Like other rorquals, it has no teeth, but has two rows of baleen plates. Among rare visitors to the archipelago, there are other species of penguins, orcas, and rorquals. Mysticetes consist of four families&colon; rorquals (balaenopterids), cetotheriids, right whales (balaenids), and grey whales (eschrichtiids). Like many large rorquals, the fin whale is a cosmopolitan species. Larger types of rorquals have been sighted in pelagic waters occasionally. This latter "lunging" behaviour is often a result of feeding in rorquals. The lunge-feeders are the rorquals. Whaling rorquals was not effective until the harpoon cannon was invented in the late 1860s. Some show particular detail in which there are throat pleats, typical of rorquals. In their review of extant and fossil rorquals, Demere et al. All rorquals have these unique folds. Anthropogenic noise is an increasing concern for all rorquals, which communicate by low-frequency sounds. The lifespan of rorquals ranges from 45 to 100 years. Fleeing only occurs in species that can swim away quickly, the rorquals. Rorquals also tend to be longer than the latter.