A few years back I wrote a series of columns about the mating behavior of the California market squid. Apparently one mother complained to the newspaper that she had read the column to her five year old daughter, and was embarrassed when she had to explain the word "orgy" to her youngster. Now I've never considered my audience for these columns to be in that age range, but if you have impressionable youngsters out there who might get their hands on the paper, let this be a warning. Today's focus will be on the subject of reproduction... or mating. However, I doubt its contents will sink beneath a PG rating so most of you adults will be disappointed!
On occasion I have had divers on the King Neptune or in the dive park return from a dive and ask me about the "pumpkin seeds" that seem to cover many rocks and other surfaces at certain times of the year. Others see ribbon-like formations on the rocks and wonder what creature created them. For some who dive sites below our Catalina landfill like Blue Car Wreck and Garibaldi Reef, I usually let them figure out what the large round "eggs" scattered on the bottom there are. It really is easy even for a rank novice since they are often labeled "Titleist," "Spalding" or "Wilson." Wouldn't it be nice if critter eggs were so labeled, but then I wouldn't have everyone coming up to me to ask. And I truly enjoy adding value to a diver's experience and understanding of the world below.
Identifying critter eggs can be almost as much fun as identifying the critter themselves. There are usually fewer clues and very little "behavior" to give much basis to go on. Such mysteries can make for much more fun underwater though. I usually learn the identity of the eggs by observing the process whereby they are actually laid. This way I can be pretty certain of the "culprit" if I catch them in the act. The pictures I've included with this week's column all come from different species of snails, ranging from ones an inch or so long to the largest marine snail in the world, occasionally exceeding a whopping three feet! Two of them fit the usual image of a snail, having hard shells to encase the body's soft body, mantle and foot. Two of them lack that protection and rely on other means to "defend their lives."
Now most snail sex is pretty abnormal when observed by the human mind. Although there are a lot of alternate lifestyles in our world these days, few match that of the subjects in today's column. Many snails are simultaneous hermaphrodites. That simply means each individual contains both male and female sex organs, and they are both functional at the same time. When they mate, the male organ of one inseminates the female counterpart in the other and vice-versa. Until I arrived here on Catalina in the late 1960's, I was a born-and-bred Chicagoan who frequented Wrigley Field to watch my great uncle's Chicago Bears including the likes of Gale Sayers and Mike Ditka play. Therefore I've referred to this snail sexual orientation as the Wrigley Doublemint gum phenomenon: "double your pleasure, double your fun."
For most species I'm familiar with (although by no means "intimately"), the sex organs are on the right side of the body. Thus the two snails have to line up next to one another with their right sides together. This places them head-to-toe. New underwater photographers are often surprised when they post a picture of "mating" snails on a web site and biologists comment that they aren't mating at all. How can they tell from a picture? Because the snails were lined up on the wrong side of one another, they were probably just chowing down together.
Snail sex is also abnormal in another way. We all know that snails usually move very slowly, at least by Olympic standards. However,, they also do other things slowly as well. On occasion I've observed and filmed certain species of snails mating over periods longer than a single day, including one that laid one of the eggs depicted in the pictures here. Now our "love ins" and "be ins" in the 60's lasted entire weekends and sometimes longer, but I doubt many of the individual participants did! I won't go into any further detail on that subject since it was the 60's... and I was there, so I don't remember. Of course I won't admit to participating!
Spring and summer are the times a man's fancy turns to... well, I'm not referring to golf or tennis. Many snails get the same idea... or at least half of their bodies and minds do. It is very common to see the ocean floor dotted with mating pairs (and even, dare I say it, orgies). The evidence of these couplings lasts for weeks as you can see in the photos accompanying this column. It is a great time for divers and snorkelers to observe the eggs of many local snails, and try their best to identify the critters that laid them.
I'm going to give you an opportunity to "dive dry" with me and do just that. The first reader of the print version of this column who can identify the source of the four sets of eggs depicted here will win a free "Dive Dry with Dr. Bill" DVD. You do not need to know the scientific names, just the common names. E-mail me your answers to email@example.com and the first response I receive with the correct answers will win one of my latest DVD's, the "Cephalopods of Southern California." As for the contest rules... All answers must be received via e-mail before the following week's column appears. No telephone responses... I might think you are a nasty telemarketer. You must be able to pick up the DVD here on the island. Employees of "Dive Dry with Dr. Bill" and their families are ineligible. The answers will be revealed in next week's column (if I remember).
© 2008 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. 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!
Guess what species laid each of these four egg clusters and you'll win a "Dive Dry with Dr. Bill" DVD.
This document maintained by
Dr. Bill Bushing.
Material and images © 2008 Star Thrower Educational Multimedia