Food sources of the oyster (Crassostrea gigas) and the clam (Ruditapes philippinarum) in the Akkeshi-ko estuary

Abstract

Abstract:The gut content was analyzed in order to clarify the potential food sources of the oyster (Crassostrea gigas) and the clam (Ruditapes philippinarum) in the Akkeshi-ko estuary. Benthic diatoms in the diets of oysters were most abundant and accounted for 70% in 2003 and 67% in 2004, followed by pelagic diatoms and dinoflagellates. In gut of clams, benthic diatoms represented 78% in 2003 and 87% in 2004, also followed by pelagic diatoms and dinoflagellates. There are no differences in dietary preference between oyster and clam. There are no significant correlations between phytoplankton compositions in gut of oyster/clam and water column. The Index of electivity was high particularly in dinoflagellates and several species of benthic diatoms such as Amphora sp., Cocconeis scutellum, Nitzschia sp., Paralia sulcata, Rhoicophenia curvata and Thallasiosira sp., Gramatophora marina, and so on.

Oyster aquaculture impacts Zostera marina epibiont community composition in Akkeshi-ko estuary, Japan

“…In two studies on the gut contents of cultured oysters in Akkeshi-ko estuary, Kasim & Mukai [ 52 , 53 ] found that benthic diatoms (including those found on eelgrass blades) made up nearly 70% of oyster diets. These researchers also found that the composition of diatoms in the water column did not match the composition in gut contents, showing that oysters are capable of preferentially feeding on certain species of diatoms, even when they are relatively rare.…”

Key Selections for Microalgae, the Indispensable Live Feed in Bivalve Hatchery: A Brief Review

“…Despite the enormous microalgae diversity (Parvin et al, 2007) and substantial reviews on bivalve feeding mechanisms (Gosling, 2003;Arapov et al, 2010), the knowledge on its feeding preference remains obscure (Kasim and Mukai, 2009). Yet, its microalgae selection as live feed in the hatchery, conventionally, is derived from the combination that is routinely used, regardless of bivalve species (Robert et al, 1994).…”

Prevalence of Perkinsus sp. (Apicomplexa) in the callista clam Megapitaria squalida from the central coast of Sinaloa, Mexico

“…Por otra parte, los especímenes revisados por los autores fueron extraidos en la zona rocosa de una isla, a 10 m de profundidad; por lo que la composición específica fue típica de ambientes oceánicos. Por su parte, la composición de la taxocenosis de diatomeas del contenido intestinal de M. gigas estuvo constituida por especies de Achnanthes, Cocconeis, Grammatophora, Melosira, Navicula, Nitzschia y Paralia (Kasim & Mukai, 2009); dicha composición es de formas típicamente epifitas; en particular es similar a la taxocenosis de diatomeas epifitas observadas sobre el pasto marino Zostera marina (Linnaeus, 1753) por Siqueiros-Beltrones et al (1987), Kasim & Mukai (2006) y Chung & Lee (2008.…”

“…64, 65 Las diatomeas ingeridas por C. corteziensis fueron mayormente de origen bentónico (72.6%), lo cual coincide con lo observado en otras especies de bivalvos filtradores como Chione gnidia Broderip & Somwerby, 1829, C. undatella G. B. Sowerby I, 1835, C. californiensis Broderip, 1835(García-Domínguez et al, 1994, Corbicula fluminea O.F. Müller, 1774 (Boltovskoy et al, 1995), Anadara tuberculosa Broderip, 1833(Muñetón-Gómez et al, 2010, R. philippinarum y M. gigas (Kasim & Mukai, 2009). Tabla 2.…”

“…En estudios de laboratorio se ha observado que Magallana gigas Thunberg, 1793 ingiere preferentemente diatomeas bentónicas de los géneros Navicula y Nitzschia (Cognie et al, 2001); asimismo, se ha observado que discrimina por tamaño las diatomeas que ingiere y entre aquellas vivas y muertas (Beninger et al, 2008). Los estudios de alimentación in situ son todavía más escasos, no obstante, son informativos; por ejemplo, Kasim & Mukai (2009) examinaron los contenidos del tracto digestivo de ostiones M. gigas y de almejas Ruditapes philippinarum Adams & Reeve, 1850, registrando que no había diferencias significativas entre lo consumido por ambas especies. Aunado a esto, observaron que las diatomeas bentónicas representaron entre el 70% y 87% del alimento ingerido, además de diatomeas planctónicas y dinoflagelados.…”