Posted: Sat Oct 19, 2019 12:41 pm
[Megalopa who has taken a minute larval whelk as a shell and walked onto land.]
Things are going fairly smoothly this summer. Most of my issues have been related to not having enough space and tanks to accomplish everything I need to accomplish. I finally bought a 20-tall which will be set aside as THE baby tank going forward. Right now it's holding the transition tank for megalopa to take shells and walk onto land. Then I move them to a land tank (a small bin in a ten gallon tank). When I no longer need the transition tank, the 20-gallon will become a nursery as they grow for ten months or so before being old enough to adopt out.
Here are the basic stats this year:
September 10th: SPAWN ONE, DAY ONE. I actually caught the female spawning and got a video of it. I was surprised that it was a crab that had been VERY small the year before and I would guess is no more than 3-4 years old, based on the growth I've witnessed. Of course, there's no way to tell definitively, but I do think it bodes well for the second generation of breeding being able to occur sooner than I had thought it might.
October 1st: First megalopa spotted. This was on Day 22, which was about six days earlier than last year's successful breed. I've actually been keeping the temps quite a bit lower this year, so that surprised me. Maybe it's a result of the biological imperative to hurry up and get to land if the season is ending.
October 9th: First megalopa to take a shell. This was Day 30, about ten days earlier than last year.
October 12th: SPAWN TWO, DAY ONE. This was a pretty light spawn. I didn't see who made it to the water (I had four females with eggs), but I had an aggressive little E who kept dogging the gravid females and trying to intercept them at the water. I think he developed a taste for PP eggs (a lot ditched them on the sand in the first breeding) and was really annoying them. There were also a ton of dead zoeae in the freshwater pool because I forgot to cover it that night. Just too much going on to remember to do everything, sadly.
October 19 (today) is Day 41 and Day 8. I have 114 babies in the land tank now and many more megalopa still in the transition tank. I'm trying to "stress" them a little bit more--be more like the ocean. Moving the water and shells around more and transporting them onto the ramp. I'm testing a theory that wave action actually helps them to take a shell for protection and pushes them to walk on land by sometimes depositing them there. I was thinking about the birthing process (in mammals) and how traumatic it is, but how the squeezing through the birth canal actually does some important work--the idea that not all stress is bad (or pointless) stress, I guess. Sometimes environmental (or other) stressors accomplish important things for an organism. I'm also seeing how much I can "ignore" the second spawn to see if we can find some manageable steps for others who want to try this but can't stop everything and give the zoeae two months of constant attention.