Sargassum Weed

[BadPig]

I have a LR that sprouted a ton of sargassum. Is this safe for my tank? Is it legal to have in Texas? I have not seen it sold anywhere ever. I know there are many species of sargassum. I do not know what mine is. I also have a few other plants that have sprouted from nowhere. If it’s ok to have in Texas I can “frag” it out.

[GaryP]

I doubt its actually Sargassum, but rather a similar brown algae similar to a kelp. Sargassum doesn't attach to substrate like your pics indicate. Sargassum is usually free floating, sorta like Chaeto. I don't think there is any problems you need to worry about with it in your tank. Probably quite the contrary. I would just make sure to keep it trimmed back so that it doesn't go crazy in your tank. I think it would be a great addition to something like a seahorse tank.

I'm not aware of any laws associated with marine plants in Texas. I know that there are some in California, especially in relation to Caulerpa.

[captexas]

Back when I first got started, I had the same stuff growing on my new live rock. Can't remember where I found out about it, but I was under the impression that it was sargassum, but I could be wrong. Either way, at times it can grow pretty quickly so just prune it when needed. If you don't want it at all, just try to pull it out of the rock from its base and throw it in your trash (I kept doing this and eventually it was all gone). If you don't mind it in the tank, I'd just prune it as it helps in nutrient export.

[tgray]

The first photo looks like Padina, pretty cool.
TimG

[BadPig]

I doubt its actually Sargassum, but rather a similar brown algae similar to a kelp. Sargassum doesn't attach to substrate like your pics indicate. Sargassum is usually free floating, sorta like Chaeto.

I thought Sargassum was a typ of brown. The floating sargssum is one kind of sagassum, but if you Google it you will find there are some that attach to substrates. Isnt the internet great. :D

Either way, at times it can grow pretty quickly so just prune it when needed.

I think its about time I do that.

[obtusewit]

Sargassum can be free loating or rooted to a hold fast...read on

Summary of Basic Life Cycle

Fertile branches of adult algae produce gametes . When the ova are squeezed out of the conceptacle, they are not broadcast into the surrounding water like most algal gametes, but remain attached to the receptacle by a mucilaginous stalk made of mesochitin. After fertilization, the zygotes continue to grow on the parent for several days before dropping to ocean floor. The enveloping mucilage protects them from environmental stress, as does their multicellular form. Their large size also allows them to settle rapidly, and the well-developed rhizoids adhere quickly to the substrate. This results in germlings settling near the parent (within 3 meters), where conditions are likely to be favorable.

Alternative Disperal Mechanism

Fertile branches break off from the holdfast and float away. When the germlings are released a long distance from the parent, they do not have to compete with their own relatives and can settle in new territory. The combination of these two dispersal mechanisms proves to be an effective system for global spread.

Interesting Tidbits about Settlement

Gametes are usually released during or just after the spring tide. The timing may be determined by hydrostatic pressure, or more probably by the light of the moon. (Fletcher 1975.)

Gametes are released in cycles of 13 days instead of all simultaneously, increasing the odds that some of them will encounter favorable tides and conditions. (Fletcher 1975.)

Germlings are pear-shaped, enabling the rhizoids to land first.

Rhizoids stick within 48 hours.

Germlings lose their ability to adhere over time, in connection with declining mucopolysaccaride levels. After 18 days, half can still stick, after 49 days, none can. (Deysher and Norton 1982.)

Germlings can grow on kelp, but they fall off before they reach a height of 3 cm and can no longer re-adhere. (Deysher and Norton 1982.)
Individuals that become free-floating can survive in the water column indefinitely.