February 21, 1998 

Approx. 40 tadpoles (Batch 3&4) 
8 tadpoles dead 
Batch 5 laid-50 eggs 

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. 

February 22 

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. 

February 23 

10 tadpoles dead 
28 tadpoles 

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. 

February 25 

Batch 6 laid 
20 tadpoles 

I moved about 25 eggs into the net.  Maybe I'll have figured out how to keep the next generation of tadpoles alive. 

March  3

Frustration!  I have not been able to keep tadpoles alive more that 2 weeks.  I have decided on a completely different approach:
1. I have done away with the net enclosure.  It's possible that there is not enough water moving through the net which is causing a build up of bacterial toxins.  The last two batches (7 & 8) I have left undisturbed in the tank.  I have observed several tadpoles alive in the tank over the last several days.  I have been adding the Liquifry twice daily.
2. I am now culturing brine shrimp.  I didn't want to have to do it but it's the only food that has worked in other breeding projects (RABB, 1963).  I am using a product from M&M Suppliers called Artemia Cysts (Grade B).  The lower grade gives a lower hatch out (75%) but it's less expensive than the Grade A.  I have produced one crop of larvae and put most of it in the tank.  My next crop should be ready tonight.

March 9

Here are the latest developments:
1. I have returned to using the net.  My last three batches of eggs have been eaten (as far as I can tell) by the adults.
2. I did a 75% water change since I hadn't done one in nearly two months.
3. I have lowered the temperature to 75° F. to reduce the level of abnormalities in the developing eggs.
4. Batch 11 is in the net and due to hatch by tomorrow.

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.
To make this whole thing work I am using a 1-gallon plastic container that is three quarters filled with plain water. A 50-Watt aquarium heater is set to keep the water at 84° F.  The brine shrimp hatcher filled with the brine solution with half a teaspoon of cysts is mounted inside the container with its air tube connected to a small air pump via a flow control valve.  

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.

March 13

45 + tadpoles (Batch 11)
2 tadpoles from Batch 10
pH: 7.8

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.

March 16

45 + tadpoles Batch 10/11 (hatched 3/10)
14 tadpoles Batch 12 (hatched 3/16)

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.

March 20

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.
2. The culture contained ammonia (NH₃).  Even though my culture was started with water from the tank (which has a full nitrogen conversion cycle), there was still an ammonia build up of about 3 ppm.  This probably isn't enough to affect the tadpoles but I played it safe and added some AmmoLock II to convert the ammonia to NH₄.

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.