Jump to content

What is Biofilm?


jacet

Recommended Posts

Hi All

Just a quick question what is biofilm i get that it is a food sorce but what is it??

Sorry for the stupid question

Edited by fishmosy
Link to comment
Share on other sites

Thanks Fishmosy

Once again you have explained it in a way i can understand it... I love your answers....

Link to comment
Share on other sites

Thanks, it is a skill I continuously work on. As a scientist, even if your results are awesome, if people don't understand the work you do, your results are worthless.

  • Like 3
Link to comment
Share on other sites

  • 1 month later...

fishmosy... do you think the biofilm is enough to satiate shrimplettes? Or increasing the surface area for the biofilm enough? Or do adding other food sources such as bee pollen and Biozyme become necessary?

Link to comment
Share on other sites

Depends on the size of the tank and the number of shrimps.

A 20L tank with 10 adults and several shrimplettes would require additional feeding.

A 50-80L tank with 5 adults and several Shrimplettes with plenty of mosses and plants you could prob get away with it. But think its safer to just do less additional feeding like maybe once every third day.

Remember though food is fuel so if you want the best nutrition for growth and health feeding some form of additional food is always a good idea.

Link to comment
Share on other sites

Whether or not you have 'enough' biofilm depends on many factors. The simple answer is: it depends on the aquarium.

for example how many shrimplets/ adults that you have compared to how much biofilm you have (i.e. density) is always a factor. As Triggs has indicated, there is some level where a tank can support shrimp without additional feeding, above this density and there isn't enough food. What that density threshold is will depend on the tank.

another factor is surface area. As biofilm grows on surfaces, the more surface area you have, the more biofilm. In basic terms this means that a tank without plants/ornaments/wood ect. supports less shrimp as there is less surface area than in a tank that has lots of plants for example.

This is one reason why I think moss (and plants) are an essential part of any shrimp tank, they massively increase the amount of surface area without taking too much space in an aquarium (low volume).

Other factors that can affect biofilm growth include (but are in no way limited to) nutrient availability, what organisms actually make up the biofilm, light, other biofilm consumers that compete with shrimp (e.g. snails), water flow, water parameters (e.g. pH, O2, CO2, ect) and temperature.

In my experience, unless you provide some sort of nutrition/food, the number of shrimp in the tank remains very low. In fact, the tanks in which I have the greatest numbers of shrimp (and that grow quickest) are in my L number tanks where the shrimp seem to have plenty of food (mainly left over zucchini and pleco pellets).

Triggs was spot on in saying "some form of additional food is always a good idea".

Link to comment
Share on other sites

Good answers Ben. Now I know why I get you to edit some of my stuff, so you can turn gibberish into readable stuff.

Now I am going to put you on the spot, can you look at a bio film/ algae cover from the wild and find out what Vegetable/ or other food is closest to it, to clear that up. When I build the fish house I am keep a section for experiments and Breeding Neritina snails is one of my top priorities, so I need to find out what to feed them that is as close to there natural diet as possible.

In some places where the snails are there is a thick cover on the rocks, made up of dirt, algae and I would like to know what else, or if you cant do it point me to some one that might be able to look at it and say what it is made up of. Sorry for the headache in advance.

Bob

Link to comment
Share on other sites

Thanks Bob.

You could do it yourself if you have a microscope. Simply scrape some biofilm onto a slide and stick it under the scope. If you dont have one, you could borrow mine.

I'll post pictures of some biofilm (marine, but has similar organisms to freshwater) once I get back to work so you can get an idea of what to look for.

It is my understanding that nerites feed almost exclusively on biofilm/algae. You could simply use biofilm to feed them. i'll post pictures of how we grow biofilm at work, and how I've adapted this technique to growing biofilm for my pleco fry.

I wouldn't worry too much about trying to grow biofilm that matches what you find in the wild. As I've said above, biofilm is so variable that I believe grazers don't target a specific organism or group of organisms (e.g, diatoms, or algae) but eat the whole biofilm and digest what they can/want/need out of it. That said, some organisms in biofilm can be harmful or won't be eaten. For example we try to avoid having filamentous algae in the biofilm for our urchins as it overgrows the urchins, smothering them.

Another option is to make a biofilm substitute. Mix either gellitine or agar (I prefer agar as it tends to be more stable) with spirilina , blended green vegetables, some meat (prawn or white fleshed fish works well), nori or combinations thereof, then spread it onto rocks/wood and allow to set. Spirilina is a green microalgae famous for its (possible?) health benefits i.e. superfood as its very high in nutrients. Its sold in a dried powder form in health food stores or over the net. Some people simply use spirilina only in the biofilm supplement for algae eaters like fry whiptails (fish), but that can get a bit expensive. Its probably a toss-up as to whether the nerites will eat it but certainly worth a try.

Do you know if the nerites produce swimming larvae or fully formed juveniles? Do they require fresh or brackish water? If its free swimming larvae, let me know as I may be able to give you some tips from our experience with marine invertebrate larvae (urchins, starfish, fish).

  • Like 2
Link to comment
Share on other sites

Free swimmers mate, I have your email so I will email you the photo of the young. That info will be great.

I wanted to use a veg that was close to the Bio as well, not all creeks have it either it just that where there is Bio there is more snails and more species. i have noticed that when the snails come into captivity and what they have eaten passes through there is a fine sand left behind.

Bob

Link to comment
Share on other sites

Thanks for the detail explanation fishmosy. Just via my observations different types of biofilms, is depended on the WP, temp, light etc... when I move a bunch of moss from a tank to another (especially if it came from a high lighted tank), the shrimp will gorge on it, and spend the entire day grazing on them.....this is bioflim...(pls do correct me if Im wrong)....when I do have time, I often leave a bunch of moss outiside in the sun for 2-4 days (covered so that no insect can breed/lay eggs in them etc....), I then put them in my tanks......My tanks are all LED lights and are mostly low/medium lighting, so they do not have the level of biofilm that is preferred.

Link to comment
Share on other sites

Yes BB I believe shrimp feed on the biofilm within moss, but another food source that many people don't consider is the micro-organisms (like copepods, rotifers, ect ect) that also occur amongst mosses. This is the reason why moss is great for when you have tiny fish fry as they can often find enough tiny food to grow big enough to be able to feed BBS.

Adding moss from a tank that hasn't had shrimp in it is a great way to add extra biofilm to your tank. Leaving the moss outside will encourage algae and diatoms to grow in the biofilm, both of which are highly nutritious.

Link to comment
Share on other sites

After re-reading the posts in this thread, I think I need make two important points clearer.

1. Biofilm is a collection of bacteria, diatoms, algae, fungi and other multi-cellular organisms that form a layer on every surface submerged in water (including seawater).

2. Each surface has a unique biofilm depending on what molecules, bacteria or other organisms attach to it.

So in terms of finding a food/vegetable that replicates biofilm, well that is impossible because biofilm is a collection of both plant-like and animal-like organisms. Your best bet is to replicate the biofilm using the substitute biofilm or growing your own. By taking biofilm samples from areas where you collect the organism you can get an idea of whether the biofilm is mainly plant (diatoms, algae) or animal dominated, then mix your substitute to match.

  • Like 1
Link to comment
Share on other sites

As promised here are some pics on how I grow biofilm at work.

We use polycarbonate sheets, a material used in abalone aquaculture for biofilm culture.

Note two things that make it ideal for the purpose

1: massive surface area to volume ratio,

2: clear allows easy viewing of biofilm growth.

We use pvc pipe to hold the plates upright (abalone farmers use baskets) to maximise exposure to light and prevent too much sediment from settling on the plates.

P1020963.thumb.JPG.1e3b868f6efb547659837ec0137fa43d.JPG

 

There are two factors I believe that will greatly improve your biofilm growth.

1. Water flow. Moving water promotes growth on surfaces and slows greenwater growth in freshwater, allowing your biofilm to outcompete it.

2. Nutrients. If biofilm growth is slow, we add fertiliser. Alternatively just use water from yiur aquariums as this is generally quite high in nutrients.

This is a single plate:

P5150411.thumb.JPG.19b4e4cea2c0c51dc8fd7b668ef670f3.JPG

note that on the plate you can see areas that are different to others, indicating different organisms growing on different parts of the plates.

The following are pics of scrapings taken from the plates at either 40 or 100 times zoom:

Long green things are filamentous algae, brown round things are diatoms

DSCN5163.thumb.JPG.6e94eaf4d5ac97d19f6bb6302e6c012a.JPG

Diatoms

DSCN3040.thumb.JPG.a7aca85ed4245f09c2e7828d2fa8df15.JPG

The grey things in these are stalked ciliates, attached by their stalks, they filter feed using their bulbous heads. Brown stuff is diatoms.

DSCN3002.thumb.JPG.22f77d42d56d7c92bba731f2a349335f.JPG

 

Some diatoms and a macroalgae (seaweed) germling.

DSCN2978.thumb.JPG.19b73e0fb1db86439b304d183a450510.JPG

Some more diatoms but notice the chains of bigger diatoms through the middle. These are motile i.e. they move. Crazy.

DSCN3041.thumb.JPG.43ac68aec94cda1aec5dc8eff08e5d69.JPG

 

A copepod (centre - grey coloured) found amongst the biofilm.

DSCN5166.thumb.JPG.b195c00b5a5a6fbe2d93fda4d142416d.JPG

More biofilm with an unidentified 'worm-like' organism

DSCN5173.thumb.JPG.cc76821c1dbfa769e3051f75388a6d66.JPG

Other random shots

DSCN3049.thumb.JPG.cc0bbe2a97f57707d6c5eef6f2dbdaee.JPG

DSCN3294.thumb.JPG.ec14b7d7231047dd7fc817cade3f3bbd.JPG

 

All of these scrapings came from plates cultured in the same raceway. Now that see can see this complexity, you can understand why one vegetable/food item just can't compare.

Utilising my experience with this technique I built my own biofilm plates for growing biofilm for pleco fry. The plates are roughly 200*200mm and 10mm apart. It allows fry in to feed and stops adults from eating everything before the fry.

my_plates.thumb.jpg.46e4e140eb6b4b6fbc6d190046c96948.jpg

only problem is that the polycarbonate has split (look closely) around the nylon bars. I think I'll move back to using PVC pipe to hold them apart.

Edited by fishmosy
update photos
  • Like 7
Link to comment
Share on other sites

...Wow!

That's brilliant Fishmosy, thanks for taking the time to explain that and upload all those photos! Really fascinating :D

Link to comment
Share on other sites

that is a fantastic write up and explanation mate, i think i have some new projects to start playing with :)

are those plates in the pics from fresh water or salt?

i might set up 2 tanks with the same amount of shrimp and do a test over 6 months to see the difference in growth/breeding rates using this

as an extra food source..

very interesting indeed!!

Link to comment
Share on other sites

Thanks guys.

The big plates are in saltwater.

Be aware that it takes time for the biofilm to grow to the thick brown layer in the pics, a week if heavily fertilised, several if not.

I use a system whereby I cycle the plates through the culture tub and my fry tanks so I always have some available, but only usually get a slight colouring on the plates. I think having plates with biofilm in the tub acts as a source of organisms to seed the bare plates coming in. I always leave the plates dry for a few days to kill off any snails before adding them to the culture tub.

Link to comment
Share on other sites

Fishmosy.... Once again very easy to understand you are amazing at how explain things...

Link to comment
Share on other sites

That's incredible information...thanks heaps for taking the time to explain it all.....awesome !

Link to comment
Share on other sites

Is there a reason on growing biofilm on a artificial surface, in comparison to growing biofilm on moss, IAL... .?

Link to comment
Share on other sites

For aquaculture (as in the big plates) yes, as these plates have a massive surface area to volume ratio, are easy to handle, allow you to culture lots of biofilm in a small amount of space, and allow you grow biofilms dominated by algae and diatoms by aligning them upright to expose them to light. These are the preferred food for the marine inverts we settle onto the plates.

Non-living biological material like IAL provides nutrients as it breaks down, which promotes the growth of bacteria and micro-detritivores within the biofilm, and organisms feeding on this biofilm also gain a bit of extra nutrition as some of the material will be ingested along with the biofilm.

For shrimp, I am on the fence as to whether one is better than the other. I feel a smooth artificial surface is probably more difficult for the shrimp to feed from given their style of feeding compared to the rasping action of snails or bristlenoses (fish) for example. However I regularly see shrimp feeding from the glass.

Link to comment
Share on other sites

Thanks fishmosy for informative explanation and pics about bio-film...Fascinating stuff...I noticed that IAL has been mentioned a few times in many threads and for the life of me I have no idea what it's abbreviated for...Another stupid question for you fishmosy...Thanks CJ

There are very few stupid questions, yours isn't one of them.In the context of aquarium keeping, Biofilm is a collection of bacteria, diatoms, algae, fungi and other multi-cellular organisms that form a layer on any surface submerged in water (including seawater). Biofilms form because macro-molecules (e.g. Sugars, proteins) attach to surfaces because surfaces (at the molecular level) are polar (i.e. have positive and negatively charged areas). And bacteria are the first to attach to these surfaces to make use of these molecules. The bacteria make the surfaces attractive for settlement of other organisms. Each surface also has a unique biofilm depending on what molecules, bacteria or other organisms attach to it. This is more than the average shrimp keeper needs to know. The important thing shrimp keepers need to know is that shrimp eat this biofilm and it forms an important part of their diet. Hence why we feed our shrimp IAL and similar leaves, because as these leaves break down their surfaces are colonised by micro-organisms which the shrimp eat.
Link to comment
Share on other sites

Thanks fishmosy for informative explanation and pics about bio-film...Fascinating stuff...I noticed that IAL has been mentioned a few times in many threads and for the life of me I have no idea what it's abbreviated for...Another stupid question for you fishmosy...Thanks CJ

I'm no fishmosy but I think I can answer your question : ial = Indian almond leaves

Link to comment
Share on other sites

Just out of curiosity Ben,

What species are you culturing the biofilm plates for? I don't think you mentioned it, unless you're growing Abalone which I seem to recall you mentioned earlier.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Join Our Community!

    Register today, ask questions and share your shrimp and fish tank experiences with us!

  • Must Read SKF Articles

  • Posts

    • beanbag
      Update to say that after a few gravel vacs, front wall scrub, moss / floating plant trim, that the condition seems to have improved.  My current theory is that it is due to waste / debris management, where "stuff" like that brown mulm accumulates in the substrate and behind the HMF filters.  Maybe some tanks can somehow deal with it, but mine can't.  Also another experienced shrimper suggested that maybe those "shell bugs" don't just live on the shrimps but also in this debris.  Maybe this is the reason some tanks fail due to "old tank syndrome" where all they need is a good gravel vac? Also, I am guessing that plant trim helps too because now more of the nutrients and light go into growing algae instead of more plants? Well anyway for this tank I will try weekly water change and monthly gravel vac / plant trim.  For my next tank, I'm thinking of something like an under-gravel system where this mulm can fall down and I vac it out.
    • sdlTBfanUK
      Good to have an update and good to hear you are getting shrimplets, so hopefully your colony will continue and you may not get to the point where you have to cull some to stop over population. These type of shrimp only live 12 - 18 months so the adult deaths may be natural? If you have the time I would do weekly 25% water changes, adding the new water via a drip system and do some vacuuming clean of the substrate each week, even if only a different bit each week! See if that helps in a few months and if it does then stick with that regime? It should help reduce any build-ups that may be occuring!
    • beanbag
      Hello again, much belated update: The tank still has "cycles" of 1-2 month "good streaks" where everybody seems to be doing well, and then a bad streak where the short antenna problem shows up again, and a shrimp dies once every few days.  I am not sure what causes things to go bad, but usually over the course of a few days I will start to see more shrimp quietly standing on the HMF filter, and so I know something is wrong.  Since I am not "doing anything" besides the regular 1-2 week water changes, I just assume that something bad is building up.  Here's a list of things that I've tried that are supposed to be "can't hurt" but didn't prevent the problem either: Dose every other day with Shrimp Fit (very small dose, and the shrimp seem to like it) Sotching Oxydator Seachem Purigen to keep the nitrates lower Keeping the pH below 5.5 with peat Things that I don't do often, so could possibly "reset" the tank back to a good streak, are gravel vac and plant trim, so maybe time to try those again. One other problem I used to have was that sometimes a shrimp would suddenly stop eating with a full or partially full digestive tract that doesn't clear out, and then the shrimp will die within a few days.  I suspected it was one of the foods in my rotation - Shrimp Nature Infection, which contains a bunch of herbal plant things.  I've had this in my food rotation for a few years now and generally didn't seem to cause problems, but I removed it from the rotation anyway.  I don't have a lot of adult Golden Bees at this point so I can't really tell if it worked or not. Overall the tank is not too bad - during the good streaks occasionally a shrimp will get berried and hatch babies with a 33-50% survival rate.  So while there are fewer adults now, there are also a bunch of babies roaming around.  I guess this tank will stagger on, but I really do need to take the time to start up a new tank.  (or figure out the problem)
    • jayc
      If that is the offspring, then the parents are unlikely to be PRL. I tend to agree with you. There are very few PRLs in Australia. And any that claim to be needs to show proof. PRL genes have to start as PRL. CRS that breed true after x generations doesn't turn it into a PRL. Neither can a Taiwan bee shrimp turn into a PRL despite how ever many generations. I've never seen a PRL with that sort of red colour. I have on Red Wines and Red Shadows - Taiwan bee shrimps. So somewhere down the line one of your shrimp might have been mixed with Taiwan bees and is no longer PRL. It just tanks one shrimp to mess up the genes of a whole colony. 
    • sdlTBfanUK
      Sorry, missed this one somehow! The PRL look fantastic and the odd ones look part PRL and part Red wine/Red shadow in the colour. They are still very beautiful but ideally should be seperated to help keep the PRL clean if you can do that.  Nice clear photos!
×
×
  • Create New...