Crucian and silver crucian carp
The only evidence of kinship between the two crucians is their common modesty and extraordinary vitality. In other respects, they differ significantly, and some specific data can be inferred, that they simply hate each other.
Karas feels best in shallow places, silt and overgrown warm lowland waters, where conditions exclude the possibility of other fish living. Its Asian relative has a larger living space and lives both in stagnant waters, and flowing. The origins of both species are also different. The crucian has been with us since ancient times, silver crucian carp migrated to Central European waters under mysterious circumstances (probably in the late 1950s) all the way from East Asian lands. Literally overnight, it appeared everywhere, in every type of water and began to enforce its rights even at the expense of native fish. At the beginning of its invasion in the 1970s, some streams of the Danube Plain were directly threatened by an explosion of the silver crucian carp population..
The extremely fast development enables the silverfish to reproduce in a specific way – without the active participation of sperm (gynogeneza) – during which the sperm does not fuse with the egg. This guarantees the preservation of the species, and in an emergency, it is enough, that only one individual could get into any water. It will definitely be a female (because in almost all European waters the entire population of the silver crucian carp is female, there are mixed populations in their home lands), and from her roe (into 250 thousand. eggs) will hatch, of course, more females.
The silver crucian invasion, Fortunately, it ended as soon as it began, and now its condition (in the Danube basin) stabilized at the appropriate level. Anglers gradually became interested in him, because the weighing fish 1,5-2 kg are not to be scorned, what's more - silver crucian is able to repay each type of bait offered with certain baits without any, seasonal or depending on the time of day, whims.
Both types of crucian carp can be caught using methods identical to those of similar fish. Most of all, we are looking for Karaś at the bottom, rather silvery in the mid-water, in summer, even just under the larger leaves of aquatic plants.
Crucian is a bit more sensitive to water temperature and e.g.. Polish experience shows, that it takes best in summer (66% year-round fishing from June to August), while the silver crucian is consumed evenly throughout the season.