34 replies to this topic

[Peckoltia]

No need to try be smart Scott. I'm only trying to help a fellow hobbyist out. I wasn't aware that wasn't allowed?

And FYI - the stingray you posted a picture of is Potamotrygon brachyura and NOT Potamotrygon motoro like I own. Obviously a 'big' difference between the two.

Back on topic. Best of luck with the PJ Nick. Be sure to update pics as it growns. Some feeding pics would be great too. Always interesting to see how prehistoric fish feed, so many different mechanisms to do so.

Alex

[scottyhooton]

[dazzabozza]

A 6x2 is still just a grow out tank for just about all shark species.

No way these guys are fitting in a 6x2

http://www.avocabeac...ub/Image044.jpg

http://www.smh.com.a...eb__430x295.jpg

Just to back up Alex's comment there's a serious shark keeper from MASWA that would agree. Should be fine as a pup but not so good long term. Water needs to be pristine. Let me know if u want more info about him and ill try to find some.


Daz

[Riggers]

Cheers guys, as we've been discussing in the other post on PJ's I'm upgrading tanks to accomodate a few more species, I specifically bought a small pup (this ones 25cm) so I don't need to worry about too much more space yet.

Thanks Daz any info is great, cheers

[MadDocker]

Out of interest, how quickly do PJ's grow?

[Peckoltia]

http://ogma.newcastl...ENT02?view=true

Great study on age and length comparisons. Just incase you don't want to read the whole thing (i only skimmed it) if you follow the growth curve 4years old = ~50cm and 7years = ~60cm (fork length). Was more than likley done on wild caught animals (again didn't read it in its entirity), what I found interesting was that they use markers on the dorsal spine, most fish ageing techniques usually use otoliths (fish ear bones), this is done by either staining the otolith with a chemical marker, so you can see the growth of the otolith since the date of staining. Can also count the rings of the otolith in some species, each ring is ~12months. Aquarium PJ's could probably grow a little faster due to; ample food, and increase in metabolism (due to increased water temps) and a decrease in energy expenditure.

Alex

Edited by Peckoltia, 03 November 2011 - 10:32 AM.

[scottyhooton]

And FYI - the stingray you posted a picture of is Potamotrygon brachyura and NOT Potamotrygon motoro like I own. Obviously a 'big' difference between the two.

It's actually a Potamotrygon schuemacheri (Parana River Stingray)

Not having a dig , just thought if you are going to point out a species name we might as well get the right one , I realize that it's not a motoro

[Peckoltia]

It's actually a Potamotrygon schuemacheri (Parana River Stingray)

Not having a dig , just thought if you are going to point out a species name we might as well get the right one , I realize that it's not a motoro

Hi Scott.

I already had the name correct to begin with. P. schuemacheri is actually a small species of stingray. Juveniles can be confused with P. brachyura. But there is no confusing one at this size. Most certainly P.brachyura that you posted and NOT P.schuemacheri. Your sources are all wrong mate. Go back and check them out.

Here are a couple links for you -

Firstly this, which even has the actual picture you used. Discovery says P.brachyura.

Then there are these exact same type of stingray you posted a photo of, again P.brachyura.

Isn't a whole heap on P.schuemacheri on the net but this the information from the IUCN redlist states that this species is a small species of ray.

I'm just not really sure how posting that pic of a stingray species that isn't available in Australia (and obviously a species I don't keep) was relevant to a thread on Port Jackson sharks?

I'd say this is more or less case closed!

Happy fish keeping,

Alex

edit - spelling

Edited by Peckoltia, 05 November 2011 - 09:57 AM.

[scottyhooton]

hahaha fair call mate I will stand corrected , show's what can happen if you listen to jeremy wade , i watched series three last night and it came up , he did however say that he knew verry little about the species . I just found it rather coincidental timing , no harm done

cheers, Scott

[Riggers]

It really doesn't matter what species it is, this is a topic about sharks.....

[Bowdy]

6x2 you should get a few years of enjoyment out of the pj riggers and I'm sure you will know when the tank needs upgrading just ignore those 2 lil kids hehe. Il have to swing up for a look good luck man.

[scottyhooton]

It really doesn't matter what species it is, this is a topic about sharks.....

too tru , my baaaaad enjoy port micheale jackson riggas

[Riggers]

All good Scotty no harm done

[Peckoltia]

Nick - Did you read through the link that I posted? According to the study, PJ's leave the egg at ~20 -25cm (fork length), so your PJ at 25cm would be very young. Would be interesting to get accurate measurements of your shark every 12months or so and compare it to one of the growth models in the paper, and see how your captive shark grows compared to its wild cousins (theoretically should grow just as fast or faster).

Alex

[Riggers]

At 222 pages Alex I kinda skimmed through it

I'll keep a journal going, once a month I'll post an update