information on the blue spotted ray

[bouldon]

I'm curious to know if anyone on here keeps blue spotted rays. I don't want one myself, but I do keep reticulated rays in a freshwater tank, which are quite demanding even compared to a fully stocked 150g reef tank. If I ever lose my two freshwater rays, I'd be interested in converting my big tank to marine for one of these guys, unless they're really hard to keep, which I'm sure they are.

[zenfox8]

Blue spotted rays don't do too great in captivity, even in big public aquariums.

[Fablex8]

check the other thread on the 8x2x2 marine setup, i think there's a post about blue spotted rays in there

[zenfox8]

check the other thread on the 8x2x2 marine setup, i think there's a post about blue spotted rays in there

I recall a local hobbyist who tried his hand at keeping a blue-spotted ray, but unfortunately, it didn't end well. The poor thing wasn't eating, was severely malnourished, and had that telltale death curl. To make matters worse, it was stuck in a tank that was completely unsuitable - far too much rock and hardly any sandy area. Needless to say, he ended up returning it to the shop.

If you're genuinely interested in keeping rays, I'd recommend starting with Scott Michael's Aquarium Sharks and Rays. While his recommended tank sizes might be a tad on the small side, his advice on caring for elasmobranches is top-notch.

[bouldon]

I'm not looking to keep marine rays myself, just curious about their mortality rate and specific needs. I've got my hands full with my freshwater rectic rays, they're demanding enough, so I can only imagine marine rays are a whole different ball game. I think the size of these rays is a major issue, my rectic rays can grow up to 26" and need plenty of space, but blue spotted rays in the wild are massive, you'd need a huge tank to accommodate them. I'm sure someone will say they don't get that big in captivity, but I think that's just because they're not given the space to grow, which probably contributes to their high mortality rate.

[zenfox8]

I think the other issue is the size that these rays can grow to, a rectic ray can get to 26" to the tip of its tail and requires a lot of space but having seen blue spotted rays in the red sea you would have to have a massive tank to accommodate.

Are you sure?

The largest blue spotted ribbontail ray reportedly had a disc width of 30cm, with the long tail you can end up with a total length of 70cm on the largest examples ever found. That 70cm is about the same length as 27.5". Given the population curve, you'll be lucky to get one which is longer than 2 feet including the tail. I can only assume you're getting them confused with another species in the red sea if you think a 27.5" fish which is more than half tail is so much bigger than a 26" retic.

Regards stunting, there is little actual scientific evidence of this providing for ill health. Indeed, I've found articles where they comment that the organs of a stunted fish look just as healthy as those of a normal fish. The problems with these rays in captivity is their tendency to stop feeding and then die.

[bouldon]

Every spotted ray I've seen in the Red Sea seemed to be fully grown, their disks were huge, easily over 30cm. My retic rays' disks don't usually get that large, but they've got much longer tails, which is where they get their size from. The ones I saw were identified as blue spotted rays by our dive leader, but you see so many different species when diving, it's not like the common aquarium fish you're used to.

With stunting, I mean that you won't find large specimens in captivity, they just don't live long enough.

[bouldon]

I've just had a chat with a mate who's also a seasoned diver and I mentioned the 30cm disk size, he just burst out laughing. Apparently, Taeniura lymma can reach a massive disk diameter of up to 1 meter, which makes me think my memory isn't as dodgy as I thought.

[zenfox8]

I'm curious to know if anyone on here keeps blue spotted rays. I don't want one myself, but I do keep reticulated rays in a freshwater tank, which are quite demanding even compared to a fully stocked 150g reef tank. If I ever lose my two freshwater rays, I'd be interested in converting my big tank to marine for one of these guys, unless they're really hard to keep, which I'm sure they are.

I'm afraid he's either mistaken or having a laugh. Scientific literature, like the one I mentioned earlier, puts the largest blue spotted ribbontail ray at 35cm disc, not 1 meter. Fishbase, a credible source, cites White et al. (2006) in a publication on economically important sharks and rays of Indonesia, which quotes the same maximum size. Aquarium Sharks and Rays also agrees on this size.

Given that the species was first described centuries ago, I'd say they've had ample time to get it right. Now, I know the water and mask can play tricks on our perception, but mistaking a 35cm disc for 1 meter is quite a stretch. It's possible your friend and you are underestimating the limitations of observing fish underwater.

Maybe it's time to accept that, while your experience as divers is valuable, identifying fish to a species level is best left to the experts – the ichthyologists.

[bouldon]

I love how forums like these get people who think they're experts just because they've read a book.

I've actually dived and seen these fish in their natural habitat, not just looked at them in a tank. If you just google Taeniura lymma, you'll see that most websites list their max size as way over 30cm. I've even seen the ones at the Deep in Hull, and they're bigger than that. I keep fish because I'm passionate about them and have seen them in the wild, not just because I've read about them in a book.