If your database has a key field specifier then you may want to combine
genus and species into one field.  The each record's key field must be
unique and usually the genus and species of an animal is unique.  The
problem with the substrings may be handled by specifying a difference
between uppercase and lowercase letters, or specifying that you don't care.
As for separating genus and species for printouts or whatever, it should
be easy to parse through the field to the space and either print to the space
or from the space to the end.
 
Bruce Rieber
[log in to unmask]