Jellyfish – Aurelia aurita
To replenish the main display tank, we have been attempting to strobilate a small sample of polyps (scyphistoma). They were removed and placed into a controlled environment at 13°C (much lower than the usual 28-30°C) to stimulate strobilation [*] and produce ephyrae, hopefully after 3-4 weeks. The tank water is changed daily to remove excess food and prevent nitrogen build-up.
[*] Strobilation is defined as asexual reproduction by transverse division of the body segments which develop into separate individuals.
A total of 250 ephyrae have been collected and are currently housed in our smallest Kreisel tank. They are fed once daily with enriched day-2 Artemia, and are also subjected to a daily water change. This maintenance is essential to promote quick growth and reduce mortality. Each ephyra must be removed by hand prior to daily maintenance.
Once they grow to 1cm, they are classed as “juvenile medusae” and can be relocated to a larger Kreisel tank. Feeding will then be increased to twice daily, and the daily 100% water changes will continue.
Once they grow to 4cm (in about 4 weeks), they can be moved to the display tank.
The existing population of scyphistoma have been relocated to one of our display tanks, as we will need the large Kreisel aquarium to house the growing medusae.