they look to be some of the "kelloggi" (more than likely they're hybrids) that show up in trade. these SH are raised in net pens in the ocean (usually from Sri Lanka or SE Asia), and should really be treated as WC specimens, which includes prophylactic treatment for parasites (flukes/ciliates).
unfortunately, the true cost of ownership of these SH adds a lot to their cheap price tags. just as unfortunately, these SH typically don't do very well in the long term, but i do wish you luck with them.
are they eating frozen mysis?