Phytoplankton
The diversity of phytoplanktons records 234 taxons with one specially distinguished algae Batrachospermnum in the parts of the current where there are very strong Drina springs and stronger current of the Batar side river.
The characteristics of Zasavica have conditioned this water eco-system into being populated by numerous invertebrata where the presence of the following species is emphasized: freshwater sponge (Spongilla lacustris) and jelly fish (Craspedacustra sowerbii), oligoheta (Rynchelmnis limnosela) and many species of planaria. All the above mentioned organisms are good bioindicators of water quality.
Out of the overall 220 taxa of zooplankton, 21 taxa are new and represent the first sightings for the fauna of Serbia (e.g. Collurela geophila, Collotheca ornata cornuta, Lecana elongata, Lepadella apsida, Squatinella bifurca bifurca, Ptygura forcillata, Monommata appendiulata and others).
Out of the numerous insects (a total count of 250 taxa), fifteen of them are under protection as rare natural species.
During the course of entomological explorations conducted at the Special Wildlife Reserve of Zasavica in addition to the large number of xylophagous insects (“strizibuba”) and a few endemic species of the Balkan Peninsula, there have been registered also three new species of fauna in Serbia, and those are:
Arhopalus syriacus (Reitter, 1985), which is dispersed throughout the Mediterranean, and it has been even found on the Canary Islands and it usually prefers the habitat of a pine tree. It grows to the size of 2.5 cm, is brownish in color and appears from the month of May throughout August. Its growth cycle lasts three years. At the Wildlife Reservation, it had been found in habitats at the Black Bara Jovaca, in the forest on dry alluvial ridges.
Morimus asper (Sulzer, 1776) is present from the South-West all the way to the South-East of Europe and it is dispersed along the areal of the beech xylophagous insects (Morinus funereus) a rare natural species of Serbia. It grows up to 4 cm in length, and can be found from April through to August. The metamorphosis stage lasts for about 7 years. It populates the forests of solid deciduous trees (ash and oak). This species was found in the Wildlife Reserve at the Crna bara-Drenova greda, in a forest of ash and oak trees.
Agapanthia lais (Reiche, 1858) had been found sporadically in Greece, Syria, Bulgaria, Jordan and Turkey. It grows to a length of 1.5 cm, metallic blue in color, appearing from May to June. The metamorphosis cycle lasts around one year. This species had been found in Zasavica II-Turske livade, in the forest.
Along with the known number of species, these three are among the 253 types of xylophagus insects in Serbia.
In the Natural Wildlife Reserve of Zasavica there have overall been registered 35 types of xylophagus insects. Out of the overall number of species, six are considered to be rare species in Serbia: Stenopterus similatus, Lampropterus femoratus, Cyrtoclytus capra, Pilemia tigrina, Agapanthia cynarae and Agapanthiola leucaspis. Two species are endemic to the Balkan Penninsula: Stenopterus similatus and Agapanthia cynarae and two other species, Cerambyx cerdo ssp. cerdo and Morinus funereus are under protection as rare natural species in Serbia and also on an international scale.
During field research and exploration in the shrubs and bushes along the length of Zasavica an endemic firefly under the scientific name of Zeuneriana amplipennis (br.W.) had been discovered there.
This species had been described in 1882 on the basis of specimens found in swampy areas along the Sava River near Zemun and Belgrade. In the following year, in 1883, Josif Pancic had found specimens near Makis. Later in the period from 1900 – 1951 members of this species were found by domestic and foreign researchers alongside of the Sava and Danube rivers, but also in Banat. Since 1960 the endemic firefly has been present in almost all of the marshy terrains of the lower flow of the Sava river (Obedska Pond, Grabovacke Forrests, Zabreske Meadows, Makis and other places), as well as in Pancevacki rit (Pancevo Marshes) on the aluvial plane of the Danube. This endemic firefly is obviously characteristic only for marshy habitats in the narrowest part of the Pannonian Plain and represents an endemic species of Serbia. In the aluvium of the Sava, Danube and Tisa rivers and their tributaries in the Southern part of the Pannonian Plain there had existed extensive marshes. With the recclamition of the marshes and the transformation of mesophilic meadows into fields under crops (into arrable land) many of these habitats have dissapeared. The typical habitats of this specie are shrubs and grassy meadows of the mesophilic type, which means that they have a hydrological seasonal dynamics and the waters posses an ephemeral (periodic) character. At all of the explored habitats the endemic firefly had been found to be in relatively small populations. The populated localities at Zasavica are at the same time findings of this kind that are situated in the furthest western reigions of Serbia.
