Ostracion

Part of speech: noun

Definitions

1. A type of marine fish characterized by a compressed body and a hard outer shell; often found in tropical waters and related to the pufferfish
2. Referring to a genus of fish known for its box-like shape and protective bony plates; commonly discovered in warm oceanic environments
3. Describing a group of fish that possess a distinct defensive structure and are unique within their ecosystem; prevalent in coral reef habitats

Etymology: Ancient Greek "ostrakon" meant a hard shell, such as a tortoise's or a crab's, and also a broken piece of pottery. "Ostrakion," its diminutive, meant a small shell. Zoologists borrowed that name for the genus of boxfishes, whose bodies are enclosed in a rigid, bony case of fused scales, which makes the shell comparison apt. English shares this root with a very different word, "ostracism." In Athens, citizens voted to banish a politician for a set period by scratching his name on a potsherd, and the Greek name for that practice was built on "ostrakon." A fish's armor and political exile thus trace back to the same broken piece of pottery.