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.

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.

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.

sarahs mum said:

draw a diagram. he’ll get it.

dv said:

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

The wonder is that you can admit this.

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.

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.

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

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

kii said:

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

No worries there.

roughbarked said:

kii said:

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

No worries there.

you win, I lose

roughbarked said:

kii said:

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

No worries there.

you win, I lose

is it mine

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 …

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?

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.

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?

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.

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