Publisher Summary This chapter discusses the physiology of ascidians of Ciona intestinalis, Phallwia mammillata or Ascidia nigra . It presents a comparative study of the architecture of the ascidian test and examines its functional significance. The ascidian test is an outer protective covering which completely surrounds the individual zooid in solitary ascidians or forms a common groundwork in which the zooids are embedded in colonial species. Details of fine structure and the intervention of morula cells in the deposition of complex polysaccharide microfibrils are provided. Different groups of ascidians have tests of different organization varying from gelatinous to fibrous. The chapter elucidates the fine structure and function of the ascidian test, and the type of secretion which it produces. It describes the functional significance of differences in branchial organization and how it relates to food collection. It is suggested that different ascidians are exploiting different fractions of the food supply available in the environment. Ascidians are entirely ammonotelic in their nitrogen metabolism but store products of nucleic acid metabolism as urates or higher purines. The simplicity of life in ascidians is matched by the apparent simplicity of their nervous system. Ascidian nerves are unresponsive to normal nerve stains and they are difficult to trace. The primary role of the nervous system is in the maintenance of the water current; thatseems to be achieved through vincercll control of the branchial cilia and somatic control of siphons and mantle.

The Physiology of Ascidians

The data reported in the literature and recent analyses of the composition ofPalmaria palmata (Rhodymenia palmata) are compiled and discussed. The reported values have a relatively wide spread ranging from 73–89% moisture and, on a dry weight basis, 12–37% ash, 8–35% crude protein, 38–74% carbohydrate and 0.2–3.8% lipid. Some of the variation can be attributed to seasonal and nutritional conditions.P. palmata has potassium, chlorine and sodium as its major mineral constituents and, in comparison to terrestrial fruits and vegetables, is a good source of iron, magnesium, calcium and iodine. Vitamin A (as carotene) and, in the fresh plant, vitamin C, are present in appreciable amounts.P. palmata is potentially a high protein food source, and its protein quality rates well with vegetables of good nutritional value. The major polysaccharide is a s-(l → 3) and s-(l →4) linked xylan.P. palmata is a natural source of desmosterol.

Review of chemical constituents of the red alga Palmaria palmata (dulse)

The endocrine glands and the development of the chick. I. The effects of thyroid grafts

This article will review the methods currently available to the clinician and research worker for measuring the concentration of ionized calcium in various body fluids including whole blood, serum, plasma, urine, cerebrospinal fluid, milk, and synovial fluid. The methods to be reviewed are based on procedures involving bioluminescence, colorimetry and ion-selective electrodes. Emphasis will be given to the precision and, wherever possible, accuracy of each technique. Possible sources of error and interfering agents will be identified. Attention will be given to the recommended conditions for measuring ionized calcium in each body fluid. An assessment will be made of the theoretical and practical importance of measuring ionized calcium rather than total calcium and of its value in clinical medicine.

Ionized calcium in body fluids.

Specimens of numerous marine species of the green, red, and brown algae from the Atlantic coast of Canada have been analyzed for total ash, Na, K, Ca, and Si, and the trace elements, As, Co, Cu, F, I, Mn, Mo, Ni, Pb, and Zn. Figures for fluorine in seaweeds are recorded for the first time. Thorough washing with tap water lowered the content of the ash, Na, K, and Si, but did not affect appreciably the concentrations of other elements.Accumulation from the sea water was apparent in greatly varying degrees in the following ascending order: F, Mo, Co, Cu, As, Ni, Mn, Zn, I. The ranges in concentration observed were Na 1.6–4.7, K 2.3–7.1, Ca 0.9–2.3, Si 0.5–2.0, as percentage of dry matter; I 20–2490, Zn 35–97, Mn 20–50, Cu 6–62, As 2–75, F 2–22, Pb 0.8, Ni 0.3–2, Co 0.1–0.7, Mo 0.2–1.4 as p.p.m.No seasonal variation was detectable in the concentration of trace elements in Chondrus crispus. Differences in concentration were observed between frond and stipe in two species of Laminaria.

The occurrence of inorganic elements in marine algae of the atlantic provinces of canada

http://www.jbc.org/content/63/3/687.full.pdf

A.T. Cameron

Papers

The tetany of parathyroid deficiency and the calcium of the blood and cerebrospinal fluid

Contributions to the biochemistry of iodine: iv. the effect of thyroxin on growth in white rats and in rabbits

Contributions to the biochemistry of iodine: iii. the comparative effects of thyroid and iodide feeding on growth in white rats and in rabbits

Contributions to the biochemistry of iodine ii. the distribution of iodine in plant and animal tissues. part ii

The iodine content of the thyroid and of some branchial cleft organs