You should elaborate a bit more on  this I think. For example.

What exactly do you want to analyze? The fish species or the fish age or fish gender or simply the size, weight or whatever, there are many possibilities.

Do you want to perform the analysis fully automatic, semi-automatic or manual?

Which kind of data are you working with? (2D images, color or grayscale or sth else, underwater captures of fish or dead fish photographies ...).

And most importantly: What have you tried so far and where do you get stuck?

There are many ressources available about the truss network (i just attached some of them which i found by a quick google), but it's not possible to give any good advice they way you phrased your question.

http://www.raco.cat/index.php/abc/article/viewFile/132214/182082

http://zoolstud.sinica.edu.tw/Journals/51.7/1195.pdf

http://dergipark.ulakbim.gov.tr/tbtkzoology/article/viewFile/5000029414/5000029651

My research problem is stock structure analysis of selected fishes based on Truss Morphometry. I have digital images of samples and statistical software like tps Dig2 and PAST.

I need a complete procedure for data analysis such as- how to fix Truss Network of Fish, Cluster analysis to find out the groups, Discriminant Analysis to find out the group membership within known groups, Principal Component Analysis is to find linear combinations of the variables and factor analysis is used to analyse the inter-relationship among the truss measurements.

The paper suggested by you is very good, but I am unable to fix the points on software. If there is any online help, I will be very thank full to you.

I will highly oblige if you could consider my request and do the needful.

Thanking you,

Dear Jitendra, tps dig is probably the most ideal software for digitization of the image. there are several online materials, tutorial videos and books for guiding you through the processes. Geometric morphometrics for biologist: A primer is probably a right book for the beginner to understand fundamentals of geometric morphometrics and also how to execute it using freewares [Integrated Morphometrics Package (http://www3.canisius.edu/~sheets/morphsoft.html)] to answer you biological questions and hypothesis.  

Thank you Dear Rajan for Answer...