Rocky shore marine invertebrates have various ways of reproducing. At one extreme, species release their eggs and sperm into the water where fertilisation occurs, with the larvae transported by currents. At the other extreme, the eggs are fertilised by the sperm inside the mother, with the larvae then crawling out and settling close by. Nodilittorina pyramidalis lies between the two extremes, it has internal fertilisation however the eggs, stored in capsules, are released and transported by currents. It is found high above mean tide-level from northern Victoria north to northern Western Australia. Have you ever noticed it on the seashore?