This is a blue-lined sea bream (Symphorichthys spilurus), also known as a sailfin snapper. It's a beautiful fish.
![Symphorichthys spilurus Symphorichthys spilurus](https://www.tonywublog.com/assets/images/2016/05/blue-lined-sea-bream-symphorichthys-spilurus-palau-tony-wu.jpg)
They are reported to frequent sandy-bottom areas around coral reefs, in the five to 60m range, but in over 20 years of diving, I've only ever seen them a couple of times, maybe.
They do gather in large numbers for spawning though. And by large numbers, I mean like this:
![Symphorichthys spilurus spawning palau Symphorichthys spilurus spawning palau](https://www.tonywublog.com/assets/images/2016/05/sailfin-snapper-aggregation-for-spawning-symphorichthys-spilurus-palau-tony-wu.jpg)
And this:
![Symphorichthys spilurus Palau Symphorichthys spilurus Palau](https://www.tonywublog.com/assets/images/2016/05/blue-lined-sea-bream-aggregation-for-group-spawning-palau-symphorichthys-spilurus-tony-wi.jpg)
I've been on a quest for a couple of years now to photograph the actual spawning. Unfortunately, it's super-difficult. Sigh.
Spawning takes place at depth...like, 35m is shallow (which means there's not a lot of light)...and usually in strong current...like, get swept away in the blink-of-an-eye type current.
To make it even more difficult, the actual act of spawning only involves a handful of fish at a time...even though the gathered school comprises thousands of individuals...and takes place so fast that lightning seems slow by comparison. Sigh again.
![Symphorichthys spilurus, Palau Symphorichthys spilurus, Palau](https://www.tonywublog.com/assets/images/2016/05/sailfin-snappers-symphorichthys-spilurus-palau-tony-wu.jpg)
With the help of friends (thanks Tom, Rich!), I have managed to photograph embryos of this species, if not the actual making-of part of this fish's life history.
This is at 10 hours post-fertilisation:
![Symphorichthys spilurus embryo Symphorichthys spilurus embryo](https://www.tonywublog.com/assets/images/2016/05/sailfin-snapper-embryo-symphorichthys-spilurus-palau-tony-wu.jpg)
And this at about 35 hours:
![Symphorichthys spilurus larva Symphorichthys spilurus larva](https://www.tonywublog.com/assets/images/2016/05/sailfin-snapper-embryo-35-hours-symphorichthys-spilurus-palau-tony-wu.jpg)
Cool, huh?
Glutton for punishment that I am, I'm sure I'll go back to Palau to try to photograph the actual spawning again.