There are many reasons why tadpole shrimp or fairy shrimp eggs may not hatch. These factors can include water quality and temperature, among others. However, there are steps that can be taken to improve the hatching rate of these eggs. Some of these factors include:
The type of water.
It is important to avoid using tap water to prevent the potential harm of chlorine or other pollutants to your shrimps. According to the website waterdefense.org, it usually takes about 24 hours for chlorine to evaporate from water, but this process can be affected by factors such as the volume of water and the concentration of chlorine. In some cases, it may take up to five days for chlorine to fully evaporate. However, certain conditions, such as aeration, ultraviolet light, and proper circulation, can speed up the evaporation process (accessed January 8, 2023). It is important to note that not all tap water is suitable for use depending on your location. According to the website espwaterproducts.com, boiling water for 15 minutes is an effective method for removing chlorine from tap water (accessed January 8, 2023).As an alternative, distilled water is recommended, but other options such as spring, drinking, or rain water may also be used. When using water that lacks minerals, it is essential to add compost or detritus to the tank to provide necessary minerals and microorganisms. Additionally, using distilled water for hatching can increase the hatching rate for some species due to the increased osmotic pressure causing the eggs to crack open. It is also crucial to ensure that the water used for hatching does not contain any algae, as this can significantly decrease the hatching rate for certain species.
Temperature
Each species of shrimp has a specific range of temperatures that are optimal for hatching. If the eggs are not kept within this range, they will not hatch. For warm water shrimp, it may be necessary to use an aquarium heater to maintain the appropriate temperature. On the other hand, some species of shrimp require colder temperatures and can be grown outside during the winter months to meet these needs. It is essential to ensure that the eggs are kept within the optimal temperature range for their specific species to increase the chances of successful hatching. For instance fairy shrimps in the genus Streptocephalus require temperature within the range of 68 to 78 F in order to hatch and thrive, while fairy shrimp in the genus Eubranchipus require freezing temperatures to trigger hatching.
Light
Light can be a trigger for hatching, as demonstrated by the findings of Vanhaecke et al. in their article on JSTOR(accessed January 8, 2023). They found that hatching rates increased with increasing light intensities, suggesting that increasing the intensity of light can improve hatching rates. To maximize hatching rates, it is recommended to expose the eggs to several hours of direct sunlight, or to use artificial LED lighting. In particular, keeping the eggs under LED lights for the first 24 hours may be effective in improving hatching rates, after which the duration of lighting can be adjusted to mimic natural daylight.
PH
According to Leese and Gutow (2002), nauplii, or the early stages of crustacean development, show a preference for hatching in environments with a neutral pH. The optimal pH range for hatching shrimp is between 7 and 7.5, as they prefer slightly more alkaline water. While they can survive in a range of pH from 5.5 to 8.0, it is recommended to maintain a neutral pH for most species. To raise the pH of the water, limestone can be added, as it contains calcium carbonate which forms calcium hydroxide, a strong base, when introduced to water. However, it is important to monitor the pH level to ensure that it does not become too high. Acidic water can be harmful or even deadly to shrimp, and can be caused by too much decaying material in the water. Some species are more tolerant of acidic water than others, and adding leaves or peat moss can decrease the pH if necessary.
Oxygen concentration
In rare cases, some species of shrimp may require higher levels of oxygen in the water to trigger hatching. To address this issue, an air pump can be used in the tank to increase the oxygen levels.
Salinity
Again, this is not a common requirement, but some species of shrimp may need the proper salinity in the water for their eggs to hatch. For example, brine shrimp require a high level of salt in the water in order to hatch. Additionally, certain desert species may also require a higher salinity. To increase the salinity of the water, a small amount of sea salt can be added.
Other
Hatching may sometimes be tied to the season and climate changes, as some species of shrimp eggs will only hatch in certain seasons such as winter or summer. Additionally, eggs may only hatch after a rainstorm or during a low pressure system. Another possible reason for eggs not hatching could be that they become stuck on the side of the container as the water evaporates, resulting in them not being fully submerged or exposed enough. To resolve this issue, it is recommended to add water to the container to reach the previous water line, which may trigger hatching.
In summary, the potential reasons for eggs not hatching may include insufficient light intensity, pH levels that are not neutral, low oxygen levels, improper salinity, and seasonal or climatic factors. By considering these various possibilities and taking appropriate measures, it may be possible to improve the success of hatching branchiopods. We hope that this information has been helpful in providing insight into this issue.
Cited work
Espwaterproducts.com. (n.d.). How to Remove Chlorine from Drinking Water. Retrieved from https://www.espwaterproducts.com/how-to-remove-chlorine-from-drinking-water/
Water Defense. (n.d.). Chlorine Evaporation. Retrieved from https://waterdefense.org/water/contaminants/chlorine-evaporation/
Vanhaecke, Paul, et al. “International Study on Artemia. XV. Effect of Light Intensity on Hatching Rate of Artemia Cysts from Different Geographical Origin.” Marine Ecology Progress Series, vol. 5, no. 1, 1981, pp. 111–14. JSTOR, https://www.jstor.org/stable/24812924. Accessed 9 Jan. 2023.
Leese, F. and Gutow, L. (2002). pH-related Hatching Success of Triops cancriformis (Crustacea: Branchiopoda: Notostraca). ResearchGate. Retrieved from https://www.researchgate.net/publication/225750631_pH-related_Hatching_Success_of_Triops_cancriformis_Crustacea_Branchiopoda_Notostraca.
Comments