Other examples of anadromous fishes are sea trout, three-spined stickleback, sea lamprey and shad. There are also rudd, brook lamprey, three-spined stickleback, nine-spined stickleback and eels in the lake. Three-spined stickleback populations are also found in freshwater lakes and streams. This could highly affect the spawning season for the brook stickleback species. Trout and three-spined stickleback also occur in the same habitat. All stickleback species show similar, unusual mating behaviour. Fish have been observed to be the most successful predator of the brook stickleback. Recent work has investigated the role of enhancers in morphological changes in threespine stickleback fish. The streams held salmon, perch, and stickleback. It is not a minnow but little Jack Sharp, a stickleback. Most other stickleback species are roughly similar in size or somewhat smaller. One experiment displayed this violation of IFD in stickleback fish. The fossil record of the threespine stickleback provide the ancestral shapes of the operculum bone. The weapon was also known as the "Stickleback". The marine threespine stickleback exhibits a larger and thicker opercular series.