We have discovered nine ultra-compact dwarf galaxies ( UCDs ) in the Virgo Cluster , extending samples of these objects outside the Fornax Cluster .
Using the 2dF multi-fiber spectrograph on the Anglo-Australian Telescope , the new Virgo members were found among 1500 color-selected , star-like targets with 16.0 < b _ { j } < 20.2 in a two-degree diameter field centered on M87 ( NGC4486 ) .
The newly-found UCDs are comparable to the UCDs in the Fornax Cluster , with sizes \lesssim 100 pc , -12.9 < M _ { B } < -10.7 , and exhibiting red , absorption-line spectra , indicative of an older stellar population .
The properties of these objects remain consistent with the tidal threshing model for the origin of UCDs from the surviving nuclei of nucleated dwarf ellipticals disrupted in the cluster core , but can also be explained as objects that were formed by mergers of star clusters created in galaxy interactions .
The discovery that UCDs exist in Virgo shows that this galaxy type is probably a ubiquitous phenomenon in clusters of galaxies ; coupled with their possible origin by tidal threshing , the UCD population is a potential indicator and probe of the formation history of a given cluster .

We also describe one additional bright UCD with M _ { B } = -12.0 in the core of the Fornax Cluster .
We find no further UCDs in our Fornax Cluster Spectroscopic Survey down to b _ { j } = 19.5 in two additional 2dF fields extending as far as 3 \arcdeg from the center of the cluster .
All six Fornax bright UCDs identified with 2dF lie within 0 \fdg 5 ( projected distance of 170 kpc ) of the central elliptical galaxy NGC1399 .