Little Brittles

[dupontsniper]

I have a large black brittle star, have had for approx. 2 years, have had no ther stars with it. The other day I was propping some Rhondos and noticed nickle size brittle stars, identical in shape and and detail as the adult. They were pure white, both dead, but appeared to be uninjured or picked at. How do brittle stars reproduce, and what care and/or requirements of the young are needed? Thanks in advance to anyone who may add insight or help, Shane.
Also, how do the brittles spawn, egg or LB? and how many/often. Shane

[rshimek]

Originally posted by dupontsniper

Hi Shane,

How do brittle stars reproduce, and what care and/or requirements of the young are needed?

As a group, the ophiuroids have a diverse array of reproductive methods. Some of the smaller ones reproduce asexually by fission.

Most of them reproduce sexually by spawning into the water. The females may or may not retain the eggs and care for the young. If she doesn't the larvae develop in the water and settle out on to an appropriate substrate when they are ready to take up benthic existence. If the female broods the young, the young are released from brood pouches when they can fare for themselves. A few are hermaphroditic and may be self-fertile.

Other than providing full strength salinity sea water, appropriate food, and good habitat, no particular special care is required for the juveniles.

:D

[dupontsniper]

Confusing but understandable. I must have a hermaphroditic one then, because unless pregnancy cycle is at least 2 years, this has been the only one in my tank. Thanks again for the answers to my questions, and good reefing! Shane

[ophiuroid]

It is unlikely that these are juveniles of your black brittlestar, which is probably a species of Ophiocoma. There are many many small species of brittlestars that are hitch hikers on our LR, and may not be noticed for years, if ever, but they are there....

In all likelihood, you do have the small self fertilizing hermaphrodite Amphipholis, which is very common in our tanks, and rather highly prized. It also broods its young, which means a higher reproductive success rate.

They are white, and fully grown at about the size you are seeing. If you look more closely, especially after lights out, you will probably see many many more in the sand, on the rocks, etc.