Date of Award

Spring 1965

Document Type


Degree Name

Master of Science




Larvae of the marbled salamander, Ambystoma onscum, and the goldfish, Carassius auratus, were subjected to poi­ soning by homogenates of Lonhopodella carteri. Stock homogenates were prepared by grinding specimens of frozen L. carteri in a rotary blender and adding distilled water to give a 20 percent concentration (wt./vol.); the stock was used to prepare working solutions.

Homogenates from bryozoans collected in 1964 were approximately twice as poisonous as those from the 1963 col­ lection. It ls possible that chemical changes during stor­ age and bacterial action prior to freezing caused deterioration of the poisonous principle in the material from 1963. Stock homogenates were prepared immediately before testing as their toxicity declined over a period of several hours.

The stock homogenate from 1964 was used at the rate of 2.0 ml per 50 ml of spring water; that from the 1963 collection at the rate of 4.0 ml per 50 ml of spring water. Salamanders were capable of surviving for longer periods of time in concentrations that ere lethal to fish in 60 minutes, and the stock homogenate fro 1964 was used at the rate of 5.0 ml per 50 ml of water.

Test fishes showed an increase in respiratory movements accompanied by ganing opercles, a gradual loss of balance, and emission of mucus and blood from the gill regions prior to death. Size of the fish was not related to the rate of poisoning. With the salamanders, there was a progressive increase in blistering of the gill filaments, sloughing of the epithelium, and exudation of blood and mucus from the gill region.

Histological preparations of the poisoned fiahes and salamanders showed a hypertrophy of the epithelial lining of the gills, destruction of the lamella and fimbriae respectively, a breakdown of the canillary walls, and an increase in the number of goblet cells in the pharynx.

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