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I am wondering if my 8" White Tip Shark Catfish (Hexanematichthys seemanni) is pregnant.

I have seen my pair bloat up regularly after feeding but this is different. From her gills to her anal fin she looks bloated. She acts quite normally, but the male is following her around closer than normal, sniffing around her genitalia. I know these are mouth brooders, so this action may be pertinent.

Her color is shiny and normal, but her skin is developing blotches of white. I added more salt to this tank today to help with the healing. I hope this bloating is not a disease!

The tank is a 125 gal, with a low salinity (1.5-2 tbsp salt per 5 gallon).
Tank mates: 2 adult wild kipili frontosa and 7 f1 juvie fronts. 4 L066 (king tiger plecos), an albino chinese algae eater and a common pleco.

I can post pics later if anyone can use them to help.

It is possible the fish is gravid. A pic might help to say definately.

My only observation is that as this fish is reaching maturity & max size it needs a constant salt content of the water edging towards a full marine set-up - this is not what the rest of the fish need though. Small individuals find freshwater find but salt content should gradually increase as the fish grows.

Here is a video of my sharks:

This does indeed look like a gravid female being pursued by a male who is starting to show some interest IMHO.

I couldn't notice any obvious white skin blothes in the vid (?)

the fish look more than fine to me and I'm baffled that at this size they still do fine in water fresh enough to keep frontosa in.

looking good!

false alarm...or the eggs came out last night and became food. This morning, both fish looked normal. The white specs could be simple abrasion or damage, you can see one of the white specs in the last few secs of the video, on the side of the female.

greyfolk wrote:or the eggs came out last night and became food.

I have had this happen with unfertilised Liosomadoras eggs, but as these are mouthbrooders i had hoped they'd incubate them - it did look like the female was leaking pheremones/hormones into the water which interested the other individual - maybe the other was interested in eating as opposed to breeding?

Closer inspection of the bulge next time should, if genuinely gravid, reveal the shape of individual eggs within the female.

I am looking forward to the day they begin selling hobbyist versions of small MRI machines so sexing fish will become easy.

Has anyone been successful in breeding white tip before?

wonderful video.

greyfolk wrote:Has anyone been successful in breeding white tip before?

Yes, there was a reported spawning in northern Iowa in the mid-1990s. 12-14" long fish were cycled from freshwater to saltwater and back again. If I remember correctly, the fish spawned as the salinity began to drop.

I didn't witness the spawn or the results, but it was verified by another member of the aquarium society.

How I heard of this spawn:

In the early-mid 1990s, Ginny Eckstein spoke at a Minnesota AS Show (I am guessing ~1994). After her talk, Ginny and I were discussing things catfish when an older lady walked up and politely asked: " Excuse me, but can you tell me how long is the incubation in Colombian shark cats? Because I have a male brooding now..."

Needless to say, the focus of our conversation immediately changed!

She hadn't even realized that what she had accomplished may have been the first ever reported captive spawning of this species.

Is what I have--an apparent breeding pair--common? What should I do the next time I see her bloat?

greyfolk wrote:Is what I have--an apparent breeding pair--common? What should I do the next time I see her bloat?

AFAIK it is a very uncommon - what i would suggest wouldn't suit the other tankmates (it would be to switch to a more saline set-up & then over aspawning period fade to freshwater - simulating the fish heading to an estuary then river to spawn)

I wonder if the salt content in the tank over the past year had anything to do with this. About a year ago I had the tank up to 2 tbsp per 5 gal. then i hadn't added salt all year. I recently just re-upped the tank again to 2 tbsp per 5 gal. If I continue fluctuations, perhaps I can get lucky, but i won't ever have enough salt for brackish.

If momma does get pregnant again maybe I should put the pair in a 55 brackish set-up... but i think the stress would kill any chance i have at that point. Maybe I'll just be happy to have these guys living large in my 125 as is. They are happy.