0A
..6. .. .
* 6. .. ...
... .6. ......
6. .... ....
.. ....6 .. .. .
..6. ..
0.. ...
TO PI .I 1 I 11 ii ma ti (Prochilodus sp.) ani a bund anrt tres It %ate r iI i , - -,, - -
," - - 'I- . -- ''- '. ,- ,e
RI (.111tra ira (Hopkias naubaricus., an endemic predlacious fish that is dlist ribluted th roughout northeastern B raz il; B() I GMI LI' tucuna re pinima
(Cichki temrnenis) (left) and tuctinare comnum (C. niellaris) (right): BOYFON GM IGHT-pescada I1'Iogioscion squamosistsimus). a scianid "shich is a popular
fresh"s ater fish in Northeasterni Brail.
Information contained herein is available to all without regard to race, color, or national origin
PL BLLSHM 3/78-k1MN
Length-Weight Relationships and 
Condition Indices
of Fishes from Reservoirs of Ceara, Brazil
ODILO FREIRE DOURADO and WILLIAM D. DAVIES*
INTRODUCTION
LENGTH-WEIGHT DATA on fishes collected from various
locations can be used to calculate typical average weights
for fishes of specific lengths. Differences in weight of fishes
of similar length is best expressed in terms of a relative
condition factor (4) which is calculated by dividing an
observed weight by a typical average weight for fishes of
a certain length.
Relative condition (Kn) = W where
A
w
W
W =weight of an individual or the average weight
of individuals of a certain length
A
the calculated average weight for the same
length from the equation W = aLb where a
and b are constants derived from fitting the
equation
logW = loga +blogL
A relative condition (Kn) value greater than one in-
dicates that a fish or fishes of a specific length weigh more
than the average weight, or are in better condition. This
condition could indicate an aquatic system of greater pro-
ductivity (1), or that the fish populations are structured
(predator-prey ratio) to allow rapid growth. The weight
per unit length of a fish is greater when it is growing
rapidly. A Kn value of less than one indicates that a fish is
growing slowly, which may be attributed to over-
crowding, parasites, diseases, or low productivity.
Seasonal changes as well as state of sexual maturity may
also affect the condition of fish. Godoy (2) observed that
the weight change per unit of length is greater for female
curimatc (Prochilodus cearensis) than for males; also the
condition index for this species varies between seasons.
However, Silva (5) determined that the condition of
*Engenheiro Agronomo Convenio SUDENE/DNOCS/USAID, Centro
de Pesquisas Ictiologicas, Fortaleza, Brazil; and Associate Professor, De-
partment of Fisheries and Allied Aquacultures, Agricultural Experiment
Station, Auburn University, respectively.
Pescado do Piaui' (Plagioscion squamosissimus) is not sex
related.
MATERIALS AND METHODS
Total length (2-centimeter groupings) and weights
(grams) for fishes representing 20 species were taken from
the five major reservoirs in Northeast Brazil listed below:
Reservoir
River No. years
Location (city) 
drainage sampled
Pereira de Miranda .. Pentecoste
Araras ............. . Reriutaba
Banabuiu .......... Quixada
Forquilha .......... Sobral
Lima Campos ....... Icd
Curu
Acarau
Banabuiu
Acarau
Salgado
Estimated weights were calculated from the linear
logarithmic form of the general length-weight equation:
A
W = aLb
For several species, one equation did not adequately fit
the data over the complete range of lengths; therefore, two
and sometimes three equations are occasionally used (see
Appendix for details). The length interval for which a
single equation was computed was determined at the point
where there was a noticeable change in the body confor-
mation or the condition index (3). The condition index (K)
was calculated as follows:
K= Wx 10 where
SL'
W = weight in grams
L = total length
Estimated weights are tabulated for each species by 2-
centimeter length groups. Also included are the number of
individuals in each group, range and average of empirical
weights, and the condition index. Species are listed
alphabetically by common name.
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS 
OF BOD6,
PLECOSTOMUS PLECOSTOMUS LINNAEUS
No. Average CalculatedCondition
Length of Range in weight empirical weights 
Condition
fish Minimum Maximum weight standard index
8 .... 47 5 12 9 
8 17.5
10 .... 296 10 13 11 13 
11.0
12 .... 126 17 23 18 
19 10.4
14 .... 234 24 35 30 
27 10.9
16 .... 24 51 58 53 
51 12.9
18 .... 24 52 100 68 72 
11.6
20 .... 27 79 102 97 
98 12.1
22 .... 21 110 136 132 
130 12.3
24 ..... 33 152 210 170 
167 12.2
26 .... 10 180 250 209 
211 11.8
28 .... 8 240 300 265 
262 12.0
30 .... 6 300 329 318 
320 11.7
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND 
GRAMS OF BEIRU,
CHARACIDIUM MARSHI BREDOR
No. RAverage Calculated Condition
Length of Range 
in weigt empirical 
weights Condition
fish Minimum 
Maximum weight 
standard index
12 .... 5 25 
50 35 34 
20.2
14 .... 10 35 
60 52 49 
18.9
16 .... 14 40 
77 59 69 
14.4
18 .... 21 50 
104 91 94 
15.6
20 .... 23 100 
150 129 121 
16.1
22 .... 3 130 
150 148 153 
13.8
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF CANGATI,
TRACHYCOR YSTES GALEATUS (LINNAEUS)
No. RAverage Calculated .
Length of Range 
in weight empirical 
weights Condition
fish Minimum Maximum 
weight standard 
index
12 .... 6 40 46 44 
43 25.4
14 .... 8 52 80 60 65 
21.8
16 .... 59 70 120 96 
92 23.4
18 .... 64 90 200 121 
117 20.7
20 .... 19 97 175 145 155 
18.1
22 .... 6 200 331 206 
199 19.3
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND 
GRAMS OF
CURIMATX COMUM, PROCHILODUS CEARENSIS 
STEINDACHNER
No. R Average Calculated
Length of ange 
in weight empirical 
weights Condition
fish Minimum 
Maximum 
weight standard 
index
10 ... 5 15 22 19 
17 19.0
12 .. 10 17 36 29 
30 16.7
14 .. 9 35 45 44 
47 16.0
16 .. 21 45 78 67 
71 16.3
18 ... 37 63 120 101 
101 17.3
20 ... 72 93 197 143 
139 17.8
22 .. 217 100 302 192 185 
18.0
24 ... 290 130 298 241 240 
17.4
26 ... 277 211 370 290 291 
16.4
28 ... 258 248 550 352 348 
16.0
30 ... 119 290 600 426 411 
15.7
32 ... 57 300 700 434 
481 13.2
34 ... 31 320 750 591 558 
15.0
36 ... 21 450 920 763 727 
16.3
38 ... 1 600 1,000 813 860 
14.8
40 ... 10 850 1,300 998 1,008 
15.5
42 ... 7 1,000 1,300 1,041 1,172 
14.0
44 ... 9 1,200 1,675 1,509 1,354 
17.7
46 ... 16 1,290 1,900 1,695 1,555 
17.4
48 ... 4 1,500 2,000 1,833 1,774 
16.5
50 ... 6 1,800 2,100 1,839 2,013 
14.7
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMIETERS AND GRAMS OF APAIARI,
ASTRONOTUS OCELLATUS OCELLATUS SPIX
No. Average Calculated
Length of Range in weight 
empirical weights Condition
fish Minimum Maximum 
weight standard index
16 .... 15 76 140 123 122 30.0
18 .... 5 132 172 169 172 28.9
20 .... 24 150 320 239 235 
29.8
22 .... 58 256 385 312 311 29.3
24 .... 40 300 540 400 402 
28.9
26 .... 45 380 650 473 490 26.9
28 .... 36 450 768 592 550 26.9
30 .... 14 500 800 589 612 21.8
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF
ACARA COMUM, CICHLASOMA BIMACULATUS (LINNAEUS)
No. Average CalculatedCondition
Length of Range 
in weight empirical 
weights Condition
fish Minimum Maximum 
weight standard 
index
4 14,934 1 3 2 2 31.2
6 . 36,137 4 6 5 6 23.1
8 . 14,217 10 24 12 13 23.4
10 . 7,685 20 43 32 25 32.0
12 . 2,862 28 75 41 42 23.7
14 . 1,313 45 108 62 65 22.5
16 . 439 87 137 100 94 24.4
18 . 149 90 150 117 135 20.0
20 . 54 135 250 204 187 25.5
22 . 15 140 273 250 250 23.4
24 . 2 325 325 325 327 23.5
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF GUARU,
POECILIA VIVIPARA BLOCH & SCHNEIDER
No. Average CalculatedCondition
Length of Range 
in weight empirical 
weights Condition
fish Minimum 
Maximum weight 
standard index
2 .... 296 0.15 0.50 0.28 0.29 35.0
4 .... 519 1.00 2.00 1.24 1.15 19.3
6 ...... 28 1.00 3.00 2.46 2.57 11.3
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS 
OF JACUNDA,
CRENICICHLA T SAXA TILIS ? (LINNAEUS)
No. Average CalculatedCondition
Length of Range 
in weight empirical 
weights Condition
fish Minimum Maximum 
weight standard 
index
6 . 35,828 2 3 2 
2 9.2
8 . 16,584 4 8 5 5 
9.7
10 . 6,545 9 13 10 11 
10.0
12 3,783 18 30 21 20 
12.1
14 . 1,551 25 48 32 33 
11.6
16. 898 30 77 51 50 
12.4
18 . 372 50 122 74 73 
12.6
20 . 113 99 145 102 102 
12.7
22 . 52 138 163 141 138 
13.2
24 . 6 166 197 181 183 13.0
4
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF MUSSUM,
SYNBRANCHUS MARMORATUS BLOCH
No. Average Calculated
Length of 
Range in weight 
empirical weights 
Condition
fish Minimum 
Maximum 
weight standard 
index
12 .... 63 1
14 .... 18 3
16 .... 18 4
18 .... 15 5
20 .... 15 6
22 .... 5 8
24 .... 13 8
26 .... 5 9
28 .... 20 16
30 .... 10 28
32 .... 17 30
34 .... 11 38
36 .... 52 47
38 .... 64 60
40 .. . . 51 68
42 .... 30 80
46 .... 14 122
48 .... 6 129
50 .... 12 135
52 .... 7 190
54 .... 5 190
56 .... 5 231
58 .... . 290
4
5
7
8
11
17
20
21
30
35
38
56
62
70
86
134
180
189
220
240
260
285
305
3
4
5
6
8
11
14
19
25
33
36
48
56
64
84
101
134
181
204
203
254
282
297
2
4
5
7
10
13
16
20
25
30
36
43
51
59
86
102
141
163
188
216
246
280
316
1.7
1.4
1.2
1.0
1.0
1.0
1.0
1.0
1.1
1.2
1.1
1.2
1.2
1.1
1.3
1.3
1.4
1.6
1.6
1.4
1.6
1.6
1.5
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF 
PIABUSSU,
CURIMATUSMOROWHANNAE EIGENMANN
No. Average Calculated Condition
Length of Range in 
weigt empirical 
weights Condition
fish Minimum Maximum 
weight standard 
index
6 .... 160 1 5 3 4 13.8
8 ... 312 6 17 8 8 15.6
10 .... 217 15 26 19 15 19.0
12 .... 172 20 40 26 25 15.0
14 .... 36 29 52 35 39 12.7
LENGTH-WEIGHT RELATIONSHIPS 
IN CENTIMETERS AND GRAMS OF
PESCADA DO PIAUI PLAGIOSCION 
SQUAMOSISSIMUS HECKEL
No. RAverage Calculated
Length of Range 
in weight empirical 
weights Condition
fish Minimum 
Maximum 
weight standard 
index
12 .... 7 18 40 
23 21 13.3
14 .... 27 22 50 
35 34 12.7
16 .... 68 35 98 
52 50 12.6
18 .... 137 50 140 
70 72 12.0
20 .... 304 65 148 
94 98 11.2
22 .... 268 70 256 
121 131 11.3
24 .... 250 110 
252 168 171 
12.1
26 .... 163 120 296 
199 217 11.3
28 .... 127 130 311 
238 272 10.8
30 .... 92 200 500 
327 335 12.1
32 .... 47 330 600 
417 406 12.7
34 .... 42 390 604 533 488 
13.5
36 .... 35 400 700 590 580 
12.6
38 .... 17 450 800 723 683 
13.1
40 .... 18 500 1,200 846 797 
13.2
46 .... 5 1,100 1,250 1,223 1,196 
12.5
48 .... 6 1,200 1,500 1,336 1,385 
12.0
50 .... 5 1,250 1,720 1,570 1,594 12.5
52 .... 3 1,670 1,900 1,785 1,824 12.6
54 .... 3 2,060 2,500 2,480 2,077 15.7
66 .... 6 3,800 4,300 4,017 4,143 13.9
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF
PESCADA CACUNDA, PLAGIOSCION SURINAMENSIS BLEEKER
No. Average Calculated
Length of Range in weight empirical 
weights Condition
fish Minimum Maximum weight standard 
index
10 .. 4 9 9 9 9 9.0
16 ... 42 34 90 46 42 11.2
18 ... 139 44 120 64 62 10.9
20 ... 270 65 132 85 87 10.6
22 ... 171 85 190 117 118 10.9
24 ... 53 126 200 157 157 11.3
26 ... 19 173 250 210 203 11.4
28 ... 18 203 281 248 257 11.2
30 ... 15 256 341 305 321 11.2
32 .. 3 382 443 423 396 12.9
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS
OF PIAU COMUM, LEPORINUS FRIDERICI BLOCH
No. Average CalculatedCondition
Length of Range in weight empirical 
weights Condition
fish Minimum Maximum weight 
standard index
8 ... 6 7 10 9 8 17.5
10 16 10 24 14 15 14.0
12 ... 42 15 38 24 26 13.8
14 .. 104 31 98 41 41 14.9
16 ... 143 32 100 62 60 15.1
18 ... 150 60 140 89 85 15.2
20 ... 163 87 204 114 115 14.2
22 .. .156 10 0 290 168 170 15.7
24 ... 166 120 370 223 219 16.1
26 ... 87 200 450 283 276 16.1
28 .. .57 250 520 340 341 15.4
30 ... 26 252 560 385 417 14.2
32 ... 9 353 680 519 502 15.8
34 ... 6 518 700 608 599 15.4
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS
OF PIAU VERDADEIRO, LEPORINUS SP.
No.. 
Average Calculated Condition
Length of Range in weight empirical weights ndex
fish Minimum Maximum weight standard index
22 .... 3 145 159 156 143 
14.6
30 .... 4 320 380 345 348 
12.7
34 .... 10 380 580 463 499 11.8
36 .... 10 500 700 0 560 588 12.0
38 .... 12 567 800 701 687 12.7
40 .... 16 640 1,000 798 796 12.4
42 .... 8 700 1,100 854 916 11.5
44 .... 10 760 1,200 969 1,047 11.3
46 .... 12 1,080 1,460 1,244 1,190 12.7
48 .... 7 1,200 1,750 1,342 1,345 12.1
50 .... 7 1,250 1,850 1,520 1,512 12.1
52 .... 5 1,380 2,000 1,840 1,693 13.0
54 .... 3 1,660 2,400 1,900 1,887 12.0
56 .... 6 1,800 2,750 2,175 2,094 12.3
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF PIRAMBEBA,
SERRASALMUS RHOMBEUS LINNAEUS
No. Average Calculated
Length of Range 
in weight empirical 
weights Condition
fish Minimum 
Maximum weight 
standard index
6 .... 3 4 5 4 4 18.5
8 .... 10 6 18 11 10 21.4
10 .... 20 11 26 20 21 20.0
12 .... 49 24 55 39 37 22.5
14 .... 63 40 95 62 59 22.5
16 .... 116 55 150 89 89 21.7
18 .... 87 85 164 123 127 21.0
20 .... 37 120 213 173 176 21.6
22 .... 22 181 277 230 236 21.6
C
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS
OF PIABA TIRA GOSTO, ASTYANAX SP.
No. Average Calculated
Length of Range in weight empirical weights Condition
fish Minimum Maximum weight standard index
4 .... 143 1 2 1 
1 15.6
6 .... 1,394 2 4 
3 3 13.8
8 .... 576 5 16 6 7 
11.7
10 .... 117 10 22 15 12 
15.0
12 .... 19 16 25 
18 19 10.4
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF SARDINHA,
TRIPOR THEUSANGULATUSANGULATUS SPIx
No. Range in weight Average Calculated Condition
Length of Range inweight empirical weights
fish Minimum Maximum weight standard index
12 .... 25 20 30 24 24 13.8
14 .... 87 21 60 33 34 12.0
16 .... 115 35 75 48 45 11.7
18 .... 125 45 103 65 64 11.1
20 .... 101 67 110 90 82 11.2
22 .... 10 88 116 96 101 9.0
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF TIMBIRO,
PTERENGRA ULIS A THERINOIDES (LINNAEUS)
No. Average Calculated
Length of Range in weight empirical weights Condition
fish Minimum Maximum weight standard index
8 .... 69 2 5 3 3 5.8
10 .... 73 4 8 6 6 6.0
12 .... 60 8 20 10 11 5.7
14 .... 35 12 28 18 18 6.5
16 .... 37 20 33 27 28 6.5
18 .... 11 35 58 47 40 8.0
20 .... 6 52 66 54 57 6.7
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF TRAIRA,
HOPLIAS MALABARICUS BLOCH
No. R w Average 
Calculated Condition
Length of Range in weight 
empirical weights Condition
fish Minimum Maximum 
weight standard 
index
16 ... 22 38 60 51 47 12.4
18 ... 20 50 88 63 67 10.8
20 ... 46 60 260 88 92 11.0
22 ... 65 98 310 121 123 11.3
24 ... 83 120 350 167 160 12.0
26 ... 101 150 370 219 204 12.4
28 ... 67 198 400 252 255 11.4
30 ... 46 200 411 316 314 11.7
32 ... 43 290 510 372 381 11.3
34 ... 23 375 600 461 458 11.7
36 ... 6 420 619 502 544 10.7
38 ... 7 420 700 625 640 11.3
40 ... 8 600 1,020 753 747 11.7
44 ... 5 900 1,260 1,000 995 11.7
46 ... 4 1,100 1,290 1,200 1,138 12.3
LENGTH-WEIGHT RELATIONSHIPS IN CENTIMETERS AND GRAMS OF
TUCUNARE COMUM, CICHLA OCELLARIS SCHNEIDER
No. Average Calculated
Length of Range in weight empirical weights Condition
fish Minimum Maximum weight standard index
8 .... 8 6 10 7 8 13.6
10 .... 12 9 22 13 15 13.0
12 .... 18 20 33 27 25 15.6
14 .... 45 31 48 40 39 14.5
16 .... 65 40 95 58 58 14.1
18 .. . .139 45 125 83 82 14.2
20 ....187 88 163 111 112 13.8
22 .. . .153 110 270 157 148 14.7
24 . . . .112 153 330 211 192 15.2
26 .... 73 163 380 262 242 14.9
28 .... 78 210 550 339 301 15.4
30 .... 83 300 650 408 369 15.1
32 .... 61 400 810 490 446 14.9
34 .... 33 430 860 582 533 14.8
36 .... 19 500 900 610 631 13.0
38 ... 6 600 940 667 740 12.1
40 .... 5 610 1,000 873 860 13.6
42 .... 3 850 1,100 975 993 13.1
44 .... 4 1,000 1,200 1,075 1,138 12.6
48 .... 3 1,100 1,480 1,280 1,470 11.5
LITERATURE CITED
(1) DENDY, J. S., E. W. SHELL AND E. E. PRATHER. 1966. Relatdrio
Inspeao a Curto Prazo do Agude Pereira de Miranda e da Esta!io
de Piscicultura de Amanari. Mimeo, pp. 19-20. Recife, Pernambuco,
Brazil.
(2) GODOY, M. P. DE. 1959. Age Growth, Sexual Maturity, Behavior,
Migration, Tagging and Transplantation of the Curimat'
(Prochilodus scrofa Steindachner, 1881) of the Mogiguassu River,
Sao Paulo State, Brazil. Anais da Academia Brasileira de Ciincias,
Rio de Janeiro. Vol. 31, No. 3, pp. 447-477.
(3) LACLER, F. L. 1969. Freshwater Fishery Biology. W. M. C. Brown
Company Publishers, Dubuque, Iowa. 2nd edition, pp. 159-165.
(4) LECREN, E. B. 1951. The Length-Weight Relationships and Seasonal
Cycle in Gonad Weight and Condition in the Perch, Perca fluviatilis.
J. Animal Ecol. 20(2):201-219.
(5) SILVA, J. W. B. 1969. Sobre o Comprimento e o Peso de Pescada do
Piaui', Plagioscion squamosissimus Heckel, No Agude Pereira de
Miranda (Pentecoste, Ceara, Brazil), Bol. DNOCS, Serie Fomento e
Produy'o, Fortaleza. Vol. 27, No. 1, pp. 59-60.
6
APPENDIX
Estimated Parameters of Length-Weight Equations
Common name
Apaiari
Acara Comum
Bodo
Beiru
Cangati
Curimata comum
Guaru
Jacunda"
Mussum
Piabussu
Pescada do Piaui
Pescada cacunda
Piau comum
Piau verdadeiro
Pirambeba
Piaba tira gosto
Sardinha
Timbiro
Traira
Tucunare' comum
Scientific name
Astronotus ocellatus ocellatus Spix
Cichlasoma bimaculatus (Linnaeus)
Plecostomus plecostomus Linnaeus
Characidium marshi Bredor
Trachycorystes galeatus (Linnaeus)
Prochilodus cearensis Steindachner
Poecilia vivipara Bloch and Schrieider
Crenicichlat saxatilis? (Linnaeus)
Synbranchus marmoratus Bloch
Curimatus morowhannae Eigenmann
Plagioscion squamosissimus Heckel
Plagioscion surinamensis Bleeker
Leporinusfriderici Bloch
Leporinus elongatus
Serrasalmus rhombeus Linnaeus
Astyanax sp.
Triportheus angulatus angulatus Spix
Pterengraulis atherinoides (Linnaeus)
Hoplias malabaricus Bloch
Cichla ocellaris Schneider
Length
interval
16-24
26-30
04-14
16-24
08-14
16-30
12-16
18-22
12-16
18-22
10-24
26-34
36-50
02-06
06-24
12-38
40-58
06-14
12-40
46-66
10-32
08-20
22-34
22-56
06-22
04-12
12-16
18-22
08-20
16-46
08-48
Log (a)
-1.460
0.496
-1.488
-1.721
-1.119
-1.805
-0.197
-1.081
-1.258
-1.236
-1.775
-0.977
-1.963
-1.127
-2.146
-2.682
-3.655
-1.633
-1.932
-2.644
-2.249
-1.718
-1.654
-1.702
-1.761
-1.393
-0.959
-1.032
-2.427
-1.955
-1.774
b
2.945
1.550
2.879
3.068
2.223
2.918
1.641
2.433
2.677
2.633
3.011
2.431
3.100
1.977
3.193
2.818
3.490
2.816
3.017
3.441
3.220
2.904
2.893
2.873
3.080
2.473
2.170
2.262
3.213
3.014
2.939