In December, Rich posted on infertile eggs occasionally produced by anoles, also known as slugs. These eggs are small, yellow, and uncalcified. We have found that females typically lay slugs in different locations than fertile eggs. In our breeding colony, nearly every viable egg is deposited in egg laying substrate (moistened vermiculite in a plastic yogurt container), whereas slugs are found on nearly any surface but these cups, as described in a previous comment by William Baugher.
As our hybridization experiment in distichoids proceeds, it has become clear that these inviable eggs may be an important measure of the success of hybrid matings. There are some really great studies on viable anole eggs in the reproductive biology literature (1, 2, and 3, to name a few), but I have had no luck in finding papers that discuss, or even mention the production of, these inviable eggs. Since the last post on this subject AA readership has gone up and I am hoping that someone out there has some additional information on the phenomenon.
Specifically, we are most interested in learning:
Are slugs always the result of a lack of fertilization or do failed early stage embryos also appear as slugs?
Why are these eggs produced? Stamps (1975) reported the ability of Anolis aeneus to reabsorb eggs in the absence of a mating event. Are slugs eggs that can no longer be fertilized and are thus discarded? Why wouldn’t they too be reabsorbed?
Is slug production stimulated by interaction with males? Copulation?
Are slugs produced by other species? We’ve found them from a variety of distichoid species. And Martha commented that she has seen them produced by captive A. cybotes.
So, Anole Annals community, does anyone know where we can learn more about slugs?