White speck tunicate
Didemnum conchyliatum
(Sluiter, 1898)
Description:
Tiny zooids are embedded in a thin, encrusting tunic. The excurrent siphons empty into an interior chamber that has one or several outflow openings. Multiple openings often form meandering chains. Color commonly orange, occasionally white. The whiteness is due to densely packed spicules in the test, the orange color is due to pigment cells in the tunic.
Habitat:
Inhabit reefs and lagoons. Attach to a variety of substrates, especially common on Orange elephant ear sponges, Agelas clathrodes.
Distribution:
Common Caribbean; occasional South Florida and Bahamas.
Remarks:
Positive identification requires microscopic examination of the internal body parts. The zooids have a single testis lobe and a large atrial aperture that exposes much of the branchial sac. A similar species, Didemnum duplicatum Monniot, 1983, has zooids with a bilobed testis and the atrial aperture is usually small and rounded. Zooids of Didemnum psammathodes, Sluiter, 1895 have also a single testis lobe, but spicules in the tunic are few or absent.