flow tank

Flow tank experiments show that Dactylioceras was probably a slow swimmer.

Cenocrinus asterius has been studied in a laboratory flow tank where it was found that, with the base of the stem detached, it could move itself along the substrate and climb objects.

The upward flow tank, usually conical or pyramidal in shape, with its widest part at the top, allows the water to flow up with diminishing speed, the solid matter falling to the base, from which it can be removed as a sludge by the hydrostatic head in the tank, scraping gear being unnecessary.

Flow tank experiments suggest that archaeocyathan morphology allowed them to exploit flow gradients, either by passively pumping water through the skeleton, or, as in present-day, extant sponges, by drawing water through the pores, removing nutrients, and expelling spent water and wastes through the pores into the central space.