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,
Sander (genus) Sander (genus) Sander (formerly known as "Stizostedion") is a genus of fish in the Percidae (perch) family. They are also known as "pike-perch" because of their resemblance to fish in the unrelated Esocidae (pike) family. Local names for the fish have been the basis for many geographical names, like River Suda in Russia or Saunags village on the Baltic coast. The genus includes the following 5 species: Phylogenetic relationships of the species of genus "Sander" based on the concatenated data set of six gene regions and a Bayesian analysis. "Romanichthys valsanicola" is the nearest living relative of the genus "Sander"