ground ▁into ▁the ▁se w age ▁system ▁and ▁instead ▁an ▁artificial ▁short ▁clean ▁stream , ▁named ▁Little ▁Dan ube . ▁It ▁is ▁ 1 . 5 ▁kilom eters ▁long ▁and ▁is ▁a ▁mini ature ▁representation ▁of ▁the ▁entire ▁Dan ube ' s ▁flow , ▁from ▁the ▁Black ▁Forest ▁to ▁the ▁Black ▁Sea , ▁including ▁islands , ▁pen ins ulas , ▁hills , ▁mountains ▁and ▁pla ins . L ittle ▁Dan ube ▁is ▁populated ▁with ▁ 4 0 ▁fish ▁species ▁and ▁plants ▁were ▁plant ed ▁along ▁its ▁banks , ▁both ▁fish es ▁and ▁plants ▁being ▁characteristic ▁for ▁the ▁" Big " ▁Dan ube . ▁ ▁A ▁series ▁of ▁fish ▁p onds ▁were ▁created . ▁Main ▁species ▁include ▁common ▁car p ▁and ▁tr out . ▁Inside ▁the ▁Center , ▁there ▁are ▁ 4 0 ▁aqu ari ums ▁with ▁numerous ▁types ▁of ▁fish : ▁common ▁bar bel , ▁h uch en , ▁bro ok ▁tr out , ▁common ▁min now , ▁e el , ▁gold fish , ▁European ▁mud min now , ▁common ▁ro ach , ▁common ▁b ream , ▁W els ▁cat fish , ▁z ander ▁and ▁Northern ▁pi ke , ▁but ▁also ▁the ▁gen et ically ▁mixed ▁fish ▁population . ▁The ▁fish ing ▁of ▁car p ▁and ▁cat fish ▁is ▁allowed . ▁One ▁section ▁is ▁turned ▁into ▁the ▁botan ical ▁water ▁garden ▁with ▁ 4 0 ▁species ▁of ▁aqu atic ▁plants , ▁with ▁▁ 1 5 ▁species ▁of ▁du cks , ▁ 5 ▁species ▁of ▁ge ese , ▁sw ans ▁and ▁pe ac ock