No fish story: an impressive shad caught at Milford Beach PA. NPS Photo by Rich Evans. From the mighty striped bass (Morone saxatilis) to the humble Eastern mudminnow (Umbra pygmaea), a wide variety of fish inhabit the clean waters of the Delaware River, tributary streams, lakes, ponds, and wetlands within this park. A total of 61 species are known within the park. Ten of these species have been listed as rare, threatened, or endangered by the states of New Jersey and/or Pennsylvania. One additional species, the ironcolor shiner (Notropis chalybaeus), may also inhabit park waters. However, the last report of the ironcolor shiner in park waters was in 1978, and only one known population remains in Pennsylvania. Of the 61 total fish species, 44 are native to the region, 14 are native to North America but probably did not naturally occur in this region, and three are introduced alien species that are not native to North America.