Fish Lab & Marine Aquaria

Fish Lab clownfish breeding Maldives

Clownfish Breeding

We have installed new dimmer-controlled lighting above our larvae rearing tanks, which means we can now adjust the light levels to promote more active feeding and growth amongst the larvae. We have also installed lids on the breeding tanks, which we hope will reduce stress among the fish.

We are currently satisfied that the diet is nutritious enough to produce high quality eggs, and will continue following the same feeding protocols for the foreseeable future.

  • Clark’s Clownfish (Amphiprion clarkii) – mixed success, prompting a reshuffle of the breeding pairs. We have released one pair into the main aquarium, and introduced a new large breeding pair caught from the reef. We are hopeful that this breeding pair will start producing eggs in the coming months. Breeding pair #2 is regularly producing eggs, with three spawning events in March producing healthy juveniles.
  • Maldivian Clownfish (Amphiprion nigripes) – one breeding pair laid 2 egg batches during March, however, they eat the eggs prior to hatching, so we moved the pair (with an anemone) into the main display tank to provide a more natural environment, to see if the behaviour continues.
  • Common Clownfish (Aphiprion ocellaris) – we have successfully reared three individuals to juvenile stage, which we hope to increase if production continues.

March has again seen an increase in the Fish Lab population, with tank occupancy increasing by 10%, and the number of individuals rising by 50. New inhabitants include a breeding pair of Banded coral shrimp (Stenopus hispidus), and we are monitoring the growth of a juvenile lobster specimen.

Fish Lab new light dimmers
Fish Lab new light dimmers
Aquarium Clark's anemonefish egg development

Small Aquarium One

The juvenile Maldivian anemonefish (Amphiprion nigripes) has grown in size and is better acclimatised to the aquarium, spending more time near the corals. The new zoanthid colony (Zoanthus mantoni) has been predated (by crabs or the seastar) resulting in a loss of polyps.

A new G. fasicularis coral mini-frame has been added, and we are experimenting with various transplantation methods (proximity, contact point, fragment size & orientation). Our Acropora coral mini-frame was showing some bleaching and tissue loss, so we removed the diseased fragments and relocated the frame to our coral holding tank for observation. 17 out of the remaining 21 fragments are now encrusting,  and interestingly they show some interspecific growth variation (A. latistella is encrusting to the bar not the zip tie, whereas A. hyacinthus has grown over the zip tie but is not yet encrusted to the bar).

Small Aquarium Two

We have seen an increase in algal build up, particularly on the coral plates and rocks. This has also affected the mini coral frame, which was cleaned of algae (greater on the shaded side of the frame). Any paling corals were removed, and this frame was also relocated to our coral holding tank. 11 of the remaining 16 fragments are healthy. The Clark’s anemonefish laid 3 clutches of eggs this month, and we observed that (photo):

  • Day 2-3: the eggs undertake significant organ development from the yolk sack.
  • Day 7: on all 3 occasions, the eggs hatched overnight (with a few individual eggs hatching on Day 8).
Clownfish eggs Marine Savers Maldives

Moon Jellyfish (Aurelia aurita)

With the loss of our UV-sterilising light, the water quality inside the Kreisel tank has reduced, resulting in some fatalities amongst the jellyfish. A new light has been ordered, but until it arrives, we have transferred the jellyfish into a tank inside the Fish Lab. This will provide cooler water temperatures, increased water turnover and greater amounts of food.

Large Aquarium

We have increased the monitoring of our large marine aquarium, to more carefully control the environmental parameters during this season of increased ocean temperatures. The overall temperature of the tank has risen from an average of 28.8°C during February, to over 29°C consistently during the last 2 weeks of March. As a precaution, we have reduced the water flow during the day so that the cooler air temperature may stabilise the water temperature. The pH levels spiked during week three, but is now comfortably within the recommended range (as are the ammonia and nitrate levels).

Our main aquarium has had some new additions during March, including:

  • Harlequin shrimp (Hymenocera picta) – feed exclusively on sea stars of all sizes, even crown of thorns. Live in pairs in the wild. Our specimen arrived as a larva on a rock.
  • Bicolour blenny (Ecsenius bicolour) – popular aquaria species that are great at cleaning the microalgae from rock. They are shy, often sheltering before appearing to feed.
  • White belly Toby (Canthigaster bennetti) – small species of puffer fish that feed on benthic algae and small crustaceans. Our pair can often be seen grazing around the tank.
Aquarium marine Maldives
Aquarium marine Maldives

Linckia multifora sea stars

SS1 (large specimen) – average decrease in arm length (for the second month in a row) of 0.2mm, either due to small variations in the accuracy of our measurements (especially with curved arms) or perhaps the seastar does not have sufficient nutrition.

SS3 (large specimen) – average increase in arm length of 1.8mm (continuing the increased growth rate).

SS4 (autotomised arm) – this month, hiding amongst the rocks!

REEFSCAPERS Coral Propagation Program

Coral Reef Transplanting

During March at Kuda Huraa, a total of 12 new coral frames were sponsored, and a further 38 frames were monitored (cleaned, repaired and photographed). Additionally, we spent 2 days re-mapping our frame sites around the island, and we are currently processing the ‘orthomosaic’ digital map from the data.

At Landaa, 19 new coral frames were transplanted this month, (9 sponsored by guests, 10 sponsored by Four Seasons) and a total of 154 existing frames were monitored around the island (mainly at the Coral Trail, Spa and Water Villas sites).

Check out our 2020 Diary for details on how we are working to protect our corals from the upcoming seasonal warm ocean temperatures, which peak from March – May. You can also read about 2 very unusual projects this month (photos below):
(1) the relocation of 100+ coral frames from Landaa to the lagoon at Voavah;
(2) our work to save some of the corals from the reefs at Gulhifalhu, before the commencement of a large-scale land reclamation project.

Reefscapers coral relocation to Voavah Maldives
Reefscapers coral rescue Gulhifalhu Maldives

Our Reef-Monitoring AI Catamaran

Through tuning of the parameters, we have improved the results of our frame recognition algorithm up to a success rate of 99.8%. We have also improved our coral detection deep-learning algorithm for detecting the coral fragments, and developed a frame analysis algorithm to match the detected coral fragments to the bar. For our catamaran, we have installed an additional propeller battery, and we are currently investigating issues with both the onboard cameras and external radio interference.

Read our in-depth development journal at Reefscapers for the full story, along with more photos and video.

Sea Turtle Conservation

Luchi turtle rescue rehabilitation release Maldives

Luchi, a female Olive Ridley turtle, was rescued from entanglement in a ghost net on 25 January.
After 6 weeks of care & treatments at our rescue centre, she was given a beach-side farewell.  Bon voyage, little Luchi! 🙂

On 5 March, we successfully released Luchi back into the ocean, leaving us with a total of 10 Olive Ridley turtles [Lepidochelys olivacea] in our Landaa rescue centre at the end of March.

On 25 March, we returned Georgia to the sea, after 18 days at our Kuda Huraa turtle rehabilitation centre. By the end of the month, we were caring for 11 rescued Olive Ridley’s, plus a further 6 sea turtles in our Hatchling Rehabilitation Program (1 Green [Chelonia mydas] and 5 Hawksbills (Eretmochelys imbricate]).

This month, we X-rayed 5 of our turtle patients:

  • Arielle (juvenile Olive Ridley) had not been using her left front flipper, and we thought it might be fractured. However, the X-ray showed the bone was undamaged; following several physiotherapy sessions on her flipper, we are starting to see improvements.
  • Cleo (juvenile Hawksbill) is lethargic and not eating, however the X-ray did not reveal anything unusual.
  • Pepe (post-hatchling Green turtle) was found to have deformation and curved vertebrae. Sadly, he later died on 25 March from an intestinal infection.
  • Quasi (juvenile Hawksbill) presents various body deformations. The X-ray revealed abnormal vertebrae, flippers and skull. Despite this, he is active and keeps growing, albeit at a slow rate.
  • Toby (juvenile Hawksbill) presents deformation of the carapace. The X-ray did not reveal any further problems.

Maldivian Sea Turtle Identification Program

Turtle photographs are kindly sent to us from members of the public, fellow marine biologists and dive centres stationed at other resorts around the Maldives. Submissions consist of close-up photographs of the turtle facial profile, enabling us to outline the unique pattern of scales (scutes) that act like a human fingerprint.

During March, we received submissions of 42 photo sets from the public, taken at various sites around the Maldives … a big thank you to everyone! 🙂

Our current database now totals 4683 sightings, comprising of the following uniquely identified individuals: 1220 Hawksbills, 215 Greens, 56 Olive Ridleys.

Spotted a turtle?  Share your photos

Sea Turtle photo identification project Maldives EI1214

PHOTO: Hawksbill turtle, ID #EI1214 from our database

Reefscapers coral frames – Kuda Huraa water villa flower site

Further News & Updates

You might also be interested in our Dolphin ID Project, and our Sea Turtle Enclosure out in the lagoon at Landaa.

Looking for details of our coral propagation programme ?

Head over to our Reefscapers 2020 Diary for all the latest updates.

You can sponsor your own dedicated Coral Frame, and then see how it grows in the future by viewing the photo updates every 6 months, as part of our Coral Frame Collection.

Photos: (1) Reefscapers coral frames at Kuda Huraa water villas.
(2) Junior Marine Savers learn the importance of corals.

junior Marine Savers at Kuda Huraa

Our Unreleasable Turtle Residents

Our Current Turtle Patients

Our Turtle Hatchling Patients

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