Unconventional myosin that functions as actin-based motor protein with ATPase activity (By similarity). Plays an important role in the establishment of left-right asymmetry during embryonic development (PubMed:29478852). Required for normal cilia orientation, and for normal, directed flow at the transient ciliated epithelium that functions as left-right organizer during embryogenesis (PubMed:29478852). Plays a role in endosomal protein trafficking, and especially in the transfer of cargo proteins from early to recycling endosomes (By similarity). Required for normal planar cell polarity in ciliated cells, for normal rotational polarity of cilia, and for coordinated, unidirectional ciliary movement (By similarity). Interacts (via the two IQ motifs) with calmodulin. Interacts with F-actin. Colocalizes with the actin cytoskeleton in the cell cortex close to the apical cell membrane. Colocalizes with cytoplasmic puncta that are reminiscent of transport vesicles. Detected at low levels in eggs and in embryos at stage 12. Expression increases from stage 18 to 34 during embryonic development (at protein level). First detected at stage 17, when somites begin to form. Detected in somites, neural tube and neural crest cells at stage 20-30. Binds a calmodulin chain via each of the two IQ domains. IQ domain 1 mediates interaction with calmodulin both in the presence and in the absence of Ca(2+). IQ domain 2 mediates interaction with calmodulin in the presence of Ca(2+). The TH1 domain is required for activity in complementing zebrafish defects in Kupffer's vesicle lumen size. Morpholino knockdown of the protein at the four cell stage disrupts body left-right asymmetry at the level of the heart, gall bladder and gut (PubMed:29478852). The left-right organizer, a transient ciliated epithelium of the gastrocoel roof plate, displays abnormally short cilia and disruption of the normal cilia orientation toward the posterior pole of cells, leading to disordered flow direction and reduced flow velocity. Additional phenotypes include delayed neural tube closure due to impaired convergent-extension of dorsal marginal zone tissue, and a transient delay in the ciliation of multi-ciliated cells in the larval skin, suggesting that planar cell polarity pathways are affected. Combined morpholino knockdown with sub-phenotypic doses for myo1d and vangl2 disrupts left-right axis formation, with predominantly bilateral expression of pitx2 (PubMed:29478852). Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Myosin family. Represents an unconventional myosin that should not be confused with the conventional myosin-1.