Jack Silverside

Atherinopsis californiensis, commonly known as Jacksmelt, distribution range consists of the Pacific coast from Yaquina Bay, Oregon, south to Bahía Magdalena, Baja California Sur, Mexico. The adults occur in inshore areas, such as bays. They form schools. This species is a demersal spawners in inshore habitats, it is oviparous and the larvae are planktonic, living at the very surface of the water and feeding on phytoplankton. The eggs are attached to one another and to the substrate by adhesive filaments in the chorion. This species is closely associated with coastal habitats and is frequently distributed in both marine and estuarine environments. Jacksmelt are most commonly found in shallow waters near sandy beaches and kelp forests, and Jacksmelt often school in large numbers which are easily seen during daytime. The ability of juveniles to adapt to a variety of salinity and environmental conditions is critical to survival as they move from fresh to saltwater habitats at different stages of life. Jacksmelt have the ability to thrive in a variety of environments and can exploit a wide ecological niche, and are a principal part of the coastal marine ecosystem. Jacksmelt are not confined to open coastal areas and are frequently found in bays and estuaries if they contain food resources. Typically found no deeper than 29 metres (100 ft). …

The jacksmelt diet consists mostly of zooplankton, small live fish, and bottom invertebrates. Jacksmelt studies have shown omnivorous feeding habits, though Jacksmeltapes more towards carnivory. However, this dietary preference is influenced by the habitat of these fishes; for example, Jacksmelt in kelp forests tend to consume more small fish than do those in estuarine environments where zooplankton is more abundant. Their ability to adapt their feeding strategies to a changing set of resources is essential to their survival and growth in a changing ecological context. Furthermore, competition for food may affect the diet composition as well as the general health of coastal pelagic fish species.