Xenoturbella and the acoelomorph worms (Xenacoelomorpha) are simple marine animals
with controversial affinities. They have been placed as the sister group of all other bilaterian …

The acoel worm Symsagittifera roscoffensis, an early offshoot of the Bilateria and the only
well‐studied marine acoel that lives in a photosymbiotic relationship, exhibits a centralized …

Symsagittifera roscoffensis, an Acoel flatworm that lives within the intertidal zone, was first
discovered over a century ago as a “plant animal” due to its symbiotic relationship with the …

The origin of bilateral symmetry, a major transition in animal evolution, coincided with the
evolution of organized nervous systems that show regionalization along major body axes …

Neuropeptides are neurosecretory signaling molecules in protostomes and deuterostomes
(together Nephrozoa). Little, however, is known about the neuropeptide complement of the …

Bilaterian animals display a wide variety of cell types, organized into defined anatomical
structures and organ systems, which are mostly absent in prebilaterian animals …

The Xenacoelomorpha is a clade of mostly marine animals placed as the sister group of the
remaining Bilateria (Nephrozoa) in most phylogenomic and morphological analyses …

Acoel statocysts are fluid-filled chambers formed by two parietal cells underlying basal
lamina as a capsule and contain a movable statolith cell called a lithocyte. The statocyst is …

Acoel flatworms possess statocyst, eyes, and epidermal sensory receptor cells, to exhibit
behavioral repertoires including geotaxis and phototaxis; however, the mechanism of the …

Xenacoelomorpha are a phylogenetically and biologically interesting, but severely
understudied group of worm-like animals. Among them, the acoel Isodiametra pulchra has …