Common Misconceptions In the Hobby

[Paul B]

Capn, good luck to your Son N Law and your daughter.
I wish them a speedy safe home.
I don't really come from a military background just a two year stint with one of them in Nam and Cambodia. Although I was a Sgt. in Nam I am a boat Capt. in civilian life. But I make my living as an electrician.
As for water temp, I diden't bring a thermometer with me but I dove quite a few times in The South Pacific including the Great Barrier Reef, Hawaii and Tahiti. The water seemed very warm to me, warmer than the Caribbean. I really can't say if it was in the eightees but I think it was. The next time I go I will look at the dive computer, The temp is on it.
All of the rock in my reef was dead dry rock. I collected it in the Caribbean but I bleached it to bring home. In those days there was no live rock in tanks. The rest of my rock is cement and since my nitrates are always zero I guess it works.
Have a great day.
Paul

[fishdoc11]

Originally posted by Ninong
If you google "righting reflex in snails" you will get 681 hits. That should help you understand what it is.

Sorry I meant to say whatever that means.....Astreas right themselves just fine on most substrates, just not on fine sand

[RichConley]

Originally posted by Ninong
The article was commissioned by Dennis Tagrin but written by Ron Shimek. It explains the feeding processes of Tridacna clams.

Right, and it says that Tridacna need to be fed phyto, which is absolutely false.

[fishdoc11]

Originally posted by Ninong
OK, so some of you guys don't like Ron Shimek's advice on reef aquarium husbandry. Fine. To each his own. But it's really a stretch to attack the guy on molluscan biology when that's his Ph.D. field.

Ok I'll stop.....it's not nice and I should have shut up before I even started.

Ok another misconception:

Aquarists have to rinse everything in RO/DI water and not tap water.

I actually know a very good LFS that does this. I commend them for their effort but IMO it's totally unnecessary.

Chris

[cayars]

Originally posted by pledosophy
31 or so

Base rock will become liverock in a few months

I say myth busted.

The anaerobic bacteria that is housed within tradition live rock will take years and even decades to grow in base rock. The anaerobes don't like oxygen and are not often found floating in the water column so they have no way of entering the rock which is quickly covered by the aerobic bacteria. I never believed this myself, even after I read the study, until i cracked open a piece of base rock that was in my tank for a bit over 5 years to find it void of anearobic bacteria as compared to a piece of rock that was imported with a coral attached which had a large population of the bacteria.
JME

This is not a myth and is very true. I'd like to know how you expected to see bacteria when you cracked open the rock? Do you see bacteria on the outside of the rock? How do you expect to see bacteria in the first place?

Obviously you need a microscope, patience and many, many slides and samples to come to any type of reasonable results.

Even if you did not find any bacteria in the rock does not mean anything anyway. Your tank will only require so much bacteria and the rest will die off. No food, no bacteria. In someone else's tank it could be filled with bacteria especially in systems will low volumes of subtrate or rock. This is survival of the fittest in action.

Carlo

[Ninong]

Aquaculture studies show that baby Tridacna clams that are fed live phytoplankton grow faster and have higher survival rates than those in a control group raised in a sterile environment.

Tridacna clams can survive without phytoplankton. They do better with it, especially when young.

In their natural environment, juvenile Tridacna clams get as much as 40% of their nutrition from filtering. This percentage decreases with age until it drops to less than 5% in mature clams.

[fishdoc11]

More misconceptions:

1) SPS have to be kept under metal halide lighting.

Not true... flourescent lighting, especially with the emergence of T5's, is a very good alternative. Especially if you want to save on heat and the power bill.

2) SPS can't be kept under VHO lighting.

Not true. While VHO's are no longer considered "state of the art" they are definately a usable lightning source that can produce good growth rates and excellent color of out of a good # of SPS species including lots of different types of Acropora.

3) You have to have a calcium reactor to keep SPS.

Again not true. 2 part solutions will work even on very large tanks. With the introduction of Randy's homemade recipe it also no longer costs an arm and a leg to do this. The cost is in fact comparable to a Ca reactor if not cheaper for many. I have also seen several nice mainly stony tanks supplimented with kalk alone. While this doesn't work for very heavily stocked tanks it can work well in ones that aren't.

Chris

[virginiadiver69]

Originally posted by fishdoc11
Am I the only one that finds it odd they wear 3 - 5 mil suits when the average looks to be in the mid 80's and drysuits when the average looks to be in the mid to upper 70's?
I would be burning up!

Not after an hour at about 30-50 in depth. That 80 deg water will get cold.

[Ninong]

I was searching online to see if I could find that aquaculture study on baby T. maxima clams that showed that the growth rate and survival rate was substantially higher in a hatchery fed with live phytoplankton than it was in a control hatchery with no feeding of any kind but I didn't find it.

However, I did come across something interesting. Baby gigas clams get as much as 65% of their nutrition from filter feeding, falling off to 34% when they reach 10g dry weight. I guess that's still in line with the 40% figure one of the leading clam hobby experts uses because the 65% figure is for really, really tiny clams.

"Giant clams of the family Tridacnidae are familiar and conspicuous residents of shallow coral reefs throughout much of the tropical Indo-Pacific. Their most characteristic feature is the enlarged, upwardly directed and usually brightly coloured mantle, which is packed with symbiotic dinoflagellate zooxanthellae. An estimated 95% of the carbon fixed by these algal symbionts is translocated to the host (Fitt 1993, Klumpp & Griffiths 1994), where it normally provides sufficient energy to cover at least the immediate metabolic needs of the hosts (Tench et al. 1981, Fisher et al. 1985, Mingna 1988, Klumpp & Griffiths 1999).

"Giant clams are also able to filter food particles from the water column (Yonge 1936), although the nutritional significance of this has only recently been quantified. Fitt et al. (1986) first quantified ingestion and digestion of C14-labelled phytoplankton cells by Tridacna gigas, while Klump et al. (1992) showed that particulate food constituted 65% of carbon needs in small (0.1g dry tissue) T. gigas, declining to 34% in individuals of 10g weight. This capacity to exploit both heterotrophic and autotrophic sources of nutrition, plus an ability to divert an unusually high proportion of energy to growth (Klumpp et.al. 1992), are no doubt factors that have allowed T. gigas to become the largest bivalve ever to have existed."

Reference

[fishdoc11]

Originally posted by virginiadiver69
Not after an hour at about 30-50 in depth. That 80 deg water will get cold.

FWIW I can easily spend an hour in 73 with a 3 mil. I'll get a little cold but not much.....and that's not even using much energy, mainly using a frog kick. I prefer swim trunks in 80 but in the ocean I'll wear something just for brushing up against stuff. My main reason for making that comment is that it seems colder than what the graph suggests but maybe that's just what I see.

Chris

[virginiadiver69]

I think I may just get cold easy.

[fishdoc11]

My wife says I'm like a heating pad

[Paul B]

The only thing I caqn say about tridacna clams is that they are all over the place in the South Pacific especially Bora Bora and you have to watch that you don't step on them in the shallow water. I have had many of them which I have never fed and they grow a little over an inch a year with no food what so ever.
This bay in Bora Bora is loaded with them.

[mbbuna]

Originally posted by Ninong
The article was commissioned by Dennis Tagrin but written by Ron Shimek. It explains the feeding processes of Tridacna clams.

that proves my whole point!!! he wrote the article FOR them and if you read it and believe it you would think that if you didn't feed your clam it will die. complete BS!! zoox do not live in the blood, in context or out, they dont do it.

do you think Dennis would have paid for an article that looked unfavorable of phytoplankton? that article says that clams only eat phyto, false!

i think this is the reason why some aren't so smitten with Shemik. he doesnt seem to have a problem crafting thing to his liking

[mbbuna]

Originally posted by Ninong


Tridacna

In their natural environment, juvenile Tridacna clams get as much as 40% of their nutrition from filtering. This percentage decreases with age until it drops to less than 5% in mature clams.

wrong, ill get back to ya ninong

[MiddletonMark]

Originally posted by MiddletonMark
At least according to Walt Smith in Fiji, the reefs there average more in the mid 70's for most of the year.

Ninong, while the statement about most of the year was incorrect .... they do get to the 70's, but range fairly widely.

I should have said, `they can get to the mid-70's, without issue for the health of the reef'.

I was just attemting to correct the misconception that healthy reefs don't exist in those temps. Reef is a pretty wide category, as we both know.


If I may add one common hobby misconception:
Generalizations rarely turn out to be fully correct

Seems to apply across the board, exception one thing IME .... that when you meet up with reefkeepers of all ages, sizes, and kinds - they tend to be nice in person.

[Ninong]

Originally posted by mbbuna
that proves my whole point!!! he wrote the article FOR them and if you read it and believe it you would think that if you didn't feed your clam it will die. complete BS!! zoox do not live in the blood, in context or out, they dont do it.

do you think Dennis would have paid for an article that looked unfavorable of phytoplankton? that article says that clams only eat phyto, false!

i think this is the reason why some aren't so smitten with Shemik. he doesnt seem to have a problem crafting thing to his liking

My explanation that the article was written by Ron Shimek was in response to RichConley's comment that he doesn't believe anything on DT's website. It wasn't intended to prove or refute your point.

Of course, the article is going to recommend feeding live phytoplankton. Do you think Dennis would have paid for it if it didn't?

Anyway, I think feeding live phytoplankton to juvenile clams is a good idea. It may not be absolutely necessary, but it's still a good idea in my opinion.

The operative phrase from Shimek's quote about zooxanthellae in the blood is "Tridacna and Hippopus clams have symbiotic zooxanthellae located in their blood."

I hope we're not going to get into a Clintonesque discussion of the definition of is, but no one used the word "live" except you.

BTW, on page 32 of the June/July 2004 issue of Coral magazine, Daniel Knop says "giant clams contain symbiotic algae in their blood systems."

[Ninong]

Originally posted by mbbuna
wrong, ill get back to ya ninong

OK, here's my statement that you say is "wrong" --

"In their natural environment, juvenile Tridacna clams get as much as 40% of their nutrition from filtering. This percentage decreases with age until it drops to less than 5% in mature clams."

Let me clarify it in case you're reading something into it that I didn't say.

Juvenile clams get as much as 40% of their nutrition from filtering. This has been established. I even linked to a study of T. gigas juveniles that measured this.

This percentage decreases with age until it drops to less than 5% in mature clams. It's around 5% in T. gigas and zero in other Tridacnids. It's sometimes slightly more than 5% in T. gigas depending on the environmental circumstances. T. gigas retains the ability to move between hetero- and autotrophic uptake its entire life.

[capn_hylinur]

Originally posted by Ninong
The article was commissioned by Dennis Tagrin but written by Ron Shimek. It explains the feeding processes of Tridacna clams.

is this a quantum leap--or are we not to have faith in DT phyto either.
I started my own phyto awhile ago and was discouraged from using it----reasons being that eventually it would have only one strain due to Darwinism, and it was fully of phosphates due to the nurtrient we were using (miracle grow). It was suggested that DT was the best way to go-------

and this question resurfaces( I think it got ignored in the hands vs the brains debate going on )
How much is misconception that we have to feed our coral and I guess we could add clams large daily doses of phyto and zooplankton?

[Peter Eichler]

Haha, gotta love the twists and turns this thread takes But, lets lay off on bashing people that aren't here to defend themselves (saying you don't agree is perfectly fine). Unless you all want to bash Thiel, then go for it!

Also, thanks to all for all the contributions, and all the debates that have made the thread interesting. You've all played a part in getting this thread nominated for thread of the month (even the crumudgeons ) .

Now go vote for whichever thread you like best!

http://archive.reefcentral.com/forum...readid=1193958

[capn_hylinur]

Originally posted by Ninong
OK, here's my statement that you say is "wrong" --

"In their natural environment, juvenile Tridacna clams get as much as 40% of their nutrition from filtering. This percentage decreases with age until it drops to less than 5% in mature clams."

Let me clarify it in case you're reading something into it that I didn't say.

Juvenile clams get as much as 40% of their nutrition from filtering. This has been established. I even linked to a study of T. gigas juveniles that measured this.

This percentage decreases with age until it drops to less than 5% in mature clams. It's around 5% in T. gigas and zero in other Tridacnids. It's sometimes slightly more than 5% in T. gigas depending on the environmental circumstances. T. gigas retains the ability to move between hetero- and autotrophic uptake its entire life.

What I hear you stating in praticalities is that all clams esp adult ones should be placed up high in the reef near the halides?
Like this little guy---would not open and was just plain unhappy until I moved him up high

[capn_hylinur]

Originally posted by Peter Eichler
Haha, gotta love the twists and turns this thread takes But, lets lay off on bashing people that aren't here to defend themselves (saying you don't agree is perfectly fine). Unless you all want to bash Thiel, then go for it!

Also, thanks to all for all the contributions, and all the debates that have made the thread interesting. You've all played a part in getting this thread nominated for thread of the month (even the crumudgeons ) .

Now go vote for whichever thread you like best!

http://archive.reefcentral.com/forum...readid=1193958

I asked this earlier---how many votes do we get?

Its really a toss up between this thread and and the thread where the two college kids were bashing everyone who didn't agree that could keep six tangs in a 29gal tank(slight exaggeration) ---and then when they didn't receive praise "moved on"

[Peter Eichler]

Originally posted by capn_hylinur
What I hear you stating in praticalities is that all clams esp adult ones should be placed up high in the reef near the halides?
Like this little guy---would not open and was just plain unhappy until I moved him up high

That really depends, many clams can do quite well at the bottom of fairly deep tanks (24ish inches) as long as lighting is strong enough. I had a Crocea that bleached in shipping and it regained it's full color being 24" below 6x39w T5s.

[fishdoc11]

FWIW I've had 4 clams(2 Croceas, a Deresa and a Squamosa) at the bottom of a 24" tank (first a 90 and now a 120) for several years now. The longest being there ~ 4 years and the shortest about 2. They do very well under SE 10K 250 watt MH run on manetic ballasts with VHO atinics.
Seeing as how you are running 150 watt lights it very well might like it a little higher. Deresas are a lower light clam FWIW.

hth, Chris

[Ninong]

Originally posted by capn_hylinur
What I hear you stating in praticalities is that all clams esp adult ones should be placed up high in the reef near the halides?
Like this little guy---would not open and was just plain unhappy until I moved him up high

Wow! I didn't say that anywhere in this thread that I know of. However, I do think that Tridacna crocea and T. maxima clams do better when placed on a flat rocky surface and in a location where they will receive adequate light. In most reef tanks under typical lighting that means higher on the rock structure rather than lower. If you're running 1000w lamps, then place them anywhere you please.

In their natural environment both crocea and maxima clams are found on rocky substrate or on coral heads. Gigas clams and derasa clams are found on the sand bed. Derasa clams do attach to the reef initially but they lose their byssal attachment once they achieve female sexual maturity at around 30cm and then they become unattached and fall to the sand bed. The weight of mature gigas and derasa clams keeps them upright.

P.S. -- I've kept both croceas and maximas in as 120-gal tank under 250w 10,000K DE halides and the croceas definitely retain their mantle coloration better when placed higher up on the rock structure. IME, croceas require more light than maximas but I didn't put any of them on the sandbed.