I have 2 questions.
Would 1 to 1.34 # be the original stockers?
What length/weight should I expect to see from the ones that hatched?
I wanted to answer the second question particularly but at the time you posted I had not yet developed a climate model for Moz TP. Finally got around to spending time with it this past week. Two papers contributed to the model they can be found here:
https://www.researchgate.net/public...ation_in_tilapia_oreochromis_mossambicushttps://seafwa.org/journal/1957/further-experiments-tilapia-mossambica-pondfishThe first established growth at 82.5F .... while the second served as a reference for temperature dependent growth.
It is important to understand that after the onset of sexual maturity ... that the gain of males is about double the gain of females. In your initial stocking, the small fish were females from last year's crop while the larger fish were males. It is also important to understand that fish of low relative weight have greater potential to gain weight. So if one of the males was longer but weighed no more than short males which were of higher relative weight ... he would substantially outgrow peers when placed in an environment where food supply was not limited. So TP are often overwintered under conditions of high density and where slow growth is desired on limited ration. This favors smaller fish because each fish has just one mouth and they can get by or grow on rations smaller than the larger fish. This results in shorter fish being of higher RW than longer fish. Anyways, it is likely that the longer of your fish were of lower RW than the shorter ones. Males that were above the average length of males and of the lowest RW had the most potential for growth (in average grams/day).
Below is a chart of
male MOZ TP growth in your climate with an average start weight of .5 lbs. The model is consistent with Swingle's results and your results would be only modestly different that Swingle's. For the growout period, the climate isn't different by alot. But the model assumes 1.4 grams per day at 82.5F. The modeled growth varies throughout the grow-out but from the period from 5.7.25 to 10.26.25 the average growth is estimated at 1.29 grams per day culminating in an average weight of 1 lbs on 10.26.25. I don't go beyond that date because I estimate the growth to be nil after that date due to temps at 60F and below. Assuming females averaged 1/4 lbs at initial stocking ... I estimate that they ... on average ... attained a weight of 1/2 lb on 10.26.25.
Now for the offspring. I estimate that the temps required for successful reproduction initiated around 5/15/25. It's not clear when that temp actually occurred but using that date as the fertilization date and 5/19/25 as the hatch date I estimate that male offspring of that first cohort reached an average weight of 141 grams (~0.37 lbs) by 10.26.25. The females would have been smaller averaging 82 grams (~0.18 lbs) on the same date.
From one of Mister Cody's previous posts he had some over 2#, but not sure how large they were when stocked.
It's not good to judge your observed growth with another species of TP. The appropriate yardstick is how well your Moz TP grew ... climate adjusted ... relative to their average potential for growth. Based on experiences of the two studies above ... the growth is a very high proportion of what their potential is. They grew well indeed. The 1.34 lb Moz TP, IMO, is not what a 1/2 lb Moz TP should be expected to grow to in your climate. Rather it represents an exception that may have had greater individual genetic potential or may have been longer than peers of similar weight at the time of stocking
