. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 6 F. R. BERNARD Both bacteria were retained and ingested when presented as pure cultures. If the total load (wet weight) exceeded 200 mg/liter, rejection occurred with pro- duction of bright purple pseudofaeces. With lighter loads no rejection was evident and ingestion occurred. If the Chromatium was not centrifuged out of the growing medium and washed, substantial to total rejection occurred, probably the'result of irritation to the ctenidium by traces of hydrogen sulphide. When mixed with Tetraselma ingestion followed, but
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 6 F. R. BERNARD Both bacteria were retained and ingested when presented as pure cultures. If the total load (wet weight) exceeded 200 mg/liter, rejection occurred with pro- duction of bright purple pseudofaeces. With lighter loads no rejection was evident and ingestion occurred. If the Chromatium was not centrifuged out of the growing medium and washed, substantial to total rejection occurred, probably the'result of irritation to the ctenidium by traces of hydrogen sulphide. When mixed with Tetraselma ingestion followed, but the bacteria speedily lysolized in the stomach, so that a predominance of algal cells remained. This was more evident with Clilorclla than Tctrosclina, the former passing almost undigested through the gut and producing bright green faeces. This clearly demonstrates that the Pacific oyster readily takes up and digests purple sulphur bacteria and only rejects them when their total load exceeds 200 mg/liter. While ctenidial sorting activities are figured in functional interpretations, the implicated organs have chiefly been the labial palpi. As early as 1851 Alder and EXHALANT STREAM FAECES MANTLE INHALANT STREAM LOAD. MOUTH > fe\ 77 ^-it«n^*i«iw!«w«w«'Wfss*ys*W! ^FT -tirfr—.—^ &* ABIAL *A> s A . i |];iiliL«) *A ^iLL^ste^T -O % S V: ,? \ / I PALPS /;v #•' / ! L*f;y PSEUDOFAECAL REJECTION FIGURE 3. Schematic representation of paths and fate of particulate material drawn into the inhalant pallial cavity; (1.) sedimentation of particles of high specific gravity; (2.) passage through the ostium; (3.) impingement upon ctenidium and transportation on frontal mucus bands to food grooves ; (4.) rejection of large mucus masses. Hancock suggested that the palpi of Pkolas and Mya are responsible for active particle sorting. The theory of palp ciliary sorting was much furthered by Kellogg (1915). These studies were made by the observation of the ridged surface an
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
