February 21, 1998
Approx. 40 tadpoles (Batch 3&4)
The larvae experiment was a failure. By the time the larvae are big enough to see they're too big for the tadpoles. I will continue to breed them for the froglets that I hope to be able to raise. I siphoned the net to remove the dead tadpoles old food and dead eggs that had drifted to the bottom. I didn't transfer any of Batch 5 to the net; I want to see how many tadpoles will survive in the tank.
I am trying another approach to feeding the tadpoles. I am trying a product from HBH Aquarium Products called Frog & Tadpole Bites. The two main ingredients are anchovy and krill. I have crushed the soft pellets into a powder that floats on the surface. It appears that the tadpoles are nibbling at it.
10 tadpoles dead
The remaining tadpoles seem to be eating. I expected some attrition of the tadpoles but not as much as I'm having. My water chemistry has been stable. Perhaps there are a high number of abnormalities, or the food isn't right, or something else I haven't even thought of.
Batch 6 laid
I moved about 25 eggs into the net. Maybe I'll have figured out how to keep the next generation of tadpoles alive.
Frustration! I have not been able to keep tadpoles alive
more that 2 weeks. I have decided on a completely different
Here are the latest developments:
The past six days have had more frustrations
but I think I'm getting on top of things. I have had some
difficulties hatching the brine shrimp. I discovered that table
salt does not work at all. I have had success using Scientific
Grade Marine Salt from Coralife Marine Products. I took
a guess at the ratio of salt to water and got lucky the first
time. My recipe is: 1 level tablespoon of salt to 16 ounces of
de-chlorinated water at a temperature of 84° F. with
gentle aeration for 24 hours. The cysts require high illumination
during the 24 hour incubation period. I am using a 10-inch, full-spectrum
florescent aquarium tube for illumination. The brine shrimp
hatcher is made by New Technology Laboratories, Ltd.
The above setup is why I wanted to avoid breeding brine shrimp! Once the larvae are hatched the real fun begins. The larvae are so small I don't know of any net fine enough the old them. I've had to use coffee filter paper to drain off the brine and preserve the shrimp larvae. Before this can be done the air supply to the hatcher has to be disconnected for 10-15 minutes. This lets the empty shells float to the surface while the larvae move toward the bottom. The hatcher's tubing connects at the bottom which allows the careful draining of the larvae-bearing brine into the filter-lined funnel. Once the brine has drained off the larvae need to be thoroughly rinsed with de-chlorinated water. They can now be fed to the tadpoles or frozen for future use.
Caution: Be very careful when you work with brine. It is electrically conductive so be sure that no brine is able to leak or drip into electrical devices or outlets. Keep your brine solution away from your freshwater tanks. Too much contamination of your fresh water aquarium will kill your fish and frogs. Rinse all utensils thoroughly before using them in fresh water. The best technique is to have a separate set of utensils for the brine and never use them in your fresh water setup.
45 + tadpoles (Batch 11)
I have had a record high for egg viability and hatch out. Unfortunately it's hard to determine what factor(s) to attribute this to since I made so many changes at one time (see my list from March 9). I am continuing to add Liquifry No. 1 twice daily. The tadpoles seem to respond to the Liquifry in the water and swim near the surface in semi-circular patterns. I have added a small amount of algae to the net to encourage the infusoria to grow there. I have observed one of the older tadpoles (from Batch 10) nibbling at strands of algae. It's not clear whether he's eating the algae or is after something that is growing on it.
A note on brine shrimp larvae: I found out today that one of my local aquarium shops sells frozen larvae. I discovered this by accident while talking to one of the clerks about my frog project. It had never occurred to me that a retailer would sell the larvae. This shop (Fin & Feather in Seattle) caters to breeders more than other shops do and has more of a demand for specialty foods.
45 + tadpoles Batch 10/11 (hatched 3/10)
I learned a lesson with the last batch: tadpoles will stick to eggs. I placed about 50 eggs from Batch 12 into the net. I observed that the older tadpoles were sticking to the jelly layer after coming into contact with it during the course of their swimming near the surface. I transferred the eggs to a glass container to prevent more stress to the older tadpoles but I think I badly affected the developing eggs as only 14 hatched. I have lost only a few from Batch 10/11 due to a move of the aquarium which resulted in several tadpoles being stranded on the edge of the net. A couple more died probably as a result of stress from being stuck to the eggs. All the remaining tadpoles appear healthy.
55 + tadpoles - Batch 10/11/12
Approximately 8 tadpoles have died over the last 3 days. They all appeared to be different in size so I'm assuming that they were different ages too. I placed brine brine shrimp larvae in the net last night since I probably have at least a few tadpoles that are ready for them.
It has crossed my mind recently that the Liquifry No. 1 is only useful for encouraging the growth of infusoria in the tank rather than as a direct food source for the tadpoles. I have been concerned that the other ingredients in the Liquifry (flour, yeast, egg) don't have any nutritive value for the tradpoles and may actually interfere with their ability to feed on infusoria. As of this morning I have stopped using the Liquifry and have started adding an infusoria culture from the recipe in this article. I examined a drop of my 3-day old culture at 100X magnification and verified that it was teeming with protozoa. There are two things not mentioned in the article that you should be aware of:
1. The culture became acidic. My culture went from a
pH of 7.8 to 6.5 within 48 hours. I used sodium bicarbonate
(baking soda) to bring the pH back to 7.8 before adding any to
the frog tank.
The tadpoles responded well after I added several mls. of the culture to the net. They went into what I think of as "feeding mode": swimming quickly near the surface in a combination of straight and semi-circular patterns. With 10X magnification their mouths can be seen opening and closing rapidly.
I have transferred about 8 tadpoles from the tank into the net. Judging from their size they all appear to be from Batch 12.