2. Prepared By:
Md. Shanoer Hossen
FMRT Discipline
Khulna University
Thesis title: Length weight relationship, condition factor & fecundity
estimation of Mystus Vittatus in different month.
3. INTRODUCTION
Mystus vittatus is an important edible fresh water fishes of
Bangladesh. It is locally familiar with the name Tengra and
Gholsa Tengra.
Small Indigenous Species have a high nutritional value in
terms of both protein and presence of micronutrients,
vitamins and minerals.
There are not so many literatures on the different biological
aspects of M. vittatus in Bangladesh.
Considering the commercial importance of the species,
adequate research in this field is required.
4. i) To estimate the monthly variation of length weight
relationship & condition factors of Mystus Vittatus.
ii) To identify peak breeding time through fecundity
estimation.
OBJECTIVES OF THE STUDY
5. MATERIALS AND METHODS
Sample collection
Randomly
More than 700
From Gollamari,Shondha Bazar,Rupsha,Notun bazar fish
market
Measurement of total length, standard length and body weight
6. MATERIALS AND METHODS
Experimental design
- Completely Randomized Design
Experimental design: Variables
Dependent variables: (i) weight (ii) Egg
Independent variables: (i) Length (ii) Body weight & gonad
weight
Control variable: Same weight machine , Same scale , Same
laboratory
Statistical analysis
Pearson Correlation through SPSS or Excel
For fecundity estimation poisson distribution test
7. MATERIALS AND METHODS
Length – weight Relationship
It has been found that the length – weight relationship of most fishes can be
described satisfactory by the following relationship given by Le Cren, (1951).
W = a Ln …………………………………. (I)
Where ‘a’ is a constant or intercept and ‘n’ is an exponent
Condition factor (K)
The condition factor can be calculated (Le Cren, 1951) by the following
formulas ;
. . . . . . . . . . . . . . . . . . . . . (III)
Here,W=Weight (g), L=Length (cm) and K=Condition factor
8. MATERIALS AND METHODS
Measurement of egg weight & number
Fig: Measurement of weight & petri dish for counting eggs
Fecundity estimation
The fecundity was obtained by using following formula (Lagler, 1952)
N x Gonad weight
F =
Sample weight
9. Table: Different relationships, equation, condition factor (b) and
coefficient of determination (R2). of M. Vittatus.
RESULTS AND DISCUSSION
Month
Length-length relationship
Linear Regression equations and Regression parameters
Equation A b R2
January TL-BW Log BW = 2.26TL – 1.193 - 1.193 2.26 0.50
February TL-BW Log BW =1.93TL – .821 -.821 1.93 0.52
March TL-BW Log BW = 2.10TL – 1.018 -1.018 2.10 0.64
April TL-BW Log BW = 2.50TL – 1.456 -1.456 2.50 0.61
January SL-BW Log BW = 1.52SL – .26 -.26 1.52 0.41
February SL-BW Log BW =1.40SL – .16 -.16 1.40 0.30
March SL-BW Log BW = 1.49SL – .20 -.200 1.49 0.40
April SL-BW Log BW = 1.45SL – .179 -.179 1.45 0.30
10. Graphical presentation among different parameters of M. vittatus
1
1.1
1.2
1.3
1.4
1.5
1 1.05 1.1 1.15
LogBW
LogTL
BW-TL relationship in january
1
1.1
1.2
1.3
1.4
1.5
0.95 1 1.05 1.1 1.15 1.2
LogBW
Log TL
BW-TL relationship
1
1.1
1.2
1.3
1.4
1.5
1 1.05 1.1 1.15
LogBW
Log TL
BW-TL relationship in March
1
1.1
1.2
1.3
1.4
1.5
1 1.05 1.1 1.15
LogBW
Log TL
BW-TL relationship April
11. Graphical presentation among different parameters of M. vittatus
1
1.1
1.2
1.3
1.4
1.5
0.9 0.95 1 1.05 1.1
LogTW
Log SL
BW-SL relationship in january
1
1.1
1.2
1.3
1.4
1.5
0.9 0.95 1 1.05 1.1 1.15
LogBW
Log SL
BW-SL relationship in February
1
1.1
1.2
1.3
1.4
1.5
0.9 0.95 1 1.05 1.1
LogTW
Log SL
BW-SL relationship in March
1
1.1
1.2
1.3
1.4
1.5
0.9 0.95 1 1.05 1.1
LogBW
Log SL
BW-SL relationship in April
12. Total length of the specimens ranged from 10.6 cm to 14.3cm.
The lowest fecundity was found at 18,210 and the highest was at 44,620 in the
sample of total length of 10.6 cm and 14.3 cm.
A positive and linear relationship was found between fecundity and total length and
standard length
Fecundity Estimation
y = 2.1471x + 2.1553
R² = 0.4924
4.2
4.25
4.3
4.35
4.4
4.45
4.5
4.55
4.6
4.65
1 1.05 1.1 1.15
Logfecundity
Log TL
Fecundity-TL relationships
y = 1.8943x + 2.5643
R² = 0.5094
4.2
4.25
4.3
4.35
4.4
4.45
4.5
4.55
4.6
4.65
0.9 0.95 1 1.05 1.1Logfecundity
Log SL
Fecundity-SL relationship
13. Fecundity Estimation
The average fecundity was observed to be 32,142.
There was also found a positive and linear relationship between fecundity
and body weight as well as gonad weight.
