Fish 🐟
Fish 🐟
Where there is water there is fish! Of course there are exceptions - like for example temporary wetlands where water does not stay for the entirety of the year and keeps cyclically drying out. But in permamently flooded places with high enough water level there is a good chance of seeing some interesting fish species.
The list below presents some of the fish inhabitants of Polish wetlands!
Northern pike. Source.
Northern pike (Esox lucius) - a carnivorous fish which can grow up to 40-55cm in size. It is found throughout Europe, Asia and Northern America. It is not an active hunter - northern pike prefers to hide and wait for the pray to pass by although bigger individuals are known to chase other fish (including its own species), small land animals like rodents or frogs, and even some aquatic birds. Northern pike's population has decreased due to overfishing and habitat loss.
Eurasian ruffe. Source.
Eurasian ruffe (Gymnocephalus cernua) - a freshwater fish reaching 15-20cm in size. It is greenish or yellowish in color with multiple brown spots along its body. It has a characteristic spiny dorsal fin which makes it uncomfortable for its predators to eat them. It feeds on tiny invertebrates like mosquito and mayfly larvae and it tends to feed intensely in early morning hours. It prefers stationary waters and avoids ponds with excessive vegetation.
Wels catfish. Source.
Wels catfish (Silurus glanis) - this freshwater fish is sometimes refered to in Poland as "the king of the Polish waters"! It is due to its size - it is the biggest freshwater fish of Europe. It can reach even 3m in length! Its characteristic feature are two long barbels on the upper jaw and four shorter barbels on the lower jaw referred to as "moustache" in Polish. Maximum lifespan of wels is 80 years.
Weatherfish (Misgurnus fossilis) - freshwater fish reaching 30cm in size. It enjoys sludgy and muddy waters in which it spends days hidden on the floor. It is active at night when he feeds on tiny molluscs and insect larvae. It is under partial protection and labelled as being close to endangered. An interestic fact about weatherfish is that it can breathe atmospheric oxygen - it gulps air with their mouth which then passes through their digestive system and eventually through their intestines which are capable of absorbing oxygen.