Inter-Research > MEPS > v358 > p173-179  
Marine Ecology Progress Series

via Mailchimp

MEPS 358:173-179 (2008)  -  DOI:

Diet–tissue isotopic fractionation of the Pacific oyster Crassostrea gigas

H. Yokoyama*, Y. Ishihi, S. Yamamoto

National Research Institute of Aquaculture, Fisheries Research Agency, Minami-Ise, Mie 516-0193, Japan

ABSTRACT: Juveniles of the Pacific oyster Crassostrea gigas were reared on a monospecific microalgal diet in order to quantify their 13C and 15N diet–tissue fractionations. The weights of these juveniles increased by up to 18-fold within 33 d. The juveniles reached isotopic equilibria with the diet, enabling calculations of fractionation values. The 13C fractionation for tissues containing lipids ranked as 0.6‰ (gill lamella) >0.3‰ (adductor muscle) >–0.2‰ (mantle lobe) >–0.9‰ (whole soft body) >–2.2‰ (midgut gland), while the 15N fractionation ranked as 8.7‰ (adductor muscle) >6.5‰ (mantle lobe) >5.4‰ (whole soft body) >5.2‰ (gill lamella) >2.3‰ (midgut gland). Removal of lipids shifted the diet-equilibrated δ13C and δ15N values in all tissues except the adductor muscle, with resultant increases in the 13C and 15N fractionation values. The expected annual mean δ13C value for the diet of the oyster in the field is –17.0‰, which is an intermediate value among the δ13C of coastal phytoplankton (–20.2‰), epilithon (–20.0‰), epipelon (–14.8‰), and seaweeds (–14.9‰), suggesting that the oyster feeds on a mixture of these micro- and macroalgae. The expected δ15N diet value is 3.1‰, which is more depleted than values for micro- and macroalgae, suggesting that the 15N fractionation in the field is smaller than that obtained from the feeding experiment.

KEY WORDS: Stable isotopes · Trophic enrichment · Bivalve · Feeding experiment · Chaetoceros · Crassostrea gigas

Full text in pdf format
Cite this article as: Yokoyama H, Ishihi Y, Yamamoto S (2008) Diet–tissue isotopic fractionation of the Pacific oyster Crassostrea gigas. Mar Ecol Prog Ser 358:173-179.

Export citation
Share:    Facebook - - linkedIn

 Previous article Next article