Herklotsichthys quadrimaculatus (Rüppell, 1837)
The only sardine common in Hawai`i, this species can be identified by two yellow-gold spots behind the gill covers, one above the other. It forms dense silvery schools in harbors and protected waters throughout the Islands, dispersing somewhat at night to feed on plankton at the surface. Such schools are sometimes found during the summer in protected coves, such as at Pupukea, on O`ahu’s north shore. Otherwise, they are seldom seen by divers or snorkelers. The species was unintentionally introduced in the 1970s, probably in the baitwell of a fishing boat returning from the Marshall Islands. The Marquesan Sardine (Sardinella marquesensis) also exists here. Brought in as a baitfish between 1955 and 1959, it was intended to supplement the nehu, or Hawaiian Anchovy, whose numbers were declining. The Marquesan Sardine spread through the Islands but never became abundant. After the Goldspot Sardine arrived it all but vanished. To about 5 1/2 in. Indo-Pacific. Photo: Pupukea, O`ahu.