Could it be a "sunomono" salad? If so, it's a basic Japanese vinegared vegetable dish that often includes shellfish. Typically, thinly sliced veggies (ie. cucumbers) or bean thread noodles are dressed in vinegar/sugar (also sometimes light soy sauce & salt) liquid. I've seen crab, octopus, shrimp, shirasu, etc. in sunomono. It's sometimes topped with sesame seeds or sliced green onions. Very light, served in small portions (almost like a Japanese amuse bouche).
re: Deb H.
thanks so much for the reply and the details...my fiance is from Peru...from him, i have learned what ceviche is and enjoy that dish a lot...we ordered sunomono recently at our favorite sushi restaurant here in Orlando and both agreed it was a lot like ceviche... now that we see the ingredients, it truly IS a lot like ceviche, but with the sesame and vinegar, slightly different...we loved it and will continue to order it...thanks so much again for the info...