- Posterior end of male is expanded to a copulatory bursa
- Has two spicules that do not fuse at their distal ends
- Has two broad lateral lobes and a smaller dorsal lobe
- Fleshy rays support both lateral and dorsal lobes
- Arrangement of rays within bursa is a characteristic for each species
- A. duodenale: dorsal ray is divided into small rays at the tip, which again divide into 03 unequal portions
