Reefscapers coral frames provide an important habitat for various species of reef fish

Fish Lab & Marine Aquaria

Plankton Production

During September, our Rotifer production stabilised, without the Ciliate issues from last month. Artemia production (food source for juvenile clownfish, jellyfish, seahorses) has been increased due to the number of growing jellyfish. Artemia are now hydrated for 24 hours to facilitate hatching as this has proven more reliable than the bleaching process. The hatched larvae are then siphoned daily and a new batch hydrated every 2 days.

Clownfish breeding

No eggs were produced this month, but all of our 49 Clark’s Clownfish juveniles are healthy and continue to grow well.

Linckia multifora sea stars

• SS1 (large specimen) – was found with one of its legs recently amputated. We will keep a close eye on the recovery of both the parent and the detached arm.
• SS3 (large specimen) – the developing arm has grown significantly this month, whilst the longest arm decreased in size by 3mm.

Small Aquarium One

• Mini coral frame – seven fragments remain healthy, but show little signs of growth since last month.
• Maldivian anemone fish (Amphiprion nigripes) laid a clutch of eggs on 9 September.

Small Aquarium Two

• Mini coral frame – following the loss of 2 of the Acropora digitifera fragments last month, one more fragment is now showing the same symptoms of white coloration and some dead tissue. The other fragments look healthy and are encrusting onto the coral frame.
• The Galaxea fascicularis colony encrusted onto the aquarium wall continues to grow.
• Clark’s anemonefish (Amphiprion clarkia) laid 3 clutches of eggs this month. The first clutch was soon eaten by the resident sea stars, but we were able to monitor and photograph the eggs from the subsequent 2 clutches.
• Blue damselfish laid their first 2 batches of eggs this month.
• Two new surprise specimens found hidden in the rocks… a sea slug and a mantis shrimp! Plus, we introduced a pair of juvenile batfish.

Jellyfish – Aurelia aurita

During September, we closely monitored (and subsequently reduced) the salinity in each of our staging facilities. As a result, we were able to successfully strobilate [*] 1400 ephyra, and now have approximately 1000 jellyfish of varying sizes over our 4 holding tanks. The largest individuals are approximately 10cm across, and will soon be ready for relocation to the main display tank. Most individuals are still in the staging process, and will be added to the display tank once they reach sufficient size.

The staging tanks (photos, below) require twice-daily feeding regimes and 100% water changes, which are very labour intensive. However, the larger individuals are more robust and once introduced to the large display tank, will receive daily feeding and monthly maintenance. To reduce algae blooms, we have engineered and fitted a new opaque cover for the tank light, alongside an external UV steriliser which is run inline when filling. The display tank will be run on a closed system due to the current sea surface temperature. In the coming months we will look into adjusting the existing pipe work to enable us to accommodate the UV steriliser and filtration into the closed system loop. This will provide us with more flexibility and a more stable environment.

[*] Strobilation is defined as asexual reproduction by transverse division of the body segments which develop into separate individuals.

from: Jellyfishes – Diversity, Biology