They may be consulting for a shark known as a cuckolded suño ( Heterodontus francisci ); or be a yerro per sign (sign), dream, wedge, . . . or even some word of the Idiolect glycol of Cortázar.
It is one of the names of a small cuckold shark found in the Galapagos Islands. Suncing. Its scientific name is Heterodontus quoyi and belongs to the family Heterodontidae .