A systematic search for 22 GHz H2O megamaser emission is reported for
50 nearby (z less than or similar to 0.15) FRI galaxies. No detection
was obtained, implying that ultraluminous H2O masers (L-H2O > 10(3) L-
.) must be rare in early-type galaxies with FR I radio morphology. Des
pite higher radio core luminosities the detection rate for our sample
is lower than in similar surveys of late-type Seyfert galaxies. This p
uzzling difference between Seyferts and low-power radio galaxies could
be explained in several ways: a) the maser emission is saturated and
therefore independent of the radio core luminosity, b) the masers are
unsaturated and originate in a thin circumnuclear gas disk, so the 'se
ed' radio continuum would come from the far jet which is relativistica
lly dimmed or c) the amount, kinematics, or the distribution of the mo
lecular gas in the nuclei of Seyferts and radio galaxies is different.
Further studies of maser properties may provide clues to the differen
ces between radio-loud and radio-quiet AGN.