I received the seeds for this variety from USDA to grow it as part of their seed re-generation effort. Germination rates were low but I was able to propagate seeds for it. Beautiful variety, and a limited quantity of seeds are now also available from our store:
http://twoseedsinapod.com/product/siskun/
Here is the description from our website:
This is a beautiful squash from Yucatan region of Mexico and is locally called Siskun. Plants have small leaves and plenty of 7-8 ft vines. Fruits change color from dark green to black, and to burnt orange at full maturity. Flesh color is tangerine. Fruits are oblate, ribbed, and in early 2017, the heaviest of them weighed a little less than 2 lbs. Rind is thin and easy to cut through. Plants are prolific. Our seed stock in 2017 is limited so get your seeds before we run out.
We grew our plants from USDA's germplasm collection orno 284710. Our special thanks go to Dr. Bob Jarret who sent the seeds to us as part of a re-generation effort.