Fish Lab & Marine Aquaria

Large Aquarium – we recently added four new brewing pumps, which will keep the water aerating and mixing throughout the 4000L volume. Our hard and soft corals are very healthy, apart from the Palythoa and Zoanthid specimens which were eaten by a sea urchin, so we returned the hungry culprit back to the ocean!

Small Aquarium One – the Acropora digitifera coral fragment grew little this month; the encrusting has plateaued and the corallites on the cable tie show minimal change.
Our regenerating starfish (Linckia laevigata) has shown substantial growth, with the two arms adjacent to the large arm growing at a faster rate than the others (approximately 1mm per week).

Regenerating starfish (Linckia laevigata) at day: 1 – 18 – 26

Clownfish release: Apprentice Programme 2018

Our captive-bred clownfish and anemones are doing well since their release out on the house reef, and have settled into their new wild homes. So far, of the 10 fish released, only the smallest 2 did not survive (chased away from their protective anemone). The Clark’s Clownfish (on a wild Merten’s anemone) have grown noticeably in size.

Clownfish Breeding

The rate of egg production has been falling in recent months, so we plan to return some of our Clownfish breeding pairs to the house reef, inside a relocated anemone under a protective cage. We hope returning them to the wild will encourage the broodstock to start laying again, and then we can bring them back inside the lab once more. This process might take some time, but it can be easily tested in the coming months.
Some of our juvenile Maldivian clownfish are developing a new body pattern, consisting of half-bar stripes and three spots. This is often seen with hybrids between different Clownfish species, but in our case the parents appear to be pure-bred, so maybe the hybridisation occurred some generations ago (hybrids are found in nature). To follow these heredity varieties, we have started recording the proportion of each pattern per generation. We have also isolated a future breeding pair of half-barred three-spotted Clownfish and hope to breed an original “Made in Landaa” Clownfish.

Anemone Bleaching Experiment

To study the bleaching recovery process of our captive anemones, we placed them in sunlight with clownfish and an enriched diet (Mysis & Selco). We monitored their health daily by recording colouration, size and response to stimuli (food). Anemone-A died after 5 days, whereas anemone-B shows improved health (maybe due to greater presence and activity of the Clownfish?)

Anemone-B on recovery day #5

Marine Life

This month, we spotted some eggs from a giant squid floating in the lagoon, so we collected a sample and relocated the others out to sea. Hopefully, the eggs will develop and hatch in our Fish Lab (we have succeeded in doing this once before).
We have also welcomed a small Moray eel (Gymnothorax richardsoni) to the Lab, rescued by the launch team as it was sheltering in mooring lines. They usually live in shallow rubble, easily identified by a distinctive starry pattern, and growing to 30cm in length (our specimen is 10cm).