Question for RFA experts

[saltyhog]

Are rock flower anemones either male or female or are they hermaphroditic? I have 5 and they spawned tonight, all 5 were expelling what looked like semen to me. What are the odds of acquiring 5 RFA's and them all being the same sex?! (1:32 as I recall)

I can easily identify semen and eggs when my snails spawn but there is nothing that looks like eggs tonight.

 

[Ron Reefman]

Saltyhog, you ask some very good questions there.

First let me invite you to join a discussion about Rock Flower Anemones here at R2R. Here is a link to the thread: https://www.reef2reef.com/threads/ron-reefmans-rock-flower-experience.409436/page-3#post-4983555

I've had 2 rounds of babies in my tank over the last year. I believe that RFA's are male and female but I'm only 95% sure of that. And your having 5 of them all spawning at the same time does seem a bit unusual (that 5 out of 5 would be male). The females do not expel the eggs, they take in the sperm and as I understand it, it takes about 4 to 6 weeks of gestation and then they expel the baby RFA's. They are fully developed and extremely small, in fact they are smaller than the diameter of the eraser on the end of a pencil. I've never really tried to measure them, but when released I'd say they are 1/16th to 1/8th inch in diameter. Here are some of my kids and remember, this branch of dead coral is only 2" long!

20180622_144303 R1 by Ron Lindensmith, on Flickr


Over time I found about 12 to 15 RFA babies growing after the first delivery (I didn't see it happen). Most were fairly close to the parents but some did end up far away and in a field of zoas and one was even on the magnet behind a wavemaker powerhead! The second round I found about 15 or 16. I think there may have been more delivered to the water from the female, but like so many babies, their fate in the real world can be treacherous. They could get eaten by hungry fish like a wrasse, or collected in filter socks.

Please come and post in the discussion thread. There is more info there and quite a few RFA keepers are subscribed there so you can get some other opinions. If you do, I even have a few questions for you. Thanks!

 

[reef lover]

Females are much larger than males but seeing them spawn is the easiest way to tell....and funny cause i have 90 % females and only a couple males.

 

[reef lover]

Females are much larger than males but seeing them spawn is the easiest way to tell....and funny cause i have 90 % females and only a couple males.

 

[Ron Reefman]

reef lover, can you share some info about this size situation? I have not seen any difference in size of RFA's other than due to age or availability of food.

I have 5 adults that are all about the same size and mine have spawned twice. I haven't measured them, but I'd estimate they are 3" or 4" in diameter. There is no way I could say one of mine is female because it's bigger.

 

[reef lover]

Hmmm...been searching all morn cant find where i read it.....so until i can find it...disregard my first post...

 

[Ron Reefman]

Hmmm...been searching all morn cant find where i read it.....so until i can find it...disregard my first post...

To bad, that might have been some good info. As far as I know there is no easy way to tell a male from a female except by whether it spawns by putting sperm out into the water or takes it in to fertilize the eggs held inside. I'm pretty sure a DNA test would work, but who has that ability at home!

 

[reef lover]

Lol not me!! I can remember reading it somewhere....im gonna keep looking. Hopefully i can find the reference....

 

[saltyhog]

@reef lover
I would like to think you are right. I have two that I bought at the same time. They were the same size when I got them but one is more than twice the size of the other. The smaller one is the only one I've not positively identified as male.

 

[reef lover]

Rwally wish i could find the info...had that stuck in my head at least 4 years now....going to pay closer attention to mine when they spawn to see if theres any truth to it....

 

[Ron Reefman]

Rwally wish i could find the info...had that stuck in my head at least 4 years now....going to pay closer attention to mine when they spawn to see if theres any truth to it....

If you come up with any info or conclusions based on your own RFA crew, please let us know. I'd love to have the info in my RFA discussion thread!