הלכה על מנחות 87:2

I found in the work of the brilliant Sephardic Rabbi David Pardo of Blessed memory, in his precious book Sifre Deve Rev, who brings up the point in connection with the above mentioned Sifre and asks regarding the query of Rabbi Yose 'is it to be found, 'was it not found during the days of the Amoriam? And he answers that 'since the old man told him that his livelihood comes from the Hillazon, and did not say (that it comes from) the Techelet, it was implied that his work is not the dying of the Techelet or the selling of the Techelet, that he was always hunting the Hillazon itself, and it was from this that he made his livelihood. And this was Reb Yose's question; "How was he able to make a livelihood from the Hillazon," because this implied that he was able to track it down at any time; Is it so common? And the old man answered him "indeed it is not to be found except in a certain place, in the seas." And he explained there 'that only the choicest is hidden for the Righteous," see there. It seems that the meaning of this scholar's words, of blessed memory, that it is only because he (the old man) said that his livelihood was from the Hillazon, that Reb Yose asked, 'is it (so easily) found.' This is in accordance with what is written (Menachot44a) that it (the Hillazon) surfaces only once in seventy years, see there. And since it only surfaces once in seventy years how can it be so common as to be captured at any time? However, the dye of the Techelet (on the other hand) was readily obtainable for although the Hillazon only surfaced once in seventy years, nevertheless, at the time that it surfaced, they prepared enough Techelet dye for seventy years. This seems to be the meaning of his words of blessed memory. And perhaps he himself said this explicitly, however his book is not in front of me now, so that I can look at it, I am merely quoting from memory.

1. The color of the body of the Hillazon resembles the color of the sea as the Rabbis in Tractate Menachot (44A) taught that the color of the Hillazon resembles the color of the sea. Rashi explains that the Hillazon emerges from the sea and the Techelet resembles the sea, that is to say that the sea it is found in and that it emerges from is the cause of its color.