Page:Hardwicke's Science-Gossip - Volume 1.pdf/227

Barnacles and Corals.—Mr. P. H. Gosse, at page 282 of his new book, "A Year at the Shore," says that about one specimen in every six of the Cup-coral (Caryophyllua Quicthii) carries a Coral-barnacle (Pyrgoma Anglicum) affixed to it as a parasite. I, however, have not met with it so numerously, and, indeed, not one of the Caryophylleæ (35 in number) living in the Hamburg aquarium, has Pyrgoma. I have often looked for them but in vain; and yet the corals came from Torquay and from Ilfracombe. The tank, holding 30 gallons of seawater, which contains these 35 corals, also contains about an equal number, or say 40, of the other commonly met with coral—the Royal Star-coral (I do not like these English names, and I much prefer the Latin Balanophyllea regia), and the whole of them are cemented firmly by their stony bases to the rockwork, of dark colour, with which the tank is lined. Some are fixed to perpendicular or to overhanging surfaces, as found in nature, and others are fastened as they are not found in nature, with their faces looking upwards horizontally or obliquely, but, in every instance, the aspect of this coral tank, as seen through its glass front, is very charming; and towards evening, when the animals become much expanded, they form a brilliantly-coloured crowd of animals, so thickly studded as to touch each other, (like an assemblage of flowers in a garden,) where they are thickest together. They reach their greatest degree of expansion and beauty late at night, when I sometimes illuminate the tank by means of a powerful gas Argand burner and conical shade, placed over the water. They are regularly fed with oyster and mussel, given to each separately in little morsels, and on this dict they thrive wonderfully. A stream of sea water runs through the tank day and night, and the condition of the whole is so excellent, that numerous other animals are constantly making their spontaneons appearance in the same case,—such for example, as Serpulæ, Sabellæ, Ascidians, both simple and compound; sponges, and various other interesting things.—W. Alford Lloyd, Hamburg.

Effects of Lightning on Fish in an Aquarium.—On Friday, July 7th, 1865, at 3 p.m., a flash of lightning did much damage to a house in Marienstrasse, St. Pauli, in the suburbs of Hamburg. About 200 feet away from the house in question, a friend of mine, Mr. C. C. H. Muller, had in his garden, in a shady spot, and in the open air, a large fresh-water Aquarium, containing forty-three fish consisting of trench, carp, dace, reach, gold-fish, eels, loach of two species, and others, and at the moment of the flash of lightning, every one of these fish became suspended perpendicularly downwards in the water, with their tails at the surface, feebly and vainly trying to swim towards the bottom of the tank, with all their fins strangely attenuated and as transparent as fine tissue-paper, and densely covered on both sides with myriads of fine air-bubbles. Their heads and bodies were not so covered. In less than half an hour forty-one were dead, strongly curved, almost in the form of semi-circles, and already fast decomposing, but two gradually recovered by being placed in running water. It is well known that when fish become sick and die under ordinary circumstances, they turn belly upwards horizontally, instead of hanging nose downwards, as in this case. The manner in which the eels were almost jerked out of their hiding-places in the sand at the bottom of the tank, was very remarkable. None of the animals in the aquarium in the Zoological Gardens, about a mile off, were affected in any way.—W. Alford Lloyd, Hamburg.

Fresh-water Aquaria.—Having had some little experience in the management of fresh-water aquaria, I would advise "F. C." to cover the bottom of his aquaria with well-washed small stouts, which may be picked up on any gravel walk. For a long time I had nothing at the bottom of mine, but simply built up my rock-work of stones cemented together, and clinker. A layer of small stones, however, about an inch deep, greatly improves the appearance; hut I never used gravel or sand of any kind. The weeds I used to plant in small chemical crucibles, which are easily concealed in the cavities of the rock-work. I found the same difficulty as your correspondent in procuring the small red worms, so I used now and then to put in a little finely-shredded lean raw beef; but I firmly believe that it it is better not to feed the fish at all when once you have got the proper balance between the animal and vegetable inmates. In my aquarium, I kept most successfully for nearly three years, a gold-fish, roach, a tench, minnows, young dace, and newts. I ought to mention that I used to have some sprigs of Canadian water-weed floating on the top, both to keep the water cool and shady and to afford a resting. place for the newts. Never having used the powdered charcoal, I cannot form an opinion of its merits.—A. J. N. M.

Aëration of Aquaria.—I have seen several contributions lately, mentioning the difficulties which attend the production of a movement in the water in aquaria, and am surprised that no one advocates a small fountain. I have used one in my aquarium, for the past three years, with perfect success, and have never had to change the water, except when I clean it out each spring; but I do not think even that is absolutely necessary. The water always keeps clear and sparkling, and the fountain has a very pretty appearance. My jet usually passes about half a gallon to one gallon per hour, and the waste water is used again if clear.—W. E. S. Willes.