Definition of St Peter's fish in English:

St Peter's fish

noun

  • A fish with a dark mark near each pectoral fin, in particular a widely farmed cichlid of Africa and the Middle East (also called tilapia).

    • ‘In the Pacific regions or in small lakes in the United States, St. Peter's Fish are known by the name Tilapia or, more often than not, Sunfish.’
    • ‘In Galilee St Peter's fish, Sarotherodon galilaeus (Cichlidae), male care, female care and biparental care all occur in the same population.’

Origin

With biblical allusion to Matt. 17:27.