Pls help me ID these critters on my LR

[bpeitzke]

I have a 65-gal FOWLR tank with lots of LR that's been in the tank since I set it up 7 or 8 yrs ago. I have three types of critters growing on my LR, only one of which I've ID'd. I've attached a close-up photo that shows examples of all three.

1. Yellow ball sponge - you can see one in the left side of this photo. These have been in my tank for maybe a year & a half now. At any given time I have a dozen or fewer - individual sponges only live a few months, gradually withering & getting overgrown with algae, but new ones keep popping up. They get up to ~ 2 cm in diameter.

2. Clusters of tiny brown filtering worms. I'm not sure they are worms, just a guess. I've only recently noticed several clusters of these on a few of my LR's. Each one has a little fan of presumably filtering filaments, ~ 2-3mm across, and a little stalk or body that attaches to the rock, ~ 2mm long & maybe 0.4mm diameter. These are fascinating, and are what prompted me to post this note. Notice the cluster in the center of this photo, with a couple of individuals nearby at the top - this is where you can see their stalks/bodies.

3. Skinny little purple hard-shell filtering worms, each with a tiny white bud-like tip that may be a filtering element but is too small to tell. Again I'm not sure they are worms, but I think they are. You can see a couple of these peeking out, mainly below the yellow ball sponge and the tiny brown filtering worm cluster. These are all over my tank, not just on the LR. They've been around almost as long as I've had this tank. Each one has a little purple hard tube shell ~ 5mm - 1cm, ~ 0.3mm diameter. I'm curious about what these are too.

Appreciate any identification suggestions.

Bob

 

[Flreefer]

The larger group to the right of the sponge are Yellow Colony Polyps.
The tubes with the white heads are just a type of tube worm, like a feather duster without the duster. I have many of these as well. They let out a strand of mucus to collect food and then reel it back in to eat. They are harmless. Good luck with your tank!

 

[bpeitzke]

Thanks for the ID's

Thanks, Flreefer, for IDing these critters. I found several articles & threads on yellow colony polyps - apparently very popular but prone to getting out of control & taking over too much of tank real estate. Someone suggested a simple siphon method to control their population - I'm a long way from needing that.

Interesting that these just showed up in my tank recently, after nothing introduced in several years. I don't feed them at all; apparently they thrive on whatever bits they catch and production from their embedded zooxanthellae.

Does this mean I can no longer post in the FOWLR forum?

Seriously, I've been dragging my feet on venturing into reefkeeping, intimidated by thoughts of increased care & complexity. But maybe I'll start looking into some of the easy-care corals. I have a great LFS nearby, that specializes in corals.

Bob

 

[Flreefer]

Happy to help, Bob.
Yeah, Colony polyps spread well. I've got some I've had for years and they definitely reproduce quickly, but I target feed mine Cyclopeze. They are a type of Palythoa.
Things will just spring up out of the blue, even after years in the tank.
It seems your tank has decided to make the jump to reef all by itself!!
Soft corals and a lot of the LPS are actually pretty easy to care for, as long as you do regular water changes, monitor your Ph, Ca and Alkalinity, and have sufficient lighting.
By the way, to have ball sponges just "sprouting up" all over is awesome! Wish I did.
Best of luck moving forward!