Labyrinthomyxidae Cavalier-Smith, 2012

Anderson, O. Roger & Cavalier-Smith, Thomas, 2012, Ultrastructure of Diplophrys parva, a New Small Freshwater Species, and a Revised Analysis of Labyrinthulea (Heterokonta), Acta Protozoologica 51 (4), pp. 291-304 : 300

Labyrinthomyxidae Cavalier-Smith fam. n.

Diagnosis: Filoplasmodial heterotrophs whose spindle-shaped cells with bipolar projections form linear, branching, anastomosing rows and parasitize solenocysts of the brown alga Laminaria ; with uninucleate amoeba or uniciliate phases; cyst or theca unknown. Type genus Labyrinthomyxa ( Dubosq 1921) .

Another protist with similarities to labyrinthulids is Chlamydomyxa labyrinthuloides ( Archer 1875) , but its taxonomy is confused by probable later misidentifications. Unless Archer conflated multiple organisms, we support his interpretation of the original Chlamydomyxa labyrinthuloides as probably a labyrinthulid (distinct enough to merit its own family), unlike subsequent authors who questioned that or described other probably unrelated ‘ Chlamydomyxa ’ species ( Geddes 1882, Hieronymus 1898, Lankester 1896, Pascher 1930, Pearlmutter and Tumpano 1984, Penard 1904) – clonal cultures more similar to those of Archer are needed to check this. In particular we consider the non-reticulose, filose amoeboid heterokont alga identified as Chlamydomyxa labyrinthuloides by Wenderoth et al. (1999), whose 18S rDNA places it in Picophagea within the phylum Ochrophyta ( Cavalier-Smith and Chao 2006), was misidentified and is really a new species in an undescribed genus – to be established elsewhere.