Translucent dark blue glass; cast, wheel-cut and polished. Narrow oval dish or cover in form of fish, with four projections from rim, cut in form of dorsal, caudal and anal fins, and tail; interior hollow; exterior has rounded contours of fish, except at highest point, which is flat; anatomical details indicated by incisions and cutting in low relief: mouth, eye, cheek, operculum, pectoral fin and rear part of lateral line; details on head shown in relief, pectoral fins indicated by long incised lines, lateral line by row of notches; exterior surfaces of fins and tail plain, interior surfaces have incised lines indicating spiny components.

Roman glassmakers sometimes produced objects in unexpected and highly original forms. This unique fish was cast in a mold. The upper surface was polished and wheel-cut with realistic (and anatomically correct) details, including the mouth, eye, gills, and fins. The underside is hollow, and the only “details” consist of groups of parallel cuts on the fins and tail. Clearly, only the upper surface was meant to be seen, and it is assumed that the object was a lid - the cover of a dish for serving fish. One lifted the glass fish (the cuts on the underside of the fins and tail would have made a firm grip possible) and found the real fish (about the size of a trout) resting on the dish.