Egg-Laying Sharks. Of the approximately 400 species of sharks, about 40% lay eggs. This is called oviparity. When the eggs are laid, they are in a protective egg case (which sometimes washes up on the beach and is commonly called a mermaid's purse).
what s the truth i am asking this b c there seems to be posts on here that say y sperm swim faster which is what we all prob have heard for the longest time but there have been some recent posts on here that state newer studies now say y sperm aren t any faster than x and they can both swim just as fast so im just wanting to know which one is true if anyone really knows thanks
This study also found that sperm motility changed with age. Sperm motility is how well the sperm swim. Sperm motility was best before age 25 and lowest after age 55. In fact, when comparing the number of âgood swimmingâ sperm in men between the ages 30 to 35 with men over age 55, sperm motility decreased by 54 percent. These strong variations could not be blamed on sexual abstinence, which was tracked in the study.