The first five abdominal segments each bear a pair of biramous ( branching in two ) pleopods ( lamellar structures which serve the function of gas exchange, and in aquatic species serve as gills and propulsion ), and the last segment bears a pair of biramous uropods ( posterior limbs ).
22.
The first five abdominal segments each bear a pair of biramous ( branching in two ) pleopods ( lamellar structures which serve the function of gas exchange, and in aquatic species serve as gills and propulsion ), and the last segment bears a pair of biramous uropods ( posterior limbs ).
23.
Appendages may become " uniramous ", as in insects and centipedes, where each appendage comprises a single series of segments, or it may be " biramous ", as in many crustaceans, where each appendage branches into two sections . " Triramous " ( branching into three ) appendages are also possible.
