I believe that to be an old wives tale or urban legend.
I have eaten Ray and Shark. Scallops don’t taste or even resemble anything like them.
There was a video somewhere on the net where a guy was actually trying to make ‘scallops’ out of a stingray. Didn’t work out too well. The work itself would be discouraging to any would-be con man..................
There are disreputable seafood restaurants who pass off something that is definitely not scallops, as scallops. Can we at least agree to that? I know it’s so, I’ve had it happen to me before.
Pistachio-Crusted Scallops
PREP Make salsa/dressing first to steep flavors:
MANGO SALSA toss diced mango, handful chp flat-leaf parsley, minced jalapeno, minced small chunk purple onion, juiced 1/2 lime, pinch salt; set aside to meld.
KEY LIME DRESSING Blender creamy/pale green cup fresh arugula, 1/4 c lime juice, 1/2 c canola or grapeseed oil, 2 juiced Key limes, 2 tsp grainy Dijon, 1 1/2 tsp honey, pinch ea cayenne, s/p.
SCALLOPS P/towel pat dry 6-12 scallops; spread w/ combined 2 tb mayo/tb wasabi paste; dip both sides in chp pistachios. In hot skillet w/ drizzle of canola oil sear briefly1-2 min per side; plate.
ASSEMBLY Layer on plate arugala, scallops, Mango Relish, Lime Dressing. (can add heirloom tomatoes, avocado slices)