Natural History Notes: It has been shown for Platyhelminthes that spermatogenesis and the ultra-structure of sperm contained a great deal of information regarding the phylogeny and taxonomic system. Characteristics: The species has a grey coloration pattern. However, a light blue gradient is present on the dorsal side that is becoming lighter toward the edges of the animal. The spermatozoa are biflagellate and filiform. The nuclei are located toward the posterior end of the sperm and the axoneme shows a microtubular pattern of 9 (doublet microtubules) +1 (single microtubule), which is common for all Platyhelminthes.