Fin

{
  "id": "MLC-T-ENV-011000",
  "term": "Fin",
  "field": "Environment",
  "definition": "Organ of locomotion and balance in fishes and some other aquatic animals; in fishes, fins are of two types: paired (pectoral and pelvic fins) and unpaired or median (dorsal, adipose, anal, and caudal fins and finlets). Fins of bony fishes contain hard spines and/or soft rays, which may be jointed and branched. The spines and rays are covered by integument. Counts of spines and rays are used as diagnostic characters in fish taxonomy; a membranous, finlike, swimming organ, as in pteropod (having the anterior lobes of the foot modified so as to form a pair of winglike swimming organs), and heteropod (where the foot developed into a median fin) mollusks",
  "references": [
    "NOAA Coral Reef Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/fin/"
}