Midland Naturalist/Volume 01/Marine Zoology at Arran

by William Richard Hughes

Marine Zoology at Arran.

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By W. R. Hughes, Esq., F.L.S.

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In the early autumn of 1873 upwards of twenty members of the Birmingham Natural History and Microscopical Society ventured upon a marine excursion at Teignmouth, on the south coast of Devon. The weather in a somewhat rainy year proved very fine, consequently dredging was pursued daily on board the yacht "Ruby," hired for the purpose, and there were regular botanical and geological excursions in the neighbourhood for those who were minded to go, as well as a special excursion to Kents Cavern. Upwards of a week was thus passed pleasurably and profitably, many interesting forms of marine life being taken. On the whole the experiment gave such general satisfaction that it was determined to repeat it this year (1877) on a more extended scale, and in a locality which should, as far as possible, offer a decided contrast to that previously visited. The Island of Arran was selected, and the results were equally satisfactory. About twenty members—ladies and gentlemen—formed the party; the arrangements were left to a small Sub-Committee, and, as the number of members was sufficiently large, very favourable terms were granted by the Midland Railway Company, and the luxury of a Pullman Sleeping Car was indulged in at a moderate expense. A small sum—about a sovereign—was contributed by each member to a common fund, and thus a boat for dredging, or a carriage for land excursions, was at the service of the members daily as they felt inclined, An admirable general account of the proceedings having already been given ^[1] by one whose kindly disposition and richly- stored mind did much to add to the social gentility of the party, it is thought that a record of the Dredgings my not be uninteresting here, accompanied by some suggestions for another excursion during 1878. When we arrived at "the Island of the Many Peaks," much difficulty was experienced in obtaining a suitable boat, but eventually we made arrangements with the "Cutty Sark.” a herring smack, and the "Mona," a small yacht, both of which did the work very well. The Dredgings, which commenced at the neap tides succeeding the August full moon, were carried on for a week principally in Lamlash Bay, but we had several good hauls both in the Bays of Brodick and Drumadoon. The depths did not exceed about twenty-five or thirty fathoms, and thus it was not found necessary to take temperatures, although we had provided ourselves with one of Negretti and Zambra's "Deep Sea Thermometers," in addition to the "Miller Casella" which we used before, both of which worked well. The results were officially reported to the Society on our return by Dr. Marshall and the writer, at a General Meeting, held on the 18th September last. Mr. John Morley, the Hon. Sec., also alluded to the Botanical excursions which were made under his guidance, and that of the President, Mr. Edmund Tonks, B.C.L. On the present occasion it is not, therefore, proposed to give more than a brief account of the more interesting forms of marine life taken.

The ground which we went over has long been a favourite spot with marine naturalists. Among others of eminence who had been there, we were informed that the late Dr. Landsborough had, with Major Martin, dredged the locality for five years. Our hopes of taking any novelty were not therefore very great. Nevertheless, on referring to the lists in the chapter on Marine Zoology in Dr. Bryce's book, "Arran and other Clyde Islands." (4th edition, 1872,) a charming volume, which should be in the hands of all naturalists visiting the Island, we have reason to believe that two forms, Thyone and Elysia—to be hereafter referred to—have been added by us to the local fauna. The distribution of marine life was extremely local. Within a few yards each line of the dredge usually brought up an entirely different series of animals. Sometimes these consisted of the rosy feather star—sometimes of brittle stars-another haul would contain Pectens only—another the nest-building bivalve, Lima hians—another the common egg urchin Echinus sphæra—another yielded four beautiful specimens of Prideaux's Hermit crab, (Pagneus Prideauæii,) with its "commensal," the Cloaklet anemone (Adamsia palliata)—another would be of Malobesia calcarea, a curious coralline, largely composed of calcareous matter, prettily coloured purple or pink when living, but speedily becoming white after taken from the sea. Sometimes the dredge would contain nothing but mud or sand—to the great disappointment of the dredgers—and on one occasion a communion wine bottle came up. It was brought from about twenty five fathoms, was unbroken, full of sand and covered with specimens of Polyzoa and Hydrozoa. As at Teignmouth, in the year 1873, we were too late to observe the developmental processes in the Hydrozoa; but it was an interesting fact that, although in point of date we were synchronous with the Teignmouth excursion, when we took several stalked forms of the rosy feather star, (Antedon (Comatula) rosaceus) not a single specimen was obtained in Lamlash Bay, although every frond of Laminaria dredged was diligently searched. Numbers of the adult form were taken in many varying shades of richness of colour. On thy whole, our best prizes were In Echinodermata and Mollusca, but there were several objects of interest: in-other classes. For instance, in Porifera we took specimens of the little calcareous sponges, (Grantia compressa and G. ciliata; in Zoophyta, a fine mass of Antennularia racemosa; but with the exception of the four beautiful specimens of the Cloaklet anemone, (Adamsia palliata,) before alluded to, no other anemones of interest were dredged, nor any corals, In Echinodermata, what immediately struck us on our first hauls of the dredge in Brodick Bay, and again and again in Lamlash Bay, was the gorgeous colour displayed by the lovely star fish, Goniaster Templetoni (Templeton’s cushion star.) It was of bright scarlet above, varied with cloudy whitish markings, and of straw-colour beneath, When living there is a peculiar viscosity about the animal—the colour soon fades in confinement, But the brilliant colony of this star fish. as well as that of others of the class, served to dispel the popular notion, in those of us whose experience had been limited to a southern fauna, that as one proceeds northward colour diminishes in intensity. The fallowing is a list of the Echinoderms:—Antedon rosaceus (the rosy feather star)—Many specimens in the free or adult form, taken off Holy Island. In brittle and sand stars we took numerous specimens of Ophiocoma bellis, O. granulata, and O. rosula; also Ophiura texrturata. Uraster glacialis, (the spiny cross-fish,) and U. rubens, (the common cross-fish,) the former very fine specimens—the latter in many instances renewing lost parts. Cribella rosea, the rosy cribella,) one specimen. (two only are recorded in "Bryce;") Solaster endrea, (the purple sun star,) one specimen only, (of this beautiful star fish only one is recorded in "Bryce;") S. papposa, the common sun star, several specimens. Goniaster Templetoni (Templeton's cushion star) was taken numerously, and was most interesting, as indicating the connection—as the late Professor Ed. Forbes pointed out—between the true Asteriadeæ and the Echiinidæ, both in the general form and the shape of its spines. Asterias autantiaca (the Butthorn) was represented by one specimen. Echinus sphæra (the common Egg Urchin) was taken plentifully; and a few specimens of Echinus miliaris (the purple-tipped Sea Urchin). Echinocyamus pusillus, (the green-pea urchin,) one specimen only. Holothuriadæ were notably absent, if we except a solitary specimen of Thyone papillosa, the common Thyone. This, which is not in the local list, was most valuable, as showing the passage of the class towards the Annelida. The linear arrangement of the suckers peculiar to the class is, in this genus, replaced by a diffused series spreading over the whole extent of the body. In Annelida our principal capture was Nemertes Borlasii, so graphically described by the late Rev. Chas. Kingsley. Crustacea were represented by about twelve species, in which Stenoryuchus and Inuchus were conspicuous; all are referred to in the local list. In Polyzoa we took Salicornaria farciminoides, (alive,) but in this class the specimens were not very numerous—nor were those of the Tunicula. In the class Mollusca, many specimens were taken which space will prevent recording. The most noteworthy (taken alive) were Lima hiaus, Scaphander lignarius, Dentaliam entarlis, and Aporrhais pes-pelicani. All these greatly interested us, but especially Lima hiaus. Several "nests" of this remarkable bivalve were taken, in each case tenanted only by a single individual. The "nests" themselves consisted of comminuted shells, stones, &c., formed into a matted cluster by their byssal threads. When the animals were removed and placed in a vessel of sea water, their great beauty was apparent—some of the tentacles which had become detached remained apparently alive for some hours afterwards, twisting about like small earth worms. In the Nudibranchiata we dredged a single specimen of Elysia viridis—not recorded in "Bryce." This animal is exceedingly interesting, as belonging to the order Pellibranchiata, wherein the respiratory function is effected by the whole surface of the body, which is clothed with vibratile cilia. In the class Pisces, which terminates the collection. Our most interesting finds were a few specimens of both the pretty little sucking fishes, Lepidogaster bimaculatus and L. Cornubiensis. They were very small, and the colours were not very well marked. I expect they were immature specimens. One, which was unfortunately lost, exhibited markings of a beautiful pale green colour, and differed in same other minor respects from the normal conditions of the species.

In the evenings after our day's work was done, the examination and comparison of our captures afforded great interest to the members; and Mr. Marshall, Professor Keeping, and Mr. Chas. Pumphrey were indefatigable with their microscopes, and exhibited and explained peculiarities of structure and potted out analogies and affinities.

Such of the specimens as were not required were returned to the sea, and the remainder were put up in spirits and preserved, as a nucleus for our museum.

If, as seems probable, another excursion is organised during this year, it would be desirable, for those interested, to give in their names soon to Mr. John Morley, the Hon. Sec. of the Society, Sherborne Road, Birmingham, so that a meeting may be held in the early spring, and plans determined accordingly. If it is possible to arrange for a week in the month of June, or not later than the first week in July, opportunities would be afforded for the examination of many most interesting forms of marine life in the larval condition, not to he found in the autumn, it is suggested, that if a small steam launch could be chartered for a week, much time would be saved. and dredging might be attempted in deeper water than hitherto. In fact, more work could be done, and it would be done in a better manner. A trawl similar to that which Sir Wyville Thomson states proved so serviceable in the Challenger Expedition might be used as well as the dredge and the towing net. Some shore collecting might also he undertaken with advantage.

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1. Birmingham Natural History Society. "Excursion to Arran."—Birmingham Daily Post, Monday, Sept. 10th, 1977.