English-language descriptions of exhibits

Before you go underwater in our 3D cinema, approach the glass barrier. You now see mosquitoes in front of you. A male is hanging just in front of you. You will recognize it by its feathery antennae. A female is sitting on the wall on the left. As you can probably see, it was already feeding on blood. You know it. But are you sure? Mosquitoes, both males and young females, feed on nectar and are important pollinators! Only after copulation does the female needs the blood of warm-blooded animals to produce eggs. Okay, now it’s time to recover from this news. Let’s go underwater – please take 3D glasses and do experience!

How is your impression? You probably didn’t recognize all the organisms you saw. Don’t worry, that’s what this exhibition is for, to show you a world you don’t see every day. On the spheres you can take a closer look at the structure of individual creatures.

Cyclops. Cyclops are small crustaceans with a body length of up to 5 millimeters long. Their cylindrical and elongated body is composed of 16 segments. The absence of a carapace allows for greater flexibility and mobility. The cyclops’ wide head and thorax region support a pair of long antennae, which play a crucial role in locomotion. By vibrating these antennae, cyclops can generate a current that effectively counters gravitational pull, allowing them to suspend themselves in the fluid medium. The trunk’s free segments are equipped with bifurcated swimming legs, which propel the cyclops through the water with ease. The cyclops are dioecious, meaning they have distinct male and female sexes. The females exhibit a remarkable trait of carrying fertilized eggs in specialized pouches alongside their bodies.

Globe alge. Volvox. Volvox is a genus of green algae that forms spherical colonies composed of one layer of cells, filled with a gelatinous secretion. Cells within the colony show a certain specialization. Somatic cells in the volvox colony play a key role in nutrition, growth, and movement, while other cells specialize in reproduction. Somatic cells have a single chloroplast that gives the cells their green color. In addition, they are equipped with two flagella directed outside the colony. The cells move their flagella in a coordinated manner maintaining the front and rear poles of the colony. The cells of the anterior part have eyespots, thanks to which the colony can move towards the light. Reproductive cells are capable of forming new offspring colonies within the parent colony. They are released into the environment by disrupting the parent colony, which then dies. Volvox occurs in small freshwater reservoirs, ponds, ditches and even in shallow puddles.

Phacus. Phacus is a representative of Protists – the fourth kingdom of living organisms next to plants, animals and fungi. Demonstrating an astonishing ability to adapt to various environmental conditions. Its unique feature is the ability to switch between autotrophy and heterotrophy depending on the availability of light. Thanks to chloroplasts and chlorophyll, Phacus can perform photosynthesis, similar to plants, which allows it to produce essential organic compounds. In situations where light is unavailable, it can adapt to feed on external organic material, showcasing its remarkable flexibility. The bi-flagellate movement system enables it to navigate effectively.

Holarctic clam shrimp. Lynceus brachyurus, known generally as the clam shrimp, is a fascinating example of a small crustacean that has found its niche in freshwater ecosystems. Its unique structure, with a spherical body and a characteristic beak-like head, is an adaptation to life in specific conditions of small, often temporary water bodies. The thoracic limbs, which are used for filtering food, are an example of complex adaptation, allowing the exploitation of available food resources in the water.

Water flea. Daphnia, is a planktonic crustacean that plays a crucial role in aquatic ecosystems. These microscopic organisms are not only an important part of the food chain but also serve as indicators of the environmental condition of water bodies. Their transparent carapax covers the entire body except the head. There is a gap between the flaps of the carapax through which water flows. There is one large eye on the head. Daphnia have two pairs of antennae. The former are short and equipped with numerous sensory hairs, while the latter are long and branchy and are used for swimming.

Lesser diving beetle larvae. Acilius sulcatus is a species of water beetle in the family Dytiscidae. Its larvae are impressive predators during their juvenile stage. After hatching from eggs laid by females in moist locations, most often in dead trunks and branches, these larvae migrate to water. Their ability to swim is the result of specially adapted limbs that allow them to move quickly and agilely in the aquatic environment. In case of danger, the larvae can perform sudden movements with their body, enabling them to jump over the water surface, effectively evading predators. The initial larval stages feed mainly on planktonic water fleas, copepods and ostracods, while the older larvae prey on the larvae of mosquitoes, bloodworms, mayflies and dragonflies.

Now go to our first aquarium. This is an aquarium with small animals that you can view using a magnifying glass (both traditional and electronic). The tables show examples of creatures that can be found in small ponds. You won’t see all of them. Some, like the holarctic clam shrimp you already know well, can only be found in spring. Take a moment and use a magnifying glass to see the mouth of a snail eating algae on the glass. Maybe a fresh-water polyp is lurking somewhere? If you have trouble recognizing the creatures you are interested in, ask the staff for help.

Turn around. Here you can see the subsequent development stages of the mosquito: egg, larva, pupa and adult insect. Mosquitoes lay their eggs in calm waters: puddles, pools or even buckets of rainwater left outdoors. Mosquitoes lay several eggs at once, tightly, one next to the other. The eggs can overwinter, but they usually hatch into larvae after a few days. The larvae live in water but breathe atmospheric air through a single tube on their abdomen. At this stage of their lives, they are food for many underwater predators. Unless they are eaten, they can live in this form for several days, weeks or even months. It all depends on the species of mosquito and the conditions in the environment. After some time, the larvae transform into a pupa. At this stage, the body is completely rebuilt. Organs dissolve and new ones are formed. Interestingly, the mosquito pupa is very mobile. It breathes atmospheric air using two breathing tubes located on the sides of the dorsal part of the body. In this form, these insects usually live for several days. The adult mosquito emerges from a pupa attached just below the surface of the water. It gains strength for a while and begins its adult life on land, feeding on nectar, and only before laying eggs do the females look for a mammal from which they must suck blood in order to lay eggs. Adult mosquitoes live from several days to several weeks, although those that appeared in autumn can overwinter, hiding in basements, bunkers or badger holes.

Stand at the balustrade and look at the wall above the reed bed. See (the model of) the brown insect? This is the larva of our largest dragonfly: Anax imperator, the emperor dragonfly or blue emperor. In fact, it is not that huge, reaching just over 5 cm in length. It can most often be found in small water reservoirs such as peat bogs, clay ponds, oxbow lakes or field ponds. After hatching from the egg, for a year (sometimes even longer), the larva lives in water, where it hunts animals smaller than itself. When it is mature enough, it leaves the aquatic environment. It climbs onto plants growing above the surface of the reservoir and undergoes a transformation process there. An adult insect, an adult emperor dragonfly, emerges through a crack in its back. Its body length is over 8 cm and its wingspan reaches 11 cm. The whole process takes several hours, but if you look through the binoculars next to you, you can watch it accelerated. The binoculars are adjustable on the side, adjust them to your height for more comfortable viewing.

Time for some fun in the sandbox! But this is no ordinary sandbox. Here you can create a model of the area and observe how water flows depending on the terrain. What’s more, your hand can become a cloud from which rain begins to fall – raise it above the sandbox and watch the water flood the area. When you’re done, go down the stairs.

The peat core presented here is an enlarged copy of a peat sample taken from a peat bog in the Urwitałt area. Detailed analyzes will be carried out in the coming years and the results will be published presented in this exhibit successively as new data becomes available. According to preliminary analyses, the peat bog went through various fates. This peat bog is approximately 6,000 years old, at the beginning it was a lake (and for quite a long time) in which sediments accumulated, overgrowing and shallowing of the reservoir, to change into other peat formations in subsequent stages, and in recently it has become a raised bog. Are you sure? And what exactly was happening here? We will discover this story!!

Hidden lake. A peat bog is a reservoir full of water, but you can’t see it because it is hidden. Sphagnum moss is also a natural sponge – it absorbs huge amounts of water, and because it is retained in the tissues, it does not evaporate as easily as other reservoirs, e.g. a lake. During drought, the peat bog slowly releases moisture and, thanks to evaporation, it locally lowers the temperature. In areas where there are swamps, the soil is slightly cooler. However, in times of heavy rainfall, it captures excess water and stores it for difficult times of drought.
Coal warehouses… Due to the fact that preserved plant remains do not decompose, peat bogs are a huge storehouse of carbon that has been accumulating for thousands of years, since the peat bogs began to form, i.e. after the retreat of the glacier. Plant remains do not decompose, so the carbon remains trapped in them. It is true that the annual growth of the peat bog is only about 1 mm per year, but it accumulates there for centuries. Therefore, peat bogs are our allies in the fight against global warming.
…and a ticking bomb. But if we dry them… then the situation is different. All the carbon accumulated over thousands of years is released, converted into CO2 and begins to heat the atmosphere. What protects against overheating may become a threat. Therefore, the swamp must be wet!

Dr. Jekyll and Mr. Hyde. A wet peat bog supports local water circulation, retains it during downpours, slowly releases moisture during droughts, creates a friendly microclimate, and is a treasure trove of knowledge about the past. It’s our ally in the fight against global warming, it’s perfect!
But a dried peat bog changes its appearance – without water, peat begins to decompose, loses its ability to bind carbon and retain water, everything that has survived for centuries dries out, decays and mineralizes. It then releases carbon dioxide (CO2) and methane (CH4) into the atmosphere – these are greenhouse gases that accelerate the greenhouse effect, the peat bog does not retain excess water during rain and does not release moisture during drought. Then the ideal is gone and only problems remain!

If you are looking at the board with the peat core, on the right you have an aquarium with a swamp minnow (Rhynchocypris percnurus). This fish is true loner by choice. The swamp minnow occurs in northern regions of Asia and Eastern Europe – the western border of this species’ distribution is in Poland. As it happens at the edge of its range, it occurs in islands, irregularly, only in a few water bodies. It is a species associated with colder regions, so it is believed that there are only small populations living here last after the glaciation, when the climate was colder and the species withdrew from the area. Such species are called a glacial relic. However, it could have been exactly the opposite – after the glacier retreated, the minnow expanded its geographical range and in an area that later became today’s Poland its expansion from the east stopped. The swamp minnow is a small fish that often occurs in small overgrown reservoirs, including peat ponds (pits after peat removal that have filled with water), that can get quite hot. So why do we find it in a colder climate and associate it with glaciation, when it can cope with higher temperatures? Well, the mud minnow adapts well to environmental conditions.They eat whatever they can find, and are not picky: usually eating small invertebrates, but when necessary also consuming algae and even dead organic matter. They also feel quite good in acidic waters and can also live in small, shallow reservoirs. These conditions are too harsh for most other fish. And other fish are what the minnow has a problem with. Fish of other species either hunt minnow, eat its eggs, or eat their food. So minnow feels best alone, when they are the only species of fish in the tank. For this to happen, the tank must be inhospitable to others – e.g. acidic, sphagnum water. This is why flooded old workings are a perfect place for her to live. In turn, a peat bog is a habitat whose stability and duration are related to temperature. In colder regions, water evaporates more slowly, peat bog plants grow slower and slower transform into a swampy forest. Thus, the colder climate favors the creation of small acidic reservoirs, which the minnow chose as its habitat so as not to compete with other fish.

Before you leave our peat corner, be sure to see fragments of living peat bogs! Just as our gardens grow plants that like acidic or alkaline soil, there are also plants in nature that prefer more acidic or more alkaline conditions. This is determined by the type of substrate and the method of water supply – two factors that create an environment for plants to live. In the garden, we sprinkle the plants with the soil they like. In nature, this habitat (place and its properties) causes plants to grow there that like the conditions prevailing in this place – then plant communities are created, i.e. groups of plants that feel good in such and no other conditions. We present two types of habitats here: one is acidic (raised peat bog) – right side, and the other is alkaline (alkaline peat bog) – left side. They look similar at first glance, but take a closer look! The raised bog grows mainly Sphagnum moss and cranberries and sundew (Drosera). Brown mosses grow in an alkaline fen (that’s their name, although they are usually green), and an orchid may grow here (e.g. Epipactis marshes), and between the plants you can sometimes find a tiny whorl snail. Raised bogs are fed only with rainwater, which does not contain any minerals, and the plants growing on them produce humic acids, which is why they are acidic and mineral-poor environments. Alkaline peat bogs are fed by flowing water, so it is an environment rich in minerals and is more alkaline in nature.

In front of you is the aquarium and terrarium section. Here it is always worth asking the staff what interesting things you can see at a given moment. All our aquariums are biotope aquariums – reproducing the conditions in the environment. They change a lot during the season. Let’s start with three aquatic terrariums with amphibians. We present here models or live individuals of newts, frogs and European fire-bellied toads.

 

Underwater dancers. Newts belong to a group of salamanders, Order: Urodela. Adults have an elongated body and tail, which is why they are sometimes confused with lizards. There are two species of newts in Warmia and Mazury: the more common, small smooth newt and the dark-colored great crested newt, which is the largest newt found in Poland. The latter is more difficult to see because it has greater habitat requirements and is less common. On the counter, adult newts seem inconspicuous. They hide in moist ground, most often in shaded places, in the forest litter. However, their mating season is a real spectacle. They take place in water. During this period, the male develops a high crest on his back. thanks to which it resembles an underwater dragon. During the underwater mating dance, it spreads a scent from special glands that is intended to charm females. He swims around her, shaking his tail spectacularly, trying to block her path, but not even touching her (how different from the chaotic mating of loud frogs). If the partner accepts the advances of such a dancer, she stops and waits until he deposits a bundle of stuck sperm in front of her (the so-called spermatophore). Then, it neatly introduces this package through the cloaca and into the body. There, when eggs are laid, internal fertilization will take place, and each egg will be carefully wrapped by the female in the leaves of aquatic plants. Newt larvae live in water. They are predatory just like adults. They clearly have feathery gills sticking out just above their heads. Great crested newt larvae are larger than common newt larvae, have more dots, and have long, thin fingers and a pointed tail tip.

Who wallows in shallow water. The European fire-bellied toad is one of the smallest Polish amphibians. It has dark camouflaging coloring on the outside, while its belly is decorated with a unique dark orange pattern for each individual. It uses it as a warning to predators – when threatened, it reflexively raises its limbs, showing the color, thus informing the predator that it is poisonous. The toad’s skin contains irritating substances that make it at least unpalatable. Although associated with the aquatic environment in which they spend most of their lives, are not the best swimmers. They have a poorly developed swim membrane and prefer shallow reservoirs, in which they swim around like unruly children, hardly leaving the water all summer. Their mating call lasts a very long time, the roar of fire-bellied toads can be heard until summer. To make a characteristic sound, the male inflates itself with air from its lungs, which may make it look like an inflated balloon for a moment. They stick the eggs individually under water to the plants. Tadpoles hatch from eggs and have almost transparent bodies with two dark stripesalong spine. The European fire-bellied toad is called KUMAK in Polish. And it is from this amphibian that the name of our education center comes from.

Fans of winter swimming and beach girls. Common frog and Moor frog are real fans of winter swimming. They start mating the earliest of all amphibians: they migrate to the water as soon as the ice melts and the temperature rises above zero. Mating takes place in the shallows and lasts quite a short time. The frogs spawn and quickly leave the cold water. These frogs spend most of the year on land, most often in forests, and have camouflaging colors that resemble forest litter. Beige and brown. Only during mating season do male common frogs get a blue-pink coloration of their dewlaps, while male moor frogs take on a surprising blue coloration. Pool frog, Marsh frog and their hybrid Edible frog are real sunbathers, they feel best when the water warms up properly, and they are in no hurry to leave the tank. Their mating season lasts a long time, and after spawning, these frogs continue to use the bathing area, basking in the sun on the shore and diving into the water from time to time. However, remember that amphibians are cold-blooded, their temperature depends on the ambient temperature, and they do not feel temperatures like we do.

What might you encounter in this dark corridor? Hide and seek game.  See if you can count all the tree frogs? Will you be able to spot a spadefoot spadefoot or a common toad?

Eastern tree frog. Hylidae is a wide-ranging family of frogs commonly referred to as “tree frogs and their allies”. They are distinguished by their bright color and lead an arboreal lifestyle. The discs on the frog’s toes, which it uses to climb trees and hedges, is the other characteristic feature. They like to sit on vegetation near bodies of water. They are usually slow and remain stationary for protection, relying on camouflage. Likewise, they are usually light green, sometimes olive, although dark green and various colors of brown or gray can be found. Their skin color changes due to the environment and the animal’s emotional state. They meet in Masuria eastern tree frog, but it is also found in Poland European tree frog.

Common spadefoot. It is sometimes known as Garlic toad due to the garlic scent released when irritated. These animals like to burrow to protect themselves from predators and spend most of the day this way. Unlike other amphibians, it has a vertical pupil.

Common toad. Toads have a stocky body and sinuous legs, walk rather than jump, and have skin covered with glands. Adults are active mainly at night, but juveniles can also be found during the day. In late summer and autumn, it is easy to see Common toad colored red. Common toad is the largest of the true toads. They begin their activity early, in March and April. The other species living in Poland: European green toad and Natterjack toad are thermophilic, so they start their activity later, when it is warmer. The European green toad has a distinctive camouflage coloration and can be easily found in gardens. The Natterjack toad has a distinctive white stripe along its body and moves quite quickly, which is why people sometimes mistake it for a mouse.

A fish that farts. Silty channels, shallow ponds or overgrown drainage ditches may become shallow and warm in hot summers, becoming low in oxygen. In the process of evolution, the organisms inhabiting them have developed adaptations that allow them to survive in such an environment. European fingernailclam, a species of small clam, are exceptionally hardy. They often inhabit muddy bottoms of reservoirs, tolerate oxygen deficiencies, and, if necessary, wander among plants higher up, where the oxygen content in the water is higher. In such a situation, we observe a color change in daphnia, from transparent to red or pink. This color is provided by hemoglobin, a red respiratory pigment that helps capture oxygen more actively. If the oxygenation of the tank improves, daphnia return to their transparent form within a few days. The body of the ramshorn snails also contains efficient hemoglobin instead of the hemocyanin present in most snails. Similar mechanisms work for some bloodworms or Oligochaeta (like sludge worms). Thanks to this, all the animals mentioned here can live in waters where the oxygen content periodically drops.

Can a fish survive in an environment where there is a temporary lack of oxygen? It turns out that yes! It inhabits the murky waters of ditches and canals, weatherfish. These fish like to stay at the bottom or bury themselves in mud. They methodically search the bottom, looking for invertebrates and plant remains and finding them, with barbels placed on the lips. From time to time, these fish come to the surface to swallow air and push it into the digestive system, where they breathe through the intestines. He releases the stale air through the end of his digestive system, making it look like it’s farting.

Caring fathers. In ordinary overgrown ditches with slowly flowing water, you can meet creatures whose mating habits amaze naturalists. Sticklebacks, inconspicuous, grey-greenish fish. They have 2 to 5 spines on their backs to protect against predators. For most of the year they live in small schools, hunting for small invertebrates. In spring, at the turn of March and April, mating begins. Sexually mature males take on intense colors. The belly becomes red, the back olive-blue and their entire body shimmers with a metallic shine. Additionally, the iris of the eye will turn into a distinctive blue celadon color. Males ready to breed migrate to shallower waters, where they establish their territories. In such a territory, the male digs a small hole in which he builds a circular nest from pieces of rotting leaves, filamentous algae, soft plants, etc. Then he forms it into a tunnel. Finally, it performs a zigzag dance, attracting partners. Many females lay eggs in one nest and are chased away by the male after spawning. The caring male takes care of the nest and even gently returns the small fry to the nest. Finally, when the fish grow up, the male loses interest, loses his mating colors and returns to normal matters.

The two largest aquariums are dedicated to various aquatic invertebrates. You can find there the largest water beetles, leeches, water snails, predatory bugs, dragonfly and mayfly larvae. There are times when aquariums are teeming with life, but they may seem empty. Especially when most of the larvae have completed their aquatic life stage and transformed into flying adults. You can always ask the staff for help if you don’t know what to observe. Our guides can also lend you a magnifying glass or a cheat sheet with selected invertebrates.

What about plants? They can be fascinating too. Read their story!

Difficult relationships between plants – a race to the sun.  At first glance, it seems that aquatic plants are a group of organisms that are peaceful and stable. We treat them as a permanent, unchanging element against which we observe the animals’ life struggles. Nothing could be further from the truth! There is intense competition in the world of plants and algae. Due to the different time scale, we rarely think about it, although we can easily see the effects of these impacts.
The great race in water reservoirs begins in spring. Organisms wake up from dormancy and begin intensive growth – primarily to ensure access to light, which is necessary for photosynthesis. Emergent plants (such as cattail or reed) raise their leaves above the water surface, use the nutrients contained in the substrate, but avoid competition for light with other species in the tank. The rest try to occupy as much space as possible and thus provide themselves with access to light (at the same time they make it difficult for other organisms to have access to light). Water lilies produce both underwater leaves (which are responsible for photosynthesis, especially in early spring, when the light reaches deeper into the reservoir) and floating leaves, which become more important in the following months.
It is for supremacy at the surface that the most intense battle takes place. Semi-aquatic knotweed produces a bare, limp and very long stem enabling the production of floating leaves. Although the frogwort hibernates at the bottom of the reservoir in the form of survival buds, it floats on the surface throughout the entire vegetation period, drawing nutrients directly from the water and not from the ground. Plant species such as duckweed function similarly. The water trough (a species of liverwort, a simple plant without roots) is not always able to dominate the surface of the tank, so it floats just below it, still providing it with the maximum possible access to light. Plants that produce only submerged leaves and cannot compete for light on the surface are adapted to cope with limited access to sunlight, and yet they present a very similar strategy – occupying as much space as possible near the surface of the tank. Pondweeds produce long stems by developing leaves at the top. Others, such as the hornwort, often float in the water column without anchoring to the bottom. As a result of this competition, different species dominate in different months and in different reservoirs. However, at the end of the season, most reservoirs are characterized by a similar structure – the surface is tightly covered with floating species, a thicket of submerged plants floating just below the surface and practically devoid of plants, the water depth and the bottom of the reservoir are strongly shaded.

Difficult relationships between plants – an invisible fight. Plants need not only light to live (which enables photosynthesis) but also nutrients and carbon, the source of which is most often CO2. The factor that is missing in the environment becomes the one due to the lack of which growth and development stops. Therefore, the competition for him will be the strongest. But not everyone wants to take part in such competition and there are other ways to do it! Some plants reach into a different environment to get what they need, e.g. plants with leaves sticking out above the water obtain CO2 from the air instead of water. Others use solutions that are unusual for underwater plants, e.g. The plant does not use CO2 at all, but takes carbon from other compounds. In poor environments, competition for nutrients (especially nitrogen and phosphorus compounds) is very strong. Carnivorous plants found an interesting solution. Swimmers, and the very rare aldrowanda, produce bubble-like traps that catch small animals (primarily daphnia, eyeworms and young mosquito larvae). But plants not only avoid competition, they can also actively fight each other! They produce and release compounds into the environment that affect other organisms. This phenomenon is called allelopathy. These substances act as mild poisons that deter, poison and weaken the remaining inhabitants of the tank! This chemical war takes place primarily between higher plants and algae (including cyanobacteria, often responsible for blooms). The rapid growth of algae may even lead to the death of plants. It is no wonder that higher plants secrete compounds that inhibit the development of algae, e.g. the compounds secreted by the yellow water lily are so strong that in extreme situations they can kill the competition, allowing this plant to dominate in the tank. Interestingly, some larger algae, such as stoneworts (looking a bit like underwater horsetails), have similar problems with access to light as aquatic plants and, like them, secrete substances that inhibit the development of smaller algae that cause water blooms. In this battle, large algae and aquatic plants support each other in stopping water blooms.

Turtle soup. The European pond turtle is the only native turtle found in Poland. Today, only a few populations remain in the Warmian-Masurian Voivodeship, mainly near Mikołajki and Olsztynek. It was once a common species, and the inhabitants of these areas appreciated these turtles, unfortunately also as food. There was an inn near Waplewo that served turtle soup, their eggs were sold at the fair, and it sometimes happened that a turtle shell was nailed to the doorstep of the house to protect against evil forces. Changes in the environment and exploitation of this species led to the extinction of the population in 150 years.

Where is my swamp? The main habitat of turtles are water reservoirs. As their name suggests, they like small bodies of water, including swamps, with a lot of vegetation and duckweed. In such conditions, they camouflage themselves perfectly, their yellow dotted head sticking out of the water looks like a stick covered with duckweed. This turtle hibernates in mud, basks on tussocks and fallen tree trunks in spring, and cools in water in summer. The female comes onto land only to lay eggs. Agriculture, reduced water levels and widespread drainage of the niche of their habitats and homes.

Water is not everything. In addition to ponds, turtles also need a good place to lay eggs, close to where they live. If there is no good place nearby, females have to travel long distances to find one, which is very risky for them and their future young. In such situations, females often lay eggs in inappropriate places. Turtles choose unique places for breeding grounds. Sandy, with light soil and in places facing south where the sun shines the longest, covered with small sun-loving plants. This gives the eggs a good chance of developing. On warm, muggy evenings in June, females come out to the breeding grounds. It is suspected that they do this at such a time that the storm will wash away the traces of their passage, making it difficult to find the eggs. If the rain falls earlier, the female changes her mind and does not lay eggs that day. To make the process go smoothly, the female takes some water with her to soften the ground, make digging easier and provide adequate humidity for the eggs. Wandering, digging and laying eggs is a huge effort, after which the female rests for many hours. In warm summers, young turtles hatch in autumn, and in cold summers they can hibernate until spring.

Fake incubator. If breeding grounds are unavailable (built-up or fenced), females may lay eggs in random places that are inappropriate and do not provide opportunities for the development of young turtles. It happens that even good breeding grounds change their character when they are plowed or fertilized. Similarly, sown plants can imitate turtles’ favorite habitats, but they grow much faster and higher, shading the places with eggs that need warmth.

The next aquarium may seem empty, but it is an aquarium that represents a puddle. And the animals we can meet there live to the rhythm of the rain. If you’re lucky, you might see some of the rare puddle-dwelling animals.

Can a puddle be a good place to live? It is an unstable environment, it freezes completely in winter and dries out quickly in summer. Its existence depends on the intensity of precipitation, so it may happen that it does not appear at all in a given year. Moreover, the puddles are shallow, they heat up significantly during the sunny day and cool down at night, and significant temperature fluctuations also result in changes in oxygen content. This periodicity and instability makes living conditions in the puddle too difficult for most aquatic animals. But through evolution, there are also some that can cope perfectly with these extreme conditions.

1. The secret of their success lies in the specificity of their life cycle. So let’s look at it – using the example of European tadpole shrimp. Adults, after reaching sexual maturity, produce significant amounts of eggs. From some of them, the larvae hatch in the same season. However, most of them develop for a while, then the process stops and cysts (survivable eggs) are formed, and the so-called cyst bank (i.e. a stock of cysts that will begin to develop when environmental conditions are favorable again).
2. Cysts are resistant to drying, freezing and the harmful effects of UV radiation. Moreover, periodic drying (and sometimes freezing) is usually necessary for the hatching process to occur at all. It is a kind of information that the puddle has just formed and its duration will be long enough to complete the entire cycle.
3. Cysts from dried puddles can be carried by the wind and colonize new areas. This passive transport is the only way for individuals to move over long distances!
4. When the days get longer after winter and spring rains come, puddles form on the sandy roads. Appropriate temperature, soft rainwater and light signal the start of hatching of the new generation. Higher temperatures and longer days suggest the end of winter, and the light reaching the cysts is a signal that they are shallow enough in the substrate and the hatched larvae will be able to get into the water column. Rainwater low in minerals indicates that the puddle is young and freshly formed. All this is a signal that it is a good time to hatch and the process begins! During the season, the nature of the water changes, which limits the hatching of larvae.
5. At one time, there can be eggs, cysts, larvae and adults in the same puddle. This mechanism of uneven egg development additionally protects the population against extinction. If for some reason the spring pool dries up before the larvae mature, the cyst bank will still remain and provide the population with a chance to complete the cycle during the next rains.
6. Hatched larvae grow rapidly. Initially, they filter microscopic organisms from the water, over time they cope with larger and larger food particles, and fully grown moths, apart from filtering food, can obtain it more actively and sometimes hunt other smaller animals. Growing up and reaching sexual maturity may take just a few days.

Four smaller aquariums, the last one in this section, change frequently. In early spring you can see tadpoles here, at other times there may be water beetle larvae or heteropterans here.

Amphibian kindergarten.  Common toad tadpoles are very small (although the adult toad is really big), but pelobates fuscus tadpoles are very large (although the adult pelobates fuscus is quite small). European fire-bellied toad tadpoles, by contrast, are light-colored. Tree frog tadpoles are golden and have a fin that extends to the head. Their characteristic feature is the wide set of eyes and nostrils. European fire-bellied toad tadpoles have an almost completely transparent body, with dark stripes running along the spine (adult are dark above and have orange-black spots on the belly). Green frog tadpoles are olive green with spots, and brown frog tadpoles are dark with shiny metallic spots. Newt larvae definitely look more like their parents. They have elongated bodies ending in a tail and four legs. They grow their front limbs first and at this stage they look a bit like a mermaid. They are predatory just like adult newts. They have very clearly visible feathery gills sticking out just behind the head. Great crested newt larvae are larger than common newt larvae, have more dots, long, thin fingers and a pointed tail end.

Take a deep breath. During gas exchange, animals living in an aquatic environment can take in oxygen dissolved in water or use atmospheric air. Depending on their size and evolutionary fate, individual species cope in different ways.

Animals that use atmospheric air obtain oxygen by:

1. respiratory tubes and appendages
2. trachea (breathing tube system) – in order to dive, they store air under the wing covers (diving beetles) or on the underside of the body (silver water beetles, hemipterans)

Animals that use oxygen dissolved in water get it by:

1. body shell
2. internal or external gills
3. rectal gills – gills located inside the body, in the hind intestine

Time for a break! There are photos of amphibians on the board, most of which you have already read about, but you haven’t had the opportunity to hear them croaking yet! Sit in an armchair, press a button and be transported to the shore of a small reservoir in spring.

Toddler zone. This is a place where the youngest children can relax for a while and explore the world in their own way.

Building a nest is a difficult task. Try if you can do it. Look at the nests, you can draw a nest to make. You have tweezers and tongs to help you, just like birds have beaks. Try not to use your fingers for this.

A small, agile weaver. The Eurasian harvest mouse is the smallest Polish rodent and one of the smallest Polish mammals (only some shrews are smaller). They usually weigh around 6g: the same as a five-złoty coin or 20 euro cents. When you are such a small animal, the reeds and grasses become a tall forest. And it is in this environment that the harvest mouse can most often be found. Thanks to its prehensile paws, it agilely climbs the stems, looking for ears of grain. To maintain balance, it balances with its long tail, which it often wraps around plants, treating it as an additional paw or a safety rope when climbing. Harvest mouse do not dig burrows. They weave spherical nests suspended high (up to about a meter above the ground) on the stems or twigs of shrubs – in them, they rest, protect themselves from bad weather and raise their offspring. Whenever possible, the nest is built of live blades of grass, which the grasshopper holds with its front paws and tears into thinner strands with its incisors. Then he weaves them into a loose ball. The entire structure is mounted on stiff, straight stems. In winter, they also weave such shelters, but smaller and placed closer to the ground (where there is less wind) – to keep them warmer.

A big one with iron teeth. The most characteristic feature of rodents are their teeth, especially their incisors. Why are they so unusual? Let’s take a closer look at them using the example of beaver teeth – Poland’s largest rodent, which can weigh up to 30 kg! There are incisors at the front of the skull (two at the top and two at the bottom). These are the teeth that the beaver uses to cut down trees. They grow throughout their lives, wearing out while foraging for food. The front layer of the teeth contains a thicker layer of enamel, so it wears off slower than the back layer – thanks to this, the teeth sharpen themselves. But it is not everything. Beavers’ incisors are clearly orange. This is because their enamel contains iron (in most other rodents, magnesium is present there). Thanks to it, the teeth are exceptionally hard and durable, and beavers are able to cut down quite thick trees without any problems. All this to get to the leaves, branches and young thin bark that these animals like the most. In the beaver’s skull, you can also see a gap between the incisors and the remaining teeth. During this gap (called diastema), the animal can suck its cheeks. This prevents shavings from felled trees from getting deeper into the mouth.

Skinny larvae and fat larvae. Dragonfly larvae hid under the water in the reeds. You can spot them and count them. But be careful, not all larvae are the same. If you look closely, you will see that there are skinny larvae and fat larvae. When they transform and fly out of the water, they will also look different. Skinny larvae are Damselfly (Zygoptera in Latin). Skinny as the Z in their Latin name. They are long and swim somewhat awkwardly in a zigzag pattern (again, like the Z in their name). At the end of their abdomen, they have three gills that resemble leaves. They use them to breathe. Adult Damselflies have a delicate structure – they are long and delicate and have two pairsthin similar to each wings which, when resting, they lie parallel to each other above the body. Fat larvae are Dragonfly (Anisoptera in Latin), wide and bulbous like the A in the Latin name. They are shorter and more massive. They walk majestically over the bottom and plants. They do not have protruding gills because they breathe through the intestine (which contains the gills). The larvae pump water into their abdomen, which also allows them to use jet propulsion.

Natural sewage treatment plant. The waterside reed bed is a favorite habitat of birds. They can build nests in them, which are hardly visible and difficult for predators to access. Reed beds provide both a home and shelter. Phragmites, Typha and other waterside thickets are great habitats not only for birds. They contain both small invertebrates and even large mammals, such as moose. But that’s not all. These bushes have amazing water purification properties: among other things, they can remove huge amounts of nitrogen and phosphorus, which is why they are used in natural treatment plants. Reeds in field ponds, on the edges of lakes or in river bends fulfill the same task. It oxygenates (with the cooperation of microorganisms) and purifies the water flowing into the tank. Thanks to this, cleaner water flows further through the rivers to the sea. But beware! Reed is a very expansive species, which means it spreads easily and can displace other species. In many countries, it is considered an invasive species.

Success of the silver girls. Prussian carp, sometimes known as Silver Prussian carp, can be found in small, well-heated water reservoirs. The species, whose homeland is Asia, was brought to Europe two thousand years ago. It is able to inhabit isolated ponds, reproduces quickly and is quite resistant, easily becoming the dominant fish species in the water reservoir. But how does it come to inhabit various tanks so easily? The culprit turns out to be ducks, which eat their eggs and do not digest all of them thoroughly, transferring them along with their excrement to other water reservoir. A large part of the population of these fish in Poland are females, which, although they need sperm to develop eggs, it does not have to be sperm of their own species.

Toothless goldfish. Crucian carp, a Polish native species, occurs in shallow, overgrown and muddy reservoirs. It has golden scales. In poor and crowded reservoirs, it sometimes takes on a dwarf form, with a more elongated body but smaller dimensions. It feeds on aquatic invertebrates and plants. The Crucian carp has no teeth or a separate stomach. At the back of the throat there are so-called pharyngeal teeth, crushing and grinding food digested in the intestine. In case of danger, instead of running away, they dive into the mud at the bottom. Currently, there are fewer and fewer of them, being replaced by Silver Prussian carp.

Giants from the Caucasus. Mantegazzi’s hogweed or the most frequently mentioned Sosnowsky’s hogweed are the largest herbaceous plants currently found in Poland. They are very similar to each other, they come from the Caucasus and were imported on purpose as fodder plants. Due to their size and large annual increase in biomass, they seemed to be an ideal fodder solution for animal breeding and a great plant for silage. It turned out differently. There were problems with cultivation, and it was discovered that these plants posed a threat to human health. They secrete substances that can cause burns similar to those caused by boiling water. These substances are activated especially on hot days by sunlight. So crops were abandoned and borscht spontaneously began to spread. They like moist areas, so they wander along alder forests, lakeside and riverside thickets. They displace native plants, are very resistant and difficult to combat. Additionally, they produce huge amounts of seeds, which remain in the soil for years in the form of a seed bank, waiting for a convenient moment to germinate.

American troublemaker
Slender, with beautiful fur and piercing eyes, the American mink is a very skillful predator. It lives and hunts on the border between land and water habitats. In both of them, he moves efficiently and chooses as his victims what is easier for him to obtain. Due to this plasticity, it is a more effective predator than other European species. It enters the parade and easily competes for food with several of our native species – the ferret, the stoat, the otter. And if he likes something, he eats it without the slightest sentiment. In Masuria, the number of coots and great crested grebes decreased several times after the appearance of minks in the area. In England, as a result of colonization by the mink, the number of water vole decreased in 96% of the monitored sites. The mink causes trouble wherever it appears. It is also responsible for rebuilding the prey-predator system in the area where it appears. The wild population of American mink in Poland comes from escapees from farms where these animals are bred for fur. The expansion of the American mink began in Poland in the 1980s and is progressing: soon the mink will be found throughout Poland.

Blooming lakes. When the water noticeably changes color due to the massive growth of algae in a body of water, we say that the water is blooming. Most often, colonies of green algae and cyanobacteria bloom, but they can also be diatoms or several species at once. Of course, phytoplankton do not bloom in the sense that meadows do. It is simply the mass development of small organisms in a short period of time.

A riot of colors. Depending on what blooms and when, the water has different colors. The green-blue color is characteristic of cyanobacteria blooms, and in certain phases the water may take on a distinct bluish, yellowish or red-brown color. If the bloom is caused by diatoms, the water turns brown, if dinoflagellates – reddish brown, if eugleninia – red, and if golden algae – brownish.

Let us eat and multiply. Massive development of phytoplankton occurs when there are a lot of nutrients in the water (especially phosphorus and nitrogen) that it uses: since it has everything it needs within its reach, it multiplies rapidly. There are conditions that favor this: e.g. a dry and hot summer, when there is little water in the reservoir, nutrients thicken, and high temperatures favor the development of phytoplankton. Mass blooms also occur when a lot of nutrients from outside enter the reservoir – these may be sewage or fertilizers flowing from the fields. This phenomenon occurs more frequently in such conditions.

Toxic balls. We most often hear about cyanobacteria and their toxic properties, because bathing in blooming water can cause skin reactions such as burning, swelling or rash, but also food poisoning. Interestingly, just inhaling the air floating above the blooming water can cause serious poisoning. The toxins produced by cyanobacteria are strong and in high concentrations may prove more dangerous: there have been fatal cases among dogs and cattle. The blooms are often caused by the cyanobacterium Microcistis, which has the form of balls stuck together. Fortunately, not every bloom that appears in water is toxic.

A growing problem. Every bloom, even non-toxic ones, is dangerous because it leads to disturbances in the ecosystem. The cells of the organisms causing the mass bloom eventually die and organic matter becomes denser, which in turn worsens the living conditions of other organisms. The decomposition processes of organic matter cause oxygen to be depleted at the bottom of the reservoirs. This, in turn, may lead to the death of fish or invertebrates. Due to climate change, drying of reservoirs, long periods of high temperatures – the phenomenon of blooms is increasing all over the world. Algal blooms are becoming more common and more intense. And toxic blooms, especially when they occur on a large scale, affect drinking water supplies, agriculture, fishing, recreation and tourism.

In this aquarium you can see not only algae, but also… garbage. This is garbage pulled from a lake in Masuria. This is just a small part of what was caught,
only a small part of one lake was cleaned up. There’s garbage like this everywhere. Do we really need this
to do? Take bottles, bags and other rubbish with you. Save nature!

This is almost the end of our trip. Take a walk across the wetlands and see how different the selected habitats are: alder carr, sedge bed, coniferous swamps and raised bogs. Then go back upstairs.

Do you remember what a stickleback looked like? And how did the beetle larva move? Time for some fun again! Here you can color one of several aquatic organisms however you want. And then we will try to bring it to life in our virtual aquarium! Have fun!

Before you leave us, you can meet one of our scientists who answers the most frequently asked questions related to his research. Unfortunately, this exhibit is entirely in Polish, but someone from the staff will be happy to be your translator!

 

Thank you for visiting us and we invite you again!