Tadpoles

We do not track the type of tadpole that are sent in each shipment. Species identity should be indicated on the bag label. 

Why did my tadpoles die and how can I care for my new shipment?

Most often when you have complete loss of a shipment soon after arrival and transfer to a new tank, it is due to toxic materials in the water. Did you use treated tap water? If so, there may be contaminants in your tap water that are not suitable for tadpole survival. We are seeing this more and more. If tap water is used, water conditioner must be used, but there are some sanitizing chemicals in some tap water supplies that the water conditioner does not remove.

To avoid this problem, we recommend using bottled natural spring water for tadpoles. Deer Park and Poland Spring are nationally distributed brands that we have used with tadpoles successfully. Collected rainwater is also an option many customers choose.

Beyond what is discussed on our care guide for tadpoles found here: https://www.carolina.com/teacher-resources/Interactive/living-organism-care-guide-tadpole/tr10550.tr, we can offer the following advice.

Tadpoles have a very low survival rate, even in the wild. You can improve your chances of success with them by taking some additional steps.

Small Tadpoles need at least 1 quart of water per tadpole for optimal development(bullfrog tadpoles need 1 gallon per tadpole). Surface area of the container is more important than depth. We use baby pools here with bubblers but any shallow container of an appropriate volume for the number of tadpoles you have will work fine. Some appropriate containers would be plastic storage boxes or shoe boxes. Depth should be anywhere from 3-6 inches depending on the type of tadpoles you have. 

Optimizing the surface area to volume ratio in housing improves oxygen turnover in the water, which helps the tadpoles be more active and helps you avoid problems with bacteria buildup. With a smaller container, you will need to be diligent about your water changes to ensure that water quality remains at the very highest level.

Water needs to be changed when it becomes fouled. Indications that a water change is needed are cloudy appearance, unpleasant odor, tadpoles lingering at the top of the container, and waste settling to the bottom.

As far as food goes, they really don’t eat very much and when they do eat, it can be hard to detect. You can offer the tadpole bites as well as parboiled greens to see if they prefer one food over the other.

Of course, if you are doing most of these things, you will still lose some, but having the best possible water quality, will improve your chances of success with some. 

Care guide

Caution
[body]
This care sheet provides general information only for handling Carolina™ bacterial cultures. When you work with bacteria, it is imperative that you use sterile techniques at all times. Failing to use sterile techniques can contaminate cultures and work areas, and cause health and safety risks. See our Carolina™ Techniques for Studying Bacteria and Fungi Manual (item #154664) for descriptions of sterile techniques and standard practices for handling bacterial cultures.
[subhead]
Immediate care and handling
[body]
When your bacterial cultures arrive, immediately open the shipping container and remove the cultures. We ship cultures in tubes, plates, and as MicroKwik Culture® freeze-dried cells. Visually inspect each culture. Ensure that tubes are intact with caps securely in place, plates have no cracks and lids are secured by tape, and plastic bags containing MicroKwik Culture® cells are securely closed with the enclosed tube and vial intact.

You must seal any culture damaged during shipment—and anything it contaminated—in an autoclavable bag, and then sterilize it by autoclaving or soaking all contaminated materials in disinfectant. Note: Never discard a damaged, unsterilized culture in the trash. Know and follow your school or district’s guidelines for proper disposal. Contact our Customer Service at 800.334.5551 for a replacement of your damaged culture. It will help to have your order number available when you call.

Hold most cultures at room temperature, 20 to 22° C (68 to 73° F). For tube cultures, loosen the cap and keep the culture tube upright in a test tube rack or beaker. For best results, use cultures within 3 to 5 days of receipt; however, most bacterial cultures remain usable for up to 4 weeks when held at room temperature. Keep in mind that Carolina provides a variety of bacterial cultures and some have very specific care and handling needs that differ from these general guidelines. Vibrio fischeri, for example, must be kept in the dark and subcultured 2 to 3 times per week to maintain bioluminescence.

[subhead]
Maintaining and culturing
[body]
Eventually your bacterial culture will deplete the nutrients of the medium in or on which it is growing and will need subculturing. Before working with bacterial cultures, wash your hands with soap and water, ensure that the work area is draft free, and wipe the work surface with 70% alcohol or similar disinfectant. Note: Always check the culture for signs of contamination immediately prior to using. Never work in an area where food is prepared or consumed.

Transfer broth cultures to fresh broth using a sterile pipet or loop or streak onto agar using a sterile inoculating loop. For faster growth, you can incubate most cultures at 25 to 30° C (77 to 86° F). After making the transfers, clean the work area with disinfectant and wash your hands again. Either autoclave the old stock cultures and glassware, or cover them with disinfectant overnight. We recommend the use of Clavies® Autoclavable Bags (item #831642) for disposal.

[subhead]
Biosafety
[body]
In the US the CDC (Centers for Disease Control) sets standards for the safe handling of microorganisms according to their Biosafety Level (BSL). There are 4 Biosafety Levels with BSL-1 being the lowest risk microorganisms and BSL-4 being the highest risk. Bacterial cultures provided by Carolina Biological Supply Company fall into BSL-1 and BSL-2. Our catalog and online listings identify BSL-2 bacterial cultures as pathogens. They are only available as MicroKwik Culture® freeze-dried cells, and we can only ship them to colleges and universities. Cultures not identified in our listings as pathogens are BSL-1.

The CDC standards for working with BSL-1 microorganisms include the following:
[bulleted list]
Follow all standard microbiological practices.
Work can be performed on an open lab bench or table.
Wear personal protective equipment (PPE), i.e., lab coats, gloves, and eye protection, as needed.
A sink for hand washing.
Doors that separate the lab room from the rest of the facility.

For working with BLS-2 microorganisms the CDC recommends all of the above, plus the following:
[bulleted list]
Restricted access to the lab room while cultures are being used.
PPE to include face shields as needed.
All procedures that can produce a splash or an aerosol must be performed within a biological safety cabinet.
An autoclave or other method of decontamination for proper disposal.
Self-closing doors that separate the lab room from the rest of the facility.
An eyewash station.

For a fuller discussion of CDC criteria for handling microorganisms see the following link: http://www.cdc.gov/biosafety/publications/bmbl5/bmbl5_sect_iv.pdf [link].

[subhead]
FAQs
[body]
Which agar should I use for my bacterial cultures?
In Carolina’s print and online catalogs, the product descriptions for our bacterial cultures include the type of nutrient medium that we use for each culture. This information also appears on the label affixed to the culture. A wide range of bacteria will grow on Nutrient Agar (item #821862) and Tryptic Soy Agar (item #822022).

Can I pour my own plates if I don’t have an autoclave?
See our Nutrient Agar Bottle (item #776360) and other prepared media bottles. A bottle containing 125 mL of medium will pour 4 to 5 standard 100 × 15-mm plates. Watch our “How to Melt and Pour Agar Plates” video (at www.carolina.com) for a demonstration of the technique.
Should I order a tube, plate, or MicroKwik Culture®?
Tube cultures are best for stock. A tube culture is often streaked on a plate and incubated before lab use. Order a plate culture for convenience and immediate use. You can receive a plate culture and use it in a lab on the same day. A MicroKwik Culture® is best used for longer-term storage and to receive a culture of a pathogen. A MicroKwik Culture® can be held at room temperature for up to 2 months before being activated or for 6 to 8 months refrigerated.

Which cultures should I order for antibiotic testing?
Gram-positive and Gram-negative bacteria often give different results when tested against the same antibiotic. For that reason, we recommend testing against Bacillus cereus (item #154872), which is Gram-positive, and Escherichia coli (item #155068), which is Gram-negative. We recommend broth cultures because this makes it easier to spread the culture over the surface of an agar plate. See our Carolina BioKits®: Antibiotic Sensitivity kit (item #154740) for more information.
You recommend holding a culture at room temperature, but the recommended temperature for Escherichia coli (item #155065) is given in your catalog as 37° C. Why is that?
Thirty-seven degrees C is the incubation temperature, the temperature needed for maximum culture growth. The culture is mature when we ship it out and does not need further incubation. Maintaining the culture at room temperature allows you to hold it longer before use.

Care guide

Salmonella precautions

Always wash your hands after touching an amphibian or any part of an amphibian’s habitat. For more information, see our “Amphibians, Reptiles, and Prevention of Salmonella Transmission” statement.

Immediate care and handling

Open the shipping container as soon as it arrives and acclimate the tadpoles to holding pails or habitats immediately.

Allow 50 to 60 minutes for acclimation. Have a habitat or holding pail made of glass, plastic, or stainless steel prepared with room-temperature water before proceeding. Use spring water, pond water, or dechlorinated tap water only. Spring water is available from Carolina (item #132458) or your local grocery store. If you buy spring water at the store, read the label carefully to be sure it contains no additives. If you use tap water, you must treat it first with a chemical water conditioner (such as item #971160, #672291, or #672292) to remove chlorine and chloramines.

To acclimatize your tadpoles:

1. Float the bag in the holding pail or set the bag next to the habitat.

1. After 20 to 30 minutes, remove about 1/4 of the water from the bag and replace it with water from the holding pail or habitat.

1. Wait 15 minutes and then repeat step 2.

1. After another 15 minutes, position a net over an empty cup or bucket (not the holding pail or habitat) and gently pour the tadpoles from the bag into the net. Transfer the netted tadpoles to the holding pail or habitat and discard the shipping water and shipping bag. Your tadpoles are now acclimated to their new environment.

Habitat setup and maintenance

Shallow trays, aquariums, and large culture dishes are all suitable tadpole habitats. Keep tadpoles in glass, plastic, or stainless steel only.

Clean the habitat with hot water before use, but do not use soap or detergent. Native tadpoles generally live in shallow water, so fill the habitat to a depth of 2 to 5 cm (3/4 to 2”). Bullfrog tadpoles can have a water depth of 8 to 13 cm (3 to 5”), and Xenopus tadpoles should have a depth of 10 to 20 cm (4 to 8”). Remember to always use spring water, pond water, or tap water that has been treated with a chemical water conditioner.

Change 1/4 to 1/3 of the water 2 to 3 times a week, or more often if it becomes cloudy. Be sure that any water you add matches the temperature of the current water. We do not recommend a filter, since it may suck up the tadpoles. A small aquarium pump with an air stone or other bubbler will help keep the water oxygenated. Keep the habitat at room temperature, away from heating or cooling vents, and out of direct sunlight.

Once a week, clean and rinse all habitats and utensils in hot water, without soap or detergent. Transfer the tadpoles to a holding pail while you clean the habitat.

Tadpoles can tolerate a wide range of temperatures but not a sudden temperature change. Never transfer tadpoles to water that differs in temperature by more than 1 to 1.5° C (2 to 3° F).

For maximum growth, put no more than 30 small tadpoles in every 4 L (1 gal) of water. As the tadpoles grow, decrease the population density by setting up more habitats and dividing the tadpoles among them.

Care and feeding

Most native tadpoles are vegetarian and live on a variety of plant materials. You can add aquatic plants such as Elodea (item #162101) to the habitat for decoration and as a food source. Provide enough light for the plants to carry out photosynthesis, but always avoid placing the habitat in direct sunlight.

Our Tadpole Food (item #146500) is an excellent food source for native tadpoles. Other options include pelleted rabbit food, fish food, and algae supplemented with finely powdered beef liver or powdered egg yolk. Parboiled lettuce and spinach are also suitable, but you should supplement them with other foods; tadpoles fed exclusively on lettuce or spinach may develop tumors. Xenopus tadpoles are filter feeders and will eat our Xenopus Tadpole Food (item #146501), nettle powder, or pea soup.

Do not feed more than the tadpoles can consume in a few hours. If your tadpoles are newly hatched from eggs, wait to begin feeding them until they are actively swimming. For 2 to 3 young tadpoles, a small pinch of food every other day is a good starting point. The amount you feed will depend on the size and number of your tadpoles, so it may require some trial and error. Increase the amount of food you provide as the tadpoles grow.

Remove any uneaten food from the habitat a few hours after every feeding. You may find that a pipette, turkey baster, or aquarium siphon makes it easier to remove the uneaten food, but be careful not to siphon up or injure the tadpoles.

After the front limbs appear, tadpoles may stop eating. This is because they are literally digesting their tails and need no additional food. Tadpoles also develop lungs at about the same time as their front limbs, and they will need a way to reach the air to breathe. Add a flat rock or other object to the habitat once the tadpole has hind limbs, so that it will be able to climb out as it matures. (Xenopus are completely aquatic, so they don’t need a way out of the water.) Frogs can climb on almost any surface, but toads need a surface that provides traction. Spring peepers are excellent climbers and will escape from any container that does not have a lid.

Frog habitat

Once frogs or toads are crawling out of the water with their tails mostly gone, move them to a terrarium. (Xenopus are completely aquatic; keep them in an aquarium as you would goldfish.) The terrarium should have a sand substrate and a source of water.

For frogs, put about 5 cm (2”) of clean sand in the bottom of the terrarium and bulldoze it to one end to create a land side and a water side. The depth of water depends on the size of the frogs, but it should be a few centimeters at most. Toads are terrestrial and can drown if they are trapped in water, so cover the bottom of their terrarium with clean sand and place a shallow dish of water on top. Keep the terrarium at room temperature and away from direct sunlight.

Native frogs and toads need live insects to eat. Start by offering them fruit flies, then add small cricket nymphs as the frogs grow. Larger frogs and toads can be fed redworms (small whole worms or chopped pieces), waxworms, mealworms, and crickets. Feed frogs and toads 2 to 3 times a week. Once or twice a week, dust the insects with a commercial vitamin/mineral supplement prior to feeding.

Xenopus frogs do not need live food. You can feed them pelleted food such as HBH Frog & Tadpole Bites (item #146503).

For additional information, see our Carolina™ Reptiles and Amphibians: Care and Culture manual as well as our individual Small Toad Carolina™ CareSheet, Tree Frogs Carolina™ CareSheet, and Xenopus Carolina™ CareSheet.

FAQs

How do I know if I have Xenopus tadpoles?

Unless you raised Xenopus tadpoles from the egg stage, you probably have tadpoles of a native frog or toad. Native tadpoles are heavily pigmented. Xenopus tadpoles, especially in early stages, are nearly transparent.

What species of tadpole does Carolina have?

We ship a variety of species depending on seasonal availability. In general, spring peeper tadpoles are available in the early spring, followed by toads and then grass frogs. In the winter we may send lab-reared grass frog tadpoles. Refer to any information that came with your order for the exact species you received.

Our tadpoles are now frogs. Can we release them into a pond?

No. A frog may be native to North America, but it may not be native to your area. Do not release Xenopus into the environment because it is not native and could damage native amphibian populations. Your state Department of Natural Resources or Department of Wildlife can advise you on relevant laws, guidelines, and regulations.

Our tadpoles are dying. What can we do?

Rushing the acclimation procedure can kill the tadpoles. Also, soap and detergent can leave a toxic residue.

You can try switching to a different water source. Tap water can have toxic metal ions, spring water from a grocery store might contain trace contaminants, and locally collected spring or pond water might contain a pollutant.

When performing water changes, be sure that the new water is the same temperature as the old water. It is also less stressful for tadpoles if you change small amounts of water more frequently, rather than changing a large amount of water all at once.

Unfortunately, the death rate of native frog tadpoles is often extremely high, even if you do everything right.

How long before the tadpoles become frogs?

Spring peeper and toad tadpoles transform into small adults in 6 to 8 weeks. Other species, including Xenopus, take from 10 to 14 weeks. Bullfrog tadpoles may take from 4 to 18 months to metamorphose.

Problems?

We hope not, but if so, contact us. We want you to have a good experience.

Orders and replacements: 800.334.5551, then select Customer Service.

Technical support and questions: caresheets@carolina.com