It is ironic that at this point in Scene 1, Shylock feels justified in demanding the taking of a pound of flesh from Antonio, an act that will clearly kill Antonio and make him "bait" [dead meat] for the fishes. For shortly after this assertion of his desire for revenge against Antonio's accusations that Shylock is a loan shark, he declares that he wishes his own daughter who has run off with some of his jewels were lying dead--
I would my daughter were dead at my foot, and the jewels in her ear! Would she were hearsed at my foot and the ducats in her coffin! (3.1.83-85)
In addition, he laments that there is "no revenge, no satisfaction" against the thieves of his jewels. These selfish and avaricious desires come, also, ironically, in the wake of his "Hath not a Jew eyes" monologue in which he seeks sympathy.
As a final note, the renowned Shakespearean critic, Harold Bloom, who himself is Jewish, declares that in Merchant of Venice, Shylock is "a murderous villain" as he is a"would-be slaughterer" and not the "hero-villain that the last two centuries of stage tradition have made him."
Source: Bloom, Harold. Shakespeare: The Invention of the Human. New York: Riverhead Books, 1998. Print.