You Are What You Eat: Stable Isotopic Evidence Indicates That the Naticid Gastropod Neverita duplicata Is an Omnivore

摘要: Species belonging to the family Naticidae (commonly called moon snails) are important infaunal gastropod predators found in soft-bottom marine communities worldwide that traditionally have been thought prey on other mollusks, giving them expected trophic position of a predator (trophic = 3). Realized estimates naticid Neverita duplicata from Long Island Sound, however, range between 2.3 and 2.5, indicating omnivory or an anomalously low nitrogen (N) fractionation factor. To evaluate likelihood omnivory, this study presents whole body stable isotopic analysis carbon soft tissues laboratory-reared field-collected N. duplicata. Experimental organisms were maintained diet bivalve Mercenaria mercenaria for one year. The median N factor derived experimental snails was 3.58 ‰ thus precluding presence atypical (substantially lower than 3.4 ‰). Numerous molluscan taxa collected Sound order ecology context natural food web. Evidence (C) signatures indicate reliance littoral sources is inconsistent with filter-feeding M. mercenaria, even when calculated using species-specific C laboratory experiments. Field-collected also show considerable overlap (N C) grazing Littorina littorea. For these reasons, we hypothesize feeds some combination benthic primary producers (most likely macroalgae and/or epiphytic diatoms), carrion, bivalve/gastropod tissue discuss ecological implications potential omnivory.