Northern Moonsnail as shown in all the images above.There are five species of moonsnail that range from Alaska to southern California or northern Mexico. While I have found no research to support this, I wonder if the the mucus may have a chemosensory role so that individuals may more easily find one another for mating. Notice the mucus trails behind the Northern Moonsnails in the images below. It’s where their prey live and they also need the sand to make their egg collars. Moonsnails clearly need to live in sandy habitats. I believe the tracks in my image below are from Northern Moonsnails. Note that I have found moonsnail shells with holes drilled into them from. It can take another day or so for the moon snail to ingest the clam innards. Once a perfectly rounded hole is made in the shell, the moon snail inserts its tubular, straw-like mouth and slurps up the “clam smoothie” inside. In order to speed things up a bit, the moon snail produces hydrochloric acid and other enzymes to help dissolve the shell and liquefy the clam’s insides. See bottom of my blog at this link for more information on the radula.įrom Washington State’s Department of Ecology: “The average moonsnail takedown lasting 4 days as it drills ½ mm per day. That’s also a clue that the predator was a moonsnail species, not a whelk species. Notice too how the hole is almost always near the “umbo” of their prey’s shell (highest part). While some whelk species also drill holes into their prey with their radula (rough tongue-like structure), when moonsnail species drill holes into their prey, there is the sunken / bevelled edge you see here. The siphon is not related or connected to the water system in the foot. The structure indicated with the arrow is the moonsnail’s incurrent siphon, which draws fresh, oxygen-rich water in and over the moonsnail’s gills for respiration. A Northern Moonsnail’s operculum – the structure attached to the bottom of the animal’s foot so that when it retreats into its shell, the opening is sealed. See my “Shut the door” blog on opercula at this link. With the entry to the shell having to be big, of course moonsnails need an “operculum”, a door-like structure that seals off the opening to the shell. It’s the most common moonsnail species off the coast of British Columbia. The Northern Moonsnail is the largest moonsnail species to 14 cm long (Neverita lewisii). They need such a big foot to dig for their clam prey AND for females to construct their egg collars below the sand. Through the rapid uptake of seawater, the foot of can inflate up to four times the size of what it is when in the shell The water is expelled when moonsnails squeeze back into their shells. You might be wondering how a snail THAT big can fit into their shell. What has catalyzed my finally also adding this content to my blog is that Mickie Donley shared her video with me showing a female Northern Moonsnail pushing her eggs to the surface. Photos taken in British Columbia, Canada but there are moonsnail species, and their collars, off so many coasts.” The moonsnail species in the photo above is the Northern Moonsnail whose shell can be up to 14 cm wide (Neverita lewisii is also known as Lewis’ Moonsnail). There is contradictory information on how long it takes the eggs to hatch (one reliable source relays about 1 week while another reports up to 1.5 months). The larvae are plankton for 4 to 5 weeks and then settle to the ocean bottom to develop further. The collar disintegrates when the larvae hatch. When the egg collar is intact as you seen in the images above, the young have NOT hatched out. The process of making the egg collar takes 10 to 14 hours and reportedly starts at the beginning of a flood tide.Īs long as conditions are good, the egg collars found on beaches are likely to have embryos developing inside them (if they are still rubbery and moist). The thousands of eggs develop in the the sand-mucus matrix. The female forms the collar under the sand and then forces it above the sand when done. They are wondrous constructions to house and protect moonsnail embryos (of several moonsnail species on our coast).ĭetail: The female moonsnail forms one layer of the collar by gluing together sand grains with mucus then the fertilized eggs are laid on this layer and THEN she seals them in with another layer of sand and mucus! With recent low tides it has surfaced again that (mostly) well-intentioned people are moving or “cleaning up” moonsnail egg collars. Text provided with the above image: “ Oh oh.
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