I described some of the difficulties aquatic invertebrates face in finding mates. These are pretty much the same in ponds, lakes and oceans. It is more intriguing in highly turbid ponds but the method of doing the process by scent and taste works whether there is sufficient light or not. Not being able to see your mate also means that you can’t see if someone has already found her. The result is that, in Daphnia at least, the ménage a trois is not uncommon with two males attached on either side of a female that is desperately swimming trying to keep all three from sinking to the bottom. Both males are doing their best to get their sperm where they can be used for fertilization, but remember that males have no sexual appendage to insert nor is there any place to insert it. That would explain why both males have a fair chance of their sperm being used to inseminate the eggs. I am unaware of anyone looking at the sibs that hatch from an ephippium, but I suppose it is possible that there could be half-sisters from any one ephippium.
While the Daphnia ménage is kinky it is tame compared to fairy shrimp in arctic ponds I looked at on Igloolik Island. Those animals are really freaky. Male fairy shrimp have large grasping mouthparts by which they attach to females. There are photographs and even videos of brine shrimp (which are just fairy shrimp living in salty water) at http://www.captain.at/artemia-mating.php. At least in Daphnia the females are larger than the males they have to carry around. Female fairy shrimp have no such luck and males are often much larger than their mates. Worse yet is the fact that males have a behavior called mate guarding in which they stay attached to their mate for long periods to make sure that no other male comes along to mate with the female.
Mate guarding is interesting but not kinky. The kink comes from finding the ménage a trois again but this time the second male is grasping the first male and not the female. Kinkier yet is the ménage a quatre with yet a third male attached. And the poor female, smaller than even one of her suitors, has to carry all of them along. Want even kinkier stuff? I have seen a number of instances where at least one of the males in line was dead and partially decomposed with another male attached, unable to reach the female because of the original suitors body. That is kinky.
Mate guarding occurs in other pond dwellers as well. Amphipods, also called scuds, have a similar behavior. Much larger males will cover a much smaller female and essentially ride her even while she is carrying already fertilized eggs. At least scuds are bottom dwellers and the females don’t have to try and keep the couple afloat. It is not unusual to see seemingly many legged individuals that are actually the mating pair
Other species have kinky sex as well (snails in particular) but I’ll stick to telling about what I’ve seen. Tomorrow I’ll write about flatworms, their sex and other hungers.
