Larva of Tubulanus polymorphus collected 11 February 2013. Note thin and short apical tuft at 1 o'clock. Scale 100 µm.
Tubulanus polymorphus
Sequence Data: 16S, COI
Months collected: Feb
The larvae of Tubulanus polymorphus are lecithotrophic and short-lived (Stricker 1987). We collected this larva in February and, at first, did not recognize it as the larva of a nemertean. It was large (550 µm), slow-moving and blimp-like, orangish in color and had an inconspicuous apical tuft. This larva drifted in the plankton sample, rather than moving with apical tuft forward as is usually the case for other nemerteans. Furthermore, this individual tended to compress itself back and forth in variety of shapes, similar to cnidarian planulae.
Sequence data revealed that this is the larva of T. polymorphus a common bright orange nemertean in local rocky intertidal areas (e.g. Cape Arago) where males and females deposit eggs within their parchment tube (Coe 1943). Tubulanus polymorphus is reported to be sexually mature in early (San Juan Island, WA, Stricker 1987) to late summer (Coe 1905) and can produce large numbers of eggs up to 350 µm in diameter which are used in developmental research (Stricker et al. 2001, 2013). The larvae develop quickly and have a short pelagic duration, suggesting that this larva would rarely be encountered in the plankton.