Mating Fish

Is there a specific time that we could determine when fish mate. i.e. Is there a time of day, or month, or year? Or are there specific places on the reef where fish congregate to mate or spawn?

I am aware of the full moon thing when coral spawn. We have also been adorned with images of fish "shooting" eggs into the water with the males fertilising them, on TV.

But the more common guys we see on the reef should be a challenge, or is there a secret time or place?

This is a bit of a "how long is a piece of string question" and as always with wildlife there are always countless examples that break the rules.

You can see some of my fish spawning photography here:

http://www.amustard.com/?page=pro&ext=spaw...age=news&size=s

http://www.amustard.com/?page=pro&ext=ham&...age=news&size=s

But here goes.

Reef fish spawn regularly. Egg layers tend to spawn in the morning, broadcast spawners at dusk. Small fish are more fecund for their size than large fish and spawn more frequently. Many small reef fish spawn each day to each week during season. Large fish (groupers, snappers) spawn en masse one or two times a year.

The best place to start is looking is for egg laying species. Activity often peaks in the morning, but will continue all day. Damselfish are one of the first you will spot usually in pairs. Once you get your eye in you will start spotting spawning regularly.

As a shameless plug, in September I am running the Eco Week event for Ocean Frontiers where much of the diving will be focused on seeing these behaviours and of course coral spawning.

Hope this helps get you started.

Alex

Fish sex....one of my favourite topics. Not a lot of the other kind around here....

Anyhoo, from what i have found over the years most mating activity seems to centre around the New and Full moons. A couple of days on either side. Damsels seem to have eggs lying around all the time, horny little buggers. Attached is a photo taken today with some damsel eggs fairly well along, full moon being one week ago. Also noticed some coral spawning a day before the full moon last week.

Triggers also seem to do so on both moons at certain times of year. The Yellow Margin is an attacking fish of death for 2 or 3 days twice a month from about Jan-Apr and then again in the fall. The Titan on the other hand only seems to mate two or three times a year, again coinciding with moon cycles.

In Palau we get huge schools of several varieties of surgeonfish as well as Moorish Idols during the months of Jan-Apr. With most mating activity peaking at the full moon. Grey reefs and white tips at this time as well bear a lot of mating scars.

Mantas-they are fish, also mate in the winter months of Jan-Apr on new and full moon as do Eagle rays in Rangiroa.

Basically, seems to be the most mating action in the winter months when water is a bit cooler and always peaking at new and full moons

These are just personal observations, i am not a marine biologist but i spend more time in the water than most people so i think these are pretty accurate. I am sure mating occurs year round with most fish species but the biggest and most spectacular in my region is in the winter.

But saying that...them horny little Mandarinfish are mating everynight at dusk...lucky fish

Mike

The Mating of Fish

The female fish lays her eggs in shallow water. The male, swimming several feet or yards behind the female expells from his body the many sperm cells which are to be used in fertilizing the eggs. It will be observed that there is no sexual contact between the male and female fish at the time the eggs are fertilized. Several days before this event, these fish might have been seen on the riffles, or in deep water, swimming along side of against and over each other. Many mistake the action of the fish at this period for mating. They are not mating, they are love-making. Sexual 'excitement is necessary to the development of the eggs in the ovaries of the female, and especially for the generation of thousands of sperm cells by the male. From this we see that the function of these demonstrations among fish is sexual excitement.

The most reliable mating activity I've found was between the Hamlets in Bonaire. As Alex mentions, he's seen it so often he's experimenting with different exposures, models etc. It seemed every evening, they would mate just at dusk. I'd head out in the very late afternoon and as it started getting dark, look for a Hamlet, follow him (her?) around until eventually, it would hook up with another Hamlet. They'd swim about the reef together for a bit, then find a sponge and start going at it. (Apprently, they never get headaches)

Rand