An evo-devo perspective on terrestrial isopod respiratory organs.

The evolution and diversification of respiratory structures enabled arthropods to colonize terrestrial habitats multiple times independently. One such group of ancestrally marine arthropods, the Isopods, successfully colonized freshwater and terrestrial habitats. The transition to land was facilitated by the evolution of novel respiratory organs on the abdomen, the pleopodal lungs, which either complemented or replaced the ancestral pleopodal gills. Here, we review the current understanding of terrestrial isopod respiratory structure evolution and development and explore its potential molecular basis. We hypothesize how pleopodal gills and lungs may share common developmental features and propose candidate genes for respiratory structure development. We propose that work in this area holds significant implications for our understanding of breathing structure evolution and physiology across the Arthropoda.