T he R iv er Р е к ta k e s its source in th e H om oljske P la n in e m ountains, a t an a ltitu d e o f a b o u t 1065 m a.s.l. I ts u p p e r course assum es th e ch a rac te r o f a m o u n tain s tre a m . I t s m iddle an d low er courses flow p a r tly th ro u g h
low lands. T h e R iv e r Р е к receives along its course m an y clear, u n p o llu te d
T h e riv e r segm ent im m ed iately below th e o u tb re a k p o in t o f V alja F u n d a ta
In 1976, i.e. in th e th ird y e a r o f th e riv e r’s re sto ratio n , m ore a b u n d a n t
C om parison of th e g ro w th ra te s of th is species in th e riv ers Р ек , T im ok a n d R a d o v a n sk a (a tr ib u ta r y of th e Crni Tim ok) a n d in L ak e B or (D anube B asin) (Ja n k o v ic 1970) has show n t h a t it is n early th e sam e in th e first year, w ith th e r a te decreasing to som e e x te n t in th e R iv e r Р е к in th e following years (Fig. 2). T h e g ro w th in w eight of chub in th e R iv e r Р е к is variab le.
I n th e first y e a r it is ra p id , th e n follows a re ta rd e d g ro w th in w eight as com pared w ith th e specim ens from o th e r stream s, w hereas in th e fo u rth
y e a r (3 + ) it e x h ib its an average value. C hub fro m th e R iv e r C rni T im ok a n d th e L ak e o f B o r grows v e ry fa s t in th e first a n d second years, th e lake specim ens grow ing la te r in co m p arab ly fa s te r th a n th e o th ers (Fig. 3).
T h e g ro w th o f chub in th e R iv e r Р е к reflects re la tiv e ly fa v o u rab le feed ing conditions d u e to ra p id re sto ra tio n o f algae (C ladophora a n d D iatom ea), insects a n d y o ung fish c o n s titu tin g its p rim a ry food d u rin g th e first years a fte r th e gangue p o llu tio n of th e river.
T h e g ro w th o f b arbel, a n o th e r a b u n d a n t species a fte r th e gangue p ollution o f th e R iv e r Р е к , w as s tu d ie d in 0 + to 4 + -year-old specim ens, th e only ones t h a t could be fo u n d in th e river. I n th e first y e a r th e specim ens reach 5.9 cm, in th e second y e a r 9.4 cm, in th e th ir d y e a r 13.0 cm an d in th e fo u rth (only one specim en exam ined) 18.7 cm . A nalysis of th e g ro w th in F ig . 2. T h e g ro w th in le n g th o f ch u b (L e u -
ciscus cephalus L .) fr o m som e riv e rs a n d lakes; in S erb ia. 1. S v rlj. T im o k ; 2. T rg . T im o k ; 3. C rn i T im o k ; 4. S tr e a m R a d o -
v a n s k a ; 5. L a k e B o r; 6. R iv e r Р е к
F ig . 3. W e ig h t in c re a se o f c h u b (L euciscus cephalus L .) f r o m som e riv e rs a n d la k e s in S erb ia. 1. S v rlj. T im o k ; 2. C rn i T im o k ; 3. S tr e a m R a d o v a n s k a ; 4. R iv e r Р е к ;
5. L a k e B o r; 6. T rg . T im o k
w eight shows t h a t th e specim ens reach only 7 g in th e first y ear, 8 g in th e second, 18.5 g in th e th ir d y e a r a n d 86 g in th e fifth (4 + ).
C om paring th e g ro w th of b arb el in th e R iv e r Р е к an d o th e r m entio n ed riv ers o f th e D a n u b e B asin, it w as concluded t h a t th e specim ens fro m th e R iv e r Р е к show s tu n te d g ro w th in length. T h e specim ens fro m Crni T im ok a n d th e L ak e o f B or grow in co m p arab ly fa s te r (Pig. 4).
F ig . 4. T h e g ro w th in le n g th o f b a rb e l (B a rb u s m e rid io n a lis p e te n y iH .) fro m som e riv e rs a n d la k e s in S e rb ia . 1. C rn i T im o k ; 2. S v rlj. T im o k ; 3. T rg . T im o k ; 4. S tre a m R a d o v a n s k a ; 5. L a k e B o r; 6. R iv e r Р е к
F ig . ,5. W e ig h t in c re a se o f b a rb e l (B a rb u s m erid io n a lis p e té n y i H .) f r o m som e riv e rs a n d la k e s in S erb ia. 1. C rn i T im o k ; 2. S v r l j.
T im o k ; 3. T rg . T im o k ; 4. S tr e a m R a d o v a n s k a ; 5. L a k e B o r; 6. R iv e r Р е к
A nalysis o f th e w eight increase shows t h a t in th e first a n d th e fo u rth y e a r b a rb e l grows fa ste r, a n d specim ens from L ak e B or grow v e ry fa s t (Fig. 5).
L a rv a e o f chironom ids p re d o m in a te d in th e d ie t o f b arbel. T rich o p tera, som e la rv a e o f B a e tid a e or H e p ta g e n ia (E p h e m ero p tera) a n d som e gam m a- rids w ere also fo u n d in th e g u t c o n te n t o f fish.
I t sh o u ld be stresse d t h a t th e hydrological régim e o f th e R iv e r Р е к w as m ost fa v o u rab le in 1974 a n d 1975, a n d th ese years w ere re g ard e d as w a te r-a b u n d a n t y ea rs (m ean a n n u a l flow a t th e s ta tio n K u cev o am o u n te d to 6.98 m 3 p er sec in 1974). I t p ro v id ed conditions for a re la tiv e ly ra p id w ashing aw ay o f th e p re c ip ita te d gangue fro m th e riv e r b o tto m a n d b a n k s b y a large w a te r m ass. T h e rem aining gangue h as con so lid ated a n d h as been covered b y a sa n d a n d m u d lay er enabling re sto ra tio n o f th e bio ta.
10* 147
A fte r th e ore g angue p o llu tio n , th e fa u n a of th e R iv er Р е к consists of
SUMMARY
S y m p . B iol. H ung. 19, p p . 151-167 (1979)
TABLK I
p e r 1 o f su spended p articles. T he m olluscs filtered 3 m 3 w a te r in 24 h an d a fte r t h a t th e q u a n tity o f suspended p articles was 0.2 mg p e r 1 (Skadow skv 19(i 1 ). T his m eans t h a t one m ollusc rem oved 99.5 p e r ce n t o f th e p a rtic le s from 15 1 w a te r each day.
N a tu ra lly , in m ore p o llu te d w aters th e ra te o f cleaning decreases. T he m olluscs Unio an d Anodonta k e p t in th e w a te r o f th e I rtis h -K a ra g a n d a C anal filtered 5 m 3 o f w a te r p er 24 h. T h e q u a n tity of su sp en d ed p artic le s decreased from 562 mg p er 1 to 238 mg p e r 1, while th e a m o u n t o f dissolved organic com pounds decreased from 395 m g p er 1 to 254 mg p er 1 (B ervald). T hus th e m olluscs rem oved 58 p e r ce n t o f th e su sp en d ed p articles an d 35 p er c e n t o f dissolved organic com pounds, i.e. 1.5 kg o f su spended p articles a n d 0.7 kg o f dissolved organic com pounds p er d ay . A to ta l a m o u n t o f 63 kg d ry w eight o f organic m a tte r was p re c ip ita te d in a co n tain e r in 27 day s.
D u rin g th e ex p e rim en t th e average w eight of one m ollusc increased from 219 to 245 g, i.e. b y 26 g. T he whole w eight o f th e molluscs in th e co n tain e r increased b y alm o st 3 kg.
F ig . 2. T h e q u a n titie s o f p o llu ta n ts , in g p e r m 3 (c u rv e 1), o f th e m o llu s c a n b io m a ss, in kg p e r m 2 o f riv e r-b e d cro ss-se c tio n (c u rv e 2), a n d th e r a t e o f w a te r flow , in m p e r
sec (c u rv e 3) a lo n g th e R iv e r O k a in 1959 (a f te r S h a d in 1964)
T he role o f m olluscs in th e cleaning o f p o llu te d n a tu ra l w aters can be seen from th e in v estig atio n s carried ou t on th e R iv er O ka (S hadin 1964a).
N e ar K a lu g a , th e n u m b e r o f filtra to r m olluscs is n o t v ery large a n d th e p o llu tio n o f th e w a te r (50 g o f su sp en d ed p artic le s p er 1 m 3) along a d istan ce of ab o u t 80 k m rem ains p ra ctically th e sam e (Fig. 2, curve 1). N e a r th e to w n o f S erpukhov, th e p o llu tio n o f th e R iv e r O ka sh a rp ly increases, re ach in g 95 g o f su spended particles p e r 1 m 3. E ig h ty km below S erp u k h o v , th e d e n sity o f large filtra to r m olluscs ( Unio a n d Anodonta) reaches 150 sp ecim en s p e r m 2 of b o tto m , a n d w a te r p o llu tio n decreases b y 70 p er cen t; th e level is a b o u t 30 g o f su sp en d ed p artic le s p e r 1 m 3 of w a te r a t th e inflow of th e R iv e r Moscow into th e R iv er Oka. T hus, ow ing to th e high d en sity o f
filtra-153
to r m olluscs (Fig. 2, curve 2), th e R iv er O ka is cleaned o f in d u s tria l a n d o th er
I t is a p p a re n tly anabiosis th a t enables m olluscs to su rv iv e fo r a long tim e
neurones o f th e m ollusc Lym naea stagnalis have allow ed us to estab lish t h a t th e yellow a n d orange colour o f th e g ia n t neurones (Fig. 4) is caused b y carotenoids an d h aem oproteins localized in cy to p lasm atic granules (Fig. 5) w ith specific u ltra s tru c tu r a l org an izatio n (K a rn au k h o v an d V á rto n 1971). T hese gran u les h av e been called ‘cvto so m es’ b y N o lte e t al. (1965) who fo u n d som e re sp ira to ry enzym es in them .
T he a b so rp tio n sp e c tra o f th ese g ranules (cytosom es) show c e rta in changes in th e neurones o f m olluscs in th e an aero b io tic s ta te as well as in response to in h ib ito rs of o x id ativ e m etabolism (K a rn a u k h o v 1968, 19696, 1971) suggesting t h a t carotenoids p a rtic ip a te in th e o x id ativ e m etab o lism . B ased on th ese findings, we h ave p u t fo rw ard a h ypothesis o n th e fu n c tio n o f caroten o id -co n tain in g granules in th e cells (K a rn a u k h o v 1969a, 197 0, 1971, 19736). A ccording to th is hypothesis, carotenoids m ay a c t as elec tro n acceptors, an d , to g e th e r w ith haem oproteins, form a system of in trac ellu la r oxygen reserve (accum ulator) in th e cytosom es (Fig. 6). T hus, cytosom es can p rovide energy for th e cell w hen th e ra te o f o x y g en p e n e tra tio n in to th e tissu e is low.
T he elec tro n -ac cep to r a n d electro n -d o n o r p ro p e rtie s o f th e co n ju g a te d double-b o n d chain o f carotenoids (P u llm an a n d P u llm a n 1963) allow it to con n ect an oxygen m olecule in place o f a (central) u n s a tu ra te d double bond w ith th e help o f a h aem o p ro tein . T h e decrease o f double bonds in th e con
ju g a te d chain o f ca ro ten o id leads to th e loss of its colour. T he colourless, o x y g en a te d ca ro ten o id m ay serve as an elec tro n -ac cep to r e q u iv a le n t of m olecular oxygen a n d can be considered analogous w ith th e oxidized form
F ig . 4. N e u ro n e s o f L y m n a e a stagnalis
F ig . 5 a a n d b. U ltr a s tr u c tu r a l o rg a n iz a tio n o f c a ro te n o x y so m e s (cy to so m es) in L y m n a e ù stagnalis n e u ro n e s
157
o f th e w ell-know n cyto ch ro m e oxidase (a -[- a 3) o f th e m ito ch o n d rial re sp i
ra to r y chain. C arotenoids can accu m u late (or concen trate) oxygen (or elec
tro n -a c c e p to r eq u iv ale n ts o f oxygen) in restin g cells u n d e r conditions of low -rate oxygen p e n e tra tio n (in hypoxic condition). W h en th e cells e n te r an ac tiv e p h ase u n d e r th ese conditions, th e ra te o f th e ir oxygen consum ption (solid line 1 in Fig. 7a) becom es hig h er th a n th e r a te of oxygen p e n e tra tio n from th e en v iro n m e n t (base line 2 in Fig. 7a). T he oxygen deficiency arising in th is s itu a tio n is relieved b y oxygen released from th e ca ro ten o id in tr a cellular ac cu m u lato r (Fig. 76) a n d carotenoids once m ore assum e th e ir colour. W hen th e cell re tu rn s to re st, th e oxygen reserve in th e ca ro ten o id in trac ellu la r ac cu m u lato r can be re sto re d (K a rn a u k h o v 1973a).
Such granules rich in caro ten o id (Fig. 6) are c h a rac te ristic n o t only of th e m olluscan cells (cytosom es; N o lte e t al. 1965, Z s.-N agy 1967, 1971, Zs.- N a g y a n d K e rp el-F ro n iu s 19716, K a rn a u k h o v a n d V á rto n 1971), b u t also o f p la n t cells (carotenoid p lasts; M atienko a n d C h ab an u 1973), o f th e cells o f w arm -blooded anim als a n d also o f m an (lipofuscin g ranules; B jö rk eru d 1963, K a rn a u k h o v 19736, K a rn a u k h o v e t al. 1972, K a rn a u k h o v a n d F e d o ro v 1977). T herefore th e y m ig h t be considered u n iv ersal energy p roviding organoids o f cells, phylogenetically o lder th a n m itochondria. T herefore we
K r e b s c y c l e
F ig . 6. I n te r r e la tio n b e tw e e n th e r e s p ir a to r y c h a in s o f m ito c h o n d r ia a n d o f earo-te n o x y s o m e s
Fig. 7 a. S ch em e o f in te r r e la tio n b e
s tra te s , such as « -k eto g lu taric acid or succinic acid, w ere used, a d d itio n o f K C N to th e hom ogenate re su lted in re sp ira to ry inhibition, w hich is qu ite usu al for m itochondria.
F ig . Sa, b. A c tio n o f K C N (5 mM ) , so d iu m a m ita l (1.8 mM ) a n d N A D H (1 mM ) on th e r a t e o f o x y g e n c o n s u m p tio n o f m o llu s c a n (L ym n a ea sta g n a lis) n e rv e tissu e h o m o g e n a te b lo ck s, c. C h an g e o f N A D H o x id a tio n as a fu n c tio n o f K C N c o n c e n tra tio n
T h e e x p e rim e n ta l d a ta o b ta in e d show t h a t th e carotenoxysom es are capable o f oxidizing s u b stra te s an d a p p a re n tly o f produ cin g energy w hen m ito c h o n d ria fail to fu n c tio n due to oxygen deficiency or suppression b y in h ib ito rs. T his conception is in accordance w ith th e re su lts o b tain ed for e n e rg y -d e p en d en t S r ++ ac cu m u latio n in m olluscan n erve cells (Zs.- N a g y a n d K e rp el-F ro n iu s 1970a). I t has been show n t h a t u n d e r n o rm al aerobic conditions, S r + + is ac c u m u la te d m ainly in th e m ito c h o n d ria and, to a lesser degree, in th e cytosom es (carotenoxysom es). U n d e r anaerobic conditions th e s itu a tio n is reversed: S r + + accu m u latio n is o b served m ainly in cytosom es (carotenoxysom es), while m ito ch o n d ria show v ery weak ac tiv ity .
T h e above considerations allow us to suppose t h a t th e high re sistan ce to e n v iro n m e n ta l p o llu tio n is c h a ra c te ristic o f m ollusc species w ith high caro ten o x y so m e co n ten t, w hich th u s c o n ta in large am o u n ts o f carotenoids in th e ir tissues.
THE ROLE OF CAROTENOIDS IN THE TOLERANCE of Environm ental Pollution and the Carotenoid Concentration in T heir Bodies
Species T N