In case it helps: fingerling eupterus have stripes, squiggly stripes, bloches, or stripes combined with spots, while the adults have the well known look. Browse through these photos, if you will, and you will immediately see the difference
http://www.planetcatfish.com/common/species.php?species_id=121
And this is what Synodontis grandiops looks like:
http://www.planetcatfish.com/common/species.php?species_id=710 It appears from reading around that ~90-99 times out of 100, people that have this fish think they have the multipunctatus
http://www.planetcatfish.com/common/species.php?task=&species_id=95 , both called the cuckoo synodontis.
Pretty hard to tell apart, btw:
General Remarks S. multipunctatus and
S. grandiops are most reliably separated by pectoral-fin ray counts with
S. mutipunctatus having 1 pectoral fin spine with 8 soft rays and
S. grandiops having a count of 1, 7 . The soft pectoral-fin elements (i.e. the rays) are almost always branched (the only exception being the last one or two rays, which are sometimes unbranched) a ray is counted as one at its base before it branches out. Also keep in mind the larger adult size of
S. multipunctatus. It appears a southern and northern (at least) tribe exist, with the northern being the ''regular'' form and the southern being generally paler with more spacing between the spots.