The analysis of the results below uses only the data couples (weight + length). The weight-only are not used.The point cloud below allows us tu process the theoric chart of te weight/size ratio for the species of the studbook.
Process of the theoric chartData are adjusted with a 3rd degree polynom, i.e. it is such as y = a + bx + cx² + dx
3We use the mathematic formulas of the least squares to get 4 equations with 4 unklnowns a, b, c et d :

Thus :4174 = 45
a + 334.2
b + 2627.14
c + 21580.512
d35028.1 = 334.2
a + 2627.14
b + 21580.512
c + 183328.9654
d301956.45 = 2627.14
a + 21580.512
b + 183328.9654
c + 1598138.48352
d2657896.693 = 21580.512
a + 183328.9654
b + 1598138.48352
c + 14215620.211294
dWith the Gauss pivot we get :4174 = 45
a + 334.2
b + 2627.14
c + 21580.512
d4029.1933333333 = 0
a + 145.148
b + 2069.6189333333
c + -158201.65018667
d58274.619777778 = 0
a + 2069.6189333333
b + 29954.196964444
c + 338249.01028267
d656184.31326667 = 0
a + 23057.69628
b + 338249.01028267
c + 3866320.2516908
dthen :
4174 = 45
a + 334.2
b + 2627.14
c + 21580.512
d4029.1933333333 = 0
a + 145.148
b + 2069.6189333333
c + -158201.65018667
d823.64002795575 = 0
a + 0
b + 444.16217780022
c + 2593995.7688388
d16120.956324777 = 0
a + 0
b + 9476.6897537048
c + 28997673.084654
dthen :
4174 = 45
a + 334.2
b + 2627.14
c + 21580.512
d4029.1933333333 = 0
a + 145.148
b + 2069.6189333333
c + -158201.65018667
d823.64002795575 = 0
a + 0
b + 444.16217780022
c + 2593995.7688388
d-1452.3117376378 = 0
a + 0
b + 0
c + -26348086.532828
dThus :d = 5.5120197659452E-05b = 5.9685006883698c = 1.5324548159878a = -41.06301772032We get the chart below (in red) :y = -41.06 + 5.97 x + 1.53 x² + 0.00 x
3simplified by (in green) :y = 5.97 x + 1.53 x²
Bodymass index (BMI) of all the Cuora mccordi
BMI = Weight (g) / size² (cm.mm)
Histogram of the distribution of the BMI of all the Cuora mccordi
Histogram of the distribution of the BMI of all the Cuora mccordi juveniles
Histogram of the distribution of the BMI of all the Cuora mccordi adults

The Bodymass index (BMI) is "the weight divided by the square of the size". Do it for yourself with your size in m,cm and your weight in kg, You will get a value between 20 and 25. A value above is said an overweight (and the same goes below 20). It is a good index, ask your doctor.
Mean of the BMI of the Cuora mccordi : 1.48Standard Deviation of the BMI of the Cuora mccordi : 0.51