Someone please tell me ... don't squashes, marrows and pumpkins hybridize like crazy if they are grown too close together?
Could this unknown fellow be utterly unique?
They can cross-pollinate but the resultant hybrid fruit will only manifest in the next generation. That is, if you save seed from the cross-pollinated fruit and sow it next year. In the season that it's grown, cross-pollinated fruit will be exactly what you planted.
I've had problems for a couple of seasons with crossed melon seeds from bought packets of seeds. The seed company, or their supplier, has been less than thorough in their safeguards.