Tube-Dwelling Worms on Seldovia Beach
Observation: This jelly was observed on almost all tube worms on this beach. It appeared to be attached or coming out of the worms and you could see them moving inside of it. We thought they were egg masses or some type of spawn.
LEO says: There are a number of tube-dwelling marine worms belonging to the Annelida: Class Polychaeta. The species seen in the images have attributes similar to the sedentary polychaeta. The tube worms are usually adapted to living permanently in tubes or burrows; some attach themselves to rocks or piers. Most are permanently attached to a particular base, and the worm seldom, or never, ventures outside. However, one species of sedentary polychata, the tube worm Cistenides, moves about the seafloor, dragging along its delicate tube of sand grains.
Most polychaetes reproduce sexually, and the sexes are separate. Sex cells develop from masses of tissue in the metameres and leave by way of tubules or by rupture of the body wall. In most cases fertilization of the eggs by sperm occurs externally in seawater and results in the formation of free-swimming larvae. Variations include internal fertilization, laying of egg masses that are attached to objects with mucus, and brooding of developing eggs in the worm's body.
Source: "Annelida: Class Polychaeta." The Columbia Electronic Encyclopedia. © 1994, 2000-2006 on Infoplease.
According to NOAA Fisheries, an estimated 194 species of polychaetes can be found in the Southeastern Bering Sea.
This post was sent to the College of Fisheries and Ocean Sciences, University of Alaska Fairbanks.
Resources:
SeaNet – Phylum Annelida: Subtidal Segmented Worms. Polychaetes comprise the largest class of the phylum. Source: Stanford University
Observations From Members 