5 Nov 2010

Fishy Fridays ep. 11: Special News Flash!

We interrupt our regular broadcast (which has been on hold since February, lol!) to bring you a special announcement!

The freshwater stingray population in the Liège Aquarium has recently been increased by two!

Mr.  Potamotrygon motoro

and Mrs. Potamotrygon motoro 

are proud to announce that their family has just recently (end of Aug / early Sept) welcomed two little young'uns into their tank!

Both parents are immigrants from the Amazon and Orinocco rivers in South America where their usual diet consists of small prey such as molluscs. They're not really a small species as they can reach up to a meter in length, and yet they have a special defense mechanism in the form of a poisonous needle which can be very painful (or lethal) for anyone who gets too close.

Although a long way from home, they appear to have adapted very well to their new life in Liège (they arrived in 2008) as is proven by the recent increase in their little family! Indeed, this is the first time such a glorious event has taken place in the Liège Aquarium! Spotted dogfish and catsharks reproduce regularly here, since their oviparous reproductive system (i.e. they lay eggs! c.f. FishyFridays ep.3 and ep.9) makes it much simpler for them. Mrs. P. motoro on the other hand is ovoviviparous! What's that you say? It means that after she was fertilised by Mr. P. motoro she didn't actually lay any eggs, but kept them within her uterus. The young'uns hatched from the eggs inside the uterus and were nourished by a "uterine milk" for just over 3 months! When they were finally "born" - about 100 days after "hatching" - they were already some 10 cm long and quite capable of searching for their own food!

Hopefully this won't be a one time event since their caretakers have been noticing another increase in mating behaviour within the tank... ;o)

Here's another male in the tank (you can clearly make out one of his pterigopods -penis- alonside the base of his tail), not quite sure which one is the dad! :p



  1. Very cool post. Stingrays are awesome, but I've never saw a freshwater one.

  2. I love the baby rays! AND I love the return of Fishy Fridays!

    I know I'll be doing the "Stingray Shuffle" in Sanibel this week while I'm looking for more shells.

    So happy to see you back! I'm going to go read about Paul and your other post, it's taken me a while to get back into a regular routine, but I'm glad to be back with my friends!

    New Zealand for Christmas sounds F A B U L O U S!!!!

    I was in Jacksonville, FL for about 5 weeks, but now I'm back in Tampa for an extended and much needed break from reality.

    Hugs Cris, I've missed you!

  3. Dive Girl, I didn't know there were freshwater stingrays until I saw them in Liège! And these babies are adorable!

    Welcome back Rhonda!!! I'll definitely be thinking about you when I see all those shells on the Kiwi beaches! ;o)
    Are you back in Tampa permanently?


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I might stop by your place with an answer, but I'm more likely to reply right here so click on "email follow up comments" if you'd like to see what I and others have to say and come continue the conversation! ;o)