Egg Care Sheet
What to do when your frogs lay eggs:
When your frogs lay eggs, your choices in most cases are to either let the parents care for themselves and transport the tadpoles to water or pull the eggs from the vivarium at some point and hatch the tadpoles out yourself. This caresheet covers the latter option and can be used successfully for the eggs of most dart frogs with the exception of obligate egg feeders such as pumilio.
If you are planning to remove the eggs and care for them yourself, you should allow for 24-48 hours after the eggs are deposited before you remove them from the viv. This will give the male adequate time to fertilize the eggs. However if you are confronted with egg eating behavior by competing females in a community tank, your options are either to shorten this time window or move the breeding pair to a separate setup.
Dart frogs lay eggs in a variety of places and most successful breeders will provide for multiple spawning sites and discover over time the preferred locations of their frogs. Terrestial frogs such as auratus, tincs, azureus and leucs tend to spawn either on broad leaves or under an enclosure such as a cocohut. Placement of a petri dish under a coco hut provides for an egg laying surface that is easily removed. Medium sized dart frogs such as E. tricolor/anthonyi, vittatus and castaneoticus have been known to lay on leaves, including smaller ones that will support their weight, bromeliad axils, film cannisters and less frequently under cocohuts. Thumbnail species have the most diverse egg laying practices and eggs can be found in film cannisters (water filled and not) kept at various angles, leaves, bromeliad axils and on the glass of the vivarium.
How to tell good eggs from bad ones:
The appearance of dart frog eggs varies across species. Some dart frogs have dark gray to black eggs and their development can be followed as described below. However others such as galactonotus, castaneoticus, quingquevittatus and imitator have white eggs and their development is a bit more difficult to assess in the early stages.
For frogs whose eggs ultimately end up as gray/black, fertile eggs will initially show a bipolar hemispheric distribution of black/white as shown below...
E. tricolor/anthonyi 'salvias' egg clutch...note the black/white hemispheres representing the animal and vegetal poles of the egg
Over time the black coloration covers the entire egg and a thin line marks the appearance of the developing tadpole...
D. auratus 'green and bronze' eggs showing early development
D. truncatus eggs showing early development
Over time the line will become a ridge and begin to show a recognizable tadpole...oftentimes the external gills of the embryo are visible....
D. tinctorius "New River' developing tadpoles
D. ventrimaculatus developing embryos
In contrast with frogs whose eggs stay white, one needs to look for the telltale 'ridge' that ultimately becomes the developing tadpole...
D. quinquevittatus developing embryos
What about infertile/bad eggs?
Infertile eggs generally have an irregular appearance...oftentimes white with some black as shown below....
Overtime they tend to expand in size and mold over....
Infertile D. castaneoticus eggs
E. trivitattus developing tadpoles showing infertile egg
Removing eggs from the viv:
First off a few observations about moving dart frog eggs. It is important to realize that fertilized eggs have a top and bottom side to them and accidentally flipping them upside down will generally stop their development. Therefore it's important to move them as gently as possible and keep the right side up.
Secondly, while your frog eggs didn't come from a sterile environment, cleanliness is a major plus in handling them. Washing/disinfecting your hands prior to removing eggs and after pulling them prior to going into another viv is good husbandry practice, minimizes the chances of transferring pathogens from viv to viv and will prevent transferring undesirable things to the egg mass. Third, it is important to minimize any disruption to the jelly mass surrounding the eggs since the jelly is a protective layer for the eggs themselves. Finally while dart frog eggs are not indestructible, the occasional mishap occurs and you will find yourself with eggs that dropped to the countertop or the floor. In those cases gently remove them from the surface (a single edge razor blade or other fine edge implement is very helpful) and place them into an appropriate container.
Given that dart frogs lay their eggs in a variety of locations, a variety of approaches are used to remove eggs from the vivarium. The simplest and most obvious is when the frogs have laid their eggs in the petri dish under the coco hut and one merely removes the dish and replaces it with a fresh one. However in many cases one finds eggs deposited on leaves, in film cannisters and on the glass sides of the vivarium. In those cases more aggressive techniques are employed and we will now discuss the various scenarios.
Eggs on leaves/bromeliad axils:
There are two main approaches here. One involves cutting off the leaf or portion of leaf containing the egg mass and transferring the leaf plus egg mass to a petri dish, oftentimes trimming the leaf portion to a size suitable for the dish. as shown below.
Imitator eggs in later stages of development on leaf cuttings
However given that one is removing leaves or axils, it can be fairly destructive to the vivarium foliage over time. Therfore a second option is to gently squeegee (scrape) the egg mass off the leaf using a straight edged surface (a plastic credit card works well for this task) into a petri dish. Care must be exercised to avoid significant tearing of the jelly mass and ensuring that the eggs land right side up in the dish.
Eggs on glass:
In this particular case, one employs a variation of the squeegee theme only this time using a razor blade to gently work under the egg mass and detach it from the glass as shown below...
Infertile imitator egg mass being removed from glass
Fertile egg masses detached this way can be placed into a clean petri dish
Eggs laid in film cannisters:
Several approaches are possible if the eggs have been laid in a film cannister. Eggs that have been laid in water containing film cannisters right below the water line such as is the case with D. ventrimaculatus can be gently decanted into a clean petri dish. If the breeder has included a half cylinder inner sleeve inside the film cannister, oftentimes this sleeve can be removed from the film cannister with the egg mass intact. However in the case of direct attachment to the inside wall of the film cannister, several options are suggested. If the egg mass is deemed to be loosely attached, one can attempt to use mild mechanical means to lift the eggs off the film cannister wall by use of a blunt probe or gentle syringing of water into the film cannister. However both of these approaches run the risk of damaging the egg mass. An alternate approach is to place the film cannister with the side containing the egg mass oriented at the bottom into a deli cup and add just enough water to partially flood the bottom of the film cannister as shown below. Thumbnail eggs are fairly tolerant to total immersion so this approach can be safely used. Under these circumstances the eggs can be allowed to develop to hatching or in some cases (usually a few days) become sufficiently detached from the film cannister to be decanted into a petri dish
Photos showing film cannister in deli cup technique
Egg care outside of the vivarium:
Once the eggs have been removed from the viv and placed into a petri dish, you may notice additional debris in the dish (this is especially true with dishes removed from coco huts). It is a good idea to remove the extra dirt and debris using a Q-tip or tissue but avoiding any disturbance of the egg mass. Oftentimes the eggs themselves will be partially covered with debris and even parental fecal matter. Removing this material is problematic and it doesn't appear to cause significant issues with development [note: parents that are infected with various pathogens can pass those pathogens via fecal matter left on eggs so expecting to obtain pathogen free offspring from infected parents is unlikely].
The goal is to provide appropriate temperature and moisture for them. Room temperature is appropriate in most cases. While some individuals find that frequent misting with good quality water is adequate to maintain hydration of the egg mass, many opt to add sufficient water to the petri dish to partially submerge the eggs as shown below.
side view of E. trivittatus egg clutch showing partially submerged eggs
If molding is a problem, the addition of methylene blue to the water (1 drop per 3-5 ounces of water) or the use of 'tadpole tea' is suggested. Tadpole tea is a solution that is rich in tannins, making the water more acidic and antimicrobial. Tadpole tea is most commonly prepared by the addition of black water extract (2-10 mL per gallon of water) or by boiling oak or Indian Almond leaves and using the resulting solution. Insufficient air movement around the petri dishes holding the eggs may also increase the chance of molding so placing the dishes on an open rack or shelf can be of assistance.
Whether dart frog eggs need to be protected from light during development is an open question. Some find that the presence of light is deleterious to dart frog eggs, particularly those that are white such as galactonotus and castaneoticus. However it is important to note that imitator and intermedius eggs are oftentimes laid in exposed places in vivariums and if left undisturbed will develop and the tadpoles transported to water. If one choses to shield the eggs from light, it should be done in a way that still allows sufficient air movement.
In addition, the question of whether infertile/bad eggs should be removed from egg masses is an open matter. Depending on the situation, the risks of disrupting and damaging good eggs in the effort to remove bad ones is balanced by the potential for mold growth on the bad egg(s) to overwhelm the good ones. One observation is that in the presence of either methylene blue or tadpole tea, the chance of bad eggs damaging good ones is substantially reduced. If bad eggs are to be removed, the surest way to safely excise them is with the corner of a razor blade making judicious cuts in the surrounding jelly and lifting out the bad egg.
Leucomelas tads developing in the presence of two bad eggs (indicated by the arrows)
Finally after 10-14 days of development depending on the species, one will notice the tadpoles that had originally maintained a curved orientation begin to straighten out. This is a sign that hatching will occur within a few days and at this point more water can be added to the dish to assist the tads in breaking free from the egg sac. In short time you will have freely swimming tadpoles and are on your way to next part of the adventure, tadpole rearing.
FINAL NOTE: Assuming that you have been diligent enough to plow through all of the above, it is important to remember that this document is meant as a guideline as opposed to THE WAY things are supposed to be done. Every successful breeder has approaches that work for them (but perhaps not you) and oftentimes has used trial and error to figure that out.
Egg Development pictures:
Day 4 the tad just starting to form
Day 5 noticable changes in development
Day 6 the gills are starting to form
Day 7 The gills are more noticable
Day 8 Notice the gills and tail growth. Movement is noticable.
Day 9 Eyes are more pronounced. lots of movement in the devloping tads, they seem to be responsive to light and vibration.
Day 10 Eyes are formed and lots of movement, swimming around and flipping themselves over. looks less like an egg with a tail now.
Day 13 The mouth is more defined now and they look more like a tadpole. Looking close you can see blood flowing through the gills.
Scott Olin (Frognut) Egg Development Pictures
If you would like to see any updates or modifications to this care sheet please let myself or a moderator know.
Last Updated: 1/30/2007