The Book of the Aquarium/Part 1/Chapter 6
REPTILES, MOLLUSKS, AND INSECTS.
The lower orders of creation supply many interesting specimens for the aquarium. Among the reptiles—newts, or water lizards, and the common frog, may be recommended as offering some forms of positive elegance, and some habits worthy of observation. The smooth newt, the warty newt, and the noble triton, are almost essential to the completion of the collection, and as they respire air at the surface, they do not exhaust the water of oxygen. The beautiful markings on the belly, and the graceful motions of these strange creatures, are sure to afford entertainment to those who can overcome the very common repugnance felt towards such creatures.
Some of the mollusks commend themselves for their beauty, and will be prized by the aquarian enthusiast. Among the univalves, lymnea, physœ, planorbis, and paludina, are the most useful and ornamental. I must caution the amateur against the too ready adoption of any species of lymnea; they are destructive, and particularly fond of Vallisneria, Stratoides, and Callitriche, and while they are the best of cleaners, they are also the most indiscriminate of gluttons.
Paludina Vivipara is a handsome snail, with a bronze tinted, globular shell; but Planorbis Corneus and carrinatus are still handsomer, having a spiral form, resembling the horn of a ram. These latter are to be trusted anywhere; they are good cleaners, and seldom attack the plants. Water snails breed rapidly in tanks, but the carp devour the young as fast as they appear; hence it is advisable to remove the spawn into jars containing healthy plants, such as Callitriche, in which they may remain for observation of growth, till stout enough to be committed to the tank.
PLANORBIS CORNEUS, PALUDINA VIVIPARA, LYMNEA STAGNALIS,
UNIO PICTORUM, TUMIDUS, & ANODON CYGNEUS.
Among the bivalves, the fresh-water swan mussel, Anodon cygneus, and the Duck mussel, Unio pictorum, are interesting burrowers, and perform a great service in the tank. They act as scavengers, not by the process of eating off objectionable growths, as in the case of univalves, but by the straining off of matters held in suspension in the water, and filtering it in a pure state, by the mechanism of their syphons, and ciliated gills. It is very interesting to watch them thus engaged, and to note the force of the stream which they project from time to time.
The only creature of the insect kind that I can recommend for general adoption is the caddis worm, a comical and interesting creature, that can never mar the beauty of the tank. Half-a-dozen may be thrown in, and searched for occasionally—the search will always be well rewarded. When the cad closes his hybernacle, it will be desirable to remove it to a jar, to obtain a better opportunity of witnessing the transformation of the dormant worm into a four-winged fly of Stephens’s family of Phryganea.