A question about retained sperm clutches

[Chameleophlaged]

Last July I had two clutches of common Jackson Xanths (Hawaiian Type) 12 & 13. On December 28, I had a clutch of 4 T.J. Jacksoni, from what I thought was a baby (she is only about 4 1/2 inches tail and all, her rostral horn is only about 3/8 inch long). Three died very quickly (2 on day 1 and the other within a week). The remaining one seems to be doing fine, I think a female unfortunately. Every three weeks or so after, another one of the T.J.J. had another clutch, 21, 12, 14 respectively.

This morning at feeding time, I went to the first T.J.J cage, opened the door and started looking for her ( a habit) I looked down and saw one baby walking across the lower cage door, looked around and found no more. Continuing down the line, I fed everyone and at the last cage (Hawaiian type) I found 4 babies wandering around.

OK now the question.

How long can they retain sperm? The T.J.J that had the single baby this morning had her clutch in mid-Feb, (only about 7 weeks ago) the Hawaiian had her clutch in July.

I am assuming that since these clutches are so small that they are the end of the supply and wondering if possibly the first T.J.J clutch of 4 was a retained sperm clutch and not the clutch of an immature female.

So since one interval was 7 weeks and the other 8 months, what is the norm?

Also all of todays babies are really, really small, is that normal?

 

[JacksJill]

The female my avatar came from had 3 or 4 clutches over the course of a year aprrox 3 mos. apart. I don't know if she breed her back after the births. She's not on here anymore to ask.
@leedragon do you have any info?

 

[Chameleophlaged]

Well after a couple of hours looking through the vegetation, the Hawaiian clutch of 4 is now 13.

 

[leedragon]

The female my avatar came from had 3 or 4 clutches over the course of a year aprrox 3 mos. apart. I don't know if she breed her back after the births. She's not on here anymore to ask.
@leedragon do you have any info?

11.5 cm sounds really small if you are counting the tail aswell, jacksonni jacksonii are not that big, about a finger long in body lenght without the tail. but I don´t really understand, do you keep all your females together? if that is the case it is most probaböy that the neonates are from the older females that have retained sperm yes. my females lay a clutch after about 4-6 months. i don´t remeber any specifict number for how long they can retain sperm. if i don´t making this up and remeber correctly from a text I read about 10 years ago, some species of chameleons can retain sperm up to around a year. but several months is definitely common.
I belive it has to do with the conditions they are kept in, how big the clutches are and how mutch sperm will they save.

 

[leedragon]

"To answer the basics of your question, yes, she can and probably will deliver another clutch without breeding. As to whether or not they store sperm, I'm not so sure anymore. It is apparently common to find embryos at very different stages of development during necropsies of live-bearing chameleons. Do they have the ability to do this and store sperm for future fertilizations? I haven't found any scientific papers or anything that ever said "I found viable sperm stored inside of X organ in a female Y species of chameleon."

You can let the male see the female and initiate his head-bobbing courtship dance. If she is receptive, let them go for it. You're only strengthening the chances of a good next clutch, imo. If she rejects his advances, wait a few weeks and try again.."

"The duration of sperm storage by females differs markedly between reptiles (maximum: 2555 d [7 years] and birds (maximum: 117d), with mammals showing both very short (< 1 d) and relatively long periods (maximum: 198 days). The females of many reptiles, probably all birds and some mammals have specialized structures for storing sperm, suggesting that selection for sperm storage has operated on females. Sperm storage, together with delayed implantation and delayed development, separates copulation from fertilization, and hence, copulation from the timing of birth. All three types of separation mechanism occur in mammals. Delayed implantation cannot occur in reptiles and birds because their eggs do not implant, but delayed development occurs in some reptiles. Comparisons among vertebrate classes suggest that sperm storage in the female tract may have an upper limit of a little over 100 days in endotherms: non-hibernating mammals have circumvented this limit by using delayed implantation as an uncoupling mechanism. A long reproductive cycle (up to four years) probably makes sperm storage obligatory for some reptiles. We consider existing hypotheses for prolonged sperm storage and the other reproductive delays, and propose a new hypothesis. Our hypothesis extends Sandell's (1990) hypothesis which states that in mammals delayed implantation has evolved to allow females to time both their copulation and birth seasons optimally. We propose that the other separation mechanisms, namely sperm storage and delayed development, have also evolved for this reason. Sandell suggested that the optimal time for females to copulate is when the opportunities to obtain the best quality male exist, and thus the dislocation of copulation and birth seasons has occurred through sexual selection. We propose that the other two separation mechanisms may also have evolved through sexual selection, in part at least. Of the three separation mechanisms, sperm storage has additional advantages for females in that it also allows them to modify their choice of male after copulation has occurred, through sperm competition. Thus we propose that: (1) all separation mechanisms have evolved when the optimal time for copulation is not compatible with either the optimal time for fertilization (birds) or the optimal time for birth, given a constant gestation period (reptiles, birds and mammals); (2) separation mechanisms have evolved through sexual selection enabling females to improve the quality of the male that fertilizes their eggs, either through pre-copulatory male-male competition (via any of the separation mechanisms) or through post-copulatory sperm competition (via sperm storage).

Here's the link:
http://www.blackwell-synergy.com/do...12.1993.tb00933.x?cookieSet=1&journalCode=bij "