Accession Number : ADA319312

Title :   The Use of Diapausing Eggs from Killifish for Rapid, Sensitive Biological Screening of Toxicants in the Aquatic Environment. Phase II.

Descriptive Note : Final rept. 3 Dec 93-2 Apr 95,

Corporate Author : ORBIS SCIENTIFIC INC MILTON FL

Personal Author(s) : Hull, Eugene

PDF Url : ADA319312

Report Date : 02 MAY 1995

Pagination or Media Count : 54

Abstract : A 108-tank recirculating system was constructed for the commercial breeding and maintenance of a large adult population of annual killifish, Nothobranchius guentheri. Embryos were harvested and successfully shipped to collaborating USABRDL for use in preliminary toxicant assessment studies. Several studies investigating the effects of temperature on Diapause 3 termination and hatching were conducted. Drops in temperature were found to terminate Diapause 3 and initiate the hatching process. Egg water loss induced by exposure to hypertonic NaCl solutions or dry storage in peat moss were able to inhibit temperature induced hatching. Results permitted the development of long term storage techniques for embryos to be used in portable toxicant assessment kits. Embryos that were preconditioned to enter Diapause 2 by adult exposure to short light cycle (10 hours light, 14 hours dark), removed from water and stored in peat moss at a temperature of 21 deg C, remained viable for 300 days. Results support the use of annual killifish eggs in a portable rapid toxicant assessment kit with a 90 day or greater shelf life.

Descriptors :   *WATER POLLUTION, *TOXIC AGENTS, *BIOLOGICAL DETECTION, *EGGS, *FISHES, *DIAPAUSE, PORTABLE EQUIPMENT, COMMERCE, WATER, LIGHT, SENSITIVITY, POPULATION, SHORT RANGE(TIME), TEMPERATURE GRADIENTS, EXPOSURE(PHYSIOLOGY), STORAGE, EMBRYOS, DRY MATERIALS, AQUATIC BIOLOGY, SHELF LIFE, BREEDING, PEAT.

Subject Categories : Biological Oceanography
      Water Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE