. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 292 LIBBIE H. HYMAN A number of Aequorea containing an ingested prey, chiefly Nereis, were captured and the gastric fluid removed by a fine pipette. Such fluid was in all cases but one more acid than the sea water, which has in Puget Sound a pH of Of 12 individuals, the gastric juice was in 1 case, — in 9 cases. in 2 cases, and in the twelfth specimen. A piece of Mytihis placed in the combined juice from four animals, with a pH of , was much dissolved in three hours, while a control piece in
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 292 LIBBIE H. HYMAN A number of Aequorea containing an ingested prey, chiefly Nereis, were captured and the gastric fluid removed by a fine pipette. Such fluid was in all cases but one more acid than the sea water, which has in Puget Sound a pH of Of 12 individuals, the gastric juice was in 1 case, — in 9 cases. in 2 cases, and in the twelfth specimen. A piece of Mytihis placed in the combined juice from four animals, with a pH of , was much dissolved in three hours, while a control piece in sea water was unaffected. The possibility, of course, remains that the acidity of the gastric juice might have come from the disintegrating FIG. 8. Halidystus, pendent from a seaweed, seen from the aboral surface, showing anchors and arms with tentacle clusters. 1, tentacle cluster, 2, anchor, 3, gonads. BEHAVIOR OF HALICLYSTUS The stalked scyphozoan, Halidystus sanjuanensis, one of the Stauro- medusae, is common on seaweeds in a shallow bay of San Juan Island. During exceptionally low tides one can wade out and observe this in- teresting form in its natural surroundings. Halidystus (Fig. 8) has a trumpet-shaped body with the flaring oral end scalloped into eight arms, each terminating in a ball of small capitate tentacles. In the bottom of each scallop is an oval body, called the anchor, which, according to Schlater (1891), is provided with sen- sory cells and mucous glands. Seen in their natural habitat, the animals are fastened by the pedal disk to seaweeds and hang in a pendent atti- tude with the anchors erected. The medusa is relatively inactive. The chief activities seen in nature were: swinging on the stalk, flicking of the tentacles, sudden bending of an arm to the manubrium, or the folding. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrati
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
