Affinities and Systematic Position of Balanoglossus with non-chordate

Affinities with non-chordates :-

(B) With Phoronida :-

(a) Similarities :-

(i) In Adult Form :-

(i) Body → Worm like

(ii) Mode of Feeding → Ciliary

(iii) Sense Organ → Absent

(ii) In Larval Form :-

(i) Body → Spindle shaped; Transparent; Free-swimming;

(ii) Pre-oral cilia → Present

(iii) Coelomic Compartment → Five

(iv) Apical Plate → With a turf of cilia and eye spots.

(v) Blastopore → Become Anus in adult.

(b) Dissimilarities :-

(i) In Adult Form :-

Features	Balanoglossus	Pheronida
Body	Divisible into 3 parts	Not so
Pharyngeal gill slits	Present	Absent
Stomochord	Present	Absent
Sexes	Separate	Not Separate

(ii) In Larval Form :- 

Features	Tornaria	Actinotrocha
Ciliated bands	Pre-oral & Pre-anal	Along the arms
Arm like Projection	Absent	Present
Coelom formation	Enterocoelic	Schizocoelic

Remark :-

Similarities are so superficial that Balanoglosssus can not be grouped with Phoronids; as suggested by Goodrich at al.