But from all the nature shows I’ve watched, generally the female lays her eggs on the floor of the water body and then the male excretes sperm over the eggs to fertilize them. With mammals such as whales, however, the male and female actually physically copulate, then after a gestation period, the female gives birth to a live calf.

And then there's the cast-it-all-into-the-sea approach, where tight gatherings of males and females dump all their gametes in the water at once, not much different from pine trees. There are times and places along the seacoast where the waves are frothy with fish spooge after such spawnings, usually timed to the phases of the moon.

Different environments, different adaptations, different "strategies".

I don't know what other fish do, but herring form very large schools, so that probably has a lot to do with it. Sheer force of numbers -- what programmers call the "Mongolian hordes" approach (ironically, not actually the devastating tactic the Mongols usually used. They preferred to flee into a pre-set ambush by concealed reinforcements, then turn and finish off their pursuers).

Google "satellite imagery of herring milt" to get some idea of the scale involved.

Swordtails and Black Molly's are live bearers.


Siamese Fighting fish lay eggs. This an extremely elaborate "dance" and process.

whenever anyone talks about aquariums, I just assume they're talking a fresh water fish because that's what I had for many years.


There's salt water aquariums as well but I know nothing about salt water fish or aquariums.




I had success breeding Black Molly's. But because they're live bearers, the aquarium keeper needs to remove the babies ASAP because all and any adult fish will mistake the newborns for a meal.

They build floating nests out of bubbles, and the male squeezes the female to get her eggs into the nest.

The female will deposit her eggs somewhere on the gravel…in real water…like a lake…the fish may …depending on species fan out a shallow depression in the sand with her fins…then the male will swim over the eggs and deposit the sperm…hopefully the eggs meet the sperm and little fishies are created. The depression keeps the sperm more localized so currents have a harder time washing it away.

Not real romantic from our perspective.

a good dose of fish porn might help???

… sound pretty fishy to me.

facts.

Some fish practice internal fertilization (sharks, for instance) while others fertilize eggs externally. In the latter case, females lay eggs and then males release semen into the water over them. Some fish also routinely reproduce parthenogenetically (without mating), and others change sexes sometime during their life cycles, so they play both sides of the mating game during their lives.

...but I taught general zoology for 20 years. Glad I'm not teaching any longer!

that you just needed to get that joke off your chess!

Privacy please!

to take to the zoo, deb!

to lock me in a cage with a silverback gorilla and throw away the key?

We could make a DU field trip out of it.

Start living a bit

You'd be bonded with the tigers in no time!

I promise I won't sneak a tiger on the field trip bus!

Note that "mating" is not necessary for reproduction.

-- Mal