jacet

What is Biofilm?

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jacet

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

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jacet

Thanks Fishmosy

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

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fishmosy

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.

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Naraic

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?

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Triggs

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.

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fishmosy

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".

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northboy

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

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fishmosy

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).

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northboy

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

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BlueBolts

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.

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fishmosy

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.

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fishmosy

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.

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fishmosy

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

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Diatoms

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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.

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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.

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More biofilm with an unidentified 'worm-like' organism

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Other random shots

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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
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Jess

...Wow!

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

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Dean

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!!

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fishmosy

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.

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jacet

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

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BlueBolts

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

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BlueBolts

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

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fishmosy

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.

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Neo-shrimp

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.

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njslocksmith
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

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sajica

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.

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