How to Prune fishbone cactus?
No pruning required

fishbone cactus · Disocactus anguliger
In areas where temperature drops below 10⁰C, grow in epiphytic cactus compost in bright filtered light as houseplants or in a greenhouse with a minimum temperature of 15⁰C in the growing season. In warmer climates grow outside in fertile, sharply drained soil in light or dappled shade. See epihyllum cultivation for more information
No pruning required