Citations:
http://www.sms.si.edu/IRLFieldGuide/Vallen_gabrie.htm
http://www.sms.si.edu
http://kboyer.weebly.com/uploads/2/8/6/2/2862577/adv_bio_unit_2-_porifera_fact_sheet.pdf
http://en.wikipedia.org/wiki/Nematode
http://www.sms.si.edu
http://kboyer.weebly.com/uploads/2/8/6/2/2862577/adv_bio_unit_2-_porifera_fact_sheet.pdf
http://en.wikipedia.org/wiki/Nematode