Alpha particles as a fission product?

[kilele]

Hello. Why isn't there alpha decay in fission reaction or fission fragments evolution ? is there only gamma and betas?

 

[Astronuc]

Transactinides do decay by alpha or beta decay, and some decay by spontaneous fission.

Fission products have significantly reduced masses peaked around 90 and 140 amu, so they most decay by gamma or beta emission, and occassionally neutron emission (delayed neutrons). The absorption of a neutron (by a fissile nuclide like U-233, U-235 or Pu-239) usually leads to a distortion of the nucleus resulting in fission. However a fissile nucleus can absorb a neutron and not fission, but decay by gamma radiation, and subsequently alpha decay. U-236 decays by alpha emission to Th-232.

http://www.nndc.bnl.gov/chart/reCenter.jsp?z=92&n=144 (select Zoom 1 if the details don't appear)

 

[kilele]

Fission products have significantly reduced masses peaked around 90 and 140 amu, so they most decay by gamma or beta emission, and occassionally neutron emission (delayed neutrons).

Thanks Astronuc didnt know about this chart of nuclides.
so why they most decay by gamma or beta emission? could you provide some explanation based maybe on nuclear and coulomb forces?