This something I've mentioned to various members in posts (usually breeding topics), but never really had a picture to help illustrate my description:
Glair Glands
Glair glands are visible on a female crayfish only after she is sexually mature. The glair glands become visible prior to egg laying (whether she has mated or not), and are located on the underside of the abdomen and tail fan. The glair glands release a mucus-like substance called glair, which is used to attach the eggs to the swimmerets.
Prior to laying eggs, the glair glands enlarge extensively and create creamy/milky patches, most notably visible on the tail (see below picture):
(the white "petal" like patches are the glair glands)
Side Notes:
1.) Glair glands are not always visible. Some crayfish do not display the patches well or their coloration mutes them out. So, you may not always be able to see them.
2.) A female can mate when her glair glands are not visible (no relation to the prior note), but she is more likely to be the aggressor and pursue the male when they are visible. Rather than shying away or even fighting with an over zealous male suitor.
*Many thanks to my lil' Procambarus clarkii, whose glair glands are very vivid this week.
Glair Glands
Glair glands are visible on a female crayfish only after she is sexually mature. The glair glands become visible prior to egg laying (whether she has mated or not), and are located on the underside of the abdomen and tail fan. The glair glands release a mucus-like substance called glair, which is used to attach the eggs to the swimmerets.
Prior to laying eggs, the glair glands enlarge extensively and create creamy/milky patches, most notably visible on the tail (see below picture):
(the white "petal" like patches are the glair glands)
Side Notes:
1.) Glair glands are not always visible. Some crayfish do not display the patches well or their coloration mutes them out. So, you may not always be able to see them.
2.) A female can mate when her glair glands are not visible (no relation to the prior note), but she is more likely to be the aggressor and pursue the male when they are visible. Rather than shying away or even fighting with an over zealous male suitor.
*Many thanks to my lil' Procambarus clarkii, whose glair glands are very vivid this week.