Plankton is produced in the aquarium to support the growth and development of many marine organisms. Phytoplankton (plant plankton; the Isochrysis, Nannochloropsis, Tetraselmis and diatoms) are at the basis of the food chain. They are grown in cylindrical tanks. The larvae of the zooplankton Artemia salina (animal plankton) are also grown in aquariums as standard because of their size and nutritional value. The necessary quantity of Artemia is ensured by using a modern system (INVE Aquaculture – SEP Art technology) that enables the newly hatched larvae to separate from their shells, which results in pure and high-quality food.

In addition to plankton, for the purpose of sustainability, crickets are also grown in the aquarium (Gryllus assimilis), the main food of the veiled chameleon (Chamaeleo calyptratus), the central bearded dragon (Pogona vitticeps), the leopard gecko Eublepharis macularius) and the European green lizard.


An essential part of every aquarium is a breeding facility for its own needs. The strictly controlled conditions of Aquarium Pula supports the continuous reproduction of many species, such as the common jellyfish (Aurelia aurita), the clownfish (Amphiprion ocellaris, Amphiprion clarkii), the alpine newt (Pleurodeles waltl) and shrimps (Lysmata wurdemanni, Palaemon elegans), which help maintain the number of animal species in the exhibits constant. We exchange the


On arriving at the aquarium, all animals go through an acclimatisation phase. They are placed in quarantine to adapt to their new environment, to reduce the stress caused by transport and prevent potential illnesses and parasites from spreading. The stay in the quarantine lasts 3 to 4 weeks, depending on the species. Quarantines are also used to treat sick or injured organisms and for their recovery.

Filtration System in the Aquarium

The most important feature of any aquarium is the seawater filtration system. Appropriate biological filtration ensures optimal living conditions in every pool. Today’s modern equipment replaces the many biological and chemical processes which occur naturally in the sea.

Semi-Open System

Aquarium Pula utilises the benefit of its location by the sea to maintain optimal conditions by constantly drawing fresh marine water, which flows to the aquariums through collection basins. Deep water is extremely clean and has an ideal temperature (15° – 17°C). Physical processes compensate for the inadequate concentrations of oxygen, as well as low pH values of seawater.

Closed System

Tropical pools demand very high temperatures. That is why we use filtration systems that keep microbiological and chemical parameters of water within tolerance limits. The process of food degradation produces harmful substances, such as phosphate, while metabolic by-products of fish contain high levels of poisonous compounds: ammonium, nitrite and nitrate. To eliminate these harmful compounds, physical (sand filters, protein skimmers, UV filter) and biological (biological filters) methods are utilised.


A lot of knowledge and experience is required to meet the needs of every organism. Every species shows different behaviour conditioned by its own feeding strategy. That is why their feeding is diverse and balanced. To ensure our animals receive good nutrition suitable for their needs, the acquiring, storing and use of food are strictly controlled, as this is the only way to ensure high nutritive values adapted to the animals’ realistic needs.


In the aquarium, we feed animals with live or frozen feed. Some inhabitants, such as seahorses, pipefish and young cuttlefish, cannot survive without live food, so we provide them with crustaceans from the Mysidae and Palaemonidae families, and we feed octopuses, grey triggerfishes and rays with live decapod crustaceans. For special Adriatic fish like the striped red mullet, but also young (juvenile) specimens and tropical marine fish, we order high-quality frozen feed (small and large mysids, krill, artemia, worms, fish eggs) from Italy and the Netherlands. We catch crustaceans for our Adriatic fish ourselves: mysids and shrimp.
A large quantity of feed (anchovies, sardines, European sprats, European hakes) is ordered and then re-packaged and frozen at the temperature of -20°C to eliminate harmful bacteria and possible parasites. The fish is defrosted in a special defrosting machine which helps retain nutritional characteristics: taste, texture and colour of food. The frequency of feeding is influenced by water temperatures; animals living at lower temperatures need a smaller quantity of food three times a week, while tropical animals feed two times a day.

Workshop Natura 2000

Through teamwork and interaction with nature, the main goal of in situ workshops is to convey knowledge and basic information on the areas important for the conservation of endangered species and habitats of the ecological network Natura 2000. Here, we present the modern methodology we use, we measure the abiotic factors of the marine environment (temperature, salinity, pH, density, dissolved oxygen level) and research the meiofauna (invertebrates) of the sediment, as well as algae, plankton and the presence of fish. Special attention is paid to the seagrass communities within the complex Natura 2000 area, which is an important spawning ground, nursery and feeding ground for different marine organisms.