On FitDay.com, there's an entry outside the database that includes sea urchin (we are sushi enthusiasts), but within FitDay, there is no entry.
^^ That is the link that we found off a Google search for entering sea urchin or uni as a custom food and we discovered that FitDay had an entry! But it's not found if you log into FitDay to enter it into your daily tallies.
Frustrating. I had to create a custom food for my entry, though there are soooo many divergent representations of sea urchin's nutritional value.
Once I add sea urchin as a custom food (I can only choose "1 serving"), if I change the entry to "oz" (which isn't an option during the entry phase), the calorie content changes from 64 calories to 1,800+ calories!! That doesn't make sense at all.