How many rows of teeth do mako sharks have?
That’s a bit of a tricky question. First of all, not all of the row of teeth in sharks are functional. Elasmobranchs (sharks, skates, and rays) have polyphodont dentition, where used teeth break off and are constantly replaced by new teeth. For the most part, it is only the first one or perhaps two rows that are functional. Teeth are lyodont, that is, they are not anchored in the cartilage of the jaw (palatoquadrate on the upper, Meckel’s cartilage on the lower jaw), but rather in the connective tissue covering the jaw cartilage. As teeth mature, they are continuously being pulled forward and the anchoring tissue migrates forward as well. Now, in the shortfin mako (*Isurus oxyrinchus*) the number of rows of teeth is somewhat variable. Some rows are actually covered by tissue and are not visible as they are not yet fully matured. In the lower jaw the rows around the symphysis (where the left and right Meckel’s cartilages fuse in the center of the lower jaw) you can find about 5 to 7 row
