Comparison of the ultrastructure of the food-concentrating filter of two appendicularians

D Deibel, CVL Powell
1987 Marine Ecology Progress Series  
Houses of Oikopleura longicauda were removed from preserved zooplankton samples and prepared for transmission electron microscopy. Pore slze and f~b e r diameter of the food-concentrating fllter were determined for cornpanson with similar measurements on larger oikopleurids from cold ocean waters. The filter was con~posed of 3 types of fibers arranged In a regular rectangular array. In accordance with nomenclature used previously, we identified microfibers, nodulated fibers, and smooth fibers
more » ... and smooth fibers There were dense nodes where microfibers and nodulated fibers crossed. Mean pore size was 0.15 + 0.02 X 0.61 + 0.13 ,um ( t SD), with a mean wtdth-to-length ratio of 0.25 f 0.03 and mean porosity of 0.85 + 0.01. Mean pore size is sim~lar to that of O~kopleura djoica, a temperate-ocean oikopleund of similar body size, but is smaller than that of Oikopleura vanhoeffeni, a large, cold-ocean oikopleund. The rnicrof~bers of 0. longicauda were 17.1 f 2 6 nm in diameter, while the nodulated fibers were 38.9 t 8.8 nm in diameter, and the smooth fibers 48.1 f 10.2 nm in d~a m e t e r All 3 fiber types formed branches, which contributed to high variance of mean pore slze.
doi:10.3354/meps039081 fatcat:emfnqm5k65fhvm7lo6s4oxpzw4