Allis shad Allis shad The allis shad ("Alosa alosa") is a widespread Northeast Atlantic species of fish in the herring family, Clupeidae. It is an anadromous fish which migrates into fresh water to spawn. It is found in the eastern Atlantic Ocean, the western Baltic Sea and the western Mediterranean Sea. In appearance it resembles an Atlantic herring but has a distinctive dark spot behind the gill cover and sometimes a row of up to six spots behind this. It sometimes hybridises with the twait shad ("A. fallax"). This fish becomes mature when three or more years old and migrates to estuaries,
Indo-Pacific tarpon living in saltwater, growing just over , while saltwater examples grow over . They live upwards of 44 years and mature within two. They complete their metamorphosis from their larval stage in ten days. They are opportunistic feeders, feeding on smaller fish, crustaceans, and even plants rarely. In saltwater, they mainly feed on prawns and herring, but also many other small fish. In fresh water, no significant difference in their food habits is seen; they eat freshwater prawns and bony bream, mainly. The Indo-Pacific tarpon migrates between the open sea and inland rivers. As with all Elopiformes, it spawns mainly