portrait

Description:

Thalassophysa (thal-ass-owe-fie-sa) is a large radiolarian protist has a cytoplasm that is full of bubbles. The bright area in the centre of the cell is the capsule and within this lie most of the cytoplasmic organelles. The yellow colour comes from symbiotic algae living in association with this protozoa. The algae are dinoflagellates from the genus Scrippsiella - the same genus is also found in symbiotic association with the by-the-wind sailor (Velella). The light region towards the outside is the region of the axopodia. This is an example of one of the four types of large amoebae which is common in the marine water column. Dark ground illumination, image by Dave Caron.