spawning; eggs and larvae then drift downstream, and young fish hatch in the floodplain zone. Larvae and small juveniles feed on zooplankton, switching to phytoplankton once a certain size is reached. The species is somewhat sensitive to low oxygen conditions. The species is currently classified as near threatened in it original range, as its habitat and reproductive behavior are impacted by construction of dams, pollution, and overfishing. Population declines appear to have been particularly significant in the Chinese parts of its range. Sport fishing Silver carp are filter feeders, thus are difficult to catch on typical hook-and-line gear. Special methods have been developed for these fish, the most important being the "suspension method", usually consisting of a large dough ball that disintegrates slowly, surrounded by a nest of tiny hooks embedded in the bait. The entire apparatus is suspended below a large bobber. The fish feed on the small particles released from the dough ball and bump against the dough ball, with the intention of breaking off more small particles that can be filtered from the water, eventually becoming hooked on the tiny hooks. In some areas, using "snagging gear", in which large weighted treble hooks are jerked through the water, is legal to snag the fish. In the United States, silver carp are also popular targets for bowfishing; they are shot both in the water and in the air. In the latter case, powerboats are used to scare the fish and entice them to jump out of the water, and the fish are shot when they are airborne. Related species Two other species are in the genus Hypophthalmichthys, the bighead carp (H. nobilis) and the largescale silver carp (H. harmandi). The genus name Aristichthys has also sometimes been used for bighead carp, but is deprecated. The bighead carp differs from the silver carp in its behavior (it does not leap from the water when startled) and also in its diet. Bighead carp are also filter feeders, but they filter larger particles than silver carp, and in general consume a greater proportion of zooplankton in their diets than silver carp, which consume more phytoplankton. In at least some parts of the United States, bighead and silver carp hybridize in the wild and produce fertile offspring. The largescale silver carp is closely related to the silver carp, but its native range is to the south of that of the silver carp,