heterocercal
/ˌhɛtərəʊˈsəːkəl
/adjective Zoology
(Of a fish’s tail) having unequal upper and lower lobes, usually with the vertebral column passing into the upper. Contrasted with diphycercal, homocercal.The tail is heterocercal, with the upper lobe containing long, thread-like filaments....
- The body shows well-developed paired lateral fins (presumably true pectoral fins), indicating good stability, dorsal and anal fins, and a heterocercal tail (the lower lobe of the tail is elongated).
- The sturgeon heterocercal tail is extremely flexible and the upper tail lobe trails the lower during the fin beat cycle.
Origin
Mid 19th century: from hetero- 'other' + Greek kerkos 'tail'.
- fall in (or out of) love (with someone)
- fall into place
- fall into step
- fall in with
- fall line
- fall-off
- fall off the back of a lorry
- fall on deaf ears
- fall on one's sword
- fall on (or upon)
- fall on stony ground
- fallopian tube
- fall (or drop) into someone's lap
- fall (or drop, or sink, etc.) to one's knees
- fall (or get) into the wrong hands
- fall out
- fallout
- fallout shelter
- fall over oneself to do something
- fallow
- fallow deer
- fallowness
- fall prey to
- fall prey to (also be or become prey to)
- Fall River