How the facilities are used
The facilities keep stable cultures of marine model organisms all year. Researchers can therefore plan experiments independently of the season, and get animals at the exact developmental stage the experiment needs: eggs, embryos, larvae, juveniles or adults.
All systems use natural sea water from the Bergen fjord, filtered and UV-treated before it reaches the animals. Temperature, salinity, light and feeding are automated in most rooms. Several rooms are GMO certified, and the drains run through the Centre's own disinfection system. The ctenophore and worm facilities were fully renovated in 2022.
The facilities are located in the High Technology Centre at Marineholmen, in the same building as the laboratories and microscopy rooms.
The six facilities
Each facility is built around one model organism. Open the boxes for details on the set-up, capacity and daily operation.
Appendicularians (Oikopleura dioica)
The facility has eight individually temperature-controlled aquariums with eight experimental units in each. The main culture produces around 2,500 spawning animals per week, and on average 300,000 juveniles per week. Another 48 tanks are available for experiments.
The culture is kept at 12 ± 0.5 °C, which gives a seven-day life cycle. At 20 °C the cycle drops to four days. Sea water is collected at ten metres depth at the Espegrend Marine Biological Station, filtered down to one micron and UV-treated. Salinity varies with the season between 28 and 32 ppt.
Why this species
Oikopleura dioica is a planktonic chordate that keeps its tadpole-like body plan throughout life. It is closely related to vertebrates, has a short life cycle, a transparent body, only about 4,000 cells in a fully formed juvenile, and a compact genome of roughly 56 megabases with around 18,000 coding genes. Morphogenesis is complete ten hours after fertilization.
Daily operation
The animals are filter feeders that renew their house every three to five hours. They must be kept in constant motion with rotating paddles, and they do not tolerate metals such as aluminium and copper. The water is changed daily, automatically in 24 of the tanks.
Cnidarians (Nematostella vectensis)
The cnidarian facility is a semi-automated culture system with room for more than 400 boxes on a shelf system, and around 1,000 individual boxes in total. The sea anemones are kept in one litre of brackish water that is replaced automatically once a day, five days a week. The brackish water is produced automatically in 1,000-litre tanks by mixing filtered sea water from 200 metres depth with reverse osmosis water.
The animals are fed daily with freshly hatched brine shrimp. Adults are kept at room temperature of 18 °C, while growing animals are kept in incubators at 25 °C. Spawning is induced by 12 hours of light at 25 °C. Normal egg production is 60,000 eggs per day from 120 induced females, and the facility delivers around 1,000 wild-type animals per week in addition to transgenic lines.
Why this species
The starlet sea anemone Nematostella vectensis has a simple body plan, a transparent body and reproduces both sexually and asexually. It was the first cnidarian to have its genome published. ChIP-seq, ATAC-seq and single-cell RNA sequencing are all established for the species, as are transgenesis and CRISPR/Cas9 knock-out and knock-in. At the Centre it is used above all to study how the environment controls growth.
Ascidians (Ciona intestinalis)
The ascidian facility has 31 tanks and can house up to 10,000 adult Ciona intestinalis. System A consists of six large tanks for adults collected from the sea around Bergen. System B has 16 smaller tanks for juveniles, with water filtered through 50 and 10 micron filters and UV-treated.
The facility has continuously running sea water with computer-regulated temperature and flow rate. Two inlets supply water at 8–10 °C and 20 °C. Salinity is around 32 ppt. The culture is supplemented with live algae produced daily in the facility.
Why this species
The sea squirt Ciona intestinalis is closely related to vertebrates. It reaches sexual maturity in two to three months, and goes from fertilization to a swimming tadpole larva in only 18 hours. Embryos and larvae are optically transparent, and the genome is compact with around 160 megabases and 16,000 coding genes.
Daily operation
Adults are collected from jetties and piers around Bergen, including Sotra and Askøy, every two weeks to once a month depending on the season. They survive one to three months in the facility. Larvae hatch 36 hours after fertilization at 14 °C, and metamorphosis follows roughly 16 hours after hatching.
Ctenophores (CtenoFarm)
The ctenophore facility has 60 kreisel tanks of 10, 25 and 180 litres across six independent recirculating systems. The kreisel design separates the inlet and outlet chambers with a screen that protects the animals, and a spray bar creates a circular flow that keeps the comb jellies suspended in the water column.
The facility has kept a stable culture of the sea walnut (Mnemiopsis leidyi) since 2018, Bolinopsis infundibulum since 2022 and Pleurobrachia pileus since 2023. Beroe cucumis, Beroe gracilis and Euplokamis dunlapae are kept periodically.
Sea water is drawn from 100 metres depth, filtered down to one micron, passed through an activated carbon filter and UV-C treated. Temperature, salinity and photoperiod are monitored continuously. Spawning is induced on demand, and the facility produces 1,000–5,000 eggs a day.
Feed and field collections
Comb jellies feed exclusively on live plankton, so the facility cultures its own food supply: rotifers (Brachionus plicatilis), brine shrimp nauplii and copepods, in sizes matched to the life stage. Two to ten cruises a year, mainly in Korsfjorden on the research vessel Bratstrøm, bring in new species.
The facility is GMO certified at biosafety level 1 and is listed in the EMBRC Norway catalogue.
Closed ascidian facility (Christiaen group)
The Christiaen group runs its own closed facility where Ciona robusta and Ciona intestinalis from different European locations are grown from fertilized eggs to adults in artificial sea water. At 18 °C the animals are harvested around day 130, and adults reach four to five centimetres. Five to six animals give a batch of 2,000 eggs.
The room has eight separate temperature aquariums, three coolers, a 300-litre mixing tank and a 300-litre storage tank, a paddle system, automatic feeding and aquarium lights with sunrise and sunset simulation. Feed is live algae cultured on site, with eight incubators for algal cultures.
The laboratory also has two incubators, an electroporator, stereo microscopes with cameras and a dedicated work bench. The group keeps several other ascidian species as well, including Ascidia virginea and Ascidia mentula.
Annelid worms
The worm facility houses two annelid species: four boxes of Malacoceros fuliginosus in tanks at 21 °C, and seven bowls of Dimorphilus gyrociliatus in an incubator at 18 °C. It supplies mature males and females, embryos and juveniles at various developmental stages.
The room is GMO certified, has space for several sea water and fresh water tanks with different species, a continuous supply of sea water at several temperatures, an automated day and night cycle from 08:00 to 20:00, and bench space for sample processing and microscopy. It was renovated in 2022 and is equipped to take in new marine model organisms.
The facility is used above all by the Lynagh group, which studies how neurotransmitter receptors work and how they have evolved in bilaterian animals.
Access for external researchers
The Michael Sars Centre is part of EMBRC Norway, the Norwegian node of the European research infrastructure EMBRC. Through EMBRC, researchers and companies can apply for access to the cnidarian, appendicularian and ctenophore facilities at the Centre. The University of Bergen is the national coordinator for EMBRC Norway.
You can also come to the Centre through the visitors programme. It gives you laboratory space, access to the facilities and a host group to work with. Contact the group leader closest to your field before you apply.