Ecological attributes of fish fauna in the Taquaruçu Reservoir, Paranapanema River (Upper Paraná, Brazil): composition and spatial distribution.

12 

Loading....

Loading....

Loading....

Loading....

Loading....

Full text

(1)

Ecological attributes of fish fauna in the Taquaruçu Reservoir,

Paranapanema River (Upper Paraná, Brazil): composition and spatial

distribution.

BRITTO1, S.G. d e C.& CARVA L H O2, E . D .

1 Environmental Board, Duke Energy International, Brazil. Rodovia Chavantes / Ribeirão Claro, Km 10.

C h a v a n t e s , S P. C E P 1 8 . 9 7 0 - 0 0 0 . e - m a i l : s g b r i t t o @ d u k e - e n e r g y . c o m

2 Fish Biology and Ecology Laboratory, Department of Morphology, Institute of Biosciences, UNESP –

Campus at Botucatu, SP. Caixa Postal 510. CEP 18618-000 – Botucatu – SP. e-mail: carvalho@ibb.unesp.br

ABSTRACT: Ecological attributes of Fish fauna in the Taquaruçu Reservoir, Paranapanema River (Upper Paraná, Brazil): composition and spatial distribution. Construction of dams leads to several environmental alterations on flora and fauna specially on fish. This study determines the composition and spatial organization of fish fauna, in the longitudinal limnological gradient of the Taquaruçu Reservoir, Paranapanema River Basin. Twenty-nine collections were carried out every three months with gill nets in three zones of the gradient. A total of 73 species of fish were captured, among native, transposed and exotic ones. There were differences in the distribution, along the limnological gradient especially between fluvial and lacustrine zones. Greater values of some ecological attributes (species richness, diversity index, abundance and constancy of species) and trophic groups of ichthyofauna were obtained in the fluvial zone. In general, piscivorous and carnivorous are dominant in this reservoir. Different icththyofaunas were found among the zones, and those most influenced by the damming were similar. Comparing our results with other studies on the Paranapanema and Upper Paraná River Basin, it is noted that the ichthyofauna structure along the limnological gradient is a predictive condition of reservoir formation in this basin. Also, the addition of nonnative species is a differential factor in the reorganization of Taquaruçu reservoir, in relation to other reservoirs of the upper stretch of the Paranapanema River basin.

Key-words: Reservoirs, ichthyofauna, ecology, fish, nonnative species.

RESUMO: Atributos ecológicos da fauna de peixes do Reservatório de Taquaruçu, Rio Paranapanema (Alto Paraná, Brasil): composição e distribuição espacial. A construção de barragens provoca diver-sas alterações ambientais sobre a flora e a fauna e em especial sobre as populações de p e i x e s . N e s s e s e n t i d o , o p r e s e n t e e s t u d o o b j e t i v o u a v a l i a r a o r g a n i z a ç ã o e s p a c i a l d a fauna de peixes, num gradiente limnológico longitudinal estabelecido pela variação do fluxo da água do reservatório de Taquaruçu, bacia do rio Paranapanema. Foram realizadas 29 coletas com redes de espera em três compartimentos, com periodicidade trimestral. Os resultados demonstraram a ocorrência de 73 espécies de peixes, entre nativas, trans-postas e exóticas, cujas populações se distribuem diferencialmente ao longo deste gradi-ente limnologico entre os compartimentos fluvial e lacustre. A distribuição diferencial da ictiofauna nesses compartimentos foi observada em termos dos seus atributos ecológi-cos (riqueza, diversidade, abundância e constância das espécies) e dos grupos trófiecológi-cos, com maiores valores obtidos no compartimento fluvial. De maneira geral, piscívoros e carnívoros são dominantes neste reservatório. Especificamente, diferenças na similarida-d e i c t i o f a u n í s t i c a e n t r e o s c o m p a r t i m e n t o s f o r a m similarida-d i a g n o s t i c a similarida-d a s , s e n similarida-d o q u e o s m a i s influenciados pelo barramento são mais similares entre si. Comparando-se os resultados de outros estudos das bacias do Paranapanema e Alto Paraná percebe-se que a estruturação da ictiofauna ao longo do gradiente limnologico é uma condição preditiva da formação dos reservatórios nessa bacia. Revela-se, também, que a adição de espécies não nativas é diferencial nesta reestruturação de ictiofauna para Taquaruçu, em relação a outros do trecho superior da bacia do rio Paranapanema.

Palavras chave: Reservatórios, ictiofauna, ecologia, peixes, espécies não nativas.

Introduction

L a r g e a r t i f i c i a l l a k e s f o r m e d f r o m d a m m i n g l a r g e r i v e r s c a u s e a s e r i e s o f

impacts which affect chemical, physical and specially biological components in the area o f i m p o u n d m e n t ( B i a n c h i n i J r . , 1 9 9 4 ) , p r o m o t i n g c o n s i d e r a b l e a l t e r a t i o n s i n t h e

(2)

h y d r o l o g i c a l r e g i m e a n d e c o l o g i c a l dynamics of the rivers (Henry, 1998).

Britski (1994) states that damming river has severe implications on fish community. In this aspect Agostinho & Gomes (2005) a r g u e t h a t t h e d e g r e e o f i m p a c t s r e l a t e s mainly to the characteristics of local fauna, location of the dam in relation to the area o f p o p u l a t i o n d i s t r i b u t i o n , b a s i n m o r p h o m e t r y , t h e e x i s t e n c e o f o t h e r impoundments, the design of the dam and o p e r a t i o n a l p r o c e d u r e s o f t h e p l a n t . Furthermore, an inevitable impact of dams in relation to aquatic fauna is the alteration in the abundance of animal species, with e x c e s s i v e p r o l i f e r a t i o n o f s o m e a n d reduction or even local extinction of others (Agostinho et al., 1999). In addition, local p r o c e s s e s a n d f a c t o r s , m a i n l y t h e limnological and structural characteristics o f t h e a q u a t i c e c o s y s t e m a n d t h e interactions among species, are regarded a s r e s p o n s i b l e f o r t h e c o m p o s i t i o n a n d structuring of fish communities (Agostinho & Gomes, 2005).

In the spatial context, the construction of dams, as a rule, leads to changes that determine a marked compartmentalization of the dammed water mass (Nogueira et al., 2005), producing a spatial heterogeneity in l i m n o l o g i c a l a n d b i o t i c v a r i a b l e s ( H e n r y , 1 9 9 8 , N o g u e i r a e t a l . , 1 9 9 9 ) . I n l a r g e reservoirs, this spatial heterogeneity may lead to formation of a longitudinal gradient, distinguishing the lacustrine, transitional and r i v e r i n e z o n e s , w h i c h o n e c o n t a i n i n g distinct biota (Thornton, 1990; Carvalho et al., 1998; Train et al., 2005).

N e v e r t h e l e s s , t h e r e l a t i o n s b e t w e e n s u c h v a r i a b l e s a n d t h e i c h t h y o f a u n a c h a r a c t e r i s t i c s o f e a c h s i t e , t a k i n g i n t o account its geographic location and position in the basin, make each reservoir a rather p a r t i c u l a r e n t i t y ( D i a s & G a r a v e l l o , 1 9 9 8 ; Agostinho & Gomes, 2005).

Lowe-McConnell (1987) states that the formation of these artificial “lakes“ allows a n a m p l e s t u d y o n h o w f l u v i a l s p e c i e s become fit for the colonization of these semi-l e n t h i c e n v i r o n m e n t s a n d h o w semi-l a c u s t r i n e communities adjust to such conditions. Still, L y o n s ( 1 9 9 6 ) a f f i r m s t h a t t h e c a t e g o r y o f e n v i r o n m e n t s r e f l e c t a g r e a t n u m b e r o f e c o l o g i c a l v a r i a b l e s , a r e f a c t o r s w h i c h s t r o n g l y i n f l u e n c e t h e c o m p o s i t i o n , distribution and abundance of fish.

Thus, this work aims to evaluate the fish composition and to differentiate some e c o l o g i c a l a t t r i b u t e s o f t h e i c h t h y o f a u n a c o l l e c t e d i n t h r e e l i m n o l o g i c a l l y d i s t i n c t z o n e s o f t h e T a q u a r u ç u R e s e r v o i r , l o w e r Paranapanema River.

Material and methods

Study area

The Taquaruçu Hydro-electrical Plant is l o c a t e d a t 2 2o3 2 - 2 2o4 2 ’ S a n d 5 2o0 1 ’

-5 1o2 2 ’ W, i n t h e l o w c o u r s e o f t h e

P a r a n a p a n e m a R i v e r, between the States o f S ã o P a u l o a n d P a r a n á , B r a z i l . T h i s r e s e r v o i r p r e s e n t s m a x i m u m d e p t h o f 1 8 meters and a low water hydraulic retention ( m e a n o f 8 d a y s ) , w i t h f e w w a t e r l e v e l fluctuation. Further, it’s surface area is 105.5

km2, with a 301-km perimeter. Also, there

are few large tributaries emptying on the reservoir (Fig. 1).

Three zones (compartments), the fluvi-al, the transition and the lacustrine, were s e l e c t e d a l o n g a l i m n o l o g i c a l g r a d i e n t o f the Taquaruçu Reservoir (sensu Pagioro et al. 2005), for the collection of fish. However, f o r t h e d e f i n i t i o n o f t h e s e z o n e s , m e a s u r e m e n t s o f t h e w a t e r f l o w w e r e carried out with a General Oceanic flowmeter a n d d a t a o n t h e c o n c e n t r a t i o n s o f p h o s p h o r u s a n d w a t e r t r a n s p a r e n c y , according to CESP (1996), and suspended solids published by Nogueira et al. (2002) were compiled (Tab. I). The arithmetic means of these data were statistically compared

by ANOVA, with α = 0.05.

Twenty nine samplings were carried out i n t h e s e z o n e s ( f r o m O c t o b e r 1 9 9 3 t o N o v e m b e r 2 0 0 0 ) , e v e r y t h r e e m o n t h s ( a t o t a l o f 8 7 s a m p l i n g s ) . T h e s e s a m p l i n g s were performed in a standardized manner, i . e . , u s i n g g a n g o f g i l l - n e t s w i t h d i f f e r e n t meshes (between 30 and 120 mm between o p p o s e d k n o t s ) , s e t f o r 2 4 h o u r s a n d checked for fish every 12 hours. All captured fish were identified based on Britski (1972), N e l s o n ( 1 9 9 4 ) a n d R e i s e t a l . ( 2 0 0 3 ) , a n d some testimony specimens were deposited at the Museu de Zoologia located in Uni-v e r s i d a d e E s t a d u a l d e L o n d r i n a ( M Z U E L ) ; Londrina, PR., Brazil.

The ecological attributes used to com-pare fish communities in the three zones were: i) absolute and relative number (%)

(3)

Figure 1: South American hydrographic complex (light grey). The Paranapanema River basin (dark grey), with the Taquaruçu Reservoir, between the States of São Paulo and Paraná.

*(From Nogueira et al. (2002), **CESP (1996) and this work)

Ta b l e I : Mean values of the limnological data (suspended solids, total phosphorus, water transparency and current velocity) for the three zones of the Taquaruçu reservoir, lower Paranapanema River basin. (N = number of samples; equal letters = differences no statistically significant (ANOVA,

α = 0.05).

São Paulo State

Paraná State

Limnological variables

N

Lacustrine

Transition

Fluvial

Suspended solids (mg/l)* 4 2.43 3.05

Total phosphorus (µg/l)** 14 19.50b 21.75b 23.30b

Water transparency (m)** 14 1.30b 1.15a 1.17a

(4)

of species captured; ii) relative importance curve (in number) of species (Whittaker plot, in Krebs, 1989) adjusting a regression model a s Y = A + B X , w h e r e Y i s t h e r e l a t i v e abundance (% do individuals) of species (log n+ 1) and X is species order, for the entire r e s e r v o i r a n d e a c h z o n e s e p a r a t e d . P e a r s o n ´ s ( r ) l i n e a r c o e f f i c i e n t w a s a l s o d e t e r m i n e d ( r ) ; i i i ) i n d e x e s o f d i v e r s i t y ( S h a n n o n - W i e n e r ) , e v e n n e s s ( P i e l o u ) a n d s p e c i e s r i c h n e s s ( M a r g a l e f ) ( i n L u d w i g & R e y n o l d s , 1 9 8 8 ) ; i v ) t h e c o n s t a n c y o f species capture (Dajoz, 1972); v) catch per unit of effort (CPUE), in number and weight) according to Carvalho & Silva (1999), whose r e s u l t s w e r e s u b m i t t e d t o d e s c r i p t i v e s t a t i s t i c s a n d t h e i r m e a n s s t a t i s t i c a l l y

compared by ANOVA, with α = 0.05); and vi)

t h e s i m i l a r i t y o f f i s h f a u n a a m o n g z o n e s (Jaccard, 1902, in Krebs,1989); and finally, vii) possible trophic structures for the fish c o m m u n i t i e s f o r e a c h z o n e o f t h e T a q u a r u ç u w e r e e m p i r i c a l l y d e f i n e d . W e u s e d t h e n u m e r i c a l a b u n d a n c e ( % ) o f d o m i n a n t t r o p h i c g r o u p s , r e p r e s e n t e d b y s p e c i e s w i t h a n o c c u r r e n c e > 2 % . T h e classification of trophic groups was based on data on feeding for the same species p r o p o s e d b y H a h n e t a l . ( 1 9 9 8 ) a n d B e n n e m a n n e t a l . ( 2 0 0 0 ) i n t w o o t h e r tributaries/reservoirs of the upper Paraná River.

Results

S e v e n t y - t h r e e f i s h s p e c i e s w e r e captured, belonging to Characiformes (34 species = 46.57%), Siluriformes (29 species = 3 9 . 7 3 % ) , G y m n o t i f o r m e s ( 5 s p e c i e s = 6.85%) and Perciformes (5 species= 6.85%). The dominance (considering the abundance) w a s g r e a t e r f o r S i l u r i f o r m e s ( 4 7 . 5 9 % ) , f o l l o w e d b y C h a r a c i f o r m e s ( 4 0 . 3 5 % ) , P e r c i f o r m e s ( 1 0 . 6 0 % ) a n d G y m n o t i f o r m e s ( 1 . 4 6 % ) . G r e a t e r s p e c i e s r i c h n e s s w a s recorded in the fluvial zone (64 species), as compared to the lacustrine and transition zones which harbored 50 and 55 species, respectively.

Fourteen species, out of 73 contributed with 75% of the total abundance (Tab. II). We verified that among these 14 species, s e v e n w e r e t h e m o s t r e p r e s e n t a t i v e , regardless of the zone of the reservoir. Out of the total sampled fish (7,874 individuals),

2 7 . 2 1 % w e r e c a u g h t i n t h e l a c u s t r i n e , 23.20% in the transition, and almost 50%, in the fluvial zone.

The numerical distribution of species along the gradient was distinct. Then, we notice greater dispersion in the inner parts of the reservoir (r=0.82 lacustrine) and lower dispersion in the upper part (r=0.93 fluvial) (Fig. 2).

The values of the ecological attributes ( D i v e r s i t y i n d e x , e v e n n e s s a n d s p e c i e s richness) (Tab. III) also support the idea that there is a gradient tendency from the upper (fluvial) to the lower (lacustrine) zone, with smaller values in the lenthic (H = 2.84; E= 0.73 and R= 4.69) and greater in the fluvial (H = 3.32; E= 0.80 and R= 5.91). In a similar manner, a larger number of constant species (14) was observed in the fluvial zone when c o m p a r e d t o t h e l a c u s t r i n e o n e ( 1 1 ) . However, only 9 species were constant in a l l z o n e s ( A c e s t r o r h y n c h u s l a c u s t r i s , S e r r a s a l m u s m a r g i n a t u s , S t e i n d a c h n e r i n a i n s c u l p t a , L e p o r i n u s f r i d e r i c i , S c h i z o d o n n a s u t u s , P i m e l o d u s m a c u l a t u s , I h e r i n g i c h t h y s l a b r o s u s , L o r i c a r i c h t h y s p l a t y m e t o p o n , P l a g i o s c i o n squamosissimus ) . T h e a n a l y s i s o f C P U E ( i n w e i g h t ) e v i d e n c e d m e a n v a l u e s w i t h s t a t i s t i c a l l y

significant differences (α = 0.05) between

t h e f l u v i a l a n d t h e t r a n s i t i o n / l a c u s t r i n e zones and showed that there was a greater abundance in the fluvial in relation to the lacustrine zone (Tab. IV). The differences a m o n g z o n e s a n d t h e I n d e x o f J a c c a r d s h o w e d t h a t t h e l a c u s t r i n e a n d t r a n s i t i o n zones (J = 0.75) have more common species a n d , t h e r e f o r e , a r e m o r e s i m i l a r t h a n t h e fluvial and lacustrine zones (J = 0.58).

T h e e m p i r i c a l c h a r a c t e r i z a t i o n o f t h e trophic structure of the Taquaruçu Reservoir i c h t h y o f a u n a ( T a b . V ) d e m o n s t r a t e d t h e dominance of piscivorous (23.91%) over the o t h e r g r o u p s , r e g a r d l e s s o f t h e z o n e . H o w e v e r , t h i s t r o p h i c g r o u p w a s q u i t e representative in the three zones (fluvial = 21.73%; transition = 23.07% and lacustrine = 2 7 . 7 9 % ) . T h e r e w e r e a l s o v e r i f i e d t h e great participation of carnivores (33.18%), in the lacustrine zone, and the importance o f o m n i v o r o u s ( 2 1 . 6 7 % ) a n d i l i o p h a g o u s ( 1 7 . 7 4 % ) i n t h e t r a n s i t i o n z o n e a n d t h e e x p r e s s i v e n e s s o f d e t r i t i v o r o u s ( 2 1 . 7 3 % ) and omnivorous (19.49%) in the fluvial zone.

(5)

Table II: Absolute and relative number (%) of captured fish, and taxonomic position of the species of the Taquaruçu Reservoir, lower Paranapanema River basin.

SPECIES ORDER / FAMILY Lacustrine Transition Fluvial TOTAL %

Loricarichthys platymetopon1 Siluriformes / Loricariidae 340 175 566 1081 13.73

Plagioscion squamosissimus2 Perciformes / Scienidae 238 131 318 687 8.72

Steindachnerina insculpta Characiformes / Curimatidae 95 253 307 655 8.32

Auchenipterus nuchalis1 Siluriformes / Auchenipteridae 240 53 194 487 6.18

Iheringichthys labrosus Siluriformes / Pimelodidae 286 81 95 462 5.87

Serrasalmus marginatus1 Characiformes / Characidae 112 67 226 405 5.14

Pimelodus maculatus Siluriformes / Pimelodidae 194 87 116 397 5.04

Parauchenipterus galeatus1 Siluriformes / Auchenipteridae 45 96 203 344 4.37

Acestrorhynchus lacustris Characiformes / Acestrorhynchidae 130 90 115 335 4.25

Trachydoras paraguayensis1 Siluriformes / Doradidae 19 43 227 289 3.67

Astyanax altiparanae Characiformes / Characidae 25 84 142 251 3.19

Schizodon nasutus Characiformes / Anostomidae 38 83 128 249 3.16

Schizodon intermedius Characiformes / Anostomidae 30 50 84 164 2.08

Moenkhausia intermedia Characiformes / Characidae 10 23 130 163 2.07

Leporinus friderici Characiformes / Anostomidae 38 42 51 131 1.66

Serrasalmus maculatus Characiformes / Characidae 31 41 46 118 1.50

Hypostomus margaritifer Siluriformes / Loricariidae 3 15 93 111 1.41

Apareiodon aff. affinis Characiformes / Parodontidae 4 13 88 105 1.33

Hoplias malabaricus Characiformes / Herythrinidae 6 35 64 105 1.33

Cyphocharax modestus Characiformes / Curimatidae 0 16 77 93 1.18

Hypostomus regain Siluriformes / Loricariidae 24 34 29 87 1.10

Roeboides paranensis1 Characiformes / Characidae 18 12 56 86 1.09

Crenicichla sp. Perciformes / Cichlidae 47 17 11 75 0.95

Eigenmannia virescens Gymnotiformes / Sternopygidae 11 7 49 67 0.85

Pinirampus pirinampu Siluriformes / Pimelodidae 41 13 10 64 0.81

Hypostomus ancistroides Siluriformes / Loricariidae 0 5 54 59 0.75

Loricaria sp. Siluriformes / Loricariidae 24 19 14 57 0.72

Rinelepis aspera Siluriformes / Loricariidae 0 50 7 57 0.72

Schizodon borelli Characiformes / Anostomidae 0 10 36 46 0.58

Leporinus octofasciatus Characiformes / Anostomidae 6 6 33 45 0.57

Hypostomus sp2. Siluriformes / Loricariidae 4 11 28 43 0.55

Pimelodella sp. Siluriformes / Heptapteridae 7 6 22 35 0.44

Myleus tiete Characiformes / Characidae 8 26 0 34 0.43

Crenicichla britskii Perciformes / Cichlidae 8 19 7 34 0.43

(6)

Ta b l e I I : Cont.

SPECIES ORDER / FAMILY Lacustrine Transition Fluvial TOTAL %

Galeocharax knerii Characiformes / Characidae 0 0 27 27 0.34

Pterodoras granulosus1 Siluriformes / Doradidae 3 8 15 26 0.33

Hypostomus sp6. Siluriformes / Loricariidae 3 9 13 25 0.32

Leporinus elongates Characiformes / Anostomidae 6 7 11 24 0.30

Leporellus vittatus Characiformes / Anostomidae 2 10 11 23 0.29

Prochilodus lineatus Characiformes / Prochidodontidae 10 5 7 22 0.28

Rynodoras dorbgnyi Siluriformes / Doradidae 1 0 19 20 0.25

Crenicichla niederleinii Perciformes / Cichlidae 0 11 9 20 0.25

Cyphocharax nagelli Characiformes / Curimatidae 0 8 11 19 0.24

Geophagus brasiliensis Perciformes / Cichlidae 7 0 12 19 0.24

Gymnotus cf. carapo Gymnotiformes / Gymnotidae 0 0 19 19 0.24

Sternopygus macrurus Gymnotiformes / Sternopygidae 2 0 16 18 0.23

Apareiodon piracicabae Characiformes / Parodontidae 0 0 14 14 0.18

Pseudopimelodus zungaro Siluriformes / Pimelodidae 1 4 8 13 0.17

Hypostomus sp3. Siluriformes / Loricariidae 0 0 12 12 0.15

Leporinus striatus Characiformes / Anostomidae 0 0 12 12 0.15

Hypostomus sp. Siluriformes / Loricariidae 2 2 7 11 0.14

Hypostomus sp4. Siluriformes / Loricariidae 3 1 6 10 0.13

Pimelodus ornatus1 Siluriformes / Pimelodidae 4 5 0 9 0.11

Leporinus lacustris Characiformes / Anostomidae 6 1 2 9 0.11

Raphyodon vulpinus1 Characiformes / Characidae 0 5 4 9 0.11

Porotergus ellisi Gymnotiformes / Sternopygidae 0 0 9 9 0.11

Clarias gariepinnus3 Siluriformes / Clariidae 0 0 7 7 0.09

Leporinus paranensis Characiformes / Anostomidae 2 3 2 7 0.09

Metynnis maculatus Characiformes / Characidae 3 4 0 7 0.09

Leporinus amblyrhynchus Characiformes / Anostomidae 4 2 0 6 0.08

Schizodon altoparanae Characiformes / Anostomidae 0 3 2 5 0.06

Megalancistrus aculeatus Siluriformes / Loricariidae 3 1 0 4 0.05

Hypostomus sp1. Siluriformes / Loricariidae 4 0 0 4 0.05

Rhamdia sp. Siluriformes / Heptapteridae 0 0 3 3 0.04

Leporinus obtusidens Characiformes / Anostomidae 1 2 0 3 0.04

Triportheus angulatus2 Characiformes / Characidae 0 0 2 2 0.03

Rhamphychthys sp1 Gymnotiformes / Rhamphychthidae 0 2 0 2 0.03

Sorubim lima1 Siluriformes / Pimelodidae 1 0 0 1 0.01

(7)

1 species transposed from the lower Paraná River; 2 species introduced, originating in other Brazilian

basins, 3 species introduced from other continents.

Ta b l e I I : Cont.

Figure 2: Species importance curve, with the linear lift transformed abundance data (log n + 1) and species orders for A) fluvial zone, B) transition zone and C) lacustrine zone (r = Pearson´s respective c o e f f i c i e n t s ) .

H'

E

R

n

N

Lacustrine 2.84 0.73 4.69 2150 50

Transition 3.30 0.82 5.21 1819 55

Fluvial 3.32 0.80 5.91 3905 64

Table III: Ecological attributes of the fish communities for the three zones of Taquaruçu Reservoir, lower Paranapanema River basin. (H’ = Shannon-Wierner diversity, E = Pielou evenness, R = Margalef species richness, n = number of individuals and N = species.)

SPECIES

ORDER / FAMILY

Lacustrine Transition Fluvial TOTAL %

Astyanax fasciatus Characiformes / Characidae 0 0 1 1 0.01

Salminus hilarii Characiformes / Characidae 0 0 1 1 0.01

Salminus maxillosus Characiformes / Characidae 0 0 1 1 0.01

(8)

Discussion

W e v e r i f i e d t h a t t h e 7 3 s p e c i e s registered in the Taquaruçu reservoir are inserted among the 221 already catalogued f o r t h e U p p e r P a r a n á B a s i n ( A g o s t i n h o & J ú l i o J r. , 1 9 9 9 ) . I n g e n e r a l , d e s p i t e t h e r e p l a c e m e n t o f s o m e s p e c i e s , t h e c o m p o s i t i o n o f t h e i c h t h y o f a u n a o f t h i s r e s e r v o i r c o r r o b o r a t e s A g o s t i n h o e t a l . (1995), in the review on the ichthyofauna of the Upper Paraná Basin, whose majority of species do not undertake long migrations and adjust well to new lacustrine conditions derived from river damming (Carvalho et al., 1 9 9 8 ) .

H o w e v e r , t h e s e s p e c i e s d i f f e r e n t i a l l y d i s t r i b u t e d a l o n g t h e r e s e r v o i r , b e i n g s t r o n g l y i n f l u e n c e d b y t h e i r l i m n o l o g i c a l conditions. Contain still, a greater lato sensu s p e c i e s r i c h n e s s ( a n d a b u n d a n c e ) i n t h e

f l u v i a l a r e a , t o t h e d e t r i m e n t o f t h e l a c u s t r i n e o n e , i n d i c a t i n g t h e i r s t r a t e g i e s of life and capacities of adjustments in the f a c e o f e n v i r o n m e n t a l c h a r a c t e r i s t i c s . Several authors (Carvalho et al., 1998; Agos-tinho et al., 1999; Orsi, 2005), studying the fish communities in reservoirs of the upper Paraná river also discussed this influence o f t h e a q u a t i c e n v i r o n m e n t u n d e r t h e structuring of these fish communities.

Further, as for the lato sensu richness of the Taquaruçu’s fish, our result coinci-d e s w i t h t h e t h e o r y a coinci-d v o c a t e coinci-d b y L o w e McConnell (1987) and Minns (1989), in which they suggest that, the lato sensu richness of fish in great rivers, shows a spatial trend of increasing from the river source towards the mouth. That is so, because the number registered in this study is greater than those verified in the reservoirs of Jurumirim (Car-valho et al., 1998) and Salto Grande (Dias & Table IV: Descriptive statistics of CPUE (kilograms) for three stretches of the Taquaruçu reservoir, lower Paranapanema River basin. (Number of samplings N = 29; equal letters = diferences not statistically significant (ANOVA, α = 0.05)).

Table V: Relative frequency (%) in number of the trophic groups present in the three zones of the Taquaruçu Reservoir, lower Paranapanema River basin.

Trophic groups

lacustrine

transition

fluvial

reservoir

Piscivorous 27.79 23.07 21.73 23.91 Carnivorous 33.18 12.41 17.02 20.74 Omnivorous 13.84 21.67 19.49 19.35 Detritivorous 19.69 15.78 21.73 18.11 Iliophagous 5.50 17.74 13.03 10.97 Herbivorous 0.00 9.33 6.99 6.92

CPUE(b)

Statistics

Fluvial

Transition

Lacustrine

Total 815.82 620.54 617.96 Maximum 0.63 1.31 5.12 Minimum 131.30 114.80 47.10 Amplitude 130.67 113.49 41.97 Mean 28.13a 21.40a 21.31a SD 249.70 227.46 107.46 Variation Coefficient (%) 104.76 106.30 50.43

(9)

Garavello, 1998), of the Upper and Middle Paranapanema, respectively, with 49 and 51 fish species, but close to those of the Capivara reservoir, in its amount, for which 79 species were identified (Orsi, 2005). A m o r e p l a u s i b l e h y p o t h e s i s f o r t h i s “ s i m i l a r i t y “ ( n u m b e r o f s p e c i e s , b e i n g T a q u a r u ç u = 7 3 a n d C a p i v a r a = 7 9 ) i s p r o b a b l y l i n k e d t o C a p i v a r a ´ s m o r e d e n t r i t i c a l c o n d i t i o n ( o w i n g m a n y m o r e tributaries = habitats). Species richness has b e e n a s s o c i a t e d w i t h s e v e r a l v a r i a b l e s , among which the complexity of the habitat ( W o o t o n , 1 9 9 8 ) , a n d t h e m a r g i n a l development (Eadie & Keast, 1984).

Fernando & Holcik (1991) claim that the diversity of fish in reservoirs is smaller and directly proportional to that in their forming r i v e r s , w h i l e To n n ( 1 9 9 0 ) , d i s c u s s e s t h e importance of predation/competition proces-ses in the structuring of fish communities. The drainage basin area of the Taquaruçu is small, with a few tributaries, and its main b o d y i s a l m o s t t o t a l l y i n s e r t e d i n i t s accumulation basin, presenting very distinct l i m n o l o g i c a l c h a r a c t e r i s t i c s a m o n g i t s c o m p a r t m e n t s , m a i n l y c o n c e r n i n g w a t e r flow (velocity) and water transparence (CESP, 1996). This way, one may infer that the lato s e n s u s p e c i e s r i c h n e s s i n T a q u a r u ç u i s most related to factors such as the number of pre-existing species in the phase river; the addition of nonnative species and the inter and intra-specific relations established following the filling of the reservoir.

I n o t h e r r e s e r v o i r s , u p s t r e a m , i t i s verified that there is always a predominance in the number of Characiformes species over the other Orders (Dias & Garavello, 1998, C a r v a l h o e t a l . , 1 9 9 8 ; B e n n e m a n n e t a l . , 2 0 0 0 ; O r s i , 2 0 0 5 ) , b e i n g t h i s s i t u a t i o n m a i n t a i n e d i n T a q u a r u ç u ( i n t h i s s t u d y ) . Nevertheless, when abundance is analyzed, a numerical predominance of Siluriformes over Characiformes is seen. We believe that t h i s c o n d i t i o n i s a s s o c i a t e d w i t h i t s g e o g r a p h i c l o c a l i z a t i o n i n t h e l o w e r Paranapanema river (it is the penultimate o f t h e r e s e r v o i r s c a s c a d e ) a n d t h e transposition of species originated in the lower Paraná river, upon the filling of Itaipu and the drowning of Sete Quedas in Guairá (Bonetto, 1986).

Also, we verified another inversion in a fish ecological attribute (constancy of cap-ture) between Taquaruçu and two reservoirs upstream, Salto Grande (Dias & Garavello, 1998) and Jurumirim (Carvalho et al., 1998).

These authors showed that the lacustrine compartments of these reservoirs contained a g r e a t e r n u m b e r o f s e d e n t a r y s p e c i e s ( r e s i d e n t s ) i n r e l a t i o n t o u p p e r s t r e t c h e s ( t r a n s i t i o n a n d f l u v i a l ) . H o w e v e r, w e obtained an inverse pattern. One realizes, amidst the number of species constant in t h e s e e n v i r o n m e n t s , a n i m p o r t a n t p a r t i c i p a t i o n o f n o n n a t i v e s p e c i e s . T h e species which comprise the ichthyofauna of the Taquaruçu River and the ecological relations among them, possibly reflect the situation, considering their structure, quite distinct in relation to those of the reservoirs mentioned, given the presence of species not registered upstream. At the same time, i t i s w o r t h c o n s i d e r i n g t h a t t h e g r e a t e r n u m b e r o f c o n s t a n t s p e c i e s , s p e c i a l l y nonnative ones, in the fluvial environment, i s r e l a t e d t o t h e i r p e r s i s t e n c e , g i v e n t h e e f f e c t i v e n e s s i n e x p l o r i n g t h e n i c h e s occupied in the upper stretch (Veregue & Orsi, 2003).

T h e i n f l u e n c e o f t h e l i m n o l o g i c a l c o n d i t i o n s o f e a c h z o n e o n t h e s t r u c t u r e and distribution of ichthyofauna was quite e v i d e n t i n t h e a n a l y s e s f o r e c o l o g i c a l a t t r i b u t e s , a s i t w a s v e r i f i e d i n o t h e r reservoirs of the Paranapanema (Carvalho et al., 1998; Orsi, 2005) as well as in the upper Paraná (Benedito-Cecílio et al., 1997; Santos, 1999). We verified that there is a smaller ichthyofaunistic complexity in the lacustrine environment (along the dam), in relation to the fluvial one (downstream the Capivara power plant).

I c h t h y o f a u n a c o m p a r t m e n t a l i z a t i o n d e r i v i n g f r o m t h e d a m m i n g o f t h e Taquaruçu and additional factors (e.g., the t r a n s p o s i t i o n o f n e w s p e c i e s ) i s d i s c r i m i n a t e d i n t h e s p e c i e s ´ i m p o r t a n c e curves (Fig. 2), which shows the species of fish communities, in the fluvial environment ( F i g . 2 A ) , b e t t e r d i s t r i b u t e d a n d s h a r e d (better adjustment of Pearson’s coefficient), a s c o m p a r e d t o t r a n s i t i o n ( F i g . 2 B ) a n d l a c u s t r i n e ( F i g . 2 C ) e n v i r o n m e n t s . T h i s interpretation may, indicate the degree in which damming influences the restructuring of these fish communities, with evidences of a larger unbalance among abundant and rare species, in the lacustrine environment. A similar fact has been described by San-t o s ( 1 9 9 9 ) f o r s o m e r e s e r v o i r s o f San-t h e R i o G r a n d e .

CPUE (in number and weight), utilized a s a m e a s u r e o f f i s h r e l a t i v e a b u n d a n c e ( S a n t o s , 1 9 9 9 ) , w a s a n o t h e r t o o l w h i c h

(10)

e v i d e n c e d t h e d i f f e r e n t i a t e d f i s h distribution in the Taquaruçu reservoir. CPUE i n n u m b e r a n d w e i g h t i n t h e f l u v i a l environment was proportionally greater than t h a t o f o t h e r c o m p a r t m e n t s , i n d i c a t i n g a larger seasonal recruitment of fish in this stretch of higher hydraulic instability, owing t o p u l s e s o f f l o o d i n u p s t r e a m r e s e r v o i r (Capivara), conditioning the greater variation of CPUE. The lacustrine environment, with smaller variations, reflects a greater stability, a s s o c i a t e d w i t h a s m a l l e r i n t e n s i t y o f f l o o d i n g p u l s e s a n d s m a l l v a r i a t i o n s o f water level (operational characteristics of the plant). This hypothesis is consistent with that proposed by Aggus & Lewis (1977 in Ploskey, 1986).

F u r t h e r , b y c o m p a r i n g t h e v a l u e s o f CPUE with the data for other reservoirs of this basin, with the same sort of sampling effort (gill-nets) (Dias & Garavello, 1998; Car-valho, et al., 1998; CESP, 1998; Orsi, 2005), we conclude that the Taquaruçu, presents t o d a y , a g r e a t e r f i s h i n g p r o d u c t i o n . W e postulate that this condition is associated with the reservoir being located in the lower part of the drainage (sensu Lowe McConnell, 1987), besides the presence of transposed species, which have not yet been registered in upper stretches of the Paranapanema’s drainages.

Wootton (1990) claims that the number of species present in an aquatic ecosystem is linked to the range of habitats and food s o u r c e s a v a i l a b l e , a c t i n g a s q u a l i / q u a n t i t a t i v e m o d u l a t o r s f o r t h e r e s i d e n t f a u n a , p r o v i d i n g t h e c o n d i t i o n s f o r l i f e c y c l e s t o b e c o m p l e t e d ( C a r v a l h o e t a l . , 2 0 0 5 ) . T a k i n g i n t o a c c o u n t l i m n o l o g i c a l alterations deriving from dammings promote m o d i f i c a t i o n s i n b i o t i c i n t e r a c t i o n s , particularly those of a trophic nature (Araú-jo-Lima et al., 1995; Hahn et al., 1998), it is expected that new limnological forces de-termine an availability of new food niches, ordering a new sharing of these resources w i t h a d i f f e r e n t i a l d i s t r i b u t i o n o f f i s h c o m m u n i t i e s .

F o l l o w i n g t h e r e l a t i o n b e t w e e n t h e supply of food resources and the faunistic c o m p o s i t i o n i n s e r t e d i n a g i v e n k i n d o f e c o s y s t e m , i n t h a t c a s e , l a c u s t r i n e , transition or fluvial, we verify the presence of differentiated dominant trophic groups, as it was found by Lowe McConnell (1987) and Agostinho & Júlio Jr (1996).

T h e d i f f e r e n t i a t e d s t r u c t u r i n g o f t h e i c h t h y o f a u n a i n t h e r e s e r v o i r ’ s g r a d i e n t ,

discriminated in the analyses, reflected, too, i n t h e i c h t h y o f a u n i s t i c s i m i l a r i t y f o r t h e e n v i r o n m e n t s s t u d i e d . A c c o r d i n g t o Jaccard’s index, the analysis showed that the lacustrine and transition environments are more similar to each other than the flu-vial environment. This disposition indicates a g r e a t e r c o n n e c t i o n a m o n g t h e s e e n v i r o n m e n t s , s h a r i n g m o r e c o m m o n s p e c i e s , i n r e l a t i o n t o t h e u p p e r f l u v i a l stretch, as it was also, recorded by Dias & Garavello (1998) and Carvalho et al. (1998) f o r t h e r e s e r v o i r s o f S a l t o G r a n d e a n d Jurumirim, respectively. Thus, for Taquaruçu a n d t h e o t h e r r e s e r v o i r s m e n t i o n e d , t h e greatest similarity indexes were obtained a m o n g a r e a s m o s t a f f e c t e d b y w a t e r accumulation.

Conclusions

Amidst the main impacts observed by the formation of the reservoir, we can verify t h a t t h e a l t e r a t i o n o f t h e w a t e r f l o w a n d t h e c r e a t i o n o f d i s t i n c t e n v i r o n m e n t s directly influenced the distribution of fish communities, with an explicit longitudinal v e c t o r i a l c o m p o n e n t . I t w a s a l s o v e r i f i e d that the fluvial environment, within the basin of the Taquaruçu’s reservoir, accumulates t h e g r e a t e s t r i c h n e s s , d i v e r s i t y a n d abundance, in relation to other stretches, as it was also recorded for various reservoirs o f t h e P a r a n a p a n e m a a n d U p p e r P a r a n á . T h e r e f o r e , t h e h y p o t h e s i s t h a t s p a t i a l v e c t o r i z a t i o n o f t h e I c h t h y o f a u n a i n r e s p o n s e t o t h e i m p o s e d p h y s i c a l a n d limnological variations is a predictive (and i n h e r e n t ) f a c t o r o f t h e f o r m a t i o n o f reservoirs in the basin of the Upper Paraná river, with greater abundance and diversity in the superior stretches.

The environmental changes, together with to the colonization of the basin of the Taquaruçu´s reservoir by species originating in the middle Paraná, transposed following the construction of the Itaipu reservoir, and t h e s u c c e s s f u l i n t r o d u c t i o n o f P. squamosissimus, p r e s e n t a r a t h e r u n i q u e c o n s t i t u t i o n o f t h e I c h t h y o f a u n a , a s compared to other reservoirs of the middle and upper Paranapanema.

References

Agostinho, A.A. & Júlio Jr., H.F. 1996. Peixes de outras águas. Ciênc. Hoje, 21(124):36-4 21(124):36-4 .

(11)

Agostinho, A.A. & Julio Jr., H.F. 1999. Peixes d a b a c i a d o a l t o r i o P a r a n á . I n : L o w e -McConnell, R.H. & Rosemary, H. (eds.) Es-t u d o s e c o l ó g i c o s d e c o m u n i d a d e s d e peixes tropicais. Edusp, São Paulo. p.374-4 0 0 .

Agostinho, A.A. & Gomes, L.C. 2005. O ma-nejo da pesca em reservatórios da bacia do alto rio Paraná: avaliações e perspec-tivas. In: Nogueira, M.G., Henry, R., Jorcin, A. (eds.) Ecologia de reservatórios: im-p a c t o s im-p o t e n c i a i s , a ç õ e s d e m a n e j o e sistemas em cascata. Rima, São Carlos. p . 2 3 - 5 6 .

A g o s t i n h o , A . A . , V a z z o l l e r, A . E . A . M . & Thomaz, S.M. 1995. The high river Paraná b a s i n : l i m n o l o g i c a l a n d i c t h i o l o g i c a l aspects. In: Tundisi, J.G., Bicudo, C.E.M. & Matsumura-Tundisi, T. (eds.) Limnology in Brazil. ABC/SBL, Rio de Janeiro. p.59-1 0 3 .

A g o s t i n h o , A . A . , M i r a n d a , L . E . , B i n i , L . M . , Gomes, L.C., Thomaz, S.M. & Suzuki, H.I. 1 9 9 9 . P a t t e r n s o f c o l o n i z a t i o n i n n e o t r o p i c a l r e s e r v o i r s , a n d p r o g n o s e s and aging. In: Tundisi, J.G., Straskraba, M . ( e d s . ) T h e o r e t i c a l r e s e r v o i r e c o l o g y a n d i t s a p p l i c a t i o n s . I n t e r n a t i o n a l Institute of Ecology, Brazilian Academy a n d B a c k h u y s P u b l i s h e r s , S ã o C a r l o s . p . 2 2 7 - 2 6 5 .

A r a ú j o - L i m a , C . A . R . M . ; A g o s t i n h o , A . A . & Fabré, N.N. 1995. Trophic aspects of fish c o m m u n i t i e s i n B r a z i l i a n r i v e r s a n d reservoirs. In: Tundisi, J.G., Bicudo, C.E.M. & Matsumura-Tundisi, T. (eds.) Limnology in Brazil. ABC/SBL, Rio de Janeiro. p.105-1 3 6 .

Benedito-Cecílio, E., Agostinho, A.A., Julio-Júnior, H.F. & Pavanelli, C.F. 1997. Coloni-zação ictiofaunística do reservatório de Itaipu e áreas adjacentes. Rev. Bras. Zool., 14:1-14.

Bennemann, S.T., Shibatta, O.A. & Garavello, J.C. 2000. Peixes do rio Tibagi: uma abor-dagem ecológica. EDUEL, Londrina. 64p. Bianchini Jr., I. 1994. Água como ambiente para a manutenção da fauna aquática. In: Seminário Sobre Fauna Aquática e o Se-t o r E l é Se-t r i c o B r a s i l e i r o . R e u n i õ e s Temáticas Preparatórias. Caderno I. Fun-damentos. COMASE/ELETROBRAS, Rio de Janeiro. p.7-17.

Bonetto, A.A. 1986. The Paraná river system. In: Davies, B.R. & Walker, K.F. (eds.) The e c o l o g y o f r i v e r s y s t e m . J u n k P u b l . , Netherlands. p.541-546.

Britski, H.A. 1972. Peixes de água doce do Estado de São Paulo. In: Comissão

Inte-restadual da Bacia Paraná-Uruguai. Polui-ção e piscicultura. Cibpu, São Paulo. p.79-1 0 8 .

Britski, H.A. 1994. A fauna de peixes brasi-leiros de água doce e o represamento de rios. In: Seminário Sobre Fauna Aquá-tica e o Setor Elétrico Brasileiro. Reuni-ões Temáticas Preparatórias. Caderno I. F u n d a m e n t o s . C O M A S E / E L E T R O B R A S , Rio de Janeiro. p.23-30.

C a r v a l h o , E . D . , F u j i h a r a , C . Y. & Henry, R. 1998. Study on the ichthyofauna of the Jurumirim reservoir (Paranapanema River, São Paulo State, Brazil): fish production a n d d o m i n a n t s p e c i e s i n t h r e e s i t e s . Verh. Int. Verein. Limnol., 26:2199-2202. Carvalho, E.D. & Silva, V.F.B. 1999. Aspectos

ecológicos da ictiofauna e da produção pesqueira do reservatório de Jurumirim (Alto do rio Paranapanema, São Paulo). I n : H e n r y , R . ( e d . ) E c o l o g i a d e r e s e r -v a t ó r i o s : e s t r u t u r a , f u n ç ã o e a s p e c t o s s o c i a i s . F U N D I B I O / FA P E S P, B o t u c a t u . p . 7 7 1 - 7 9 9 .

Carvalho, E.D. , Marcus, L.R., Foresti, F. & S i l v a , V. F. B . 2 0 0 5 . F i s h a s s e m b l a g e attributes in a small oxbow lake (Upper P a r a n á R i v e r B a s i n , S ã o P a u l o S t a t e , B r a z i l ) : s p e c i e s c o m p o s i t i o n , d i v e r s i t y and ontogenetic stage. Acta Limnol. Bras., 1 7 : 4 5 - 5 6 .

CESP. 1996. Relatório de implantação e de-s e n v o l v i m e n t o d o P r o g r a m a d e Monitorização do Ambiente Aquático da U H E T a q u a r u ç u . R e l a t ó r i o I n t e r n o . S ã o Paulo. 14p.

CESP. 1998. Conservação e manejo nos re-servatórios: limnologia, ictiologia e pes-ca. CESP, São Paulo. 166p. (Série Divul-gação e Informação, 220).

Dajoz, R. 1972. Ecologia geral. 2a ed. Vo

-zes/Edusp, Petrópolis. 471p.

Dias, J.H.P. & Garavello, J.C. 1998. Ecological s t u d i e s o f t h e f i s h c o m m u n i t y o f S a l t o G r a n d e r e s e r v o i r, P a r a n a p a n e m a r i v e r basin, São Paulo, Brazil. Verh. Int. Verein. Limnol., 26:2228-2231.

E a d i e , J . M . & K e a s t , A . 1 9 8 4 . R e s o u r c e heterogeneity and fish species diversity in lakes. Can. J. Zool., 62:1689-1695. F e r n a n d o , C . H . & H o l c i k , J . 1 9 9 1 . F i s h i n

reservoirs. Int. Rev. Gesamten. Hydrobiol., 7 6 : 1 4 9 - 1 6 7 .

Hahn, N.S., Agostinho, A.A., Gomes, L.C. & B i n i , L . M . 1 9 9 8 . E s t r u t u r a t r ó f i c a d a i c t i o f a u n a d o r e s e r v a t ó r i o d e I t a i p u (Paraná-Brasil) nos primeiros anos de sua formação. Interciência, 23:299-305.

(12)

H e n r y , R . 1 9 9 9 . H e a t b u d g e t s , t h e r m a l s t r u c t u r e a n d d i s s o l v e d o x y g e n i n b r a s i l i a n r e s e r v o i r s . I n : T u n d i s i , J . G . & Strskraba, M. (eds.) Theoretical reservoir e c o l o g y a n d i t s a p p l i c a t i o n s . I n t e r n a t i o n a l I n s t i t u t e o f E c o l o g y , Brazilian Academy of Sciences, Backhuys Publishers, São Carlos. p.125-152.

K r e b s , C . J . 1 9 8 9 . E c o l o g i c a l m e t o d o l o g y. Harper Collins Publishers, New York. 654p. L o w e - M c C o n n e l l , R . H . 1 9 8 7 . E c o l o g i c a l s t u d i e s i n t r o p i c a l f i s h c o m m u n i t i e s . Cambridge University Press, Cambridge. 3 8 2 p .

Ludwig, J.A. & Reynolds, J.F. 1988. Statistical e c o l o g y : a p r i m e r m e t h o d s a n d computing. John Wiley & Sons, New York. 3 3 7 p .

L y o n s , J . 1 9 9 6 . P a t t e r n s i n t h e s p e c i e s composition of fish assemblage among Wisconsin streams. Environ. Biol. Fish., 4 5 : 3 2 9 - 3 4 1 .

M i n n s , J . K . 1 9 8 9 . F a c t o r s a f f e c t i n g f i s h species richness in Ontario lakes. Trans. Am. Fish Soc., 118:533-545.

Nelson, J.S. 1994. Fishes of the world. John Wiley & Sons, New York. p.141-175. Nogueira, M.G., Henry, R. & Maricatto, F.E.

1999. Spatial and temporal heterogeneity i n t h e J u r u m i r i m R e s e r v o i r , S ã o P a u l o , Brazil. Lakes Reservoirs Res. Manage., 4 : 1 0 7 - 1 2 0 .

Nogueira, M.G., Jorcin, A., Vianna, N.C. & Britto, Y.C.T. 2002. A two year study on t h e l i m n o l o g y o f a c a s c a d e r e s e r v o i r system in a large tropical river in South E a s t B r a s i l . I n : P r o c e e d i n g s o f t h e I V I n t e r n a t i o n a l C o n f e r e n c e o n R e s e r v o i r L i m n o l o g y a n d Wa t e r Q u a l i t y. H y d o b i o l o g i c a l I n s t i t u t e , A c a d e m y o f S c i e n c e s o f t h e C z e c h R e p u b l i c a n d Icaris, Ceské Budìjovice. p.254-257. Nogueira, M.G., Jorcin, A., Vianna, N.C. &

Britto, Y.C.T. 2005. Reservatórios em cas-cata e os efeitos na limnologia e organi-z a ç ã o d a s c o m u n i d a d e s b i ó t i c a s (fitoplâncton, zooplâncton e zoobentos): um estudo de caso no rio Paranapanema (SP/PR). In: Nogueira, M.G., Henry, R. & Jorcin, A. (eds.) Ecologia de reservatóri-os: impactos potenciais, ações de ma-nejo e sistemas em cascata. Rima, São Carlos. p.83-125.

Orsi, M.L. 2005. Caracterização das estraté-gias reprodutivas na assembléia de pei-x e s d o r e s e r v a t ó r i o d e C a p i v a r a , r i o P a r a n a p a n e m a , r e g i ã o S u d e s t e , B r a s i l . Botucatu, UNESP, 130p (Thesis).

Pagioro, T.A., Roberto, M.C., Thomaz, S.M., Pierini, S.A. & Taka, M. 2005. Zonação lon-gitudinal das variáveis abióticas em re-servatórios. In: Rodrigues, L., Thomaz, S.M., Agostinho, A.A., Gomes, L.C. (eds.) B i o c e n o s e s e m r e s e r v a t ó r i o s : p a d r õ e s espaciais e temporais. RIMA, São Carlos. p . 3 9 - 4 6 .

Ploskey, G.R. 1986. Effects of water-level changes on reservoir ecosystems, with i m p l i c a t i o n s f o r f i s h e r i e s m a n a g e m e n t . I n : H a l l , G . E . & V a n D e n Av y l e , M . J . R e s e r v o i r f i s h e r i e s m a n a g e m e n t : s t r a t e g i e s f o r 8 0 ’ s . A m e r i c a n F i s h e r i e s Society, New York. p.86-97.

Reis, R.E., Kullander, S.O. & Ferraris Jr., C.J. 2003. Check list of the freshwater fishes of South and Central América. EDIPUCRS, Porto Alegre. 729p.

Santos, G.B. 1999. Estrutura das comunidad e s comunidad e p e i x e s comunidad e r e s e r v a t ó r i o s comunidad o S u -d e s t e -d o B r a s i l , l o c a l i z a -d o s n o s r i o s Grande e Paranaíba, bacia do Alto Paraná. São Carlos, UFSCar, 166p (Thesis). Thornton, W.K. 1990. Sedimentary process.

In: Thornton, K.W., Kimmel, B.L. & Payne, E.F. (eds.) Reservoir limnology: ecological p e r s p e c t i v e s . J o h n W i l e y & S o n s , N e w York. p.49-69.

Train, S., Jati, S., Rodrigues, L.C. & Pivato, B.M. 2005. Distribuição espacial e tem-poral do fitoplâncton em três reservató-rios da bacia do rio Paraná. In: Rodrigues, L., Thomaz, S.M., Agostinho, A.A. & Go-mes, L.C. (eds.) Biocenoses em reserva-t ó r i o s : p a d r õ e s e s p a c i a i s e reserva-t e m p o r a i s . RIMA, São Carlos. p.73-85.

Tonn, W.M. 1990. Climate change and fish c o m m u n i t i e s : a c o n c e p t u a l f r a m e w o r k . Trans. Am. Fish Soc., 119:337-352. Veregue, A.M.L. & Orsi, M.L. 2003. Biologia

r e p r o d u t i v a d e A s t y a n a x s c a b r i p i n n i s p a r a n a e ( E i g e n m a n n ) ( O s t e i c h t h y e s , Characidae), do Ribeirão das Marrecas, rio Tibagi, Paraná. Rev. Bras. Zool., 20:97-1 0 5 .

Wooton, R.J. 1998. Ecology of teleost fish.

2a ed. Kluwer Academic, Dordrecht. 386p.

Received: 26 October 2005

Figure

Updating...

References

Updating...

Related subjects :