[1]. In water, levels of arsenic are lowest in seawater, higher in rivers and lakes and highest in water from underground areas containing volcanic rock or arsenic-rich mineral deposits.  

Of course, arsenic is generally present in sea-living animals at higher levels than in freshwater animals,.

[2] The amounts of arsenic found in living animals, plants and microbes vary. The quantities depend on the level of local contamination and on the type of organism, as certain organisms tend to accumulate arsenic in their bodies.  

[3]In water, there are present both arsenic acid[H3AsO4] as well as arseneous acid       [ H3AsO3] which are , in fact arsenic(V) oxides and arsenic(III) oxidesin water  in acidic conditions[ because there is always the possibility of presence of Cl(-), SO4 (-2) or NO3(-)ions in  the sea water.

Plz find   attached one paper on  Channa punctatus. You can find more on different kinds of  the fish.

http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=6C2BD604353451050589BF07A0E69F98?doi=10.1.1.633.9271&rep=rep1&type=pdf

thesis gives details but only for fish muscles (2010)

Dr.Stefania Squadrone,

At my age,  vote up/ down does not matter; of course knowing things does.

 Being a student of Chemistry and having been associated with ARSENIC , may I ask for your favor-

 does your query relate to Metabolism  of fish  of any kind which are infected with the arsenic?

If , now, I got you right, I can send you at least one reference on

A rsenic speciation in the liver, intestine, ovary, bone, brain, muscle, gill and eye of the freshwater fish Tilapia mossambica .

Hope you understand the limitation of  a non-medical student but will appreciate  it  for the sake  of academic discussion.

Dear Prof. Stefania Squadrone

Please take a look in article entitled: Studies on the accumulation and transformation of arsenic in fresh organisms II. Accumulation and transformation of arsenic compounds by Tilapia mossambica

It could be very interesting for you.

Best Regards

Parisa Ziarati

Dear Manohar Sehgal,

I honestly think that downvote questions or answers is disrespectful and when people do it on the feedback that I have received is irritating to me.

Therefore, I apologize for the anonymous person who does not appreciate your effort and your desire to help in settling this issue.

Having said that, I am interested in the metabolism of arsenic in fish, and then to the different distribution of the arsenic compounds (organic and inorganic) in the various fish tissues.

I take this opportunity to thank all those, like you, are helping me answering to my question.

kind regards

stefania

One word Mdm  Stefania Squadrone,

 Indebted

Plz. find

[1]Metabolism and organ distribution of arsenic in the freshwater fish Tilapia mossambica

  Suhendrayatna1, Akira Ohki, Tsunenori Nakajima andShigeru Maeda

Applied Organometallic Chemistry

Special Issue: Dedicated to the memory of Professor K.J. Irgolic

Volume 15, Issue 6, pages 566–571, June 2001

Abstract:

Arsenic concentration and arsenic speciation in the liver, intestine, ovary, bone, brain, muscle, gill and eye of the freshwater fish Tilapia mossambica exposed to arsenic were investigated. The profile of arsenic distribution ­in tissues of T. mossambica after exposure­to a medium containing arsenate was brain >­intestine  > ovary >   eyes >  muscle  > gill >  bone­> liver. The minimum content of arsenic is in liver tissue (2.5 μgAs g-1 dry weight), whereas the maximum content is in brain tissue (61.8 μgAs­g-1 dry weight). Arsenic accumulated in liver tissue was present as methylated arsenic species, and no inorganic arsenic species were found in liver tissue. A notable exception is in brain tissue. Most arsenic accumulated in brain tissue was inorganic arsenic species, and no methylated arsenic was found in brain tissue. In a dietary exposure treatment, the maximum arsenic accumulation in the tissue of T. mossambica fed with Neocaridina denticulata dosed with arsenic from a Chlorella vulgaris diet (via the food chain) is in the ovary (7.4 μgAs g-1 dry weight), followed by gill, liver, muscle, bone, brain, eyes and intestine. Trace amounts of methylated arsenic were found in liver tissue in this treatment. Methylated arsenic in fish exposed via water was more evenly distributed in the organs compared with dietary exposure. 

[2] I Will try  to give another answer  in 2/3 days (hopefully).

[3] Though, it may look out  of context,   being 72 years of age, I did my Ph. D on ARSENIC( omitting detail due to pausity of space) in 1986 with four publications.

[4]Yes;  I know only a little   about anatomy of the fish.

This is really interesting. I would like to receive the publications related to your PhD thesis if possible!

stefania

Dear Stefania, Thank you for your kindness request. My PhD thesis was written in Turkish. But, I can send you abstract section of the thesis.

ABSTRACT

THE INVESTIGATION OF EFFECTS OF CAGE FISH FARMING

ACTIVITY TO WATER QUALITY AND SEDIMENT IN VICINITY OF THE KARABURUN PENINSULA

YABANLI, Murat

PHD,

Fisheries Fundemental Sciences

Supervisor: Prof. Dr. Özdemir EGEMEN

January 2007, 91 pages

In this study, temperature, dissolved oxygen, turbidity, pH, salinity, nutrients in water column and organic carbon, amount of burnable substances in sediment have been analyzed in the previously defined stations which are near by two different fish farms where Sparus aurata (sea bream) ve Dicentrarchus labrax

(European sea bass) are grown in net cages in the gulf of Gülbahçe and the gulf of Gerence in the Karaburun Peninsula between December 2004 – December 2005.

The results were 0.03-0.24 µg.at/L for NO −2 -N, 0.04-0.80 µg.at/L for NO−3 -N, 0.15-3.40 µg.at/L for NH+4 -N, below detection limit – 0.32 µg.at/L for PO3−4 -P, 0.11-6.35 µg.at/L for silicate, 0.41-18.24 for organic carbon (%) and 4.36-28.11

for amount of burnable substances.

Key Words: Karaburun Peninsula, aquaculture, water quality

Arsenic

Risk-based consumption limits of Salton Sea fish were determined using recent As speciation analyses of skinned fillets collected from the Salton Sea, where inorganic As averaged 0.4 percent of total As for bairdiella and corvina and 0.3 percent for tilapia

http://www.bio.sdsu.edu/pub/stuart/2007MoreauSeAsFourFish.pdf

Arsenic  is released from the Earth’s crust via natural processes . It can exist in inorganic or organic form; inorganic arsenic being generally considered more toxic.

It accumulates in bottom sediments. Fish assimilates toxic metals[ list given below]** along As by ingestion of a particular material suspended in water, ion exchange of dissolved metals across lipophilic membrane- the gills and adsorption of tissues and membrane surfaces

[Cu^2, Ni^2, Fe^2, Co^2, Mn^2, Cr^3, Zn^2, Cd^2, Hg^2, Pb^2]**

There are FOUR POSSIBILE ways for  arsenic to reach the various parts of the fish

[1] By adsorption( as explained above)

[2] In fish, most arsenic is found as arsenobetaine (an analog of trimethylglycine)[ Called Organic Arsenic],

Its formation in the fish[ bioaccumulation ] as well as laboratoty synthesis   are given in the file attached along with[ Zoom 200%]

[3]Toxic inorganic arsenic(iAs) species can be biomethylated by bacteria, algae, fungi, invertebrate  to yield monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) which are less toxic than inorganic arsenic.Methylation of inorganic arsenic mainly occurs in liver but other organs also have the arsenic methylation activity (Vahter, 2002). In this process inorganic arsenic is enzymetically biotransformed to methylated arsenicals including MMA and DMA, these are the end metabolites and the biomarker  (Biggs et al., 1997; Thomas et al., 2001)[ All these forms called Organic arsenic].

iAs (V) → iAs (lll) →MMA (V) → MMA (lll)→ DMA (V)

[4]  To a very small extent,Arsenic forms the arsenites and the arsenates{ called Innorganic arsenic} of the above metal ions as follows:

 Arsenic(V) oxides and arsenic(III) oxides from the soil of the rivers/sea are conveted into  both arsenic acid[H3AsO4] as well as arseneous acid [H3AsO3]  in acidic condions  as there is always the possibility of presence of Cl(-), SO4(-2) or NO3(-)ions in  the sea water].

As2O3 +3H2O----------- 2H3AsO3

As2O3 +O2( dissolved in river/sea water----------- As2O5

As2O5 +3H2O----------- 2H3AsO4

M^2 + 2H3AsO3 -------- M2( AsO3)3 +6H^+

M^2 + 2H3AsO4 -------- M2( AsO4)3 +6H^+

[M= Cu, Ni, Fe, Co, Mn,  Zn, Cd, Hg, Pb]

The most common metal ions involved are:  Hg^2. Zn^2, Cu^2

[5]  Two points to note:

(a)Bulk of arsenic in the fish exists as Organic Arsenic( points-2 and 3 more so as point 2)

(b)Inorganic arsenic( point4) is much more toxic  than organic arsenic( poine2,3)

[6]References: Two references:

{A}Food Chemistry,112(2009)520-24

{B} Bio synthesis and laboratory synthesis are given in the attached File.

Plz. Ignore the  end table. I had given  it in  an other answer

Dear Prof.

Thanks for the interesting and valuable information and help. I really appreciate .

Best Wishes

Parisa Ziarati