Axolotls experience this romance once per year, normally from March to June. With the romance moving behind her, the female axolotl will separately join her 100-300 jam covered eggs on sea-going plants or shakes. Around 10 to 14 days after the fact, the eggs bring forth, and the youthful fight for themselves. It takes about a year for axol o tls to turn out to be explicitly experienced.
The axolotl's natural reproductive season is in spring. Female axolotls usually produce between 80 and 700 eggs, which they lay on aquatic plants. These eggs are not always actually fertilised. If fertilised, axolotls hatch after about 10 to 20 days. Males reach reproductive maturity at about one to two years of age. Females usually become reproductively mature earlier and can reproduce after about one year.
Males and females can be distinguished by the shape of the cloaca, which is more swollen in males during the breeding season. The cloaca becomes a big split excrescence, overflowing symmetrically on both sides of the body. The axolotl is able to reproduce at the age of 18 months to two years, before having reached its maximum size. The females ready to lay eggs are distinguished by their overweight, the males are always thinner. Except in the case of a special breeding program (color selection), unrelated animals are preferred. The genetic diversity of the captive population should be maintained as much as possible.
Spawning
In its natural environment, the axolotl reproduced in spring. Domestication, as often, has more or less freed it from the cycle of the seasons. The laying of eggs can occur at any time, as soon as both partners are in condition. Increasing the food ration in the previous period, putting back in contact animals of both sexes living separately until then, lowering temporarily the temperature to 12-14° for a few days or a few weeks and then letting it come back to its usual level or to a slightly higher level are stimulating factors. The intensification of the red color of the animals' gills and the increased activity of the animals are warning signs. The females take an unusual pause, tail up. The males follow the females and touch the tail and cloacal area of the females with their snout. This corresponds to an exchange of pheromones, scent particles that inform the axolotls about the reproductive status of their partner. It has often been reported that the claws, normally gray or white, become black.
There is no mating. Breeding occurs mostly at night. The male deposits small gelatinous packets of seeds called spermatophores on the ground. The female collects them with her cloaca and fertilizes. This merry-go-round, interspersed with pauses, can last several hours. The emission of the eggs occurs 12 to 15 hours after the fertilization. The number of eggs varies from one clutch to another and according to the size and condition of the animal. One clutch usually contains between 50 and 150 eggs and clutches may be laid over several days. The eggs are weakly adhesive and deposited on the elements of the decor, or, preferably - it is also the most practical for us - on the strands of floating plant type Naja or Myriophyllum. There are no really constituted cords or clusters. The eggs are generally isolated. They are made up of a gray or white central core, according to whether the animals are pigmented or not, surrounded by a translucent jelly contained in a transparent shell. They swell after their emission, passing from 2 mm to a little less than 1 cm in diameter. The "germ" in the center of the egg is subject to intense cell division. The shape lengthens, the embryo takes the shape of a comma, the head begins to differentiate after 5-6 days, the mouth around the 12th day. The gills become visible.
If the eggs are more or less respected, the larvae will certainly be eaten by the parents after hatching. It should be kept in mind that the breeding of larvae will require a lot of space (to raise 50 larvae to a size of about 10 cm, three or four small tanks and two tanks of about 1 m.) and a lot of live food, and that it is not always easy to place the animals resulting from its reproduction. It is therefore not really advisable to keep hundreds of eggs. On the other hand it is rather rare to manage to raise all the eggs to the end. All the eggs do not hatch. Especially for the forms afflicted with a conflicting genetic heritage (albino, gold, copper). There are losses at each stage of growth, even if it is the pride of the breeder to limit them to the maximum.
At this stage, a few hours after the laying, if you want to raise the young, it is advisable either to transfer the eggs with the plants to which they adhere in separate tanks, or to remove the parents if you have installed the breeders on purpose in a laying tank which will be used at the beginning of the rearing of the young. No lighting on the breeding tank during the incubation of the eggs. It is advantageous to transfer the eggs in small quantities, between 10 and 20 per tank, in several small tanks of 20 to 30 liters. This divides the risk and facilitates further handling. Once the eggs have been isolated, special care should be taken to keep the water clean and aired. Remove moldy or non-developing eggs and make frequent water changes with prepared water at temperature. The use of an air filter is almost mandatory. Some breeders use an antiseptic (Rivanol, in low concentration) as a preventive measure to avoid moldy eggs. The tank can be bare, except for the plants that have been used as egg-laying support. The eggs can be kept in the upper range of temperatures accepted by the axolotl, around 20° or even a little above. However, they can also incubate (albeit more slowly) at lower temperatures, between 15 and 20°, and it is easier to keep the water clean and aerated at this temperature.
Looking After Axolotl Larvae
Axolotl hatchlings are similarly as curious looking as grown-up axolotl. They are about 0.5 inches long when they incubate and won't move for the initial 2 to 3 days. This is on the grounds that they have some egg yolk still in their stomachs that they feed off for the initial 46-72 hours of their brought forth lives. Try not to be frightened by their absence of development, the most exceedingly terrible thing you could do is expect they didn't endure and discard them.
Once the hatchlings begin to wriggle about this is an indication that they are prepared for food. They should be taken care of just live food until they are a lot more established. This is on the grounds that their feeling of smell isn't created and they just won't understand the dead food is really something that they can eat. This can be precarious. How are you intended to discover live food little enough for the hatchlings to eat?
Moina and recently brought forth saline solution shrimp are the perfect little live foods for the recently incubated hatchlings. Whatever else might be difficult for them to get until they begin to create legs.
On the off chance that you are uncertain if another live food alternative is proper for the hatchlings, check with the pet store before making a buy. Neglecting to give the hatchlings the correct food can bring about them eating one another. Not what we were going for!
The rearing of the larvae
The first few weeks of larval rearing, until the time when the larvae will accept common foods and then inert foods, are the most delicate time for the success of axolotl reproduction. It is necessary to have an abundance of live food. The amateur who passes this point has done his schooling to succeed in other reproductions of newts and salamanders.
Like many very young urodeles larvae (newts and salamanders), axolotl larvae only accept live food of an adapted size and do not hunt. They are content to gobble up whatever comes within reach under their noses. Decreasing the volume of water increases the density of prey. In a volume that is too large, with a water column that is too high, the larvae die of hunger because they cannot find their prey. With such a low water level, the enhancer filters do not work anymore. The breeder has to compensate by changing the water almost daily (with prepared water, before feeding). If possible, the temperature should be kept between 18 and 20°C. Lighting can be reinstalled to help with this.
Feeding the young larvae
The first "preventive" distribution takes place after the water change that precedes the supposed date of the first hatchings. These foods will have been previously grown outdoors in a large container or small garden pond (e.g., 2.00 x 0.5 x 0.4) into which strains of the desired species have been introduced in early spring, and nothing else, except aselles and snails. The large daphnia are not consumed by the axolotl larvae at first, but they can reproduce in the tank and a culture also yields small daphnia. This food is not available in winter. It will be used as a starter and as a supplement during the whole growth of the young larvae. The big advantage of wild plankton is that it stays alive for a long time in the water of the rearing tank, does not soil it and even purifies it (daphnia). However, it is rare to have a sufficient production to do without the live preys of breeding. It is therefore necessary to start the "artificial" production of micro-prey.
Various small preys common in aquaria: nauplii (larvae) of artemia, by far the most widespread and easiest, micro worms, vinegar anguillules, moina daphnia, of a capricious culture. The manuals of aquaristics develop abundantly the subject, the sites of the suppliers of strain also (for example for France: aqualiment ). For artemia nauplia, there are culture kits and preparations (salt for the culture solution, eggs (cysts), liquid food) ready-made, common in the aquarium trade. We will focus our discussion on the methods of administration to axolotl larvae.
At the time of the transition from small to large prey, the axolotls are almost out of the woods. It is advantageous to divide them into several tanks, by size, as will be done regularly thereafter, for two reasons. First, it is quite possible that the larger axolotl larvae, as has been proven for other amphibians, emit a substance that inhibits the growth of smaller ones. On the other hand, if the density of animals is high, "accidents" (taking a limb while capturing food) are also more frequent. Reducing the density of animals dilutes this effect and reduces the competition for food, which is also to the detriment of the smaller animals. Larger animals that can eat larger prey grow faster. If the size differences become too great, the larger animals will devour the others. Cannibalism becomes a more noticeable risk around two months of age.
Cannibalism
Larval cannibalism is often considered an inevitability in axolotl breeding. We believe that this is not the case, that it can be reduced to almost zero by not overcrowding the tanks and especially by distributing enough food. The scientific literature mentions a mechanism of "cannibalistic adaptation" in the axolotl, and this is well described in Ambystoma tigrinum and in the Japanese salamander Hynobius retardatus. Some larvae, in certain egg-laying stages, become specialized predators of their conspecifics. They even develop a specialized morphology of the head and jaws for this purpose, and are larger: almost twice as large as the others in H. retardatus. Cannibal and normal larvae are called "dimorphic". The "professional" cannibals are capable to a certain extent of discriminating their prey according to their relationship with themselves, favouring the consumption of genetically distant larvae. They would be selected by environmental conditions, i.e. the cannibal form appears clearly in contexts where food is scarcer. It is not sure that cannibal specialization has a simple genetic basis. The dimorphism could be induced by environmental conditions in a genetically poorly differentiated larval population.
In the weeks following the transition to large foods, and especially around the third month, inert foods in the same size range can be introduced: pellets, frozen foods, small pieces of freshwater fish, etc. It may be appropriate to mix the two types of food. Known live prey triggers the taking of food, clumsiness in the capture makes the larvae also take the inert foods that are mixed with the others and get used to them. We continue to loosen the larvae regularly and gradually align the maintenance conditions with those of the adults. A 100 x 30 or 80 x 40 tank can house 20-25 larvae of 4-5 cm but only 10-15 larvae of 8-10 cm, about six months old (preferably always with a lower than normal water level and regular water changes, more than for the adults). After a year, the larvae have become semi-adult animals that measure 12-15 cm. This is the age and size when the larvae of other species of salamanders of the genus Ambystoma metamorphose into adults, lose their gills, see their skin change, leave the water etc. The axolotls, on the other hand, have already reached the end of the limited metamorphoses that are theirs. It remains for them to reach sexual maturity, around 18 months and 15-18 cm.
Jack Nelson
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