Development in Micrura wilsoni from culture fertilized in July 2013. Sperm dissected from male (scale 50 µm), two-cell stage with two polar bodies in view and 5-day old larva (top row). Forty-one and 63-day old larvae (bottom row). Scale bars 100 µm.
Micrura wilsoni
Sequence Data: 16S, COI
Reproductive adults observed in Coos Bay: July
The development of Micrura wilsoni was described from fertilization to metamorphosis (Hiebert and Maslakova, 2015). Although the adults are not uncommon in rocky intertidal habitats, we have yet to collect their larvae in a plankton sample. The larvae of M. wilsoni are of the typical pilidial shape, but have irregular (rather than circular) patches on both (left and right) sides of the anterior lobe. Unlike other pilidia with pigment spots (e.g. Cerebratulus californiensis), M. wilsoni larvae only exhibit these spots on the anterior lobe (and not the lateral lappets or posterior lobe). In advanced larvae, the juvenile inside has two small black eyes and a caudal cirrus. The eyes are lost in adults, but the cirrus will remain.
Larval morphotype of M. wilsoni, side view (left) and top view (right). Note pigment patches on either side of anterior lobe only.