Abstract
We tested the assumption that the nitrogen isotope ratios of fish are solely determined by their diet by exposing two species offish having contrasting nitrogen metabolic profiles to 15N ammonia. Beaugregory damselfish (Stegastes leucostictus) representing ammonotelic species and toadfish (Opsanus beta) representing ureotelic species were exposed to 15N ammonia for a period of 4 weeks, after which muscle and liver tissues were analyzed for 15N abundance and compared to their respective control group. Both species showed significant 15N enrichment when exposed to 15N ammonia, with the ammonotelic fish showing a greater enrichment compared to the ureotelic fish. We propose that the toadfish showed less enrichment in its muscle tissue because its active omithine-urea cycle (O-UC) rapidly sequesters ammonia away from the circulatory system and into liver tissue, thereby preventing any substantial exchange between ammonia and muscle tissue. We propose that no such sequestering occurs in the ammonotelic damselfish because they lack a functional O-UC. These results have important implications for studies using nitrogen isotope ratios to delineate trophic structure in aquatic ecosystems.
| Original language | English |
|---|---|
| Pages (from-to) | 61-66 |
| Number of pages | 6 |
| Journal | Journal of Experimental Marine Biology and Ecology |
| Volume | 282 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Jan 8 2003 |
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Keywords
- Ammonia
- Ammonotele
- Damselfish
- Nitrogen isotope ratios
- Toadfish
- Trophic level
- Ureotele
ASJC Scopus subject areas
- Aquatic Science
- Ecology, Evolution, Behavior and Systematics
- Ecology
Cite this
Direct effects of ambient ammonia on the nitrogen isotope ratios of fish tissues. / Moeri, Onour; Sternberg, Leonel; Rodicio, Lenore Polo; Walsh, Patrick J.
In: Journal of Experimental Marine Biology and Ecology, Vol. 282, No. 1-2, 08.01.2003, p. 61-66.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Direct effects of ambient ammonia on the nitrogen isotope ratios of fish tissues
AU - Moeri, Onour
AU - Sternberg, Leonel
AU - Rodicio, Lenore Polo
AU - Walsh, Patrick J.
PY - 2003/1/8
Y1 - 2003/1/8
N2 - We tested the assumption that the nitrogen isotope ratios of fish are solely determined by their diet by exposing two species offish having contrasting nitrogen metabolic profiles to 15N ammonia. Beaugregory damselfish (Stegastes leucostictus) representing ammonotelic species and toadfish (Opsanus beta) representing ureotelic species were exposed to 15N ammonia for a period of 4 weeks, after which muscle and liver tissues were analyzed for 15N abundance and compared to their respective control group. Both species showed significant 15N enrichment when exposed to 15N ammonia, with the ammonotelic fish showing a greater enrichment compared to the ureotelic fish. We propose that the toadfish showed less enrichment in its muscle tissue because its active omithine-urea cycle (O-UC) rapidly sequesters ammonia away from the circulatory system and into liver tissue, thereby preventing any substantial exchange between ammonia and muscle tissue. We propose that no such sequestering occurs in the ammonotelic damselfish because they lack a functional O-UC. These results have important implications for studies using nitrogen isotope ratios to delineate trophic structure in aquatic ecosystems.
AB - We tested the assumption that the nitrogen isotope ratios of fish are solely determined by their diet by exposing two species offish having contrasting nitrogen metabolic profiles to 15N ammonia. Beaugregory damselfish (Stegastes leucostictus) representing ammonotelic species and toadfish (Opsanus beta) representing ureotelic species were exposed to 15N ammonia for a period of 4 weeks, after which muscle and liver tissues were analyzed for 15N abundance and compared to their respective control group. Both species showed significant 15N enrichment when exposed to 15N ammonia, with the ammonotelic fish showing a greater enrichment compared to the ureotelic fish. We propose that the toadfish showed less enrichment in its muscle tissue because its active omithine-urea cycle (O-UC) rapidly sequesters ammonia away from the circulatory system and into liver tissue, thereby preventing any substantial exchange between ammonia and muscle tissue. We propose that no such sequestering occurs in the ammonotelic damselfish because they lack a functional O-UC. These results have important implications for studies using nitrogen isotope ratios to delineate trophic structure in aquatic ecosystems.
KW - Ammonia
KW - Ammonotele
KW - Damselfish
KW - Nitrogen isotope ratios
KW - Toadfish
KW - Trophic level
KW - Ureotele
UR - http://www.scopus.com/inward/record.url?scp=0037425618&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037425618&partnerID=8YFLogxK
U2 - 10.1016/S0022-0981(02)00446-X
DO - 10.1016/S0022-0981(02)00446-X
M3 - Article
VL - 282
SP - 61
EP - 66
JO - Journal of Experimental Marine Biology and Ecology
JF - Journal of Experimental Marine Biology and Ecology
SN - 0022-0981
IS - 1-2
ER -