The wastewater exits through the excurrent siphon. The costa are long, sometimes excurrent, and lack an adaxial pad of cells. Juveniles swim out of the mussel from the margin of the excurrent siphon. Incurrent and excurrent siphons directed upwards, away from substratum. Its species produces an ideal, Apical dominant Excurrent structured crown. Fusconaia flava are filter feeders, waste is released through the excurrent siphon. There is an inhalant or incurrent siphon, and an exhalant or excurrent siphon. All reptiles retain their testes and excurrent ducts within the abdomen (testicond). The particle-free water is then discharged out the excurrent siphon.