Embryonic brooding in Crepipatella fecunda: Implications for processes related to maternal feeding

Differences in feeding adaptations in intertidal and subtidal suspension-feeding gastropods: studies on Crepidula fornicata and Crepipatella peruviana

“…Filming was initiated once snails began filtering, and then, a suspension of nontoxic bright orange particles (2-10 µm diameter, Chaparro et al 2001bChaparro et al , 2002 was added to the water near the incurrent feeding stream. These particles are easy to visualize, and they move along the gill at the same speed as does I. galbana (Mardones et al 2013). Videos were visualized on a Trinitron Sony monitor and recorded to VHS for the analysis of particle velocity.…”

“…Air was continuously bubbled into each aquarium to ensure adequate mixing and to maintain a sufficient supply of dissolved oxygen. Pure cultures of either Dunaliella tertiolecta (for C. fornicata) or Isochrysis galbana (for C. peruviana) were used as the food sources for the snails, and these microalgae were added to each aquarium to achieve initial concentrations of approximately 30,000 cells mL −1 (Mardones et al 2013). Because we could not add microalgae and take samples from each aquarium simultaneously, the addition of microalgae (and sampling) was performed sequentially with ~1 min between aquaria.…”

“…This method has previously proven successful for determining particle velocity in this and closely related species (Mardones et al 2013;C. fornicata, Shumway et al 2014).…”

“…In order to ensure that only CR = V Log e C 0 −Log e C t − a /t particles driven by ciliary filament actions (not water flow in the mantle cavity) were measured, only particles in very close contact with the gill were selected. The time elapsed was determined by stepping through the video frame by frame (NTSC format: 30 frames s −1 , Ward et al 1991), and the distance travelled by the particles was determined using the width of the gill filaments as a reference (Ward et al 1991;Beninger et al 1992;Mardones et al 2013). Gill filament widths were determined after the particle velocity experiments were finished by dissecting the gill out of each specimen and measuring the filament width with a dissecting microscope at 40X.…”

“…Using our methodology, clearance rate could be underestimated if too much of the algal suspension was grazed (>35 %, Mardones et al 2013) during the experimental time, so we repeated the above analysis after excluding data points from organisms that cleared >35 % of the algal suspension and the results did not change.…”