September is Etymology Month (15)

РЫБА [ryba] 'fish'. 11th century, from CSl. *ryba, possibly cognate with late MHG rup(p)e 'caterpillar, grub' (Ger. Raupe, id., cf. also Ger. Aalraupe 'eel-pout, burbot'). A taboo for earlier *zъvь (cf. Lith žuvis 'fish'), a word said to have been avoided by fishermen because of its similarity to звать 'to call' (to 'call' the fish would be unlucky, cf. невод 'sweep-net', lit. 'non-net'). A connection has also been proposed with рябой 'pock-marked', thus initially 'speckled fish' (e.g., a salmon).