Mastodon users can take part in Lemmy discussions and subscribe to Lemmy communities. To post in a Lemmy community simply mention the Lemmy community (@[email protected]) in a Mastodon post. The first paragraph of the Mastodon post will display in Lemmy as the title, the rest will be the text body. Hashtags won’t be displayed in Lemmy.

https://joinfediverse.wiki/Lemmy