1. No category

Dahlia - Rev. Asoc. Colomb. Ictiol. (2005) 8: 3-7
DIET OF ASTYANAX FASCIATUS AND CYPHOCHARAX
MAGDALENAE (PISCES: CHARACIFORMES), IN THE BETANIA
RESERVOIR, UPPER PART OF THE RIO MAGDALENA SYSTEM,
COLOMBIA
It
Plutarco Cala
D ep artamento de Biologfa, Universidad N acion al de Colombia, Bogota, D.C.
plutarco_ cala@h otmail.c om
Abstract
The principal food items of 98 adult specimens of A. [osciotus are plant matter (63% TW and
68%FO). and chir onomid larvae (3%PT, 27% FO) . followed by For micidae. detritus, fish scales
(characid) . and fish larvae. Summing up. this means a 63% TW and 72%FO plant mat eri al. and 28% TW
and 94%FO mid ges (Table I). The diet of this omni vorous fish is very simil ar t o its congener A.
bimaculatus . which consumes prin cipally plant matter and midges.
The principal food items found in the stom ach contents of 50 adult specimens of C. magdafenae w ere
detritus and phyt oplankt on. The taxonom ic qualitat ive analysis showe d the presence of five classes of
phytoplankton , classified in J0 orders, 13 families with 27 genera. Th e zooplankton w as represented by
Monogononta, order Ploirna and the family Brachionid ae with two genera (Table 2). The three principal
categor ies were the classes Baclllariophiceae, Chlorophiceae and Cyanophyceae (Phot o bacteri a).
Thus . C. magdaJenae may be considered rather detritivorous. nearly algivorous. The fish consumes
sediment (det rit us) in the first place in order to swallow the nutritious associat ed food it ems. Th e
stomach contents of 10more specimens show ed an average percemage of24 .6% organic mat erial and
75.2% of inorganic matter (Table 3) .
It seem sthe alimentary diet of C. magdalenae is similar to th at of Oreochromis niloticus. This could be
a competitive factor of the exotic cichlid over the native species in the Magdalena River system. since
both species occupy mostly the same habitats,
Key words: diet A. (asciatus and C. magdalenae. Magdalena River system.
Resumen
Los pr incipaJes it ems alimentarios de 98 peces adultos de A. [asciotus son material veget al
(63% TW; 68%FO) Y larvas de Chiro no mid ae (3%TW; 27%FO). seguidos por Forrn icidae. detrito,
escamas de peces (characide). y larvas de peces. Resumiendo, esto significa un 63% TW Y 72%FO d e
material vegetal. cont ra 28%TW Y 94%FO de restos aninm ales (Tabla I). La dieta de este pez
omnivoro es muy similar a la de su congenere A. bimaculatus, la cual consum e prin cip almente material
veget al y dlpteros.
EI contenido estomacal de 50 espedmes adultos de C. magdalenae fuedetritus y fito plancto n. EI
analisis taxon6mi co cualitati vo mo str 6 la presencia de 5 c1ases de fitoplancton, c1asifJcado en 10
6rd enes, 13 familias con 27 generos, El zooplancton estuvo repr esentado por Mono gononta. orden
Ploima y la familia Brachionidae con dos genero (Tabla 2). Las tres catego ri as prin cipales fuer on las
clases Bacillar iophic eae. Chlorophiceae y Cyanophyceae (Photobact eria).
Asi, C. magdalenae puede ser considerad a det ritivora, mas cer canament e algivo ra. EI pez consum e
sedim ento (det rit us) y de ahi ext rae los nutrientes asociados en el. E\ contenid o est omacal de 10
espedmenes rnostro un porcentage promedio de 24% de material or ganico y 75.2% de materi a
lnorganica (Table 3).
Aparentente la dieta aliment icia de C. magdalenae es muy similar a la de Oreochromis niloticus. Esto
podrfa ser un factor competitivo del exot ica dclido sobre la especie nativa en el sistema del Rio
Magdalena, pues ambas especies se encuentran dlstribuidas general mente en los mismos habitats .
Palabras clave: dieta A. [asciatus y C. magdalenae. Rio Magdalena.
3
Dahlia. No.8. 200 5
Table I. Food items taken byA. [osaatu « inthe Betania Reservoir, expressed as percentage ofFrequencyof occurrence (% FO) and
totalweight (% TW). PMTW = plant material totalweight, A RTW = Animal rests totalweight. n = number offishes, SL = Standard
length (mm), L = larvae, N = nymph. A = adult.
he ms
land
Detritus
Plantmatter
Seeds
Animaln;m
Filblarvae
Sca lel
Coleoptera (A)
Chironomidae (t)
Formicidae(A)
Ce r.ltopogonidaE(L)
Hemipter.l (N)
Ephemeropclr.1 (N)
Ostracoda (A)
Cyclopidae
PMTW
ARTW
N
Mean Sl
Sl interval
februa ry
%TW %fO
3
8
65
8
II
69
April
%TW %FO
44
54
<I
25
88
6
May
%TW %10
2
94
18
19
1
31
38
<I
I
II
21
13
76
(42.113)
54
3
8
85
(71. 103)
13
I
<I
<I
<I
<I
95
4
33
69
(50.93)
Introduction
This paper discusses the aspects of the diet and
the trophic level function oftwo species of chara­
cifonn fishes -Sardine Red/yellow tailed , Astya ­
nax fasciatus (Characidae), and Madre de Bo­
cahico, Cyphocharax magdalenae (Curimatidae)
- in the Betania Reservoir, upper part of the Rio
Magdalena.
Study area and methods
The Betania Reserv oir has an area of 7,400 ha,
constructed at the junction of the Rio Yaguara
with the Magdalena (02°41' north ern latitude and
75°26' Western), 35 km south east ofNeiva city,
at 560 m altitud e, with a crest high of9 8 m, a vo­
lume of 2,000 minions of cubic meters, and a
flow of473 m3/s atthe dike. For further informa­
tion on the environment and fish community see
Cala (1995).
4
6
79
~'J u ly
%TW
28
I
39
%FO
57
9
43
15
October
%TW %FO
2
15
9
55
16
59
20
60
II
<I
I
<I
3
10
<I
<I
<I
<I
<I
59
25
15
80
(68·89)
27
<I
41
7
40
20
<I
7
7
<I
<I
5
14
33
<I
D
2
42
<I
64
17
5
9
6
3
33
12
28
72
7
78
(64-86)
43
<I
<I
16
82
22
69
(42·107)
December
%TW %10
5
Total
%TW
<I
9
63
<I
5
1
2
<I
3
10
<I
<I
<I
<I
<I
63
28
98
74
(42·113)
%10
I
10
68
4
16
5
20
5
I1
10
I
I
1
I
6
n
94
The fishes were captured, mainly with cast nets
of small mesh size, in the Yagura River arm whe­
re the two species were more common since this
area is less deep than the Magdalena River arm.
Six collections separated by a 45-60-day interval
were made in 1991 (April-December). Standard
length (SL) and total weight (TW) of fresh fish
materi al was determined . Then, their stomachs
were removed and fixed in 5% formalin for later
study at the la boratory, Frequency of occurrence
(FO) and gravimetric (TW) methods were used
in the analysis of stomach content (WindeII &
Boewn 1978). Representative specimens from
the studied area were deposited at the Fish Divi­
sion of the Instituto de Ciencias Naturales-Mu­
seo de Historia Natural (ICN-MHN), Universi­
dad Nacional de Colombia, Bogota D.C.
The identifi cation of plankton and invertebrate
organisms was aided by usiug general keys (e.g.
Smith 1950, Gonza lez 1988, Pennak 1989). The
classification of phytoplankton at higher levels
of the family was made in accordance with Rey­
nolds (1984). The percentage of organic and
inorganic material in the alimentary diet was de­
Table 2. Food ite ms (taxa) taken by C. magda/enae. in the
Table 3. Pe rce ntage of organic and inorganic matte r found in
the stomach contents o f 10 sped mens o fC magdalen ae Inthe
Be tania Re servo ir.
Yaguara River arm , Betania Reservoir. O M : orgaruc matter.
Clall
Order
Oedo!" oia l.,
lignemelalfl
family
Oedogonimae
l i~ nemtta (f.iI (I
Oe> miliaCM
1M: ino rganic matt e r.
OerlOo
/ ll/j/m
l ignefllJ
l1icrolpora
~Imariu m
f r3l1tV/ll'l f
SraurilSlfum
f13l1roUrJmuJ
Sce/lerff!JmUI
Phetobartena
(Cyanophycoae)
Ulvale>
Icnilogoni.,m
Nosloc.l"
NOllocacm
Eugl!llophyce. e
Eugl,", I'l
Bacillariopny teae
(O;atomw)
Cenlrales
Penn. ln
f,.firmn
\cbilogonium
Oscilla tori. ,e.e
A" aikl,"a
[, lIIgby.
NOdulari.
Oscillalori.
Eugl' nm ..
r",,!lelomollal
~ e lo li r aceae
11e10II",
Oi.tom. " ae
N. viculaceae
f/dgili ri,
[,mbell.
Karimi,
frvrtrJliJ
Pinllufaria
Niclchia
G,rorigm.
Ephilemial' l
Acb. ntha les
O,oo pbycm
HOIlllgononta
Pillima
Ephitemiacm
Acllaml..ceae
S.rirell.
f phiwna
[O«Ollei1
Peridi,..ceae
1'Prirfinium
Bra'ruonida e
t'n te/Ii
flfina
Or!. nic ma leri. 1
InorganKma tter
termined by burning the stomach contents at 600
°C (Gonzalez 1988). See Cala and Bernal (1997)
for further details on methodology.
Results and discussion
Astyanax fa sciatus (Cuvier, 1819). 98 speci­
mens captured over a year period were examined
in order to study the stomach content. The speci­
mens were distributed evenly over a range of 42
to 113 mm SL (mean 74). Mean total length 96
mm, and maximum total length 130 mm, alt­
hough Dahl (197 1) mentioned 170 mm, and
Lima et at. (2003) reported 100 rom TL. This
species belong to the 13most abundant species of
~'
filii Tl (em)
16.4
15.5
16.1
15.1
14.5
16.0
13.2
[17
14.6
[5.0
TW (g)
70.0
58.0
58.0
50.0
42.0
60.0
31.5
37 .6
45.0
51.0
Date
May 14
Oct. 8
Oct. 10
Dec. 13
%OH
%IH
40.8
7.0
54.0
25.0
26.0
38.3
14.5
12.2
18.6
9.8
591
93.0
46.0
75.0
74.0
61.7
85.5
87.5
81 A
90.2
a total of 33 species capture d in the Reservoir
(Cala 1995). It is distributed in most freshwater
basins from Mexico to Argentina.
Its principal food items are plant matter (63%TW
and 68%FO) and chironomid larvae (3%TW,
27%FO), followed by Formicidae, detritus, fish
scales (characid), and fish larvae. Summing up,
this means a 63%TW and 72%FO plant material,
and 28%TW and 94%FO anima l rests (Table 1).
The diet of this omniv orous fish is very similar to
its congener A. bimaculatus , their two principal
food items bein g plant matter and midges (Cala
1997).
The examination of a sample of 71 adult mature
specimens of A. fascia tus deviated significantly
from a I: I ratio, the male/female relationship
being 1:12. The total mean length of 11 adult fe­
males and 4 males was 102 and 92 mrn, with an
average weight of 14.2 and 9.6 g, respectively. It
seems like females reach a greater size than males,
which could be a selective factor of these indivi­
duals concerning the mesh size of the cast nets
used in the capture of the population sample.
Thus, females of this species reach larger sizes
than females reported in other Astyan ax species ­
e. g. A. auricaudatus, the mean standard length of
females was 36.6 mm versus 43.3 for males (Ro­
man-Valencia & Ruiz-C. 2005).
5
th
71 mature Aifasciatus captured on 13 Decem­
ber were in stage prior to the spaw ning, or Stage
III with mature oocytes and spermatozoa (Cala
1996, 1997). It may be assumed that the repro­
duction strategy ofthis fish speci es is that it has a
regeneration time of 12 months and it spawns an­
nually during the first month of the rainy season
(February-May). Barbieri et at. (1996, cited by
Roman-Valencia & Rui z- C. in this publi cation)
reported the spawning time of A.fa sciatus, in the
Represa do Lobo , Sao Paulo, between October
and December.
This reproduction strategy has being reported by
CalaandBlanco (1974) for A. bimaculatus , and by
Taphorn (1992) for six other specie s from the Rio
Apure in Venezuela, which may be the general
patteru of reproduction strategy of Astyanax spp.
However, Roman-Valencia and Ruiz-C. (2005 in
this publication), suggest that A. aurocaudatus
spawns during the rainy (April-May, Septem­
ber-October) aud dry seasons (January-February),
aud Mora et al. (1997) mentioned that in the Reser­
voir of Arenal in Costa Rica, A. fasciatus spawns
during the eutire year, with a maximum between
June to September. These two last couclusions (Ro­
man-Valencia and Ruiz-C, 2005, Mora et al. 1997)
seem to need further observations , since they are
not based on conclusive studies.
Cyphocharax
magdalenae
(Steindachner,
1878). Previously known as Curimatus(a) mag­
dalenae until it was included in the genu s Cypho­
eharax (Vari 1992). Asample of 157 adult «11.5
em TL) C. magdalenae takeu between April and
Dec emb er 1991 was composed of Tl (50.7% )
mature male s and 75 (49.3 %) mature females.
The numbers do not deviate significantly from a
1:1 ratio . All fish longer than 9 em SL (I 1.5 em
TL) wa s mature (will spawn during the next re­
production period). Maximum total length 17.2
cm(n .7 g). Dahl (1971) aud Vari (2003) mentio­
ned20 and 15.5 em SL, respe ctivel y. C. magdale­
nae inhabits mainly lacu strin e waters (cienagas)
6
of the lower parts of Magdalena and Atrato River
basins, rivers of Pacific versant of Panama , and
southwestern Costa Rica.
50 specimens of the Madre de Bocachico were exa­
mined in order to analyze the composition of the
diet, distributed over a range of 90 to 140 mm SL
(mean 122). The stomach content ofanother 10 in­
dividuals, 10.2 to 13 em SL (mean 11.85), were
analyzed to establish the percentage oforganic and
iuorgarric material ofthe alimentary diet.
The principal food items are detritus and phyto­
plankton. The taxonomic qualitative anal ysis
showed the pres ence of fiv e classes of phyto­
plankton, classifi ed in 10 orders, 13 families with
27 genera. The zooplankton was represented by
Mono gononta, order Ploima and the fam ily Bra ­
chionidae with two geuera (Table 2). Th e three
principal categories were the classes Bacillariop­
hiceae, Chlorophiceae and Cyanophyceae (Pho­
tobacteria) .
C. magdalenae may be con sidered rather detriti­
vorous, nearl y algivorous. The fish consumes se­
diment (detritus) in order to swallow the nutritio­
nous food item s in it. The stoma ch cont ents of 10
specimens showed an average perceutage of
24.6% organic material and 75.2% inorganic
matter, which explains the large quantity of sedi­
ments in the fish stomac hs. The perceutage of or­
ganic material iu comparison with inorganic mat­
ter in the stomach contents was hi gher than what
wa s fouud in Oreochromis niloticus from the
same water body (I.4 % and 98 .6%, respecti­
vely) . This mean s that the diet of C. magdalenae
in terms of protein aud carbohydrates average
percentage should be richer thau the 0. niloticus
which was determined in 7.5% and 0.85%, res­
pectively (Cala & Bernal 1997).
Thus, it seems that the alimentary diet of C. mag­
dalenae is similar to that ofthe 0. niloticus (Cala
& Bernal 1997). This could be a competitive fac­
tor of the exotic cichlid with a native species iu
the Magdalena Riv er system, since both species
occup y mostly the same habitats.
Be rtaco.C , Mor eira & P.H .F. Lucinda. 2003 .
Genera incerta sedis in Characidae . 106-169 .
In R.E. Reis, S.O . Kullander & CJ Ferraris, Jr
(O rga nize rs) . Chec k list of the fre sh water
fishes of South a nd C entral America.
EDIPUCRS , Porto Alegre, Brazil. 742 p.
Acknowledgements
I am grateful to the biologist Gilberto Mora for
aid in the analysis of stomach contents. To Anni­
ka Cala for correcting my English. This study
was carried out under contract 268/90 Universi­
dad Nacional de Colombia-Central Hidroelectri­
ca de Betania.
References
Cala , P. 1995 . Trophi c level o fth e most abundant fishe s
of th e Betania Res ervo ir, upper Rio Magdal en a ,
Colombia. Mem. Symposium Fish. Ecology in
Latin America, Austin Texas ,june 1993. Acta BioI.
Venez.16 (1):47-53 .
C ala, P. 1996 . Cyclic histomorphological changes in the
ova ry of the catfish capaz , Pime(odus grosskopfr ;
(Pime lod idae, Siluriformes), in th e upper part o f
the Rio Magdalena. Dahlia (Re vist a Asoc.
Colomb. lctiol.) I : 7- 13.
Cala, P. 1997 . Espermatogenesis y cicio anual
reproductive del capaz, Pim e/odus grosskapfri
(Pisce s: Pimelodidae), en el alto Rio Magd alen a,
Colombia. Cald asia 19 ( 1-2): 45-53 .
Cala , P. & G. Bernal. 1997. Ecologfa y adaptaciones de
la Tllapia nilotica (Ore chromis niloticus) en
arnbi entes naturales - caso Emb alse de Bet ania y
Cienaga de Chilloa , sistema del RIO Magdalena,
Colombia. Dahlia (Re vist aAsoc. Colomb . !ctiol.)
2: 3-29
Dahl , G. 1971. Los peces del norte de Colombia.
INDERENA Bogota.
r '
Mora, j .M, P. Cabre ra & W. Alvar ado -Bogantes.1997.
C recimiento y rnaduracion sexual de Astyanax
fasciatus (Pisces : Characidae ) en el embalse
Arenal , Guanacaste, Costa Rica . Re v BioI. Trop .
45 : 855-859.
Pennak, R.W. 1989. Fresh-water invertebrates of th e
United Sates: Protozoa to Mollusca. 3'd. ed ., John
Wiley & Sons, New York. xvi+ 628 p.
Reinolds, CS. 1984. Th e eco logy of freshwater
phytoplankton. Cam bridges Studies in Ecology.
Cambridge University Press, Cambridge. 383p.
Roman-Valencia & R.I. Ruiz-C . 2005 . On the ecology
of Astyonax aurocaudatus (Teleostei: Characidae)
from the upper part of the Rio Cau ca , Colombia.
Dahlia (Rev. Asoc. Col omb . Ictiol.) 8 : 9-17.
Smith, G. 1950 . Th e fresh -water algae of th e United
States. Second edition. McGraw Hill, New York.
Taph orn, DC 1992. The characiforrn fishes of the
Apure River drainage, Ve ne z ue la . Mon ograff as
Cientificas del Museo de Ciencias Naturales
UNELLEZ - Guanare , Estado Portuguesa, Vene­
zuela.537 pp.
Vari, R.P. 1992. Syst ematics of th e Neotropical
characifo r m genus Cyphocharax Fowler (Pisces:
Ostariophysi). Smithson. Contrib. Zool. 529:
i-iv+ 1-137.
Gonzalez , 1988 . EI plancton de las aguas
continentales . Secretarfa Gen eral
de
la
Organizacion de Estados Americanos (O EA).
Programa regional de desarrollo cientifico y
tecnologico. Washington. 130 p.
Vari,
R. 2003 . Family Curimatidae (To ot hless
c harac ifo rrns). 51-64. In R.E. Reis, S.O. Kullander
& Cj Ferraris , jr (O rganize rs) . Check list of the
freshwater fishes of South and Central Ameri ca .
EDIPUCRS, Porto Alegre. 742 p.
Lima , F.CT. , L.R. Malaba rba, P:A Buckup, J.F. Pezzi
da Silva, R.P. Va r i, A. Harold , R, Benine, O .T.
Oyakawa, CS. Pavanelli, N .A. Nenezes , CAS .
Lucena, M.CS.L. Malabarba, Z.M .S. Lucena,
R.E. Reis, F.Langeani, L. Cassati , VA
Windell,j .T.& S.H. Bowen. 1978 . Methods for study of
fish diet. In T. Bagenal (e d .) Methods for assess ­
ment of fish production in fresh waters . pp .
219-266. IBP Handbook No. 3 (3'd. ed .),
Blackwell Sci. Publ. , Oxford. 365 p.
7