Selachians

Part of speech: noun

Definitions

1. A category of cartilaginous fish that includes sharks and rays, often recognized for their streamlined bodies and predatory nature
2. Referring to members of the subclass Elasmobranchii, which are characterized by their lack of bones and presence of gills
3. Describing aquatic creatures belonging to the class Chondrichthyes, typically known for their unique adaptations for swimming and hunting in various marine environments

Etymology: "Selachians" is the plural of "selachian", a term for members of the subclass Elasmobranchii, the group that includes sharks, rays and skates. The adjective-turned-noun traces back to the Ancient Greek word "sélakhos", meaning "shark", which was the source of Latin "selachē". That Latin form then became the name of a genus, Selache, now disused, and the plural of the word was formed from that scientific name. The Greek root is the more striking part of the story, because it shows how a single animal name passed into the vocabulary of taxonomists. Zoologists took an ordinary Greek word for shark and turned it into a formal label for an entire group of cartilaginous fish, a group whose members share skeletons made of cartilage rather than bone, as well as gill openings that the word's users needed to distinguish from bony fishes.

Synonyms: sharks, rays, chimeras