Meeting Abstract
P2.152 Saturday, Jan. 5 Feeding modes by planulae of Nematostella vectensis (Cnidaria: Anthozoa) KEHR SMITH, A. J.*; JAECKLE, W. B.; Illinois Wesleyan University; Illinois Wesleyan University akehrsmi@iwu.edu
We assessed the ability of larvae of the starlet sea anemone, Nematostella vectensis, to assimilate dissolved organic material (DOM) and ingest artificial and natural particles from seawater. Planulae were exposed to the proteins ferritin and labeled bovine serum albumin (FITC-BSA) and the polysaccharides iron dextran and labeled dextran (FITC-dextran) at solute concentrations between 0.25-1.0 mg/mL for 1-5 hours at 22°C. Other larvae were incubated with polystyrene beads (0.5 µm, 106 beads/mL and 4.5 µm and 6 µm, 103 beads/mL) or with algal cells (Dunaliella tertiolecta, 5 x 103 cells/mL) for 2.5-5 h. The label from all provided macromolecules was detected only within the gastrovascular cavity. In intact and sectioned (1µm) larvae assimilation of ferritin was detected within cells of the pharynx and the endoderm. Assimilation of BSA-FITC was inferred from the presence of a diffuse fluorescence visible only in endodermal cells. The label from iron dextran and FITC-dextran was not detected within cells. Control larvae not exposed to provided macromolecules showed no detectable label. We found no particles in the gastrovascular cavity of larvae. These data indicate that particulate foods do not contribute to the energetics of larval development of N. vectensis. In contrast, planulae assimilated some forms of DOM (proteins) but not others (polysaccharides), suggesting that specific DOM could contribute to the energetics of larval development.
