Final answer:
Cephalpod reproduction differs from other mollusks in that they are dioecious with internal fertilization and their eggs develop directly into juveniles, while most aquatic mollusks have external fertilization and a trochophore larval stage.
Step-by-step explanation:
Cephalopods are a class of mollusks which include well-known creatures such as squids and octopuses. Unlike most other mollusks, cephalopods have a unique reproductive strategy. They are dioecious, meaning they have distinct male and female individuals, and typically practice internal fertilization.
Once members of a cephalopod species mate, the female lays her eggs in a secluded and protected area. Some species exhibit parental care where the female may tend to the eggs for an extended period, which can lead to her death. Contrastingly, most aquatic mollusks like snails exhibit a life cycle that includes a trochophore larval stage, characterized by cilia for movement. Cephalopods, however, bypass this larval stage and their eggs develop directly into juveniles that are smaller versions of the adult form.
Other mollusks generally have external fertilization where gametes are released into the water. Their fertilized eggs then hatch into trochophore larvae, which may undergo further larval stages such as the veliger before the final metamorphosis into an adult. In contrast to cephalopods, many mollusks also possess a shell, which can be either external or internal, depending on the species.