Here's a description of life on Europa:
Europan life usually hybridises plant and animal characteristics, in a manner similar to the Areobiota of Mars. Most “plants” have some animal characteristics, while most “animals” can photosynthesise and produce some or all of their food from sunlight. All are asexual. To date explorers have found no dangerous or toxic species and no bacteria harmful to humans, and it is possible to live on Europan species for several weeks without ill-effects, although vitamin supplements are essential (see sidebar on page 51). Some typical examples:
- Song-Bushes are inedible but notable for their respiratory systems – they breathe in and out through flute-like tubes, creating a melody explorers have described as “sweet and plaintive.” Specimens have been grown from seeds at the Botanical Gardens at Kew, London, but quickly succumbed to fungal infections when removed from the laboratory.
- Bladder-Birds look like large flying squirrels at low altitudes, but are able to inflate a large air sac and hold their breath long enough to travel small distances through vacuum. Naturally they cannot fly in these airless regions, they must travel on foot. Their “blood” resembles dense sap and doesn’t readily boil at low pressure, which prevents decompression illnesses.
- Nutsies are small aquatic creatures which resemble small walnuts with shells. They live in salty pools on the valley floors.
- The Liver-leaf is a bush with large thick edible leaves. Unsurprisingly, they taste like liver.
- Finally, Europan Truffles are brown, fungoid lumps that grew under song-bushes, and taste like Earth truffles with an added meaty flavour.
Everything on that list comes from Weinbaum's Redemption Cairn, so it's canon for the setting (apart from a few glosses I've added, such as the sap-like blood). The emphasis on edibility isn't mine, it comes from the story.
My question should be obvious, of course - given that Weinbaum was Jewish, which of the edible creatures described would be considered Kosher?