A red alga identified as of the genus Dasya was collected at Coyote Point, San Francisco Bay in 2005. It was initially identified as Dasya (now Dasysiphonia) sessilis, a northwest Pacific species identified from southern California, but when its DNA was sequenced, it differed by 12 base pairs, and has been referred to as 'Dasya sp. A', and was treated in NEMESIS as of 'unknown establishment'. Multiple specimens of Dasya sp. A. were collected in 2019 to 2022 in Coos Bay, Oregon. One specimen from Willapa Bay, Washington, initially identified as the Northwest Atlantic species Dasya (now Dasysiphonia) ballouviana), was re-identifed as Dasya sp. A, based on sequencing. The West Coast Dasya sp. A were genetically identical to a specimen from the Netherlands then identified as 'Dasya ballouviana' (now a synonym of D. pedicellata) Dasya sp. A, are up to 200 mm tall, bright red, and branched, with very fine, dense branchlets.
The 'Dasya/Dasysiphonia sessilis' from southern California (Los Angeles, Orange County and San Diego) are genetically unrelated to D. sessilis from Japan and may represent a second unidentified Dasya in the northeast Pacific. We will refer to these specimens as Dasya sp. B.