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Clam Anatomy


Rockfish

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So, there are many here that keep Clams or have kept clams or are thinking about keeping clams that have used this forum for a couple of great write-ups on proper lighting requirements and general care and tank size. But there are some (like me) that have gotten very involved in the "in's and out's" of what actually makes them tick

 

 

 

I was very surprised to discover that when I got involved with clams for the first time that they are quite more complex they many people think they are.Clams actually have a stomach, intestines, and even a heart. I bet some people here didn't know that! Just some info for the ppl that are as crazed about them as i am on this site!!

 

First off the Taxonomy...These clams can be broken down in to:

 

Phylum: Mollusca

Class: Bivalvia

Order: Veneroidea

Family: Cardiidae

SubFamily: Tridacninae

 

The giant clams have long belonged to the family Tridacnidae, but according to the World Registry of Marine Species (WORMS) they are now included in the family Cardiidae as the subfamily Tridacninae. As such,Tridacnidae is no longer being accepted as the family though the genus names are still the same.

 

 

The Tridacninae family can be broken down into two genera containing nine species as follows:

 

Hippopus (genus)

Hippopus hippopus - Hippopus Clam, Horse's Hoof clam .

(H. hippopus also known as Bear Paw Clam and Strawberry Clam)

Hippopus porcellanus - China Clam

Tridacna (genus)

Tridacna crocea - Crocea Clam, Crocea

(T. crocea is also known as the Boring Clam, Boring Giant Clam, Crocus Clam, and Saffron-Colored Giant Clam)

Tridacna derasa - Derasa Clam

Tridacna gigas - Giant Clam

Tridacna maxima - Maxima Clam, Maxima

Tridacna squamosa - Squamosa Clam

Tridacna mbalavuana Ladd - Tevoro Clam

(Syn: Tridacna tevoroa)

Tridacna costata. This species of giant clam is very new discovery. It was first reported and described as a new living species in 2008 by Roa-Quiaoit, Kochzius, Jantzen, Zibdah, and Richter. This giant clam has a small population, is highly endangered, and not found in the aquarium industry.

This species is said to represent less than 1% of the giant clams found in nature. However most of the giant clam shells that have been found, about 80% of them, are of this species. Due to this large number of shells, experts believed that the few number of clams seen today is because it has been heavily harvested by humans for thousands of years. They suggest harvesting these clams goes back to humans occupying the Red Sea area since about 125,000 years ago.

 

 

Now that we have all the Technical crap out of the way. a closer look at a clam's anatomy is the thing that shocked me the most as they have quite a simple yet sophisticated anatomy for....well a clam

 

 

The digestive tract of typical bivalves consists of an esophagus, stomach, and intestine. A number of digestive glands open into the stomach, often via a pair of diverticula; these secrete enzymes to digest food in the stomach, but also include cells that phagocytose food particles, and digest them intracellularly.

In the filter feeding bivalves, an elongated rod of solidified mucus referred to as the crystalline style projects into the stomach from an associated sac. Cilia in the sac cause the style to rotate, winding in a stream of food-containing mucus from the mouth, and churning the stomach contents. This constant motion propels food particles into a sorting region at the rear of the stomach, which distributes smaller particles into the digestive glands, and heavier particles into the intestine.

 

 

 

The muscular system is composed of the posterior and anterior adductor muscles, although the anterior muscles may be reduced or even lost in some species.

The paired anterior and posterior pedal retractor muscles operate the animal's foot. In some bivalves, such as oysters and scallops, these retractors are absent.

 

 

here's a pretty good representation of the typical clam

 

fig03_clamjpg.jpg

 

 

Much more complex then people (us as reef keepers) think they are

 

Now, factor in there mantle system that contains the Zooxanthellae algae (Zooxanthella live in other protozoa and in some invertebrates. Most are autotrophs and provide the host with energy in the form of translocated reduced carbon compounds, such as glucose, glycerol, and amino acids, which are the products of photosynthesis. Zooxanthellae can provide up to 90% of a coral’s energy requirements. In return, the coral provides the zooxanthellae with protection, shelter, nutrients (mostly waste material containing nitrogen and phosphorus) and a constant supply of carbon dioxide required for photosynthesis. Available nutrients, incident light, and expulsion of excess cells limits their population) they need to turn light in to nutrients for sustainability and you can see why these beauties need to be well cared for in the home aquarium

 

 

hope this has been a bit interesting and not too boring for ya!!

Edited by Rockfish
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cheryl jordan

So if you dose with AA, you are thus providing the nutrition that is also produced by the zooxanthellae. And that dosing with AA is a benefit for clams as well. Just curious ;)

Edited by cheryl jordan
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I didn't really read everything but I have always liked clams because* they aren't simple creatures at all...biologically.

Edited by Jacobnano
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I didn't really read everything but I have always liked clams because* they aren't simple creatures at all...biologically.

 

 

very true...

 

 

very nice.

 

have you considered doing maybe a complete guide to clam care? perhaps talk about their lighting needs, feeding, disease, etc?

 

 

i want to combine all three of the great write ups on this site...i have to contact a mod and see how to go about doing that

 

So if you dose with AA, you are thus providing the nutrition that is also produced by the zooxanthellae. And that dosing with AA is a benefit for clams as well. Just curious ;)

 

 

Technically.....but not really. I'll explain in detail

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Pretty good write up for those who rather not read Giant Clams by Daniel Knop

I can appreciate the update on the Taxonomy though. Thanks :)

 

 

 

hey. that's what i'm here for!!

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very nice.

 

have you considered doing maybe a complete guide to clam care? perhaps talk about their lighting needs, feeding, disease, etc?

 

 

+1 then make it a sticky

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  • 7 months later...
  • 3 months later...
So, there are many here that keep Clams or have kept clams or are thinking about keeping clams that have used this forum for a couple of great write-ups on proper lighting requirements and general care and tank size. But there are some (like me) that have gotten very involved in the "in's and out's" of what actually makes them tick

 

 

 

I was very surprised to discover that when I got involved with clams for the first time that they are quite more complex they many people think they are.Clams actually have a stomach, intestines, and even a heart. I bet some people here didn't know that! Just some info for the ppl that are as crazed about them as i am on this site!!

 

First off the Taxonomy...These clams can be broken down in to:

 

Phylum: Mollusca

Class: Bivalvia

Order: Veneroidea

Family: Cardiidae

SubFamily: Tridacninae

 

The giant clams have long belonged to the family Tridacnidae, but according to the World Registry of Marine Species (WORMS) they are now included in the family Cardiidae as the subfamily Tridacninae. As such,Tridacnidae is no longer being accepted as the family though the genus names are still the same.

 

 

The Tridacninae family can be broken down into two genera containing nine species as follows:

 

Hippopus (genus)

Hippopus hippopus - Hippopus Clam, Horse's Hoof clam .

(H. hippopus also known as Bear Paw Clam and Strawberry Clam)

Hippopus porcellanus - China Clam

Tridacna (genus)

Tridacna crocea - Crocea Clam, Crocea

(T. crocea is also known as the Boring Clam, Boring Giant Clam, Crocus Clam, and Saffron-Colored Giant Clam)

Tridacna derasa - Derasa Clam

Tridacna gigas - Giant Clam

Tridacna maxima - Maxima Clam, Maxima

Tridacna squamosa - Squamosa Clam

Tridacna mbalavuana Ladd - Tevoro Clam

(Syn: Tridacna tevoroa)

Tridacna costata. This species of giant clam is very new discovery. It was first reported and described as a new living species in 2008 by Roa-Quiaoit, Kochzius, Jantzen, Zibdah, and Richter. This giant clam has a small population, is highly endangered, and not found in the aquarium industry.

This species is said to represent less than 1% of the giant clams found in nature. However most of the giant clam shells that have been found, about 80% of them, are of this species. Due to this large number of shells, experts believed that the few number of clams seen today is because it has been heavily harvested by humans for thousands of years. They suggest harvesting these clams goes back to humans occupying the Red Sea area since about 125,000 years ago.

 

 

Now that we have all the Technical crap out of the way. a closer look at a clam's anatomy is the thing that shocked me the most as they have quite a simple yet sophisticated anatomy for....well a clam

 

 

The digestive tract of typical bivalves consists of an esophagus, stomach, and intestine. A number of digestive glands open into the stomach, often via a pair of diverticula; these secrete enzymes to digest food in the stomach, but also include cells that phagocytose food particles, and digest them intracellularly.

In the filter feeding bivalves, an elongated rod of solidified mucus referred to as the crystalline style projects into the stomach from an associated sac. Cilia in the sac cause the style to rotate, winding in a stream of food-containing mucus from the mouth, and churning the stomach contents. This constant motion propels food particles into a sorting region at the rear of the stomach, which distributes smaller particles into the digestive glands, and heavier particles into the intestine.

 

 

 

The muscular system is composed of the posterior and anterior adductor muscles, although the anterior muscles may be reduced or even lost in some species.

The paired anterior and posterior pedal retractor muscles operate the animal's foot. In some bivalves, such as oysters and scallops, these retractors are absent.

 

 

here's a pretty good representation of the typical clam

 

fig03_clamjpg.jpg

 

 

Much more complex then people (us as reef keepers) think they are

 

Now, factor in there mantle system that contains the Zooxanthellae algae (Zooxanthella live in other protozoa and in some invertebrates. Most are autotrophs and provide the host with energy in the form of translocated reduced carbon compounds, such as glucose, glycerol, and amino acids, which are the products of photosynthesis. Zooxanthellae can provide up to 90% of a coral’s energy requirements. In return, the coral provides the zooxanthellae with protection, shelter, nutrients (mostly waste material containing nitrogen and phosphorus) and a constant supply of carbon dioxide required for photosynthesis. Available nutrients, incident light, and expulsion of excess cells limits their population) they need to turn light in to nutrients for sustainability and you can see why these beauties need to be well cared for in the home aquarium

 

 

hope this has been a bit interesting and not too boring for ya!!

 

How about a works cited, otherwise they consider this plagiarism.

Link to comment
How about a works cited, otherwise they consider this plagiarism.

 

 

Good Luck with that! The last time Rockfish posted was on May 25 of this year. There is speculation he was going away on an "extended" vacation.... if you get my drift. ;)

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