Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails that, over evolutionary time, have either entirely lost their shells or have seemingly lost their shells due to having a significantly reduced or internal shell. The name "sea slug" is often applied to nudibranchs and a paraphyletic set of other marine gastropods without apparent shells.
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the absence of a visible shell.
Onchidiidae are a family of small, air-breathing sea slugs. They are shell-less marine pulmonate gastropod molluscs. Onchidiidae is the only family within the superfamily Onchidioidea.
Onchidella is a genus of small, air-breathing sea slugs, shell-less marine pulmonate gastropod molluscs in the family Onchidiidae.
Onchidella nigricans is a species of small, air-breathing sea slug, a shell-less marine pulmonate gastropod mollusc in the family Onchidiidae.
Lottia pelta, common name the shield limpet, is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae. It is still designated under its synonym Collisella pelta in many textbooks.
Onchidella binneyi, also known as Onchidella carpenteri, Onchidium carpenteri, and Oncidiella hildae, is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Onchidella kurodai is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Onchidella maculata is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Onchidella carpenteri is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Onchidella celtica is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Onchidella floridana is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Onchidella armadilla is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Onchidella steindachneri is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Onchidella indolens is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Onchidella marginata is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
Pugettia gracilis, commonly known as the graceful kelp crab, is a species of small crab in the family Epialtidae. It lives among forests of kelp on the Pacific coast of North America.
Tylodina fungina, commonly known as the yellow umbrella slug or the mushroom sidegill, is a species of sea snail or false limpet, a marine opisthobranch gastropod mollusk in the family Tylodinidae.
Lottia instabilis is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae. Common names include the unstable limpet, the unstable seaweed limpet and the rocking chair limpet. It is native to the northern Pacific Ocean where it feeds on kelp in the intertidal zone and the shallow sub-littoral zone.
Saccharina dentigera is a species of brown algae, in the family Laminariaceae. It is native to shallow water in the northeastern Pacific Ocean from the Gulf of Alaska to Baja California.
