Bonneville cisco (Prosopium gemmiferum) from Bear Lake, Utah-Idaho (USA). This species occurs only in Bear Lake, and thus is considered endemic. It is an obligate zooplanktivore, feeding on copepods and cladocerans. Maximum length near 19 cm (8.5 inches). It is preyed upon by cutthroat and stocked lake trout, and by whitefish. Photo: William Sigler.