We report the discovery of 158 previously undetected dwarf galaxies in the Fornax cluster central regions using a deep coadded u,g and i -band image obtained with the DECam wide-field camera mounted on the 4-meter Blanco telescope at the Cerro Tololo Interamerican Observatory as part of the Next Generation Fornax Survey ( NGFS ) .
The new dwarf galaxies have quasi-exponential light profiles , effective radii 0.1 < r _ { e } < 2.8 kpc and average effective surface brightness values 22.0 < \mu _ { i } < 28.0 mag arcsec ^ { -2 } .
We confirm the existence of ultra-diffuse galaxies ( UDGs ) in the Fornax core regions that resemble counterparts recently discovered in the Virgo and Coma galaxy clusters .
We also find extremely low surface brightness NGFS dwarfs , which are several magnitudes fainter than the classical UDGs .
The faintest dwarf candidate in our NGFS sample has an absolute magnitude of M _ { i } = -8.0 mag .
The nucleation fraction of the NGFS dwarf galaxy sample appears to decrease as a function of their total luminosity , reaching from a nucleation fraction of > 75 \% at luminosities brighter than M _ { i } \simeq -15.0 mag to 0 \% at luminosities fainter than M _ { i } \simeq -10.0 mag .
The two-point correlation function analysis of the NGFS dwarf sample shows an excess on length scales below \sim 100 kpc , pointing to the clustering of dwarf galaxies in the Fornax cluster core .