t a i n e r . The t e s t s o l u t i o n was changed e v e r y 24 h o u r s . Twenty i n d i v - i d u a l s were p l a c e d per c o n t a i n e r . The t e s t was r e p e a t e d f o u r t i m e s . Also t h e t o l e r a n c e of t h e earthworm t o m e t a l - t r e a t e d s o i l was carried.out. - D e a t h s o f t h e t e s t a n i m a l s were r e c o r d e d a t e q u a l i n t e r v a l s . Cumulative r e g r e s s i o n c u r v e s f o r t h e m o r t a l i t y of t h e t e s t o r g a n i s m a r e p l o t t e d a g a i n s t t i m e o f e x p o s u r e t o t h e e x p e r i - m e n t a l medium and from t h i s t h e t i m e s t o 50% (TL50) and 100% (TLIo0) m o r t a l i t y c o u l d be e s t i m a t e d . Also t h e d e a t h d e v i a - s i o n s c o r r e s p o n d i n g . TL50 and TLIo0 t i m e s , s l o p e f u n c t i o n and t h e e r r o r of f i t t i n g t h e l i n e c o u l d be r e c o r d e d f o r each e x p e r i m e n t . - H i s t o c h e m i c a l l o c a l i z a t i o n o f c o p p e r mercury and z i n c i n both t r e a t e d a n n e l i d s p e c i e s was d e m o n s t r a t e d . from t h e s t a t i c b i o a s s a y t e s t s i t is e v i d e n t t h a t t h e a c u t e t o x i c i t y of t h e t h r e e heavy m e t a l s t o t h e t e s t a n n e l i d worms was a f u n c t i o n of t h e n a t u r e t o x i c e f f e c t o f each m e t a l , m e t a l c o n c e n t r a t i o n , t e s t o r g a n i s m a s w e l l a s t h e t o x i c i t y o f a m e t a l g r e a t l y m o d i f i e d w i t h o t h e r h a b i t a t q u a l i t y c r i t e r i a . The present experiments have provided meaningful comparisons of lethality among the test organisms as well as among heavy metal. With different metal concentrations, it is clear that the toxicity ranges of TLSO and TLIDO are markedly variable among the three heavy metals and both test organisms. The order of toxicity of the three heavy metals for both test species under normal conditions takes ttie following sequence Cu > Hg > Zn with concentrations of 20, 12 and 8 mg/l, however with 5 mg/l the sequence being Hg > Cu > Zn. The present data clearly show that the test earthworm was the most tolerant to the three metal tested. Also it is concluded that zinc is the least toxic metal for both species and under all experimental conditions. However both copper and mercury showed somewhat alternative position of their toxic action according to water quality criteria. In conclusion the comparative analysis of the obtained data for each species under the effect of different conditions or for the two annelid species under the effect of the same factors may indicate that the mortality rate of any test organism usually varies, as does the suceptibility to the influence of various factors. Histochemical localization of copper was recorded around the subneural blood vessel and in chloragogen tissue layer around mid intestine of earthworm however it detect in botryoidal tissue and crop wall as well as in some body vacuoles of treated leech. Mercury was found in body wall especially in longitudinal muscle layer of earthworm. In treated leech mercury was found to be accumulate in botryoidal tissue. Zinc could be easly demonstrated in both test species as a red stain diffusing; ,on the entire body tissues.