Fish Aquarium Research Articles

Tropical fish aquariums. A source of Mycobacterium marinum infections resembling sporotrichosis

Tropical fish aquariums are a possible, though uncommon, source for Mycobacterium marinum skin infections, which may assume the morphological pattern of sporotrichosis. We have observed three of six patients with this condition during the past two years. Shortly before onset, each patient experienced a minor abrasion on the hand, after which he cleaned an aquarium where many of the fish had recently died. Smear cultures of material obtained from the lesions revealed atypical acid-fast organisms, and in each case M marinum was identified. A smear culture from the fish tank of one patient showed M marinum , and acid-fast organisms were observed in the material we obtained from the tubing of the tank of another patient.

Shell Repair in the Gastropod, Marisa rotula

An ordinary tropical fish aquarium, with a six gallon capacity, was equipped with an air pump and a filtration system to provide a clean, well oxygenated environment for the snails used in the experiment. The water was changed approximately every two weeks to provide a renewed calcium supply for normal shell growth. Lettuce and other vegetable matter was fed every other day throughout the experiment. Twenty specimens of Marisa rotula, all hatched at the same time and from the same batch of eggs, were placed in this environment. The snails were numbered consecutively from one to twenty and the appropriate number was painted on each snail3. The snails numbered one through ten were designated the Control Group and the snails numbered eleven through twenty were designated the Experimental Group. No pre-sorting was done to determine which group each snail would fall into. The numbers were painted on at random with no attempt to select certain ones for a certain group. Consequently the Experimental Group, overall, was a few thousanths of an inch larger than the Control Group. Each snail kept the original number given it throughout the experiment, allowing the authors to keep an accurate account of the progress of each snail during the entire experiment. Measurements of the height of each snail were taken periodically from 31 May 1959 to 16 November 1959. The height is here understood to be from the highest point of the aperture, across the apex region, to the lowest point at the bottom of the curvature of the shell. All measurements were made with vernier calipers which could be read directly to 1/1,000th inch.

A SIMPLE IMMERSION ELECTRODE FOR TAKING CLINICAL ELECTROCARDIOGRAMS

Because of its simplicity and ease of operation, and because it has certain technical advantages, I wish to describe an electrode for use when taking electrocardiograms of ambulatory patients. Electrodes consisting of a metal plate bound to the extremity by bandages wet with hot salt solution are commonly used for bed patients, 1 but for ambulatory patients the zinc—zinc sulphate—salt solution type of nonpolarizable electrodes are recommended. 2 These latter are a quite unnecessary complication of the technic. The simple electrode to be described will take technically perfect records. It consists of a glass tank for each extremity, that for the arms being a cylinder about 7 × 10 inches and that for the leg being rectangular, about 7 ×7 × 12 inches (a fish aquarium). In these are stood metal plates 4 inches wide and extending up above the top of the tank, to which plates the wires from the galvanometer