THE CARE OF HOME AQUARIA OSBURN i H Q B 5i ;?: I— i p:; o THE CARE OF HOME AQUARIA 33 COMMON SALT-WATER SHRIMP. Tlie\' live well in the small aquarium, but not in such great numbers. and climb with ease among the vegetation. The eggs of the newt are laid singly among water plants. Young turtles are interesting, but the most of them are better adapted to moist terraria than to the ordinary aquarium as they need to have some way of climbing out of the water. The soft-shelled or fresh-water leather turtle is more aquatic than other species and does not climb out often, but must have loose sand in which it occasionally buries itself. Young alligators are frequently brought from Florida, but it should be made a punishable offense to do so, for sooner or later they die unless special care is taken to provide them with heat and sunlight. The New York Aquarium is the recipient annually of many of these little fellows, usually in an emaciated condition because they have not fed well, and many of them do not recover, even under the care of an expert aquarist. They 34 NEW YORK AQUARIUM NATURE SERIES should be considered strictly hothouse pets and handled accord- ingly. The temperature of the ordinary living room in winter is too low for young alligations, as they require 80 to 85 degrees for their best development and should not be allowed to drop below 75 degrees. Below this temperature they become sluggish and cliilled and refuse to eat. The pond and river species of crayfishes are well suited to the small aquarium. Those from the mountain streams and cold springs are harder to keep on account of the difficulty of main- taining a sufficiently low temperature during the warm months. They should not be kept with fish smaller than themselves, for they sometimes make too good use of their large pincers. They should be provided with some sort of a retreat in the form of rockwork or stones under which they can hide part of the time on bright days, as they are more or less nocturnal in habit. Some species wijl climb readily among the water weeds. There are numerous aquatic insects which can be kept read- ily and which offer a very attractive field for study. Of those available in the adult stage may be mentioned the hard-shelled water-beetles {Dytiscus, Hydrophilns) and the whirligig beetle. The water-bugs, such as the oarsman and the electric-light bug {Belostoma) are among the commoner and larger of the true bugs. The larvae of the dragon-flies, caddis-flies and the dobson or helgramite are even more interesting and may be kept until they emerge in the adult winged condition. These forms are chiefly carnivorous and if kept together the smaller may disap- pear into the rapacious stomachs of the larger. The dragon-fly larvae are even cannibalistic and unless provided with enough food the larger may devour the smaller, even of the same species. Any of the above forms may be readily collected with the aid of a small dip-net. While their study has been chiefly con- fined to the entomologist, they will amply repay the labors of the aquarist. The following list of fishes includes some of the exotic spe- cies commonly kept by fanciers. Many of them have no common names. The goldfishes, carps, tenches, ides and orfs are also exotic in origin, but have become domesticated in many places. Labyrinthine Fishes from India: Macropodus viridi-aur' cfus (Paradise fish) ; Betta rubra (Red Fighting-fish) ; Betta tnfasciata (Common Fighting-fish) ; Trichogaster lalius (Drawf Gourami) ; T. fasciatus (Striped Gourami), Osphromemis tri- THE CARE OF HOME AQUARIA 35 THE SIREX. This salamander has the legs reduced to mere vestiges. Ycung speci- mens are well suited for life in the small aquarium. diopter US (Spotted Gourami) ; Ctenops vittatus (Purring Gour- ami) ; Anabas scandens (Climbing perch). Viviparous Killi-fishes, Mexico to South America: Gam- busia holbrooki, G. affifiis, Girardinus giippiji, Mollienesia spe- cies, Poecilia species, Platypoecilia species, Xiphophorus helleri. Oviparous Killi-fishes from Central and South America: Haplochilus species, Rivulus species, Fundidus species. Barbels from India: Barbus species, Danio rerio (Zebra fish). Chanchitos from South America: Heros fasciatiis, Geo- phagiis gymnogensis, Hemichromis bimacidatus. Characin- fishes from South America: Tetragonopterus species. Loaches from Europe : Cobitis species. ANIMALS THAT WILL LIVE WELL TOGETHER. In general it may be said that all herbivorous fishes can be kept together safely and carnivorous species should be about the same size when kept in the same tank, though even then it may become necessary to separate some of the more pugnacious specimens which are inclined to ''bully" the others. 36 NEW YORK AQUARIUM NATURE SERIES ^M SOFT-SHELLED TURTLIO. Small specimens are well adapted to the aquarium. Goldfishes, carps, roach, golden ide and suckers live amic- ably together, and tadpoles and snails may be kept safely with them. The fresh-water minnows, such as chubs, shiners, dace, etc., catfishes, killiefishes, the various sunfishes and snails and large tadpoles will live together, though the fishes should be nearly the s^ime size. Sticklebacks, paradise-fish and chanchitos are better kept bj themselves, and the black basses and pickerels, unless smaller than the other forms, should also be kept separate. With these fishes it is better to keep only snails, as even large tadpoles may lose their tails by the attacks of the fishes. The three species of local salt-water killiefishes live well together and tautog, scup, cunner, toadfish, sculpin, etc., if about the same size can be placed in the same tank. Sea anemones, crabs and molluscs too large to be swallowed may be kept with them. FEEDING. It is a common but very mistaken notion that an animal should have food at hand at all times to keep it in good condition. THE CARE OF HOME AQUARIA 37 SOFT-SHELLED TURTLE. Upper side. It is well known that various forms of domestic animals, as well as the wild species confined in zoological gardens, make the best growth and keep in the most satisfactory condition when sup- plied only with what food they will clean up at one feeding. This applies with equal force to the inhabitants of the aquarium, but besides the7-e is a real and grave clanger of coiitanfiinating the ivater hij supplying more food thayi ivill be readily consumed. It is a well known fact that some aquarium animals will live for a long time without feeding, especially when kept at lower temperatures, but to maintain them in this condition results eventually in death by starvation and is the worst form of cruelty to which they can be subjected. The effects of starvation may be readily observed on such an animal as the sea-anemone, v/hich, if kept without food, may live for months, but will gradu- ally shrink in size until only a small fraction of its original bulk remains. Higher animals, such as salamanders and fishes, if kept at a low temperature require but little or no food, since many cold-blooded animals naturally spend the colder portion of the year in hibernation, but at the temperature of the living 38 NEW YORK AQUARIUM NATURE SERIES room all such forms require food more or less regularly since they remain active and so must keep up the necessary supply of energy. If they are deprived of food they become weak and emaciated, lose their vitality and become a ready prey to disease. On the other hand, it may not hurt them or cause any serious discomfort to go without food for a few days occasionally. It is certain, also, that much of the trouble the tyro finds in balancing the aquarium is due to overfeeding, especially w^hen unconsumed food is allowed to remain and pollute the water by decaying. The amount of food a fish requires depends on the tempera- ture. When this is above 60 degrees they may be fed once a day, but if the temperature is lower than 60 degrees, once in two or three days is sufficient. Ayiy food not consumed within a feiv minutes should be removed at once. In the selection of food one must naturally be governed by the needs of his animals — some species are partly or entirely herbivorous while others are carnivorous. Practically all of our native fishes are carnivorous and thrive best upon a meat diet of some sort, while the goldfishes and carp are largely vegetarian. Prepared fish foods of varying composition may be obtained from the dealer in aquarium supplies, and he may be consulted as to that best adapted to a particular species of fish. The granular foods are in general better than the ordinary wafers which tend to go to pieces too readily and cloud and contaminate the water. In the case of carnivorous fishes, the prepared dry food may be supplemented occasionally by the addition of meal- worms, earthworms or fresh beef cut into small pieces according to the size of the fish. Special care should be taken, however, that such animal food is removed if not eaten, as it decays much more readily than vegetable matter and causes greater danger of pollution. To prevent the dry prepared food from becoming scattered over the surface of the aquarium it is advisable to make use of a floating glass ring which can be secured from a dealer. This not only gives the surface of the aquarium a neater appearance after feeding, but prevents the escape of smaller particles to contami- nate the water. Care in the matter of feeding is of the utmost importance in preserving the balance of the aquarium and keep- ing the animals in good condition. It must be remembered that the usual fault is that of overfeeding and the conditions should be studied carefully. THE CARE OF HOME AQUARIA 39 ^ YOUNG GEOGRAPHIC TURTLES. Young- turtles are very attractive aquarium pets, but sliould be provided witli a float so that they may climb out of the water. Some turtles will take food only under water, so it is neces- sary to provide them with a sufficient depth of water to cover them at least during feeding time. This of course does not apply to the tortoise or land turtle. The majority of the water turtles are carnivorous and will take a variety of animal foods, fish, crayfish, frogs and earthworms, living or dead, and fresh beef or hard-boiled eggs. As the diflferent species vary somewhat in their diet this should be studied. Unless they are kept warm they will take no food. Young alligators usually take readily to almost any sort of meat diet, living or dead, and may be given the same foods as the carnivorous turtles. They will not take food unless kept very warm. Tadpoles will usually find sufficient food in the debris left after the fishes have taken what they wish, and in the minute plant life of the aquarium, which they assist in keeping under control. Sometimes, however, more tadpoles are introduced into the aquarium than can obtain food in this manner, especially if the aquarium is not sufficiently lighted to encourage the growth of the minute plants, and the tadpoles grow thin from lack of food. There are several ways of meeting this problem: (1) the tank may be placed in better light to encourage plant growth ; (2) a larger supply of vegetable food may be introduced so that c % ^ 'J }< THE CARE OF HOME AQUARIA 41 the tadpoles may have sufficient after the more active fishes have taken their share. In this case any surplus not consumed should be removed with the pipette after a few hours; (3) the tadpoles may be removed to another receptacle occasionally and fed sep- arately. However, a careful study of the conditions of the aqua- rium should make this latter method unnecessary. Although tadpoles are vegetarian in their diet, the young frogs and toads after their metamorphosis are strictly carnivor- ous and are adapted to a flesh diet only. They may be fed on insects, earthworms, mealworms, grubs, or pieces of fresh meat cut to a suitable size. Just at the time of change when the horny ^aws of the tadpoles are being shed to allow the development of the teeth, they will take no food. This period of change extends from a few days to several weeks, according to the species and the temperature of the water. These remarks apply equally well to newts and salamanders. For smaller animals, and especially for attached forms such as the sea-anemone and coral, the use of the feeding-stick is advisable. This is simply a sharp-pointed stick of sufficient length to reach the bottom of the aquarium. The point of the stick is dipped in ground meat or finely minced clam made into a thick paste and carefully introduced into the water until the animal to be fed is reached. With a little care this can be done so as to avoid the loss of much food. Crayfishes and crabs are naturally scavengers and will eat almost anything. They prefer a meat diet, however, and if deprived of this they are very likely to turn cannibal and eat each other. CLEANING THE AQUARIUM. It must be clearly borne in mind that cleanliness is abso- lutely necessary to the welfare of the inhabitants of the aquari- um. In an aquarium which is properly set up contamination can arise only by bacterial decay of organic substances allowed to remain in the water. There are three general sources of such organic matter ; first, fecal matter from the animals, relatively unimportant because the deposits are small in amount and regu- lar in occurrence ; second, decaying vegetable matter from dead portions of the plants, also relatively unimportant since in the well balanced aquarium there is little tendency for the death of the plant tissues, and third, decay of excess food matter, the usual source of pollution. 42 NEW YORK AQUARIUM NATURE SERIES iW L^ I 1 ® @ IMPLEMENTS OF USE TO THE AQUARIST. 1. Dipnet. 2. Wooden forceps. 3. Feeding- stick. 4. Cleaning swab. fi. Glass tube for removing: refuse. The first indication of serious contamination is a slight clouding of the water caused by the presence of countless mil- lions of bacteria. This may go on until the water is of a milky color and the balance of the aquarium is completely upset by the accumulation of sulphur and ammonia compounds set free in the THE CARE OF HOME AQUARIA 43 water by bacterial decomposition. The question, how can the accumulation of dead matter be prevented, is therefore one of the utmost importance. The usual means is to introduce some animal that will act as a scavenger to clean up refuse matter. The forms generally made use of are tadpoles and fresh-water snails. A convenient rule is to supply one snail or large tadpole such as the dealers ordinarily handle, to every two gallons of water, that is to say three snails or tadpoles are sufficient for a six-gallon aquarium. Either of these, under ordinary circum- stances, will clean up waste particles of food and decayed vege- tation and work over the fecal matter of the fishes, and will also tend to prevent an excessive development of the microscopic plants which form a green scum on the glass. The eggs of the freshwater snails are eaten greedily by fishes and thus serve to add to the natural food supply of the aquarium. If larger portions of plants begin to deteriorate, it will be found best to cut them off and remove them, since if they are not in good condition they will not serve for aeration, and will be- come a source of danger. If care is taken in feeding — and a little study and experi- ence in this matter is the only safe guide — no appreciable amount of food need be left to decay. If, for any reason, the food is not all consumed, or if there is any accumulation of fecal or other matter, it may be readily removed by means of a long pipette, or a rubber tube used as a siphon. For the small aquari- um a pipette with an inside diameter of one-quarter to three- eighths of an inch, and fitted with a large rubber bulb is most convenient. In using the tube without the bulb, place the thumb over the upper end of the tube while introducing it, then with- draw the thumb when the tube is immediately over the sub- stance to be removed. The substance will rush up the tube, after which the thumb is replaced while the tube is withdrawn. A special form of glass tube, with an expanded end, recently placed on the market, holds a larger quantity of refuse and must be inverted in order to empty it. This has some distinct advan- tages over the ordinary straight tube. For larger aquaria the pipette is rather tedious and the siphon is recommended. In either case the waste should be strained through a cloth net and the water should be returned to the tank rather than add fresh water to replace it. As has been stated elsewhere, the less changing of the water the better, for fear of introducing some new factor to interfere with the adjust- 44 NEW YORK AQUARIUM NATURE SERIES SKA-LETTUCE (Ulva). It is the best aerator for the salt-water aquarium. The red-seaweeds add color and variety and sliould be placed at the bottom of the tank. ment already established. It will occasionally be necessary to add water to replace that which escapes by evaporation. This should be done a little at a time and care should be taken to have the temperature the same as that of the water in the tank. For the purpose of removing any deposits on the glass of the aquarium, a swab can be made out of a stick with a bit of cheesecloth wrapped about the end. The cloth may be removed each time it is used, which should not be more often than is nec- essary to keep the glass reasonably clean, or if it is used again it should be carefully cleaned and sterilized each time in hot water. The swab will serve not only to remove ordinary dirt, but also the green scum of the minute plant life which in strong light will soon cover the glass. These minute plants do no harm — in fact they are as beneficial in yielding oxygen as are the larger ones — and they are a natural part of the balanced life of the aquarium. Plowever one keeps an aquarium to enjoy the view of its minia- ture water world, and if the green scum interferes with the view it may be removed without great detriment to the adjust- ment. The scum grows thickest on the side nearest the light and it may be allowed to develop on that side as it will serve to screen the strong light somewhat from the animals. THE CARE OF HOME AQUARIA 45 BALANCED SALT-WATER AQUARIUM. Sliowins- ulva and i-ecl seaAveed. When aquaria are newly arranged, the water may often appear clouded after a few days. If the fishes show signs of dis- comfort, it is due to the presence of bacteria causing the decom- position of impurities introduced with the sand or from decaymg plants. If the fishes appear in good condition the clouding may be due to the presence of great numbers of microscopic animals (infusoria) or plants (diatoms). This condition may even be noticed occasionally in well-balanced aquaria, especially in the spring when the water begins to warm up and particularly if the aquarium is in strong light. It is best in any case to draw off a portion of the water daily and add a fresh supply until the cloudy condition is past. If it is due merely to the presence of infusoria or other minute life, the position of the aquarmm should be changed or a screen should be arranged to cut off some of the light. If the fishes show much discomfort they should be removed until the conditions are made right. A careful search should be made for the source of decomposition. If no refuse food nor decaying vegetation is found, the sand or gravel should be removed from the bottom and thoroughly washed and the tank sterilized. The fishes, in the meantime, may be kept in any clean receptacle, and the water changed as often as is necessary. After resetting the aquarium should be allowed to stand for a few days, if possible, before putting the fishes in it. 46 NEW YORK AQUARIUM NATURE SERIES For removing inanimate objects from the aquarium or for readjusting them, a strong pair of wooden forceps is advisable. The hands should not be put into the water and on no account should the fishes be taken into the hands. If it becomes neces- sarv to remove the fishes, a small net of cheesecloth should be employed and great care should be taken not to injure them by loosening their scales, as any such abrasion offers a foot-hold to the deadly fish fungus {Saprolegma) . MARINE AQUARIA. As most of what has been said of the fresh water aquarium will apply with equal force to the salt water aquarium, a detailed account will not be necessary. The factors governing life are in general the same in both. The best plants for aerating are the species of green algae known as sea-lettuce {Viva). The most convenient of these to use is the common broad-leaved form. The best means of arranging this is to float each portion at the sur- face by a small piece of cork placed beneath it. The cork should be just large enough to float the plant, which should be aflowed to hang down in the water as far as possible. The species of marine plants are numerous, and the various red, green and brown forms with strap-like or with finely divided fronds may be placed at the bottom to give variety and color, as well as to aid in aerating the water. Very often pebbles with these plants at- tached may be secured in shallow water. Unfortunately the salt water aquarium is a practical impos- sibility for most persons who are unable to make occasional visits to the sea-shore. Artificial sea water can be prepared easily at a trifling expense, if the formula of Gosse is followed : chloride of sodium (common table salt) eighty-one parts, chlor- ide of potassium two parts, chloride of magnesia, ten parts, sul- phate of magnesia, (epsom salts) seven parts, total 100 parts. A pound of this mixture is sufficient to make about three gallons of artificial sea water. It should be filtered before placing in the aquarium. To be sure, natural sea water contains many other salts, but they have been found unnecessary for the plant and animal life of the aquarium and may be omitted. The sea water part of the problem is thus readily solved, but very little marine material is ever handled by dealers in this country and the diflficulty of ob- taining the necessary animals and plants for the purpose of THE CARE OF HOME AQUARIA 47 J.% YOUNG TAUTOG OR BLACKFISH. A very hardy and interesting- fish for the marine aquarium. stocking renders the salt-water aquarium impracticable for the person of average means who lives at a distance from the sea. To one who is within reach of the shore, however, the ma- rine aquarium offers a never-ending and ever-varied field for Ftudy and investigation. Animals and plants may be obtained the year round, and many of them live well within the restricted limits of the aquarium. The many species of hydroids and sea- anemones, marine worms, small starfishes, bryozoans, mollusks of many kinds, crabs, shrimps and other crustaceans and sea squirts or ascidians, as well as fishes, are to be obtained. These give a variety to the miniature scene which cannot be paralleled in the fresh water aquarium. Some of the small salt-water aquaria at the New York Aquarium have been maintained in a balanced condition for sev- eral years one for as long as twelve years. Of course, both animals and plants have been added to the stock occasionally, but the balance has not been interfered with during that time. Fresh water in small quantities must be added to the marine aquarium occasionally to replace that which evaporates. The addition of sea water would, in the course of time, cause the salinity to become too great, since the salts do not evaporate. i=l 3 o > o H CO Eft P< 03 u vx o THE CARE OF HOME AQUARIA 49 Special care should be taken, whenever any new animals are added, to observe that they do not die and upset the adjustment of the aquarium by their decomposition. Portions of plants w^hich are deteriorating may be removed and fresh ones added. In fact the whole method of operating is the same as in the fresh- water aquarium, except that greater care is required on ac- count of the greater variety of the animal life and the greater danger of introducing something which will interfere with the adjustment. Practically all of the marine animals are carnivorous. They may be fed upon pieces of clam, oyster or fish, cut to proper size or finely grated for the smaller animals. Some sea-snails make good scavengers, but some of them are vegetarians and may attack the plant life too freely, while others are entirely carnivorous and will have nothing to do with decay- ing matter. However, these are just the points which the aquar- ist will be interested in determining for himself, and, with the proper attention, will offer no great difficulties. As in the fresh- water aquarium, it is very important not to overfeed and to remove by means of the siphon any excess food material which might, by decaying, interfere with the proper balance of life. THE TERRARIUM. Many small animals suitable for the home collection will not live in water and some others which may be kept in the aquari- um really prefer moist situations and will do much better in such conditions than if compelled to live in water. For such animals the terrarium is the proper receptacle. Since the animals may vary from the desert lizards, such as the horned-toad, to the moisture-loving land-salamanders, or the frogs, it is evident that the conditions in the terrarium must vary accordingly. The glass-sided aquarium tank makes a good receptacle for the terrarium. For desert conditions an old leaky one will serve as well as any, and a bottom of dry gravel is all that is necessary. The addition of a few cacti or other desert plants gives variety. These may be planted in shallow dishes, sunk to the level of the bottom. One or two large pebbles may be so placed that the animals can partially conceal themselves beneath them. For the salamanders and frogs, as well as for land turtles and most insects, more moisture is necessary. A bottom of gravel covered with rich earth should be provided. This should 50 NEW YORK AQUARIUM NATURE SERIES TEIir.ARIUM IN A liOUND AQUAIUUM JAR. Suitable for small salamanders, frogs and some turtles, land snails, etc. be kept moist but not sloppy, with frequent watering. Mosses, liverwort and semi-aquatic plants, such as may be obtained in any wet woodland, will grow well and make an attractive envir- onment for the animal life. It is usually advisable to sink a shallow dish to the level of the earth in one corner of the terrari- um, as some animals, such as turtles, frogs and salamanders, may find it necessary to enter the water occasionally. Such a terrarium should be in a good light and should be placed accord- ing to the suggestions already given for the aquarium. It should be guarded in a similar way from draughts. It is often advis- able to cover the moist terrarium w4th a plate of glass which will prevent evaporation of the water and will keep the enclosed at- mosphere at the right point of saturation. In such case the moisture will often condense upon the cover and sides of the receptacle and run back to the bottom. Oxygen for the respira- tion of the inhabitants is provided, as in the aquarium, by the plant life, and in turn the animals provide carbon dioxide for the plant life. The removal of the cover for occasional feeding or cleaning will sufficiently renew the atmosphere, if necessary, but if properly balanced no such renewal is required. If mold tends THE CARE OF HOME AQUARIA 51 • V\.'T>^'' ^^4 MUDFISH OR BOWFIN. XM. .3 one o, U,e ^f-:^,SiJ^^-Z^^i^<^^' ^*-" ''"""'''" to form too freely, it is an indication that the soil contains too r^uch™rganic matter, or that some of the plants are decaymg. The cover may be removed and the terrarium allowed to dry out partially to prevent the mold from forming too freely. The well planted terrarium with a good variety of Plan* and animal life is exceedingly attractive. Larger ones may be bmlt Hke a show-case with glass top and sides held m Pl;-by wooden or metal frame. The writer has recently seen such a terrarium maTe with a cement bottom which was fashioned to contain a rn"e pool a few inches in depth for ^old fishes fro^s and salamanders. The arrangement may be varied >ndefinitely and very elaborate designs may be worked out m the planting, but in the opinion of the writer the most interesting are those which simulate as nearly as possible the mossy nook or other bit of wild nature. DISEASES AND PARASITES. Diseases: Many diseases of fishes are difficult to diagnose correctly. When fishes which have been active and bright colored become languid in their movements, or lose their colors, if they aSume abnormal positions, such as swimming head downward jf they rub themselves frequently agamst the gravel or plant stems, if they keep always at the surface, if swellings or blotcies appear, if the scales stand out from the skin, if they refuse to take food, or, if they behave otherwise in an unusual manner, it 52 NEW YORK AQUARIUM NATURE SERIES may be taken for granted that something is wrong, and a careful study should be made to ascertain the exact nature of the diffi- culty. The most frequent cause of trouble for the beginner is lack of oxygen. The symptoms are rapid or labored breathing or the fishes remain at the surface and often take air-bubbles into their mouths. On adding fresh water they should become normal in a little while. Before changing the water in a balanced aquarium it may be better to try aerating by dipping it up and pouring it back in a slender stream from the height of a foot or so. By this means small air bubbles will be carried under, and within a few minutes the oxygen in the water will be renewed. It must be remembered that insufficient oxygen means partial suffocation and therefore continual distress to the fishes until a satisfactory condition of aeration is established. On dark days, when the plants are not giving off much oxy- gen, or if the temperature is too high, so that the water does not so readily retain the oxygen, the fishes may remain at the sur- face. If they insist on doing this in bright weather with the temperature of the water not above 65 or 70 degrees there is something wrong with the balance which should be remedied at once before the fishes are weakened and rendered subject to disease. It may result from decomposition of unconsumed food or of a dead snail, and cleaning should be resorted to at once. If the condition comes on gradually, it is probably caused by lack of plant growth. At any rate, the balance is disturbed and must be restored before graver difficulties follow. Of organic diseases in fishes we know very little, except that such do exist. The most common troubles affecting aquarium fishes are due to improper feeding. The first result is, of course, mtestinal trouble, either diarrhoea or constipation. The latter is more easily diagnosed, as the evidences are a distended or bloated condition of the abdomen, coupled with difficulty in void- ing excrement. Over-feeding and improper foods are the main causes. In any case the diet should be cut down — starvation for a few days will not hurt the fishes in the least— and afterwards they should be fed sparingly on prepared fish-food until the symptoms are no longer observed. Another disease marked by a bloated appearance is that known as dropsy. In this case other parts than the abdomen are affected, and the distension of the skin causes the scales to stand THE CARE OF HOME AQUARIA 53 COMMON ROACH IX A BALANCED AQUARIUM. A very graceful and attractive species. out, producing a very rough appearance. Nothing definite is known as to the cause of this disease and if it has made much progress there seems to be no cure for it. In such a case it is better to kill the fish at once and thus put it out of its misery. If the fish is a valuable one and the disease is incipient, it may pay to attempt to cure it by putting the fish on a scanty diet and giv- ing it a tank by itself where it will have plenty of room and the best conditions of temperature, light and oxygen. Chill is a frequent source of trouble and to avoid this the I fishes should be kept from draughts in winter and water should not be added to the tank until it has been warmed to the tem-l perature of that in the aquarium. If they should happen to be-l come chilled, remove the aquarium to a warm place at once and[ put in some warm water raising the temperature to 80 or 8^ degrees, afterward allowing it to fall gradually to the normal. If prompt action is taken no loss should occur. Frequent suddei changes in temperature are very deleterious and should b( avoided absolutely. Other diseases are known to occur among fishes, but ver^ few of them have been studied with any care. Perhaps the besj known is the thyroid disease, or goitre, of the salmonoid fishes which has been a subject of much investigation in recent yean This has been proved to result from improper conditions in thl 54 NEW YORK AQUARIUM NATURE SERIES hatching and breeding tanks, to improper feeding, etc., and the disease yields readily enough to proper treatment. So far as known this condition does not attack inhabitants of the small aquarium. Parasites : These may be plant or animal and are either external or internal in their mode of attack. The plant para- sites are either fungus {Saprolegnia, etc., or water mold), or bacteria. The fungus is perhaps the most common parasite at- tacking aquarium fishes. The disease is propagated by means of very minute spores carried in the water. Probably fishes that are in a perfectly healthy condition are not attacked, but if any abrasion occurs on the skin, an opportunity is given for the de- velopment of the spores, or if the fish is weak and anaemic, the gills or the tails, especially in the long-tailed goldfishes, may be the seat of attack. The first evidence of the disease on the skin i? the presence of a white blotch or blotches, which, on close inspection, is seen to be made up of minute strands (hyphae) having something the appearance of absorbent cotton. If not checked at once, numerous spores will be produced on the outer ends of these threads, and be disseminated through the water of the aquarium to the danger of other fishes. On the appearance of this disease in the aquarium it is best to remove all the fish at once and disinfect the aquarium thoroughly. This may be done by treating the tank with a strong solution of salt, while the plants may be placed for a few hours in a solution of phenol .sodique (a tablespoonful to a gallon of water). The fish at- tacked by the disease should be removed at once from those not affected and kept separate until all evidence of the disease has disappeared. For treatment they should be placed in a three per cent, solution of common salt for an hour or so. If they show any signs of distress, such as inability to keep their balance, after they have been in the salt bath a while, they must be removed at once to fresh water. The treatment should be re- peated daily until all evidence of the fungus has disappeared. This treatment applies also when the fungus is on the gills. If the disease attacks merely the skin, it may also be treated by local application of a 50 per cent, solution of peroxide of hydro- gen, the fish being removed from the water for a few moments while the application is made. A solution of potassium perman- ganate (dark claret color) may be used in a similar way for local treatment, or the fishes may be placed in a weak solution of the THE CARE OF HOME AQUARIA 55 YOUNG MIRROR CARP. The carps are very hardy and are excellent fishes (or the beginner. permanganate (light claret color) until signs of distress appear, when they must be replaced at once in fresh water. When the fungus disease has made much progress it is bet- ter trkill the fish at once and be done with it, for there is little hope of saving it or even of giving it a presentable appearance The threads or hyphae, of the fungus work their way into the tissues and usually the best that can be accomplished by any reatmenris to remove merely the external growth without veachTn^rthe pernicious internal portion which continues to deveS" If the diseased spot is small and not too near a vital part i? may be carefully scraped and treated with the peroxide or p;rmanganate solution (deep claret color) ^^d thus the mter nnl portions of the parasite may be reached and killed When Te dfseasrattacks the gills there is practically no hope of saving ihe Me of the fish as the growth of the fungus has usually pro- gressed to a critical stage before it becomes noticeable. " Eggs of fish are also frequently attacked by fungus and m this case all eggs diseased must be removed at once Bacteria —These minute organisms attack fishes m various wavs The skin is sometimes affected by what is known as the •Se disease" in which the skin is coated with a whitish mu- cuTukfsubstance. In the so called "scurvy" the scales are p^r- Hnllv erected giving a rough appearance. The gills are also attacked by tecteria which cause the filaments to become aggluti- nated and covered with a thick layer of mucous which prevents 56 NEW YORK AQUARIUM NATURE SERIES their functioning. This disease is known among fish breeders as '"tuberculosis." The *'red disease" of the skin of goldfish, ide and other cyprinid fishes is also bacterial in origin. The weaker per- manganate solution and a 2% solution of common salt have been used with some success in the treatment of these diseases. What part bacteria play in causing internal diseases of fishes is but little known, although diseases of the liver and other internal organs have been ascribed to this cause. A^iimal Parasites. — Apparently these are much more nu- merous in species than are the plant parasites and they belong to several classes. Among the larger ones may be mentioned the leeches, crustacean parasites or fish-lice and worms (tape-worm, treinatode and round-worm) . External parasites, if large, ordi- narily give but little trouble as they may be readily removed with fine tweezers. Minute species of trematodes or fluke-worms (Gyrodactylus, etc.), are sources of great loss, at times causing the death of whole schools of goldfish. These tiny parasites are almost mi- croscopic, but can readily be seen with an ordinary lens. On young fish they may be found all over the body and even in older specimens they may occur in such numbers upon the skin that they produce serious sores, but adult specimens are more fre- quently injured by attacks on the gills. Sal ammoniac in one- half per cent, solution, common salt in two per cent, solution, and potassium permanganate in the weaker solution, say one part to 10,000 are all recommended for treatment. However, when the parasites attack the gills in large numbers it is practically im- possible to effect a cure, as any treatment fatal to the parasites is likely also to prove fatal to the fish. Internal parasites, as a rule, cannot be diagnosed, but they seldom cause much trouble among aquarium fishes. To be sure many forms of parasitic worms have been described as inhabit- ing the intestinal tract or embedded in the flesh. But even if it were possible to diagnose these cases in life, it would probably be impossible to eflfect any cures. A number of species of unicellular parasites (Protozoa) at- tack the skin of various fishes in the aquarium. Usually the presence of the parasites becomes evident to the naked eye as minute whitish flecks or protuberances on the skin. The fish becomes languid in its movements, refuses to take food and breathes rapidly in a labored manner. Two of the better known of these parasites, Costia and Chilodon, attack the skin exter- THE CARE OF HOME AQUARIA 57 STICKLEBACKS. These miniatiue fishes are found both in fresli and salt water. Their nesting habits are especially interesting. nally and often cause serious losses. The two per cent, solution of common salt and the weaker solution of potassium perman- ganate are recommended, baths of one-half hour duration being given daily until the disease is eradicated. Another protozoan attacking the skin, which is a far more serious pest, is Ichthyo- phthirms, which burrows into the epidermis producing minute capsules. Fish attacked by this parasite behave much as in the case of those just mentioned. Owing to the fact that the para- sites are embedded in the skin, treatment is more difficult. Sub- jecting the fish daily for an hour or so to a water temperature of ho to 32 degrees Centigrade (86 to 90 Fahr.) is said to be effiica- cious in producing a cure. Also daily treatment with 8 per cent, solution of common salt as long as the fish can stand it is recom- mended. Protozoa, belonging to the group known as Myxosporiclia, are of rather common occurrence and are responsible for some loss. These one-celled parasites penetrate the tissues and in the later stages of development cause tumor-like growths. These may affect the internal organs such as the liver, spleen, kidney or reproductive glands, in which case their presence is not suspected until the fish die. Frequently, however, the cysts are formed imder the skin, producing unsightly swellings on the surface 58 NEW YORK AQUARIUM NATURE SERIES known commonly as fish-pox. Eventually the cysts or swellings break and numerous spore-like cells are liberated. As it is by means of these spores that the disease spreads, the affected fishes should be removed as soon as the swellings make their appear- ance. There is no specific for this disease, but the cysts may be lanced, and peroxide of hydrogen or the stronger solution of po- tassium permanganate introduced into the wound with a small pipette. If the cysts are small and not too near a vital part, the fish sometimes recovers without treatment, but, as a rule, the disease is fatal. Both fresh and salt water fishes are attacked by these protozoan parasites, but fortunately the cultivated forms of aquarium fishes are seldom aflfected. Wild fishes, such as min- nows, killifishes, etc., may have the disease in its early stages when taken, and, if later the swellings which cause the disease should make their appearance, the aflfected fishes should be iso- lated at once for treatment, or if not valuable it is better to destroy them. THE CA'iE OF YOUNG FISHES. The breeding habits of aquarium fishes vary to such an extent that it is practically impossible to lay down any general rules to cover all cases. Nor is it possible here to more than out- line the methods of treatment for a few of the many species. According to their manner of reproduction, fishes naturally form two classes. Some species, such as the goldfishes, stickle- backs and chanchitos are oviparous and lay eggs which later hatch out into the young. Others, like the swordtailed minnows (Xiphophoriis) and topminnows (Gamhusia) , are viviparous or live-bearing and bring forth living young. Practically all fishes are cannibalistic in habit at certain stages and do not hesitate to eat even their own young. In the case of the live-bearing fishes, a good method of protecting the young is to place a plate of glass m a slanting position in the aquarium so as to shut ofl^ the adults at one side. The glass should fit loosely enough so that the young fishes can find their way into the body of the tank past the'^edges of the glass, while the adults are unable to do so. After the birth of the young, the adults should be removed to another jar. The swollen appearance of the female is an indication that the pre- hmmary arrangements should be made. In the case of the nest building oviparous fishes, such as the sticklebacks and chanchitos, the eggs are cared for by the adults THE CARE OF HOME AQUARIA 59 TUBULARIA AND ASTRANGIA, OR WHITE CORAL, EXPANDED. until the young hatch out, and often for a considerable period after this. The adults may be removed, however, as soon as the young have made their appearance and begin to swim about. As goldfishes are reared with much more frequency than any other fish, it may be well to go into the matter a little more fully with them. The sexes can be distinguished readily as breeding time approaches by the fact that the belly of the female is greatly distended with eggs, while the male is more slender. The dif- ference in form is much more evident from the top than from the side view. They can be distinguished also by watching their actions, as the male tends to chase the female about the tank, and becomes much more active in this a day or so before the time for egg laying. If there is an abundance of vegetation in the tank, and if the aquarist is not particularly anxious to secure the very best results, he may allow nature to take its course, in which cas( some of the eggs will be attached to the plants during oviposition, while others will fall to the bottom, probably to be lost. Am fishes not engaged in the processes of egg-laying or fertilizatioi may also occupy themselves in eating some of the eggs. At an: rate, after the eggs are laid, all the adults should be removed t( another tank, for if they are left with the eggs they may eat large portion of them and also devour the young fishes after the: emerge. 60 NEW YORK AQUARIUM NATURE SERIES Probably the best method for securing the highest percent- age of young is that of placing a cheesecloth net in the aquarium. This should be partially filled with water plants and a breeding female with one or more males placed in it as the time for egg- laying approaches. After the process is complete, the fishes may be replaced in the body of the tank, the plants removed to an- other jar or breeding pan, and, if any eggs have adhered to the net, as is usually the case, it also may be placed in the breeding pan. When the young emerge, they will, of course, need to be fed. The natural food of the young goldfish consists of minute Crus- tacea and other tiny water animals and these may be reared in cultures ready for their use. If this is not possible, they may be fed on the yolks of hard-boiled eggs, finely rubbed up, and they will thrive well on this diet. As they get a little older fine por- tions of prepared fish food may be added. Boiled oatmeal and other cereals strained through a fine sieve or coarse cloth are also recommended. Care must naturally be taken not to overfeed to the extent that the water becomes contaminated. THE USES OF LENSES. The observation of the smaller life of the aquarium is ren- dered easier and much more attractive by the use of lenses. For the study of the very minute forms nothing will suffice, of course, except the compound microscope. For those which are some- what larger and yet too small to be well observed by the naked eye, the simpler hand lens will be satisfactory. Even a large- sized reading glass, magnifying only two or three diameters, is very useful, and may be arranged to stand permanently before the aquarium jar. A cabinet, which has been in use at the New York Aquarium for some years, is arranged so as to cut out the view of everything except what can be seen through the lens and it is lighted by incandescent lights placed behind the aquarium jars. A reading-glass is easily arranged in a light frame of wood placed in front of an aquarium lighted from a window. By this means the exhibition of aquatic insects and larvae, the smaller crustaceans, hydroids, sea-anemones, sea-mosses, etc., may be made very attractive with little expense. For the study of very young fish, mosquito larvae, small crustaceans, etc., it is advisable to have lenses of higher magnify- ing power. Those magnifying six or eight times are perhaps THE CARE OF HOME AQUARIA 61 best for the beginner since the higher powers have a smaller field and are increasingly difficult to manage. THE STUDY OF AQUARIA. The aquarium student will naturally be interested in obtain- ing all the information he can, not only on the care and manage- ment of his aquarium, but also with regard to the natural history of his animals and plants. There are several means of accom- plishing this end. In the first place, the aquarium society affords a splendid opportunity for comparing notes with others who are interested, and many of the problems that confront the beginner can be solved immediately in conference with more experienced aquar- ists. Also much information regarding the habits and life his- tories of aquarium plants and animals may be obtained in the same manner, and a good opportunity is presented for the ex- change of specimens. Aquarium societies exist in New York, Brooklyn, Philadelphia, Chicago, Minneapolis, Boston and Mil- waukee, but the number should be greatly increased. In every city there are many people interested in aquaria, and it often happens that a small society will do better work than a larger one, on account of the greater opportunity for personal contact and informal discussion. Secondly, a vast amount of information can best be obtained through the published works dealing with the subject. The ap- pended list includes only such as are contained in the New York Aquarium library, all of which can be recommended to the ama- teur aquarist. There are undoubtedly many other useful books on this subject. Most of those issued by American publishers are still to be obtained from the regular booksellers, but a few are out of print and can only be picked up occasionally from the sec- ond-hand dealers. Thirdly, there are numerous foreign and one American jour- nal devoted to the small aquarium and its inhabitants. Subscrip- tion to at least one, preferably The Aquarmm, which is pub- lished jointly by the American societies, is strongly recom- mended as the best means of keeping in touch with advancement in the study of aquaria and aquarium organisms. PUBLICATIONS OF INTEREST TO THE AQUARIST. OLDER WORKS. The Aquarium.— An unveiling of the wonders of the deep sea. With colored plates. By Philip Henry Gosse, A.L.A. Van Voorst, London, 1854. To(>ular llistorx of the Aquarium of Marine and Fresh Water Animals and Flams. With colored plates. By G. B. Sowerby, F.L.S. Reeve, London, IS.')?. Oeeau ilardens.— The history of the marine aquarium, and the best methods now adopted for its establishment and preservation. With col- ored plates. By H. Noel Humphreys, Samson Low Son & Co., London, 1857. The Aquarium Xaluralisi.— ^ manual for the seaside, with a chapter on aquaria. Colored plates. By Thos. Rymer Jones, F.R.S. Van Voorst, London, 1858. The Fresh and Salt Water Aquarium.— ^^ith colored plates. By Rev. J. C. Wood, M.A., F.L.S. Routledge & Sons, London, 1868. The I-am.ily Aquarium.— The construction, stocking and maintenance of fresh water and marine aquaria. By H. D. Butler. Dick & Fitzgerald, New York. 1858. RECENT WORKS. The Amateur Aquarist.— How to equip and maintain a self-sustaining aquarium. Illustrated. By Mark Samuel. Baker & Taylor Co., New York, 1894. 77/t' Aquarium.— Its inhabitants, structure and management. Illus- trated. By .T. E. Taylor, Ph.D. New Edition, Grant, Edinburgh, 1901. 77k: Book' of Aquaria. - Being a practical guide to the construction, arrangement and management of fresh water and marine aquaria. Illus- trated. By the Rev. Gregory C. Bateman, A.K.C., and Reginald A. R. Bennett. M.A. Part I, Fresh Water Aquaria, Part II, Marine Aquaria. Scribner's, New York, 1902. The Home .Iquaniim, and lloz<- to Care for //.^- A guide to its fishes, and other animals and plants, with many illustrations. By Eugene Smith. Duttons, New York, 1902. 77.,' I'resh Water Aquarium and Its Inhabitants.— -^ practical guide, de- scribing especially the plants and animals suitable for aquarium purposes, and with r-hapters on feeding and tish diseases. Illustrated by E. F. Kel- ler and E. R. Sanborn. By O. Eggeling and F. Ehrenberg. Holt & Co., New York. 190S. Das .Susszi.asser-.l(iuariun!. A practical guide in the German. Illus- trated. By Dr. E. Bade. Fritz Pfennigstorff, Berlin, 1909. Can be ob- tained through dealers importing German books. Domesticated Fish. — Care and culture of ornamental domestic and foreign fish. By W. L. Brind, 500 Isham St., New York. The first part of this work has just been issued. THE CARE OF HOME AQUARIA 63 GOLDFISH CULTURE. The Goldfish tnid Its Systematic Culture. — A thorough guide for gold- fish keeping and goldfisli breeding in tlie house and out of doors. The construction and care of tlie parlor aquarium and of ponds for breeding. Illustrated. By Hugo Mulertt, New York, 19 02. Goldfish Breeds and Other Aquarium /•'/^Vk'^.— Their correct propagation. A guide to fresli water and marine aquaria, their flora, fauna and man- agement. Illustrated. By H. T. Wolf. Innes & Sons, Philadelphia, 1908. Japanese Goldfishes, Their Varieties and Cultivation. — A practical guide to the .Japanese methods of goldfish culture for amateurs and profes- sionals. Illustrated, with numerous colored plates. By H. M. Smith, U. S. Deputy Commissioner of Fisheries. W. T. Roberts Co., Washington, 19 09. VIVARIA. The J^ivarium. — Being a practical guide to the construction, arrange- ment and management of vivaria. Illustrated. By Rev. Gregory C. Bate- man, A.K.C. Gill, London, 1897. JOURNALS. The Aquarium. — This is the only journal published in America devoted entirely to the small aquarium. It is issued each month, jointly, by the aquarium societies of America "in the interests of the study, care and breeding of aquatic life," at one dollar a year. Editor, .J. N. Gage, 8 S. Dearborn St.,- Chicago, 111. NATURAL HISTORY Ponds and Ditches. — A description of the plants, animals and condi- tions of life in quiet fresh waters. Illustrated. By M. C. Cooke. E. & J. B. Young & Co., New York, 188 5. Ocean Wonders. — A companion for the seaside. With a chapter on marine and fresh water aquaria. Illustrated. By William E. Damon. Appleton's, New York, 189 6. Life in Ponds and Streams.— ^yith a chapter on aquaria. Colored plates. By W. Furneaux, F.R.G. Longmans, Green & Co., New York, 1896. The Sea Beach at Ebb Tide. — A guide to the study of the sea weeds and the lower animal life between tide marks. Illustrated. By A. F. Arnold. The Century Co., New York, 1901. The Sea Shore. — Dealing with marine animals and plants and with a chapter on the salt water aquarium. Illustrated. By W. S. Furneaux. Longmans, Green & Co., New York, 19 03. Sea Shore Life.— The invertebrates of the New York Coast (Vol. I New York Aquarium Nature Series). 181 pages and 119 illustrations. By Dr. A. G. ^Nlayer. For sale at the Aquarium and by A. S. Barnes and Company, New York. Library W. C, State Collar