Why do many cephalopod young develop without a larval metamorphosis?

Cephalopod young typically develop without a larval metamorphosis because their eggs contain a remarkable amount of yolk, which is distinct from most other mollusks. This abundant yolk supply allows for direct development, where the embryo grows within the egg and hatches as a juvenile that closely resembles the adult, rather than passing through the distinct larval stages and metamorphoses common in other molluscan groups.12

While many other mollusks rely on free-swimming, planktotrophic larvae—such as the veliger—to disperse and grow, the high yolk content in cephalopod eggs provides the necessary nutrients for the embryo to bypass these intermediate stages. Consequently, upon hatching, the young cephalopod is often already equipped to assume an adult-like mode of life, whether that involves immediate bottom-dwelling or a brief period in the plankton.12