Spawning of Tropical Fish

So, our project is on tropical fish. We will focus on guppies because guppy fry is readily availabble, so we
can run a test on the growth rate of guppy fry and what factors effect it.
Here's the deal. We've bought the fry, seven
or eight little guys that are raring to go as we speak,
and the experiment is underway and going well. We expect
to see plenty of growth, even in the small time we
have, as the fry are only 10 days old and already growing
like crazy. Read more to see how the experiment works and
to find out more about guppies.

The purpose of this experiment is to dtermine how different fish foods effect the growth of guppy fry.

To perform this experiment, we will need:
- 3 seperate breeding traps
- a 10 gallon aquarium
- a 50-100 watt aquarium heater
- a small aquarium filter, low current
- spirulina flakes
- Nutrafin powdered fry food
- First Bites powdered fry food
- aquarium gravel, etc.
- 7-10 guppy fry


First, we'll set up the seperate breeding compartments that the fry will live in. We'll add a little gravel
to the bottom of the traps,as some of them are designed to allow the fry access to the outside through the bottom.
This done, we will stabilize the water conditions: Temperature: 80 degrees pH: 7.0-7.5This done,
we will now introduce the fry to the tank. We'll divide them evenly into the different compartments and begin
feeding them their designated foods 2-3 meals per day. Trap A will recieve Nutrafin, Trap B will eat First Bites,
and Trap C will enjoy a vegetarian diet of spirulina flakes. The fry will eat only their designated food. After 1-2 weeks of close observation,
we will try to determine which fry have grown the most. It should be fairly distinctive, as they're only a week
old and already growing like maniacs.
external image Livebe11.jpg
This is a really interesting pic. Guppies are livebearing fish, meaning they (the females) carry eggs until the spawn, and then release them when they finally decide that the fry are ready to become free-swimming. This is what happens when they aren't quite ready. Unhatched eggs. The ones that don't hatch on time have little chance of survival.
(Picture courtesy Larry Arnold, Aqualand Pets Plus.)
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This is what the ones that do make it look like. This picture cannot stress just how small they really are, about the size of mosquito larvae when newborn.
(Picture courtesy )


Ben's Thoughts:
I think the spirulina(vegetarian) will induce the fastest growth rate in the fry, as it has the most fiber by far.
The body needs fiber for energy, energy for excercise, and excercise for growth. Go spirulina!

Trevor's Thoughts
Well, First Bites fry food has the most protein, and protein is essential for growth, so I think the First Bites
will make the fry grow faster because of the high protein content.

Here's the nutritional info for the fry foods we're using:
Protein Fiber Oil Moisture
Nutrafin 46% 2% 4.6% 8%
Spirulina 45% 10% 4.6% 8%
First Bites 54% 0.8% 6.7% 10%
Don't forget to check out Ben's other space at
external image Livebe6.jpg
(Pic courtesy Larry Arnold, Aqualand Pets Plus).
Here's a shot of a male guppy. You can tell that he's a male by the fin with the arrow. See the shape? Now look at the female at the bottom of the next pic. The anal fin is triangular on the females, straight on males.
external image Livebe10.jpg
(Pic courtesy Larry Arnold, Aqualand Pets Plus).

external image Livebe8.jpg
(Pic courtesy Larry Arnold, Aqualand Pets Plus).
Here's a 'hybrid' guppy. This is what happens when you take a male guppy of one bloodline, and a female from another, and cross-breed them. You end up with a half-breed, long-finned variety of guppy. Pretty, but the value goes down when people see that the bloodline is impure. People pay a lot of money for guppies that are bred from a pure bloodline.
external image Livebe79.jpg
Here's a nice show guppy. Really fancy colour pattern, probably pure-bred. My favourite male guppy, the one that fathers most of my guppy spawns, looks a lot like this. That always leads to some weird colour combinations.
(Picture courtesy Larry Arnold, Aqualand pets plus).
external image Livebe13.jpg
Beautiful show guppy here, pure-bred. See the long dorsal fin?
(Pic courtesy Larry Arnold, Aqualand Pets Plus.)


Well, Trevor outsmarted me as far as the hypothesis went, proving that protein is absolutely vital to healthy growth, even in tropical fish such as guppies. After reviewing the nutritional information on the foods we used in the experiment, Trevor thought that the food that was highest in protein would make the fry grow faster after an extended period of eating only that food, while I believed that the food highest in fiber would induce a faster growth rate. I was dead wrong. In fact, the fish eating the food that packed more fiber (pulverized spirulina) was the group that grew the slowest. There was a full 10% less protein in the spirulina, which had a bigger impact than I guessed on the growth of the fry. First Bites powdered fry food, while having a very small amount of fiber, had more protein than any of the others, and the fry eating First Bites definitely grew the fastest. They were also showing bolder colours than the other fry, and were a little more lively. The other thing we noticed was that when we fed the fry the First Bites, the ate it all. The other fish didn't finish their meals as often or as quickly, and we made sure that the feedings were even to ensure the accuracy of the experiment.
In conclusion, First Bites powdered fry food is definitely one of the best commercial foods to feed newborn fry.


This particular species has been popular in aquariums since the early 1900's. It is one
of the best known aquarium fish in existence. But what do we really know about guppies?
Well, they're also known as Millions fish, but they're original name is Poecilia
reticulata. They belong to the family Poeciliidae, the subfamily being poeciliinae.
We also know that guppies, like other poecilids, are livebearers. This means that they
give birth to live fry, instead of laying eggs. A pregnant female guppy can produce
150 fry every 4 to 6 weeks.
So what else is there to know?
Max size: Not over 2 inches.
Diet: Guppies accept all foods. They really go for frozen bloodworms, I find.
Behaviour: Peaceful. Doesn't mix well with larger, more aggressive fish.
Mostly found North of the Amazon, later introduced to several other subtropical