Turbellarian taxonomic database

Acoela Childiidae


Dorjes J 1968 (citation)- p 110 definition, list of genera, discussion p 110-111, key to genera p 79.
	Type genus CHildea.  p 101 says Otocelis species may go here eventually ?
	
	"Acoels with well developed copulatory organs.  Cone-shaped penis stylet always present.  This
	formed either from cuticularized or muscular elements, however never invaginated into the seminal
	vesicle.  The latter can be lacking.  Male reproductive pore variable in position.  Mouth
	opening ventral."
		Type genus Childea Graff 1911- 10 genera and 36 species.  Short discussion.
		
	Key:
		1. Seminal bursa lacking ----------------------------------------2
		1. Seminal bursa presnet ----------------------------------------5
		2. with 2 copulatory organs -------------------------------------Childea
		2. with 1 copulatory organ --------------------------------------3
		3. Colored. Male antrum lacking ---------------------------------Paraproporus
		3. Uncolored.  Male antrum present ------------------------------4
		4. Male antrum long, tube-shaped, ciliated.  Penis cuticularized
			by discharge of matrix cells --------------------------------Atriofronta
		4. Male antrum short.  Penis constructed of large, cuticularized
			stylet needles. ---------------------------------------------Actinoposthia
		5. Nozzle cuticularized -----------------------------------------6
		5. Bursa without a cuticularized nozzle--------------------------7
		6. Four (4) copulatory organs -----------------------------------Tetraposthia
		6. A single male copulatory organ -------------------------------Philactinoposthia
		7. Seminal bursa without an evident (light neuro?) ducctus
			spermaticus.  Outer muscle layers with outer circular and 
			inner longitudinal muscles ---------------------------------Pseudactinoposthia
		7. Seminal bursa with cellular or muscular spermatic duct.
		    Lacking this, then the outer muscle layer formed of outer
		    longitudinal and inner circular muscles----------------------8
		8. Outer muscle layer of outer longitudinal and inner
			circular muscles--------------------------------------------Paraphanostoma
		8. Outer muscle layer of outer circular and inner longitudinal
			muscles -----------------------------------------------------9	    		
		9. Ductus spermaticus muscular, invaginated into the bursa
			seminalis and divided caudally-------------------------------Pelophila
		9. Ductus spermaticus cellular, anterior directed-----------------Proactinoposthia
		
Karling TG 1974 (citation)- in list p 9.
Faubel A 1976 (citation)- lists p 42.
Ehlers U, Doerjes J 1979 (citation)- in discussion of Otocelidae genera p 48, 70.		


Hooge MD 2001 (citation) - "Childia groenlandica posesses not only a unique pattern of musculature (Figs. 6,7)
but the layering of these muscles is also unique among acoels in that the relative positions of the
subepidermal body-wall muscle fibers are reversed, with longitudinal muscle fibers lying outside of inner
circular fibers, a condition first recognized by Luther (1912) (citation). These features, along with its
unusual paired male copulatory apparatus, suggests that the Childiidae as it is presently known is 
polyphyletic. Additional endorsement for polyphyly comes from preliminary ultrastructural and
immunocytochemical studies that sugges the sclerotized copulatory structures used to unite the group are
nonhomologous among several taxa (Raikova et al., 2001) (citation). I propose leaving Childia groenlandica
as the sole occupant of Childiidae and creating a new family, Actinoposthiidae, for the other childiid taxa."

Hooge MD, Haye P, Tyler S, Litvaitis MK, Kornfield I  2002 (citation)- Phylogenetic relationships using 18S
rDNA, and morphological characters of sperm and body-wall musculature.- "The unique nature of C. groenlandica
led Hooge 2001 (citation) to remove the other species in the Childiidae to a new family, the Actinoposthiidae.
The gene tree supports this taxonomic revision; however, some further changes may be necessary, inasmuch
as members of the actinoposthiid genus Paraphanostoma also have circular muscles (Westblad, 1942) (citation)."


Tekle YI, Raikova OI, Ahmadzadeh A, Jondelius U 2005 (citation) - Found the monophyly of Childia and Paraphanostoma to be supported by molecular and morphological data. Paraphanostoma synonymized with Childia; all former members of Paraphanostoma transferred to Childia.