Larva of Nipponnemertes bimaculata raised in the laboratory from artificially fertilized gametes in May 2013, shown here in three typical postures. Note two pairs of eyes and cerebral ganglia. Scale 100 µm.
Months obtained: May
Nipponnemertes bimaculata
Sequence Data: 16S, COI
The larvae of Nipponnemertes bimaculata resemble those of P. peregrina and Zygonemertes however, they do not have as prominent an apical tuft.
Lab-reared larvae of Nipponnemertes bimaculata possessed three pairs of eyes (two pairs in young larvae) that are a mixture of black and red. The embryos in this species are also distinct, the oocytes are bright green in color which can be seen through the female body wall, are ~260 µm in diameter and are surrounded by a large egg jelly. In May 2013, we observed several hundred ripe N. bimaculata adults washed ashore and spawning in the rocky intertidal (South Cove, Cape Arago) (see blog post by Jessie Spears). As this species is known to inhabit macroalgal holdfasts (Maslakova pers. obs.), this suggests that they swarmed to spawn and somehow accidentally became washed ashore.
Eggs of Nipponnemertes bimaculata, note the reflection of the large jelly coat at 3 o'clock. Scale bar 100 µm.
Nipponnemertes bimaculata adult collected from Cape Arago on 08 May 2013. Individuals are approximately 8 cm in length.