Different vendors refer to several different types of isopods as dalmatian isopods, but the dalmatian isopods we offer are common rough woodlice (Porcellio scaber) with the dalmatian spotting gene. They're pretty similar to dairy cow isopods, but they're a different (related) species, and they have black speckling, while dairy cows have black splotching.
Common rough woodlice are temperate species. They can subsist in a wide range of living conditions. They do well in lower humidity ranges than most other isopods, making them great candidates for bio-active desert set-ups.
They're not the most prolific isopod you can culture, but they'll do quite well after becoming established under appropriate care.