question for the ichthyo-crowd: sexing spiny eels?

sidguppy · Post by **sidguppy** » 10 Aug 2005, 10:39

For the peeps who collect fish in formaldehyde and other eel-fetishists:
how do you "sex" a spiny eel? male or female marks?
except from spotting that gravid females are obviously fat.

internet doesn't cooporate (google) very much.

I'm in the process of picking up a group of Aethiomastacembelus ellipsifer for my Tanganyikan tank; one of the very few Spiny Eels that is not fiercely territorial.

I've heard "in the grapevine" that they could be bred......

is there a clou?
extra spines near the anal fin? a papilla? something else?

Mad Duff · Post by **Mad Duff** » 10 Aug 2005, 14:08

As far as I know the only species of spiney eels that have been sexed have been by obseving that the female is fuller bodied when ripe with eggs, other than that no real definate differences between sexes.

Post by **Silurus** » 10 Aug 2005, 18:53

I looked at some preserved M. ellipsifer, and it seemed to me that the females have a larger urogenital papilla. This might still be difficult to use, since the papilla is nothing more than a rounded bump in both sexes.

sidguppy · Post by **sidguppy** » 10 Aug 2005, 23:14

Wellll, the whole question of trying to get one pair of a crowd went academic when the OTHER buyer didn't show up or returned his calls....

I got a herd of 4 eels, and from what we could see on fattiness, coloration, and 'vaguely bumps' on bellies, it's 2 pairs.

A ellipsifer seems to be the more social eel, and not as nasty to each other as the rest of the species;
my tank has plenty hidey-holes and PVC pipes.

See how far we can take this; breeding eels might be a nice change to all those nearly 'unsellable' catfishes.

Post by **Barbie** » 10 Aug 2005, 23:35

Congratulations Sid! Here is a picture of my ellipsifer. We call it "sigmund" but I think it might actually female, after watching it for a few months. She feeds from my hands and does the happy dance at the glass when I'm opening the lid. It's pretty humorous! Getting her to take frozen rather than live food was an adventure all in itself though. Good luck with yours!

Barbie

racoll · Post by **racoll** » 11 Aug 2005, 10:43

good luck sid, spiney eels are great fun!

did you suceed barbie?

my circumcintus won't touch anything that's not wriggling!

Andrew · Post by **Andrew** » 15 Aug 2005, 01:35

What are you feeding your Tanganyikan mastecembelids? I read in Barlow's "Cichlid Fishes" that they are specialists in feeding on cichlid eggs.

Post by **Dinyar** » 15 Aug 2005, 03:27

Sorry, Sid, reading this thread for the first time.

I have kept A. ellipsifer, C. plagiostoma, A. albomaculatus and A. micropectus. Different species display different behavior, of course, but I noticed two other interesting things:

First, they are very shy when first introduced but get much bolder once acclimatized -- so much so that the fish you never knew you had in the beginning can become a greedy pig after 3-4 months. The key is to feed them up well in a smaller tank when you first get them, and release them into a Tang community tank only later.

Second, more than most fish, I find that these Tang eel species display considerable individual difference in "personality". Most become very curious and bold, but some remain shy forever.

Now in my experience with the species I've kept, I would say ALL of them can be kept with multiple specimens in the same tank. They may tussle a bit, but they don't do each other any real harm. They're NOT cÃ®chlids! I had six A. albomaculatus and one A. micropectus in a 30 gal for a couple of months, and they were fine. (Later I gave three of the six albos away, but still have three.)

Re the posts about feeding, in nature different species of Tang eels eat different things. None of the species I've kept are dedicated oophages (egg eaters), AFAIK. They're finicky about food when you first get them, but can readily be trained to eat flakes -- even spirulina flakes -- after a while.

sidguppy · Post by **sidguppy** » 15 Aug 2005, 13:01

They're fat as HOGS now......

I'm missing almost all baby Telmatochromis dhonti-fry, wich is an asset.

I like the adult pair, but really nobody wants this species. better eel-food than a tank overrun with unsellable fish.

they're getting bolder, allright.
what really makes me happy is that they're very nice to each other.

I've kept 3 Caecomastacembelus tanganicae as my first "Tang eel", and these were mildly territorial. very picky eaters and hence, they didn't do well.
Then I tried with the sturdier C albomaculatus -again just 3- and once acclimatized, those 3 turned mideaval on each other

One "disappeared" after a few months, the other harassed one I gave to some friends (it's still doing fine and eats OSI flake and baby Tropheus now).
the one that stayed got in trouble once I had to remove the rocks to catch a few fish.....all the fish in the tank -including some of the cats- ganged up on him

it took them less than 30 minutes to mortally wound it; when I found it (I didn't see the ganging up, only the aftermath), it had a broken back and I had to euthanize it

Now I got 4 ellipsifer (and -now that I know where to look and what to look for- it's 2 pairs), more modest tankmates (no Tropheus, less cavebrooders), and they're doing GREAT.
they're all hiding in the same pipe, despite several caves and pipes being unclaimed by cats or c ichlids.

and I have a strong hunch they're eating flakes too.

these 4 are already conditioned by their first owner, mind; they're not exactly "fresh imports" wich makes it a LOT easier for me