  We introduce isospin dependence in the cluster recognition algorithms used in
the Quantum Molecular Dynamics model to describe fragment formation in heavy
ion collisions. This change reduces the yields of emitted nucleons and enhances
the yields of fragments, especially heavier fragments. The enhancement of
neutron-rich lighter fragments mainly occurs at mid-rapidity. Consequently,
isospin dependent observables, such as isotope distributions, yield ratios of
$n/p$, $t/^3He$, and isoscaling parameters are affected. We also investigate
how equilibration in heavy ion collisions is affected by this change.
