Date: 9/05/2017 13:09:26
From: dv
ID: 1063198
Subject: Earthworm reproduction

My son asked me how worms reproduce and alas I had no clue.

It turns out it is quite an interesting story, though somewhat disgusting and not all that easy to explain to an eight year old.

https://en.wikipedia.org/wiki/Earthworm#Reproduction

Mating occurs on the surface, most often at night. Earthworms are hermaphrodites; that is, they have both male and female sexual organs. The sexual organs are located in segments 9 to 15. Earthworms have one or two pairs of testes contained within sacs. The two or four pairs of seminal vesicles produce, store and release the sperm via the male pores. Ovaries and oviducts in segment 13 release eggs via female pores on segment 14, while sperm is expelled from segment 15. One or more pairs of spermathecae are present in segments 9 and 10 (depending on the species) which are internal sacs that receive and store sperm from the other worm during copulation. As a result, segment 15 of one worm exudes sperm into segments 9 and 10 with its storage vesicles of its mate. Some species use external spermatophores for sperm transfer.
In Hormogaster samnitica and Hormogaster elisae transcriptome DNA libraries were sequenced and two sex pheromones, Attractin and Temptin, were detected in all tissue samples of both species. Sex pheromones are probably important in earthworms because they live in an environment where chemical signaling may play a crucial role in attracting a partner and in facilitating outcrossing. Outcrossing would provide the benefit of masking the expression of deleterious recessive mutations in progeny.

Copulation and reproduction are separate processes in earthworms. The mating pair overlap front ends ventrally and each exchanges sperm with the other. The clitellum becomes very reddish to pinkish in color. Some time after copulation, long after the worms have separated, the clitellum (behind the spermathecae) secretes material which forms a ring around the worm. The worm then backs out of the ring, and as it does so, it injects its own eggs and the other worm’s sperm into it. As the worm slips out of the ring, the ends of the cocoon seal to form a vaguely lemon-shaped incubator (cocoon) in which the embryonic worms develop. They emerge as small, but fully formed earthworms, but lack their sex structures, which develop in about 60 to 90 days. They attain full size in about one year. Scientists predict that the average lifespan under field conditions is four to eight years, while most garden varieties live only one to two years. Several common earthworm species are mostly parthenogenetic.
Among lumbricid earthworms, parthenogenesis arose from sexual relatives many times. Parthenogenesis in some Aporrectodea trapezoides lineages arose 6.4 to 1.1 million years ago from sexual ancestors.

Reply Quote

Date: 9/05/2017 13:28:03
From: sarahs mum
ID: 1063206
Subject: re: Earthworm reproduction

dv said:


My son asked me how worms reproduce and alas I had no clue.

It turns out it is quite an interesting story, though somewhat disgusting and not all that easy to explain to an eight year old.

https://en.wikipedia.org/wiki/Earthworm#Reproduction

Mating occurs on the surface, most often at night. Earthworms are hermaphrodites; that is, they have both male and female sexual organs. The sexual organs are located in segments 9 to 15. Earthworms have one or two pairs of testes contained within sacs. The two or four pairs of seminal vesicles produce, store and release the sperm via the male pores. Ovaries and oviducts in segment 13 release eggs via female pores on segment 14, while sperm is expelled from segment 15. One or more pairs of spermathecae are present in segments 9 and 10 (depending on the species) which are internal sacs that receive and store sperm from the other worm during copulation. As a result, segment 15 of one worm exudes sperm into segments 9 and 10 with its storage vesicles of its mate. Some species use external spermatophores for sperm transfer.
In Hormogaster samnitica and Hormogaster elisae transcriptome DNA libraries were sequenced and two sex pheromones, Attractin and Temptin, were detected in all tissue samples of both species. Sex pheromones are probably important in earthworms because they live in an environment where chemical signaling may play a crucial role in attracting a partner and in facilitating outcrossing. Outcrossing would provide the benefit of masking the expression of deleterious recessive mutations in progeny.

Copulation and reproduction are separate processes in earthworms. The mating pair overlap front ends ventrally and each exchanges sperm with the other. The clitellum becomes very reddish to pinkish in color. Some time after copulation, long after the worms have separated, the clitellum (behind the spermathecae) secretes material which forms a ring around the worm. The worm then backs out of the ring, and as it does so, it injects its own eggs and the other worm’s sperm into it. As the worm slips out of the ring, the ends of the cocoon seal to form a vaguely lemon-shaped incubator (cocoon) in which the embryonic worms develop. They emerge as small, but fully formed earthworms, but lack their sex structures, which develop in about 60 to 90 days. They attain full size in about one year. Scientists predict that the average lifespan under field conditions is four to eight years, while most garden varieties live only one to two years. Several common earthworm species are mostly parthenogenetic.
Among lumbricid earthworms, parthenogenesis arose from sexual relatives many times. Parthenogenesis in some Aporrectodea trapezoides lineages arose 6.4 to 1.1 million years ago from sexual ancestors.

draw a diagram. he’ll get it.

Reply Quote

Date: 9/05/2017 13:40:01
From: kii
ID: 1063209
Subject: re: Earthworm reproduction

sarahs mum said:


dv said:

My son asked me how worms reproduce and alas I had no clue.

It turns out it is quite an interesting story, though somewhat disgusting and not all that easy to explain to an eight year old.

https://en.wikipedia.org/wiki/Earthworm#Reproduction

Mating occurs on the surface, most often at night. Earthworms are hermaphrodites; that is, they have both male and female sexual organs. The sexual organs are located in segments 9 to 15. Earthworms have one or two pairs of testes contained within sacs. The two or four pairs of seminal vesicles produce, store and release the sperm via the male pores. Ovaries and oviducts in segment 13 release eggs via female pores on segment 14, while sperm is expelled from segment 15. One or more pairs of spermathecae are present in segments 9 and 10 (depending on the species) which are internal sacs that receive and store sperm from the other worm during copulation. As a result, segment 15 of one worm exudes sperm into segments 9 and 10 with its storage vesicles of its mate. Some species use external spermatophores for sperm transfer.
In Hormogaster samnitica and Hormogaster elisae transcriptome DNA libraries were sequenced and two sex pheromones, Attractin and Temptin, were detected in all tissue samples of both species. Sex pheromones are probably important in earthworms because they live in an environment where chemical signaling may play a crucial role in attracting a partner and in facilitating outcrossing. Outcrossing would provide the benefit of masking the expression of deleterious recessive mutations in progeny.

Copulation and reproduction are separate processes in earthworms. The mating pair overlap front ends ventrally and each exchanges sperm with the other. The clitellum becomes very reddish to pinkish in color. Some time after copulation, long after the worms have separated, the clitellum (behind the spermathecae) secretes material which forms a ring around the worm. The worm then backs out of the ring, and as it does so, it injects its own eggs and the other worm’s sperm into it. As the worm slips out of the ring, the ends of the cocoon seal to form a vaguely lemon-shaped incubator (cocoon) in which the embryonic worms develop. They emerge as small, but fully formed earthworms, but lack their sex structures, which develop in about 60 to 90 days. They attain full size in about one year. Scientists predict that the average lifespan under field conditions is four to eight years, while most garden varieties live only one to two years. Several common earthworm species are mostly parthenogenetic.
Among lumbricid earthworms, parthenogenesis arose from sexual relatives many times. Parthenogenesis in some Aporrectodea trapezoides lineages arose 6.4 to 1.1 million years ago from sexual ancestors.

draw a diagram. he’ll get it.

Yep. It will raise more questions, but that’s good.

Reply Quote

Date: 9/05/2017 13:53:10
From: mollwollfumble
ID: 1063218
Subject: re: Earthworm reproduction

sarahs mum said:

draw a diagram. he’ll get it.

Reply Quote

Date: 9/05/2017 15:07:07
From: roughbarked
ID: 1063265
Subject: re: Earthworm reproduction

dv said:


My son asked me how worms reproduce and alas I had no clue.

The wonder is that you can admit this.

Reply Quote

Date: 9/05/2017 15:24:52
From: dv
ID: 1063267
Subject: re: Earthworm reproduction

roughbarked said:


dv said:

My son asked me how worms reproduce and alas I had no clue.

The wonder is that you can admit this.

I am a humble and modest man, always content to admit gaps in my knowledge: it’s an opportunity to learn.

Reply Quote

Date: 9/05/2017 15:28:43
From: roughbarked
ID: 1063268
Subject: re: Earthworm reproduction

dv said:


roughbarked said:

dv said:

My son asked me how worms reproduce and alas I had no clue.

The wonder is that you can admit this.

I am a humble and modest man, always content to admit gaps in my knowledge: it’s an opportunity to learn.

It is so good to hear.

Reply Quote

Date: 9/05/2017 16:06:26
From: roughbarked
ID: 1063271
Subject: re: Earthworm reproduction

roughbarked said:


dv said:

roughbarked said:

The wonder is that you can admit this.

I am a humble and modest man, always content to admit gaps in my knowledge: it’s an opportunity to learn.

It is so good to hear.


Better Days

Even in the quietest moments

Reply Quote

Date: 9/05/2017 17:46:39
From: kii
ID: 1063285
Subject: re: Earthworm reproduction

Just don’t confuse him with the Earthworm Jim cartoon show.

Reply Quote

Date: 9/05/2017 17:47:40
From: roughbarked
ID: 1063286
Subject: re: Earthworm reproduction

kii said:


Just don’t confuse him with the Earthworm Jim cartoon show.

No worries there.

Reply Quote

Date: 9/05/2017 18:06:36
From: roughbarked
ID: 1063287
Subject: re: Earthworm reproduction

roughbarked said:


kii said:

Just don’t confuse him with the Earthworm Jim cartoon show.

No worries there.

you win, I lose

Reply Quote

Date: 9/05/2017 18:06:37
From: roughbarked
ID: 1063288
Subject: re: Earthworm reproduction

roughbarked said:


kii said:

Just don’t confuse him with the Earthworm Jim cartoon show.

No worries there.

you win, I lose

Reply Quote

Date: 9/05/2017 18:13:52
From: roughbarked
ID: 1063289
Subject: re: Earthworm reproduction

is it mine

Reply Quote

Date: 9/05/2017 23:01:26
From: The Rev Dodgson
ID: 1063293
Subject: re: Earthworm reproduction

dv said:


My son asked me how worms reproduce and alas I had no clue.

It turns out it is quite an interesting story, though somewhat disgusting and not all that easy to explain to an eight year old.

https://en.wikipedia.org/wiki/Earthworm#Reproduction

Mating occurs on the surface, most often at night. Earthworms are hermaphrodites; that is, they have both male and female sexual organs. The sexual organs are located in segments 9 to 15. Earthworms have one or two pairs of testes contained within sacs. The two or four pairs of seminal vesicles produce, store and release the sperm via the male pores. Ovaries and oviducts in segment 13 release eggs via female pores on segment 14, while sperm is expelled from segment 15. One or more pairs of spermathecae are present in segments 9 and 10 (depending on the species) which are internal sacs that receive and store sperm from the other worm during copulation. As a result, segment 15 of one worm exudes sperm into segments 9 and 10 with its storage vesicles of its mate. Some species use external spermatophores for sperm transfer.
In Hormogaster samnitica and Hormogaster elisae transcriptome DNA libraries were sequenced and two sex pheromones, Attractin and Temptin, were detected in all tissue samples of both species. Sex pheromones are probably important in earthworms because they live in an environment where chemical signaling may play a crucial role in attracting a partner and in facilitating outcrossing. Outcrossing would provide the benefit of masking the expression of deleterious recessive mutations in progeny.

Copulation and reproduction are separate processes in earthworms. The mating pair overlap front ends ventrally and each exchanges sperm with the other. The clitellum becomes very reddish to pinkish in color. Some time after copulation, long after the worms have separated, the clitellum (behind the spermathecae) secretes material which forms a ring around the worm. The worm then backs out of the ring, and as it does so, it injects its own eggs and the other worm’s sperm into it. As the worm slips out of the ring, the ends of the cocoon seal to form a vaguely lemon-shaped incubator (cocoon) in which the embryonic worms develop. They emerge as small, but fully formed earthworms, but lack their sex structures, which develop in about 60 to 90 days. They attain full size in about one year. Scientists predict that the average lifespan under field conditions is four to eight years, while most garden varieties live only one to two years. Several common earthworm species are mostly parthenogenetic.
Among lumbricid earthworms, parthenogenesis arose from sexual relatives many times. Parthenogenesis in some Aporrectodea trapezoides lineages arose 6.4 to 1.1 million years ago from sexual ancestors.

So when a mummydaddy earthworm and a mummydaddy earthworm love each other very much …

Reply Quote

Date: 9/05/2017 23:09:01
From: mollwollfumble
ID: 1063296
Subject: re: Earthworm reproduction

Was reading last night that back in the middle ages nobody knew how eels reproduced because they don’t have any genital openings.

So: How do eels reproduce?

Reply Quote

Date: 10/05/2017 00:33:02
From: dv
ID: 1063317
Subject: re: Earthworm reproduction

mollwollfumble said:


Was reading last night that back in the middle ages nobody knew how eels reproduced because they don’t have any genital openings.

So: How do eels reproduce?

Basically similar to other Elopomorpha: they produce eggs and sperm which fertilise externally, have a larval phase which grows to maturity.

But eels don’t reach full maturity until they leave the estuaries and head out to the ocean to reproduce, so most of the eels that people were seeing in the middle ages were not fully mature.

Reply Quote

Date: 10/05/2017 21:51:18
From: mollwollfumble
ID: 1063682
Subject: re: Earthworm reproduction

dv said:


mollwollfumble said:

Was reading last night that back in the middle ages nobody knew how eels reproduced because they don’t have any genital openings.

So: How do eels reproduce?

Basically similar to other Elopomorpha: they produce eggs and sperm which fertilise externally, have a larval phase which grows to maturity.

But eels don’t reach full maturity until they leave the estuaries and head out to the ocean to reproduce, so most of the eels that people were seeing in the middle ages were not fully mature.

I’ve seen eels in Australian lakes that have no exit to the sea. Is Australian eel reproduction different, or are these all going to die without ever reproducing?

Reply Quote

Date: 10/05/2017 21:57:54
From: buffy
ID: 1063683
Subject: re: Earthworm reproduction

mollwollfumble said:


dv said:

mollwollfumble said:

Was reading last night that back in the middle ages nobody knew how eels reproduced because they don’t have any genital openings.

So: How do eels reproduce?

Basically similar to other Elopomorpha: they produce eggs and sperm which fertilise externally, have a larval phase which grows to maturity.

But eels don’t reach full maturity until they leave the estuaries and head out to the ocean to reproduce, so most of the eels that people were seeing in the middle ages were not fully mature.

I’ve seen eels in Australian lakes that have no exit to the sea. Is Australian eel reproduction different, or are these all going to die without ever reproducing?

I have in my brain that they wriggle across land if necessary. To get to a stream. I can’t remember why I think that.

Reply Quote

Date: 10/05/2017 22:53:45
From: roughbarked
ID: 1063695
Subject: re: Earthworm reproduction

buffy said:


mollwollfumble said:

dv said:

Basically similar to other Elopomorpha: they produce eggs and sperm which fertilise externally, have a larval phase which grows to maturity.

But eels don’t reach full maturity until they leave the estuaries and head out to the ocean to reproduce, so most of the eels that people were seeing in the middle ages were not fully mature.

I’ve seen eels in Australian lakes that have no exit to the sea. Is Australian eel reproduction different, or are these all going to die without ever reproducing?

I have in my brain that they wriggle across land if necessary. To get to a stream. I can’t remember why I think that.

Because it is true?

he larvae drift on the ocean currents and eventually reach coastal waters, where they metamorphose into elvers (tiny, semi-transparent eels). From there, they migrate upstream, traversing numerous obstacles — if necessary, leaving the water and travelling short distances over moist ground. They are well fitted to this task, being able to absorb 50% of the oxygen they need through the skin. Eventually, they take up residence in a lake, swamp, dam or river, typically occupying a home range of about 400 m in length, where they remain until they reach maturity at about 14 years for males and 18 to 24 years for females.
https://en.wikipedia.org/wiki/Short-finned_eel

Reply Quote

Date: 17/12/2024 10:55:38
From: SCIENCE
ID: 2226447
Subject: re: Earthworm reproduction

anyway to happier things these are nicer kinds of tunnel

https://www.abc.net.au/news/2019-10-24/curious-gippsland-giant-earthworm/11630320

Reply Quote