Dicyemids

Part of speech: noun

Definitions

1. Tiny worm-like marine parasites that live inside the kidney sacs of cephalopods such as squid and octopuses
2. Minute multicellular organisms of the group Dicyemida, which reside in the renal appendages of cephalopod molluscs
3. Microscopic invertebrates belonging to the phylum Dicyemida, parasitic within the kidneys of squids and octopuses

Etymology: "Dicyemids" is the plural of "dicyemid", the name for a small group of tiny, worm-like parasites that live in the kidneys of cephalopods such as octopuses and squid. The singular is built from Greek roots: "di-", meaning two, and "kyema", meaning embryo or fetus. The name refers to the animals' distinctive life cycle, in which each one produces two kinds of embryos, a striking detail for an organism only a few millimetres long. The "-id" ending is the standard suffix that zoologists attach to group names, marking membership in a family or class, so a dicyemid is one member of this lineage. Because the animals were studied as a distinct group in the nineteenth and twentieth centuries, the word is a technical coinage from classical roots rather than something ancient Greeks would have recognised.