# Larvae description of S. spilopleura vs



## hastatus (Jan 16, 2003)

Sorry, I can't release the actual photos, but here is the descriptive work photos (drawings). Thought you might find it interesting. This was published in 1997.

This is just one example of the type of scientific research into the growth of baby piranas......nothing new, but still exciting.:laugh:


----------



## hastatus (Jan 16, 2003)

And before anyone asks, those S. spilopleura are now reclassified as S. maculatus from the Parana-Paraguay which is where the study was conducted.


----------



## Grosse Gurke (Jan 3, 2003)




----------



## Kain (Mar 13, 2003)

That's pretty cool Frank. Any ideas what the time span is from the very first drawing on the top left of the picture to the bottom right of the picture?


----------



## hastatus (Jan 16, 2003)

Yes, I have all the data and will be quoting some it here and publishing it at OPEFE in near complete form. It should be helpful and "scientific" but simple enough for everyone to comprehend.


----------



## Death in #'s (Apr 29, 2003)

thanks frank


----------



## hastatus (Jan 16, 2003)

What's even more interesting is that this data report includes 2 different species. That was the basis for the report. For example in Fig 3 (the one on the left = S. maculatus) starting with the top down the measurements are as follows:

a. 7.3 mm sl
b. 8.4 mm sl
c. 9.7 mm sl
d. 11.4 mm sl
e. 14.7 mm sl
f. 27.1 mm sl

For exact measurements science uses Standard Length (tip of snout to end of caudal peduncle). This ensures accurate measurement as opposed to Total Length which is variable and inaccurate for neotropical fishes.

The fishes on the right are S. marginatus and they measure as follows in comparison:

a. 7.2 mm sl
b. 8.7 mm sl
c. 9.6 mm sl
d. 11.6 mm sl
e. 13.7 mm sl
f. 26.6 mm sl

It is a gross error to assume development will follow a set pattern by hours, days, or weeks. Pirana development is variable individualistic and with wild caught based on the feeding specialization which impacts the growth rate.

So lets say for example you have baby larvae that just hatched. They will develop interdependant of each other so that if you take 10 fishes from the same batch you will get various size differences and including growth rates. So a day by day measurement of these 10 fishes will give different rates of growth. You can generalize, but will be inherently wrong.


----------



## Kain (Mar 13, 2003)

Your description of their different growth rate is apparent for my bettas too







I have 2 batches born within a day from one another but the "younger" batch is twice the size of the other. And within that batch, the size difference between them is pretty crazy too. The largest one is about 6 times the size of the smallest. ALso, I didnt know that the pic is of 2 different types of fish. I thought they were all the same fish during different stages.


----------



## hastatus (Jan 16, 2003)

Yes, that is true. When I release the information it should make interesting, educational value. I'm deciding whether or not to release the graphs, they are a bit more technical in nature and unless your into the sciences themselves, it might not be of much use. What the data includes is how each of the fin rays develop, including internal organs. How much of it similar to the separate species, which externally are similar appearing up to a certain size. Then they separate into their own species "look".


----------

