الفهرس 
Abou-Qir region ( Mediterranean sea)Only 14 pages are availabe for public view
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Abstract
This work was prolonged in the period between March 1983 and February 1984 . The holothurians were morphologically, anatomically, histologically and hsitochemically examined in an attempt to unravel the most interesting information about these animals. However, this study was divided into three main parts: I. The initial part of the work concerned with the identification fo common holothurians. Five species are collected from the Red and Mediterranean Sea coasts of Egypt. Four species belong to the family Holothuriidae; namely: tlolothuria poli i , lIolothur ia areni cola Holothuria impatie-ns and Holothuria marmorata. The other species, Synaptula reciprocans belongs to the family Synaptidae. The taxonomic characters and internal anatomy of these species are reviewed. Also, a key is suggested for their identixication. 11. The second part of the work has centred on the histological and histochemical structures of the integument of the Egyptian holothurians: Jiolothuria polii, Holothuria areni cola and Ilolothur~ rnilrmorata. It had been found that: 1. The holothurian integument is composed of three main layers as follows: cuticle, epidermis a;ld dermis. The dermis forms the greatest portion of the integument and consists of a superficial layer, calcareous zone laminated zone and the hypodermis. Attention is focused on the several types of coelomocytes in the integument. The simialrity between the morula-shaped coelomocytes of the investigated holothurians and that of the ascidians is clarified. 2. The integumentary mucous glands are important in the functional biology of the holothurian species. It seems clear form this work that the integument is an important organ as an alternative source of food. The third part of the presented study concerned with detailed histological and histochemical studies of all internal organs of the predominent species in Alexandria shores. Holothuria polii. This part revealed some interesting results which can be summarized as follows: 1. The d~qestive sys~ern: - A simpler sysLcni 01 nomenclature J:, suggested l’or ~llc parts of the holothurian alimentary tract. The ditferent regions have been named as Lollows: pharynx , o e s o p h a g u s , s t o m a c h , i n t e s t i n e , r e c t u m a n d c l o a c a . - It w a s f o u n d h i s t o l o g i c a l l y , t h a t t h e w a l l o f a l l d i f f e r e n t r e g i o n s o f a l i m e n t a r y t r a c t f o l l o w t h e same g e n e r a l p l a n a n d c o m p o s e d f o f o u r d i s t i n c t l a y e r s : p e r i t o n e a l e p i t h e l i u m , m u s c u l a r l a y e r , c o n n e c t i v e t i s s u e l a y e r a n d a n i n n e r e p i t h e l i u m ( m u c o s a l a y e r ) . P e r i t o n e a l e p i t h e l i u m i s c o m p o s e d o f a s i n g l e l a y e r o f c u b o i d a l c e l l s . In i n t e s t i n a l r e g i o n , t h i s l a y e r i s c o v e r e d by c o p i o u s y e l l o w t o orange p i g m e n t s i r r e g u l a r l y d i s t r i b u t e d . - The m u s c u l a r l a y e r c o n s i s t s e s s e n t i a l l y f r o m a s i n g l e l a y e r o f m u s c l e f i b r e s a r r a n g e d c i r u l a r l y . I n o e s o p h - a g u s , t h e r e is two t y p e s o f m u s c l e s , a n o u t e r c i r c u l a r m u s c l e a n d a n i n n e r l o n g i t u d i n a l m u s c l e f i b r e s . I n r e c t u m , t h e r e i s a n o u t e r o b l i q u e m u s c l e f i b r e s a n d a n i n n e r c i r c u l a r m u s c l e f i b r e s . - I n t e r s p e r s e d among t h e c e l l s o f t h e mucosal e p i t h e l i u m are g l a n d c e l l s a n d m u c o u s c e l l s . g l a n d c e l l s are s c a t t e r e d i n t h e s t o m a c h a n d t h e mucous c e l l s are p r e - s e n t i n t h e intest~ne. from t h e d i s t r i b u t i o n o f g l a n d c e l l s a n d mucous c e l l s i n s t o m a c h a n d i n t e s t i n e r e s p e c t - i v e l y , i t i s suggesLed t h a t t h e m u c o s a l e p i t h e l i u m i n t h e s e r e g i o n s a r e s i t e s o f d i g e s t i v e enzyme p r o d u c t i o n a n d s e c r e t i o n . - C e l l s s p e c i a l i z e d t o p r o d u c e c u r r e n t s i n t h e l u m e n o f ’ t h e g u t a r e a b s e n t . 2. The c i r c u l a t o r y s y s t e m : - The c i r c u l a t o r y s y s t e m b a s i c a l l y c o n s i s t s o f two m a i n s i n u s e s , t h e d o r s a l s i n u s a n d v e n t r a l s i n u s . They a r e r u n n i n g p a r a l l e l t o t h e g u t . The d o r s a l s i n u s i s c o n - n e c t e d t o t h e g u t w a l l v i a n u m e r o u s p a r a l l e l t r a n s v e r s e small b r a n c h e s w h i c h c o m m u n i c a t e v i a l a c u n a e i n t h e g u t w a l l s t o t h e v e n t r a l s i n u s . - The w a l l of s i n u s i s composed o f t h r e e l a y e r s : a n o u t e r c o e l o m i c e p i t h e l i u m h e a v i l y l o a d e d w i t h y e l l o w p i g m e n t s v e r y thin l a y e r o f c i r c u l a r m u s c l e f i b r e s a n d t h e c o n - n e c t i v e t i s s u e l a y e r o f v a r i a b l e t h i c k n e s s . The e p i t h e l - i a l l i n i n g i s l a c k i n g . - The r o l e o f t h e c i r c u l a t o r y s y s t e m i n d i g e s t i o n i s d i s c u s s e d . 3. The R e s p i r a t o r y s y s t e m : - The r e s p i r a t o r y s y s t e m r e p r e s e n t e d by two h o l l o w much b r a n c h e d s t r u c t u r e s c a l l e d r e s p i r a t o r y t r e e s a n d p l a c e d r i g h t a n d l e f t i n t h e body cavlty a n d o p e n i n g t o g e t h e r i n t o t h e m o s t p o s t e r i o r p o r t i o n o f t h e c l o a c a . The u l t i m a t e b r a n c h e s o f t h e m a i n t r u n k e n d i n a m p u l l a e - The respiratory tree have the same basic structure as other portions of the gut.