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Dive Dry with Dr. Bill

#587: A Mother's Day Orgy

I was alive during the 1960s and I actually remember much of it... well, most of it anyway. The days of sex, drugs and rock-n-roll were indeed "heady" days (if you get the pun). Although I looked like a full-on hippie or political radical, my bark was much worse than my bite. It would be hard to call me conservative, but I did not try every drug available at the time. And although they gave a sexual revolution, I was pretty much a one woman man (heck, that's as many as I could find in those days). Sure, I attended the be-ins and love-ins like most of my colleagues, but my level of participation was about as high as the number of times I've sung at karaoke.

What does that have to do with Mother's Day you ask? Good question. Mom has joined Dad and my grandparents so there was little my sisters and I could do to celebrate the day other than post our favorite pictures of her on Facebook. I had dive friends coming over, so my option was to head to the dive park to dive. Occasional dive buddy Catherine and her instructor Casey were over with a group from his new dive shop. My first dive was to join their group for a shallow dive over the training area. Well, between open water classes and feeding bat rays, the visibility was about the same as a foggy day up on our island's main ridge.

Despite the poor vis, there was plenty to see. In fact, it may have been too much for the youngsters because the critters down under seemed to be celebrating Mother's Day in the proper fashion by er... um... ah... making babies! Yep it was a virtual love-in down in King Neptune's realm. Almost everywhere I looked I saw signs of this. There was an as-of-yet yellow "snot" hanging all over the rocky reef that I feel quite certain was the egg mass for some unidentified snail. Moon snail egg collars littered the bottom. Horn shark eggs were embedded in the crevices of the Casino groyne (breakwater). Sea hares were holding their own love-ins and laying masses of eggs that look just like Mamma Mia's Day Old Spaghetti. Garibaldi were doing "the wild thing" (more on that next week). It seemed like everyone was getting "into the act" but me.

But the most incredible exhibit of this ardor had to be that of the lowly Kellet whelk (Kelletia kelletii, no relation to Lawrence Welk). Nearly everywhere I looked on the sandy bottom where there was a rock I saw several to dozens of these snails engaged in the arts of seduction and reproduction. One fairly small rock about a foot across had 13 of them, some mating and others laying their egg masses that look like pumpkin seeds stuck end-up on the rocks. Toward the end of my dive I really hit pay dirt when I encountered literally hundreds (if not a thousand or more) of the snails in a loosely scattered field of rocks that were studded with egg clusters.

Kellet whelks are one of the largest snail species found in southern California. They also range from Monterey down to Isla Asunción in Baja California. They may be found down to depths of about 150 ft. Their tapering, spiral-shaped shells may reach almost seven inches in length. The species apparently grows at a snail's pace... no surprise there! Although I find a few shells that are light colored and free of encrusting growth, most have encrusting red algae and critters on them and some have gnarly calcified protuberances. Smaller individuals may stay in the relative protection of the rocky reef while the larger ones I saw mating are out on the open sandy bottom.

Now as far as I know the Kellet whelk is illiterate and unable to read a calendar. I'm certain they had no idea that this orgy coincided perfectly with Mother's Day. I have no clue what environmental triggers (temperature? pheromones?) might cause so many to get in the mood at the same time. The species exhibits sexual dimorphism with separate males and females, the ladies being the larger individuals. They reach sexual maturity when their shells are about 2.5-2.8 inches long. Fertilization is internal and the female proceeds to lay egg clusters over a period of up to several days. Each "pumpkin seed" or egg cluster may contain more than one thousand individual eggs!

The embryos take about a month to hatch into larvae which then drift in the plankton for an estimated five to 10 weeks. Towards the end of this developmental period they tend to be found closer to the bottom, and then settle on it. Growth is slow, about 1/3 inch per year and becomes even slower once they reach sexual maturity (just like humans, unless you count the flab). Some researchers believe it may take 20 years to reach 3.5 inches in length. Imagine how old a seven incher must be!

These whelks are carnivorous, feeding on worms, other snails (which they will pursue... at a snail's pace of course), barnacles and tunicates. They also scavenge on dead critters including snails, clams, squid, crabs and lobster, starfish and fish. Food is often located via their chemical senses. They have a tongue-like radula located on a muscular proboscis (think elephant here) that acts like a rasp, tearing apart the prey. I was amazed to learn that the proboscis may be extended as much as twice the length of the shell! Even the hands of my hungry Toyon students could only reach halfway across the school's dining table. The bits and pieces are then sucked into the digestive tract by the muscles of the proboscis. Lobster fishers often find a cluster of Kellet whelks feasting on the bait in their traps.

Now group sex does have its drawbacks. When Kellet whelks gather to procreate, they offer their predators a virtual buffet of munchies. I have observed mating clusters of the whelks engulfed by a large knobby sea star (Pisaster giganteus). The lucky starfish could entrap the snails under its arms and munch away to its heart's content (if it had one). These sea stars are major predators on the whelks although they apparently make up less than 10% of the sea star's diet. Apparently the whelks have no avoidance reaction in the presence of the starfish. Hardly sounds prudent to me.

© 2014 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 29, 10:00 AM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. You can also watch these episodes in iPod format on YouTube through my channel there (drbillbushing). Please help me climb out of self-imposed poverty... buy my DVD's (see this link). Yes, take Dr. Bill home with you... we'll both be glad you did!

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Close-up of mating Kellet whelks and eggs and mating orgy of 13;
whelk egg cluster on rock and clusters of clusters from the orgy.

This document maintained by Dr. Bill Bushing.
Material and images © 2014 Star Thrower Educational Multimedia