Nitrogen stable isotopes reveal age-dependent dietary shift in the Japanese scallop Mizuhopecten yessoensis

Abstract

Ontogenetic niche shifts in diet are a consequence of changes in body size or resource partitioning between age classes. To better resolve the feeding patterns of the Japanese scallop Mizuhopecten yessoensis, we examined the relative importance of age and size in the diet of this species using stable isotope ratios of carbon (δC) and nitrogen (δN) from 2006 to 2009. Contribution of food sources was quantified using an isotope mixing model by comparing the muscle tissue isotope ratios to those of suspended particulate organic matter (SPOM) and their zooplankton prey (e.g. micro- and meso-zooplankton). Unlike the δC values, which remained constant with age and size, muscle δN values were more positively correlated with age accounting for 69 % of variations than size with only 46 %. Increasing N values with age suggested that shifts in diet from SPOM to micro- and meso-zooplankton occurred during ontogeny in M. yessoensis. Results of the isotope mixing model indicated that SPOM contribution to scallop's diet decreased from 68 to 8 % while those of zooplankton increased from 15 to 50 % with increasing age. This study concludes that age-related dietary shift explains the enrichment ofN, as a result of predation on zooplankton by M. yessoensis.

Trophic interactions and metal transfer in marine ecosystems driven by the Peruvian scallop Argopecten purpuratus aquaculture

“…The a posteriori analysis of metal trophic magnification will disentangle the position and relevance of each prey and/or consumer from these Peruvian marine food webs. In general, the Peruvian marine species δ 15 N and δ 13 C found in the present study are in accordance with previous studies from the region (i.e., Latin America) and other locations (Aya & Kudo, 2017; Bisi et al, 2012; Catenazzi & Donnelly, 2007; Chouvelon et al, 2018; Docmac, Araya, Hinojosa, Dorador, & Harrod, 2017; Espinoza et al, 2017; Kehrig et al, 2013; Nerot et al, 2012; Zhao, Yang, & Yan, 2013) (Table 1). The latitude, as well as the intensity of the NHCS upwelling of Peru and Chile marine domains, is again the most common factor explaining the δ 15 N and δ 13 C differences among species (Figure S1; supplementary material).…”

New insights into the seasonal feeding ecology of Pecten maximus using pigments, fatty acids and sterols analyses

“…The availability of food depends on the strong seasonality of these hydrological and biochemical conditions; therefore, suspension-feeding bivalves must have evolved to develop a plastic trophic niche (Rossi et al 2004, Nérot et al 2012. Scallops may thus feed on pelagic and benthic microalgae, protozoans, microzooplankton, dissolved organic carbon and detrital organic matter (Shumway et al 1987, Lorrain et al 2002, Mac Donald et al 2006, Lavaud et al 2014, Aya & Kudo 2017. A recent study has confirmed this diversified diet (Nérot et al 2012), yet only qualitatively.…”

Guests or pests? Eirenid hydroids living on the soft tissue of bivalves

“…It is possible that the infestation rate changed in relation to the size classes and the feeding behaviour: for example, eirenids can infest juveniles of Mizuhopecten yessoensis (Jay, 1857), but not larger adults feeding on zooplankton 10 . It is possible that the adults can prevent an infestation by ingesting the hydroid planulae 69 …”

“…10 It is possible that the adults can prevent an infestation by ingesting the hydroid planulae. 69 Co-occurrence of other parasites may have detrimental effects on the molluscs inhabited by eirenids, 68 even if this was not always reported. 14 The severity of lesions may depend on the combination of these parasites; for example, the Condition Index of M. galloprovincialis was lower when Eug.…”