. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ANNELID LARVAL FEEDING MECHANISMS 17 gers and measured body length (for the entire larva), width (at the middle segment), and prototroch diameter of live larvae (n = 36) under a compound microscope with 4X objective. A video camera and image analysis program (NIH Image : available free at nih-image) were used for these measurements. We esti- mated larval volume as a cylinder by the equation: larval volume = Tr(D/2)2(L) where D is body width and L is body length. Maximum clearance rates were estimated as
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ANNELID LARVAL FEEDING MECHANISMS 17 gers and measured body length (for the entire larva), width (at the middle segment), and prototroch diameter of live larvae (n = 36) under a compound microscope with 4X objective. A video camera and image analysis program (NIH Image : available free at nih-image) were used for these measurements. We esti- mated larval volume as a cylinder by the equation: larval volume = Tr(D/2)2(L) where D is body width and L is body length. Maximum clearance rates were estimated as the volume of water passing through the prototroch per unit of time. To calculate these rates, we measured particle velocities and particle distances to the base of the prototroch from video- taped sequences of three larvae in each of three size classes (6-7, 11-12, and 15-16 setigers). We observed larvae and 5-;u,m particles on a compound microscope with DIC optics and 20X objective lens, as described above. The larvae tethered themselves by mucous strands and were recorded for several minutes. The distances traveled by particles per unit of time and their distances to the base of the prototroch were measured from videorecorded sequences. Particles were measured as they passed within the direct influence of the cilia where velocities are negligibly affected by the slide or coverslip (Emlet, 1990). We fitted binomial regressions from the origin through the plot of particle velocity versus particle distance from the cilium base. The rationale for fitting curvilinear lines to these data was both theoretical (Sleigh, 1984) and empirical (Strathmann and Leise, 1979). The studies in both areas suggest that velocity should increase from zero near the larval body surface to a maximum near the full length of the cilia; it should then decrease beyond the tips of the cilia. Since these curves included some particles that presumably passed beyond the tips of the cilia, it was necessary t
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
