. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ELECTRICAL ACTIVITIES OF SPIROCODON -ExuEp SubuEL- Subu M SphM 377. FIGURE 1. The subtentacular region. Four and a half radial streaks are shown. Ect, ectoderm; End, endoderm; Exu EP, exumbrellar epithelium; IXR, inner nerve ring; TM, transparent mesogloea ; Oc, ocellus; ONR, outer nerve-ring; Rd S, radial streak; Rn C, ring canal; Sph M, marginal sphincter muscle ; Subt. R, subtentacular region ; Subu EL, subumbrellar endodermal lamella; Subu M, subumbrellar muscle sheet; Te, tentacle; Te C, tentacular canal; OM, opaque mes
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ELECTRICAL ACTIVITIES OF SPIROCODON -ExuEp SubuEL- Subu M SphM 377. FIGURE 1. The subtentacular region. Four and a half radial streaks are shown. Ect, ectoderm; End, endoderm; Exu EP, exumbrellar epithelium; IXR, inner nerve ring; TM, transparent mesogloea ; Oc, ocellus; ONR, outer nerve-ring; Rd S, radial streak; Rn C, ring canal; Sph M, marginal sphincter muscle ; Subt. R, subtentacular region ; Subu EL, subumbrellar endodermal lamella; Subu M, subumbrellar muscle sheet; Te, tentacle; Te C, tentacular canal; OM, opaque mesogloea; Ve, velum. For explanation, see text. MATERIALS AND METHODS Specimens of Spirocodon were collected from the Seto Inland Sea, Japan, and kept in running sea water. Half of the subtentacular region, with a small fraction of mesogloea lying under it, was dissected from the margin of the umbrella and used for histological observations and electrical recordings. For electron- and light-microscopical observations, the ocelli and radial streaks were dissected from the subtentacular region. They were fixed in chilled 2% glutaraldehyde for 2 hr and post-fixed in 2% osmium tetroxide for hr. To regulate osmolarity, M sucrose or sea water was used. In some cases, fixation was done at 15°C for the first hour to retain microtuble structure. Fixatives were buffered with M Na-cacodylate, pH Post-fixation was omitted in the dye-marking experiment described later. The specimens were dehydrated through an ethanol series and embedded in TAAB embedding resin (TAAB Laboratories). Sections were cut with a Porter-Blum MT-2B ultramicrotome. Silver to gray sections were stained with uranyl acetate and then lead citrate and observed with a Hitachi electron microscope (HS-8). Thicker sections of 1-2 ^m were stained with methylene blue for light microscopy. Experiments were performed at room temperature (18-21 °C). The arrange- ment of the recording chamber was simila
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
