Ingestion and assimilation of dissolved organic matter by feeding larvae of the families Chaetopteridae, Magelonidae, Polygordiidae, Sabellariidae, and Spionida (Annelida) and the Sipuncula.
Submission Type
Poster
Area of Study or Work
Biology
Faculty Advisor
Will Jaeckle
Expected Graduation Date
2019
Location
Center for Natural Sciences, Illinois Wesleyan University
Start Date
4-13-2019 9:00 AM
End Date
4-13-2019 10:00 AM
Disciplines
Education
Abstract
The life history of many marine invertebrates includes a free-living larval stage that must acquire food. These planktonic larvae live in an environment where the abundance of particulate foods (1-20 μm) is low and have evolved a diversity of feeding methods. Larvae are also exposed to dissolved organic materials (DOM) which may be a source of nutrition. We tested the hypothesis that feeding larvae of Polychaeta and Sipuncula are able to ingest seawater and that the cells lining the gut then assimilate DOM. Larvae were collected from Ft. Pierce, FL. Specimens were exposed to an iron-containing protein (ferritin) or polysaccharide (iron-dextran); experimental controls were not exposed to an iron-containing molecule. Iron in larvae was detected using the "Prussian Blue" reaction and the presence and distribution of the blue product was examined using light microscopy. In all examined larvae we found the blue label within the gut lumen, but not within the cells lining the digestive system, and control specimens lacked blue color. These results suggest that these larvae ingest seawater, delivering DOM into the digestive system, but do not support the hypothesis that DOM is a nutritional source. Further work is necessary to describe digestion in polychaete and sipunculan larvae.
Ingestion and assimilation of dissolved organic matter by feeding larvae of the families Chaetopteridae, Magelonidae, Polygordiidae, Sabellariidae, and Spionida (Annelida) and the Sipuncula.
Center for Natural Sciences, Illinois Wesleyan University
The life history of many marine invertebrates includes a free-living larval stage that must acquire food. These planktonic larvae live in an environment where the abundance of particulate foods (1-20 μm) is low and have evolved a diversity of feeding methods. Larvae are also exposed to dissolved organic materials (DOM) which may be a source of nutrition. We tested the hypothesis that feeding larvae of Polychaeta and Sipuncula are able to ingest seawater and that the cells lining the gut then assimilate DOM. Larvae were collected from Ft. Pierce, FL. Specimens were exposed to an iron-containing protein (ferritin) or polysaccharide (iron-dextran); experimental controls were not exposed to an iron-containing molecule. Iron in larvae was detected using the "Prussian Blue" reaction and the presence and distribution of the blue product was examined using light microscopy. In all examined larvae we found the blue label within the gut lumen, but not within the cells lining the digestive system, and control specimens lacked blue color. These results suggest that these larvae ingest seawater, delivering DOM into the digestive system, but do not support the hypothesis that DOM is a nutritional source. Further work is necessary to describe digestion in polychaete and sipunculan larvae.