Sand cleaning animals

[Tautoga]

The issue lies in their digestive system and their metabolic system.

They have very inefficient and specialized digestive systems. By that I mean that they are incapable of pulling out all the available calories in a food item because their gut is incapable of breaking down certain nutrients and the nutrients they are capable of only get broken down at a very low percentage.

For instance, let's say that in comparison the human digestive system is extremely efficient and non-specialized and able to process 90-99% of calories consumed. I.E if you are to eat a 1200 calorie double cheeseburger, almost all of those 1200 calories will be consumed. Plus those calorie counts are adjusted for humans. Some of the fiber in the bun will not be processed and not count toward total calories. So, depending on the content, human waste may contain available calories depending on the gut of the animal that tries to process it.

Now, give that same cheeseburger, that supplied 1200 calories to a cow. A cow can process the fibers in the bun that humans can't, so those calories will be used and not wasted, however the calories in the meat, cheese and other items will be wasted and not used because the cow is incapable of stripping them. So now the waste from a human digesting a cheeseburger may have an available calorie count of say 50 calories. The cows waste from the burger will be extremely high because it couldn't process half of it.

So some people will tell you that proteins are proteins and fats are fats and and everything gets broken down to glucose anyway, but when it comes to a specialized feeder like a cow, an ant eater, a giraffe or a diamond goby, they have to eat certain things in order to get the calories they need to give them energy.

So efficiency wise, a diamond goby may only absorb 10% of the calories from a food source that it ingests depending on what It is. So they have to eat constantly in order to not starve. So just because you see an animal eat and poop, does not mean that it's meeting its nutritional needs based on the information above.

Does that make any sense? I feel like I rambled quite a bit lol.

I call BS on this.

Ive had a Diamond watchman for 6 months in a 75 gallon tank. I put him in the tank when it was 2 months old so there was nothing in the sand for him to eat. Yes he moves a A LOT of sand and burns a ton of energy while doing it. He also eats like a pig. Belly is full when I feed him mysis and he eats pellets on and in the sand. He is fat and has grown over 1 inch since I got him so he obviously is converting food into growth and not starving. Starving fish do not grow.

 

[Bent]

I call BS on this.

Ive had a Diamond watchman for 6 months in a 75 gallon tank. I put him in the tank when it was 2 months old so there was nothing in the sand for him to eat. Yes he moves a A LOT of sand and burns a ton of energy while doing it. He also eats like a pig. Belly is full when I feed him mysis and he eats pellets on and in the sand. He is fat and has grown over 1 inch since I got him so he obviously is converting food into growth and not starving. Starving fish do not grow.

While that's great, and I'm happy that you have had success, many don't. Success is surely possible but IME is the exception and not the rule and that's why it's just not a fish I recommend.

It's my opinion, and doesn't need "bs" called on it.

 

[MMacro]

I call BS on this.

Ive had a Diamond watchman for 6 months in a 75 gallon tank. I put him in the tank when it was 2 months old so there was nothing in the sand for him to eat. Yes he moves a A LOT of sand and burns a ton of energy while doing it. He also eats like a pig. Belly is full when I feed him mysis and he eats pellets on and in the sand. He is fat and has grown over 1 inch since I got him so he obviously is converting food into growth and not starving. Starving fish do not grow.

Hmm.
Six months is a very short period of time.


No offense, but im sure more people would trust the facts that Bent provided over "I have had it for 6 months".

 

[Tautoga]

You can believe whatever you like. The fact is the fish is very much alive, not skinny and has grown significantly. This is not a fish that, as Bent describes, has trouble absorbing nutrients from food. It would have been dead long before now. I've seen lots of examples of people that have kept them alive.

I am also not an idiot. I may be new to keeping corals, but I have been keeping fish for 30+ years both professionally (ran a culture lab that raised fish) and as a hobby.
I currently work in the marine fisheries field and run weekly survey of local fish where I have go out and catch them in traps. On top of that I go fishing every weekend from May-October. On a typical week from May- October I handle over 300 fish, sometimes up to 500 fish of different species a week. Im pretty sure I know what a starving fish looks like.

If they are dying in people's tanks it is because they are not getting fed enough or are getting outcompeted or they just dont start eating, (it happens sometimes) not because they cant absorb nutrients. They do need some extra care. When I first got mine, I fed him twice a day and target fed him until he got aggressive enough on his own to not need to be target fed.

 

[kgeig001]

You can believe whatever you like. The fact is the fish is very much alive, not skinny and has grown significantly. This is not a fish that, as Bent describes, has trouble absorbing nutrients from food. It would have been dead long before now. I've seen lots of examples of people that have kept them alive.

I am also not an idiot. I may be new to keeping corals, but I have been keeping fish for 30+ years both professionally (ran a culture lab that raised fish) and as a hobby.
I currently work in the marine fisheries field and run weekly survey of local fish where I have go out and catch them in traps. On top of that I go fishing every weekend from May-October. On a typical week from May- October I handle over 300 fish, sometimes up to 500 fish of different species a week. Im pretty sure I know what a starving fish looks like.

If they are dying in people's tanks it is because they are not getting fed enough or are getting outcompeted, not because they cant absorb nutrients. When I first got mine, I fed him twice a day and target fed him until he got aggressive enough on his own to not need to be target fed.

You might not be an idiot but you do seem to have an attitude. Bent has helped alot of people on this forum including myself. He's well respected and does not bs.

 

[Tautoga]

You might not be an idiot but you do seem to have an attitude. Bent has helped alot of people on this forum including myself. He's well respected and does not bs.

If there is an "attitude" it is because sometimes new people to the forum are treated like they know nothing because they are new. You have no idea of the background someone has when they start posting here.

I get that he is helpful, thats great, kudos to him.

His opinion is that they are not good, an opinion is fine.

He stated that the fish doesnt absorb nutients from food and that is why they starve. This is what I am questioning, not his opinion.

If their digestive system was so specialized, they wouldn't accept any food other than what they sift, period. Clearly this is not the case.
They are listed as easy to keep and that they readily take frozen foods pretty much everywhere I look for info on them. Are all those sources wrong?

 

[kgeig001]

I understand your point but your point was lost when you called his opinion bs. We all try our best to get along around here.

 

[MMacro]

If there is an "attitude" it is because sometimes new people to the forum are treated like they know nothing because they are new. You have no idea of the background someone has when they start posting here.

I get that he is helpful, thats great, kudos to him.

His opinion is that they are not good, an opinion is fine.

He stated that the fish doesnt absorb nutients from food and that is why they starve. This is what I am questioning, not his opinion.

Questioning? You blatantly said that it was untrue.

This is not a fish that, as Bent describes, has trouble absorbing nutrients from food

If their digestive system was so specialized, they wouldn't accept any food other than what they sift, period. Clearly this is not the case.
They are listed as easy to keep and that they readily take frozen foods pretty much everywhere I look for info on them. Are all those sources wrong?

 

[MMacro]

I understand your point but your point was lost when you called his opinion bs. We all try our best to get along around here.

Yeah. All respect was lost at this point. No need to be so agressive.

 

[Tautoga]

Questioning? You blatantly said that it was untrue.

It isnt true. I knew it wasnt, but I did an extensive search anyway to see what I could find on the diet of these guys from observations in the wild, not in an aquarium. I couldnt find any scientific papers written about the diet unfortunately but I did find some information that could only have come from a diet study.

The species name is Valenciennea puellaris.

https://en.wikipedia.org/wiki/Valenciennea_puellaris

http://www.reefkeeping.com/issues/2003-09/hcs3/

Under the section titled "IN THE WILD"

The sand falling from the gills has been carefully sifted for any small invertebrates. Of course, any invertebrate the fish is able to sift from the sand is then consumed. Generally, copepods (about 60% of the diet), amphipods, ostracodes, nematodes, and shelled protozoa (foraminiferans) are the main target of consumption.

This tells me they are opportunistic feeders and will feed on whatever they can find in the sand. Amphipods are not very different from mysis shrimp. If they can digest amphipods, they can digest mysis. Copepods are the majority of the diet simply because they are the greater proportion of what is in the sand.

However I would disagree with the recommended tank size of a 30 gallons min. An animal that sifts as much sand as these guys do should be in a larger tank IMO.

 

[HuskerBioProf]

I am not an expert, but I have a potential explanation for the observations of short life span by Bent. For one, food source and processing efficiency could change with development, thus explaining why fish tend to starve after 1 year in a home aquarium. Even if it has nothing to do with "gut efficiency" or capacity to process specific food sources, it is still possible that metabolic rate and gut capacity dictate overall nutrient intake. In this instance, if the metabolic rate of these fish is high and the gut is too small to store sufficient food, constant eating would be required to maintain sufficient nutrients. If this was the case, even taking frozen mysis would n't be sufficient because survival would depend on feeding continuously throughout the day. Because the fish would be supplementing mysis feedings with sand bed organisms, the goby would be okay initially. However, after depleting the sand bed, the mysis shrimp feedings would become too infrequent to sustain life. Such is similar to the case with mandarins, which I would imagine have a similar metabolic rate and stomach capacity.

Again, my expertise is more biomedical and not zoological, so this is just a potential hypothesis. I just wanted to point out the potentiality being consistent with Bent's anecdotal (and seemingly vast) experiences.

 

[Bent]

The opinion of this old redneck is just an opinion, it was not my intent to derail the thread or to cause an argument. I formed my opinion after trying 4 different specimens that all died within 12-18 months. They would be fat and happy for nearly the first year, and then would wither away rather quickly after that. This also seems to be the case for many, many people here on the forum as well. I formed my hypothesis of why based upon human A&P and other examples in the wild. I have no peer reviewed double blind studies that neither support nor refute my claims, nor support or refute others claims that they are easy and beneficial to the aquarium. As such, anecdotal evidence and hypothesis, based on the facts presented are all someone has to go on.

Some people recommend and say that these fish are beneficial and easy to keep, and i say they are not and I do not recommend them being purchased or traded. I certainly disagree with the misleading "easy" care label that merchants give them. If you read the descriptions, right after they have been labeled as "easy", they generally say that "this animal requires multiple heavy feedings throughout the day". That statement in itself is not an easy thing to accomplish.

Tautoga, you are entitled to your opinion, and I do apologize if I said anything to make you, or anyone else, feel he or she is an idiot. Please, let's continue the debate, I do enjoy the information and hearing from the experience of others. That's why we are all here, yes?