Sexing Tailspot Blennies

[Instigate]

Tail Spot Blenny(Ecsenius stigmatura), I would be curious to know if anyone knows how to sex these guys. I've read conflicting information about it. Some say you can't. Others say the males have little streamers on the tailfin. I've seen photos of some with and without the streamers but that could be a regional morph for all I know.

 

[Maritimer]

Between the fish you've posted, I also see differences in the orange stripe and the belly - but couldn't tell you if that indicates gender, time passed since the most recent meal, or maturity.

~Bruce

 

[Instigate]

Between the fish you've posted, I also see differences in the orange stripe and the belly - but couldn't tell you if that indicates gender, time passed since the most recent meal, or maturity.

~Bruce

Ya I noticed those as well. Where's a Tailspot Blenny guru?!

 

[mort]

I've tried pairing these a couple of times and went for a larger one with long streamers and a smaller one without. They were from the same source, ruling out regional variations, and did fine in qt for weeks before going in the display. There was no aggression at first but then the larger one turned on the other relentlessly. This happened both times I tried it.
So unhelpfully my conclusion is that either the streamers aren't a sign of sex or I was unlucky and got young males who were set on as they matured.

That was in a 2ft cube so with more space they might have been better together and space could well have been a limiting factor.

 

[Tony Thompson]

I am currently trying to start a breeding project for this species. I have not encountered any conclusive evidance of a definative way of identifying gender. The approach I have taken is to try and observe specimans before making a selection. Unfortunately even when two specimans show a definate appearance of pairing. Once I relocate the apparent pair into a breeding tank, they gradually revert to typical terratorial behaviour. Maybe this is because they are not true pairs or maybe its due to disturbance. I would love to hear from anyone who has had success with pairing.

 

[mort]

I am currently trying to start a breeding project for this species. I have not encountered any conclusive evidance of a definative way of identifying gender. The approach I have taken is to try and observe specimans before making a selection. Unfortunately even when two specimans show a definate appearance of pairing. Once I relocate the apparent pair into a breeding tank, they gradually revert to typical terratorial behaviour. Maybe this is because they are not true pairs or maybe its due to disturbance. I would love to hear from anyone who has had success with pairing.

This is basically the problem I had. As I was working in a shop at the time I first ordered a dozen and took the most likely candidates to try. The second time I picked another couple of possible pairs out of dozens of individuals at the wholesalers.

Thinking further it might just be the confines of the aquarium that causes the problem. It could be that both sexes are present but just don't tolerate each other unless for breeding. I had the same thing with salarias algae blennies and I had a couple of batches by keeping them in a tank with a glass divide where they could see each other. After a while the female got really fat and I introduced them, I found eggs the next day and split them up again. This worked a couple of times but I didn't have any luck raising them before I had to give up.

Tagging along to hope you get a difinitive answer.

 

[Instigate]

I am currently trying to start a breeding project for this species. I have not encountered any conclusive evidance of a definative way of identifying gender. The approach I have taken is to try and observe specimans before making a selection. Unfortunately even when two specimans show a definate appearance of pairing. Once I relocate the apparent pair into a breeding tank, they gradually revert to typical terratorial behaviour. Maybe this is because they are not true pairs or maybe its due to disturbance. I would love to hear from anyone who has had success with pairing.

This is basically the problem I had. As I was working in a shop at the time I first ordered a dozen and took the most likely candidates to try. The second time I picked another couple of possible pairs out of dozens of individuals at the wholesalers.

Thinking further it might just be the confines of the aquarium that causes the problem. It could be that both sexes are present but just don't tolerate each other unless for breeding. I had the same thing with salarias algae blennies and I had a couple of batches by keeping them in a tank with a glass divide where they could see each other. After a while the female got really fat and I introduced them, I found eggs the next day and split them up again. This worked a couple of times but I didn't have any luck raising them before I had to give up.

Tagging along to hope you get a difinitive answer.

Thanks for the info!

 

[Katrina71]

I was told a single mated pair will require 100 gallons, despite the small size.

 

[Instigate]

I was told a single mated pair will require 100 gallons, despite the small size.

That seems to align with the above posts. I'm thinking they must only get along when they are actively mating. Thinking about finding one with streamers and putting another barnacle on the other side of the tank. This would be a 135g.

 

[Katrina71]

I'd like to see how that works out. I'm curious how they would interact.

 

[mort]

I think with enough space to evade each other they should be ok. I've seen plenty of people mix similar size ecsenius with little trouble and I don't believe stigmatura are any more aggressive.

The ones I tried to pair were initially in 1ft cubes (connected system) for qt and they showed no signs of aggression for the 8 weeks they were there. It could be the old "no real territory" to defend situation but if I had to try again with these I think I would first use a smallish tank with multiple pipes instead of a more natural situation. My thinking is that they could then evade each other if need be but still be stimulated by each others presence, in an environment that's less likely to cause territorial squabbles.

barnacle clusters are also a great idea. I've used them many times for moving blennies about as they are easy to just pick out and keep the water in, and they love them. It's always good to have an easy way to remove a fish should the need arise.

 

[Instigate]

I think with enough space to evade each other they should be ok. I've seen plenty of people mix similar size ecsenius with little trouble and I don't believe stigmatura are any more aggressive.

The ones I tried to pair were initially in 1ft cubes (connected system) for qt and they showed no signs of aggression for the 8 weeks they were there. It could be the old "no real territory" to defend situation but if I had to try again with these I think I would first use a smallish tank with multiple pipes instead of a more natural situation. My thinking is that they could then evade each other if need be but still be stimulated by each others presence, in an environment that's less likely to cause territorial squabbles.

barnacle clusters are also a great idea. I've used them many times for moving blennies about as they are easy to just pick out and keep the water in, and they love them. It's always good to have an easy way to remove a fish should the need arise.

I've been thinking moving them in barnacles might be an easy way! Never tried it yet though.

 

[eatbreakfast]

Based on how they behave, I would almost suspect that a male oversees a larger territory with multiple females in his harem that set up their own hierarchy.

 

[Tony Thompson]

Based on how they behave, I would almost suspect that a male oversees a larger territory with multiple females in his harem that set up their own hierarchy.

This species have been reported to have paired and spawned a number of times without a harem, just pairs. Smallest successful breeding tank, I think was reported 10 Gallon. It seems that the female is the one who shows aggression to the male until he can provide a suitable spawning site. I have mine in a 57 litre tank. I think I will try the barnacle method suggested by Mort. Maybe they don`t` like the real estate I am offering.

 

[Muscule]

This species have been reported to have paired and spawned a number of times without a harem, just pairs. Smallest successful breeding tank, I think was reported 10 Gallon. It seems that the female is the one who shows aggression to the male until he can provide a suitable spawning site. I have mine in a 57 litre tank. I think I will try the barnacle method suggested by Mort. Maybe they don`t` like the real estate I am offering.

Any success?

 

[Tony Thompson]

Any success?

Hi , what a coincidence, don't go on the forums much these days, just stumbled across this post. from 2018

To answer your question, No success. I could never get them to pair, no matter how many I tried. One always attacked the other and so had to stop the experiment.

 

[Zionas]

Unfortunately the consensus seems to be that they’re gonochorist rather than hermaphrodites so it’s not a case of one changing sex. That’s the problem with fish that don’t change sex, a lot more luck involved in forming pairs or groups of them. Sorry to hear about this.

 

[merkmerk73]

I do want to add that, before an ich infestation started wiping out my blennies, my Two Spot Blenny and Tailspot Blenny seemed to get along just fine without any real issue

But it's good to know that multiple tail spots will have issues.