Jonah 2:1
1 Jonah prayed to the Lord his God from the stomach of the fish 2 and said, “I called out to the Lord from my distress, and he answered me; from the belly of Sheol I cried out for help, and you heard my prayer. 3 You threw me into the deep waters, into the middle of the sea; the ocean current engulfed me; all the mighty waves you sent swept over me. 4 I thought I had been banished from your sight and that I would never again see your holy temple. 5 Water engulfed me up to my neck; the deep ocean surrounded me; seaweed was wrapped around my head.
LXX Jonah 2:1(2)
1 And the Lord ordered a great sea monster to swallow Ionas, and Ionas was in the belly of the sea monster three days and three nights. 2 And Ionas prayed to the Lord, his God, from the belly of the sea monster 3 and said, “I cried out to the Lord my God in my affliction, and he heard me; out of the belly of Hades you heard my cry, my voice. 4 You cast me into the depths of the heart of the sea, and streams surrounded me; all your surges and your billows passed over me. 5 And I said, ‘I have been driven away from your eyes; shall I add to look at your holy shrine?’
Notes and References
"... Though Jonah refers to the creature as a גָדּ (fish) four times (1:17 [2x], 2:1, 2:10), the ancients were acutely aware of the term’s ambiguity ... In Jonah, the ambiguity of the גָדּ, coupled with its enormous size, naturally encouraged the ancients to identify it as a type of giant sea monster known as a ןיִנַּתּ “Tannîn.” Thus, the authors of the LXX rendered םיִ֑לֹדְגַּה םִ֖ניִנַּתַּה “the great sea monsters” in Gen 1:21 similarly: τὰ κήτη τὰ μεγάλα. The term ןיִנַּתּ refers generally to a type of serpentine creature of which Leviathan is one kind. Thus, the word ןיִנַּתּ takes the definite article (Gen 1:21, Isa 27:1, Jer 14:6, 51:34, Ezek 29:3, Neh 2:13), whereas ןָתָיְוִל never does. Nevertheless, traditions concerning Leviathan are not entirely consistent. Thus, some texts understand the creature as possessing multiple heads, others see it as having one.27 Sometimes it also is equated with a lion or a sea monster with lionlike features ..."
Noegel, Scott B. Jonah and Leviathan Inner-Biblical Allusions and the Problem with Dragons (pp. 236-260) Studies in Judaism and Christianity from Second Temple to Late Antiquity Brescia 37, 2, 2015