Megamouth shark to be the sole extant species in the distinct family Megachasmidae, though suggestion has been made that it may belong in the family Cetorhinidae, of which the basking shark is currently the sole extant member. Researchers have predicted the feeding patterns of megamouth sharks in relation to the other two planktivorous sharks; the three plankivourous sharks have ram feeding in common, as it evolved from ram feeding swimming-type ancestors that developed their filtering mechanism to capture small prey like plankton. In addition to the living "M. pelagios", however, two extinct megamouth species – the Priabonian "M. alisonae" and the Oligocene–Miocene
Fish stock (food) milky broth. This has a rich feel and sweet umami taste. Stock can also be made using other seafoods. For example, prawn stock made from simmering prawn shells is used in Southeast Asian dishes such as laksa. Fish stock forms the basis of many dishes, particularly soups and sauces. A fish consommé is a type of clear soup made from richly flavored fish stock that has been clarified usually through a fining process involving egg protein. Fish consommés usually have too little natural gelatin, so the fish stock may be double-cooked or supplemented. Since fish gelatin melts at a lower