The biology of Asterias rubens L.V. A Porphyrin pigment in the integument

Abstract

A porphyrin was extracted by MacMunn (1886), working at Plymouth, from the integument of Asterias rubens then known as Uraster rubens. He extracted whole starfishes with ethanol and ammonia and also with ethanol and sulphuric acid. After diluting his acid-ethanol solution with water he shook the extract with chloroform; the chloroform solution showed two absorption bands, at 607-593 and 566-548 mfl-. On evaporation this extract yielded a brown amorphous residue which he found to be soluble in absolute ethanol giving a red solution with the same absorption spectrum. On adding ammonia four absorption bands appeared, at 632-622, 586-566, 548-529 and 516-490 mfl-. He considered that this and similar pigments from the slug Arion empiricorum, and the coelenterates Flabellum variabile and Fungia symmetrica were identical with the haematoporphyrin of Hoppe-Seyler (1871) which was then the only porphyrin known. Experimental work has now shown that in other animals examined and found to contain porphyrin this pigment is never present in the form of haematoporphyrin. A reinvestigation has therefore been made of the occurrence of porphyrin in the starfish, Asterias rubens.Certain details of the distribution in #le Plymouth area of different colour .forms of A. rubens have already been recorded (Vevers, 1949). In general, starfishes on the Rame-Eddystone grounds are dark brown or red-brown, but specimens coloured violet, violet-brown, red or even pale pink are not uncommon. In Plymouth Sound, on the other hand, 'a pure population of bright red starfishes was found in 1948; this population has now been greatly reduced in number but specimens can still be obtained.In the present work four different colour types were used. The choice of these types was arbitrary, but they were nearly all colours which could be easily recognized in a sample of this species. The colour types used were dark brown, violet-brown and pale, all from the Rame-Eddystone grounds, and red (bright red) from the Plymouth Sound population. The violet-brown specimens were very close to the val'. violacea of earlier writers.

The Function of the Heart-Body in Polychaetes

“…Sciurus niger has black hair, so that in these two widely differing animals an additional pigment is present, namely melanin, which protects these animals from the photosensitizing effects of the porphyrin. Aplysia and Akera which are more darkly co10ured, have more uroporphyrin I than Duvaucelia which has a bright orange pigment; there was a much greater concentration of coproporphyrin III in the body wall of the dark co10ured Arenicola and Amphitrite than in the lighter, pink specimens: the more darkly pigmented Asterias contained more protoporphyrin IX than the paler animals (Kennedy & Vevers, 1953) although protoporphyrin is not noteworthy for its photosensitizing action. Fischer & Zerweck (1924) have shown in mammals that photosensitivity to u.v.…”

“…Kench, Langley & Wilkinson (1953) found that extracts of stools of a porphyria patient, when chromatographed on paper, gave the whole gamut of porphyrins from 8-carboxyl down to 2-carboxyl. In molluscs, if free porphyrin is present it is uroporphyrin I which occurs (Kennedy & Vevers, 1954;Kennedy, 1958). In molluscs which have a shell the porphyrin is laid down in the shell, very often in a definite pattern, and in those molluscs which are without shells or have very reduced shells, such as the tectibranchs and land slugs, if uroporphyrin I is present it occurs in the integument.…”

“…It is most likely that the haematin came from the bodywall tissue. Coproporphyrin III has been found previously in the gut (Kennedy & Vevers, 1954), and chlorohaematin can be prepared from the blood (Kennedy, 19536). Ashworth (1904) reports intravasal tissue increasing with age within the hearts of Arenicola.…”

“…The tissues from the animals examined were extracted by the methods described by Kennedy & Vevers (1953, 1954. Whenever possible, the pigments detected were isolated, melting points determined, and some Amphitrite johnstoni characteristic derivatives prepared.…”

Carotenoid pigments in the optic cushion of Marthasterias glacialis (L.)

“…Fox, 1953;Vevers, 1952). In M. glacialis previous work has suggested the presence of carotenes and xanthophylls (Lonnberg, 1933;Lonnberg & Hellstrom, 1931) and whole extracts of the integument have yielded no evidence of porphyrins, despite the occurrence of protoporphyrin in the integument of the related Asterias rubens (Kennedy & Vevers, 1953).…”