ocr: about seven- ty-five feet. The blue whale is one of five species of highly stream- lined baleen whales called rorquals (genus Balaenopterd, Family Balaenopter- idae). The other four are the fin whale (B. physalus), the sei whale (B. borealis), the minke or little piked whale (B. acutorostrata), and Bryde's whale (B. edeni). In the years since this model went up, we've learned a good deal more about blue whales. We know, for example, that the 7s