Mark Zahra will appeal against the severity of a careless riding suspension, with the ban threatening to rule him out of the riding Fontein Ruby at the filly's next start.

Zahra was outed for 16 meetings at Mornington on Sunday after pleading guilty to careless riding in the third race on Chalk It Up.

His ban starts after Monday's Sandown meeting and runs until midnight on April 20.

Zahra said he would appeal against the severity, with stewards finding the incident to be in the high range.

Fontein Ruby is scheduled to have her next start in the Group Three Schweppervescence Stakes (1800m) in Adelaide on April 18.

The Robert Smerdon-trained Fontein Ruby, last-start winner of the Listed Alexandra Stakes at Moonee Valley, is being aimed at the Group One Australasian Oaks next month.