Fish-o-holic
New member
Should I place a rock under my 3" Derasa clam so it can attach? It will be placed on the substrate of the tank if that helps any.
from hereIn nature, juvenile T. derasa normally live in shallow waters attached to coral rubble. They reach sexual maturity at a shell length of more than 30 centimeters (12 inches), at which time they detach their byssal attachment. Once the byssus is detached, the water current moves them to deeper waters, where they settle on the sand and are held in place by their weight.
I find this a little far fetched. A clam of 30cm would weight about 35-40kg. If the water current is strong enough to move a clam of this weight, then the area is not going to be a suitable spot for larval clams to settle. Clams can however move themselves slowly by opening and closing their shell.at a shell length of more than 30 centimeters (12 inches), ...... the water current moves them to deeper waters
Great to hear from a Derasa owner. How long did you leave the rock under the clam and how big is the clam? I am still deciding yes or no on the rock. Dang, I change my mind fast don't I.srfmon said:My deresa & squamosa never wanted to attach to a rock or shell.
That's fine with me.
These are the 2 smallest species of Tridacnids. This means that even when fully grown they are not especially large animals and they attach to rock for protection against storms and waves but it also reduces the chance of parasites moving in from beneath the byssal opening. When a clam that is firmly attached to a rock shuts tightly, there is almost nothing that can get to the tissue.Fish-o-holic said:On a different note, why do maxima and crocea clams attach to rocks whereas other clams don't? Do they come from a different part of the ocean??? Just curious.
Sounds like a plan to me as well. I still am looking for that "perfect" rock for my clam.Pfittttz said:so maybe put a small rock under the sand and let the clam decide what's best for it? That sounds like a good plan![]()
Lifting and guessing is far inferior to actually weighing them on a set of scales. I can tell you for a fact that that is a fairly accurate estimate maybe slightly high, it could be 30-35kg but my point still stands, that is a heavy object. I was at Orpheus Island on the GBR a few weeks ago doing an aquaculture course and we weighed and measured clams as part of a 15 yr study.Vili_Shark said:Hi Firechild,
I do not agree with you on two issues:
1.A Dearsa of 30cm will not weigh 35-40Kg.
I saw and lifted quite a few Derasas of the sizes 25-35Cm and I can tell ya, none of'em waz even close to these numbers.
I think you may need to reread what I said.2.Maximas do not bore in the rock like Croceas do
I saw hundreds of Maximas in the wild.
Young Maximas were always well bored into the rock.
Mature ones and mid size ones were as ya said stay on top of the rock.
The babies and young Maxima are always well bored inside the rocks
My experience is from Red Sea Maxima only, might be that in other places, things are not the same.
Maximas do not actually bore like croceas do. They grow to about 40cm so they simply attach to a rock in a groove and they might bore slightly if the groove restricts it from opening but will generaly just stay on top of the rock. However croceas will truly bore deep in a rock and increase the size of the hole as it grows.