Book Chapter & Symposium Paper Citations and Abstracts

Crustacea serve as hosts to symbiotic, commensal, parasitic, and pathogenic representatives of all major taxa of Protozoa. Studies of microsporidian epizootics in shrimp, crayfish, and other decapod Crustacea, amoebic epizootics in crabs, and ciliate protozoan outbreaks in shrimps and crabs demonstrate the strong periodic and chronic impact of Protozoa. Mortalities ranging from 1 to 100% in natural and captive populations of Crustacea have been linked to protozoan etiologies. As pathogens of Crustacea, Protozoa have been more intensively studied than most viral, bacterial, fungal, or metazoan pathogens. Yet, there are huge gaps in our knowledge concerning life-histories, mechanisms of transmission, and pathogenesis of Protozoa associated diseases of Crustacea, even in the cases of long-known relationships. This review of representative Protozoan-Crustacean relationships emphasized disease-causing Protozoa and the related responses of their specific crustacean hosts. Examples of all major taxa of Protozoa occurring in or on Crustacea are examined. Surveys of Protozoa known to be associated with decapod Crustacea have been done but not for other orders of Crustacea. The predominant use of decapod Crustacea as exemplary hosts reflects the substantial disease research done on this taxon of Crustacea because of their commercial importance.

Walsh, Gerald E. 1983. Effects of Toxicants on Plankton. In: Health Aspects of Chemical Safety: Environmental Toxicology. EPA-600/D-82-338. World Health Organization, Copenhagen, Denmark. Pp. 117-167. (ERL,GB 448). (Avail. from NTIS, Springfield, VA: PB83-117044)

Effects of heavy metals, pesticides, and industrial and municipal wastes on plankton in the field and laboratory are reviewed. Both holoplankton and meroplankton are discussed. In many cases, meroplanktonic stages of benthic species are more sensitive than adults although death or depression of physiological activities are often used as criteria for effects of pollutants with algae and animals, algae may be used to detect effects of growth stimulants.

Davis, William P. and James A. Fava. 1983. Interaction of Aquatic Ecosystem Components with Chlorination: An Overview. In: Water Chlorination: Environmental Impact and Health Effects, Vol. 4. Robert L. Jolley et al., Editor. Ann Arbor Science Publishers, Ann Arbor, MI. Pp. 791-796. (ERL,GB X377).

The use of tools such as disinfectants, oxidants, or biocides to protect public health remains highly debatable relative to environmental issues, research, and quality of life. Increased public awareness is evidenced by regional conferences (e.g., 'Chlorination: Bane or Benefit'), which address specific stressed systems such as the Chesapeake Bay. That use of chlorination provides benefits to man is not an issue-the questions are how much to use and what risks and costs are involved. Overzealous chlorination can cause ecological damage and disfunction of ecology; control methods such as criteria and regulations are debatable and under challenge. Over the past six or more years, the basic questions about chlorination have not significantly changed; however, the details and data available to us have increased immensely. Two ongoing activities served as the motivating force behind both formal and informal discussions in the session 'Interaction of Aquatic Ecosystem Components with Chlorination' at the Fourth Water Chlorination Conference. These were (1) the recognition that in some areas of the United States, serious consideration has been given to banning all chlorination for disinfection because of the potential for ecological damage; and (2) many scientists, regulators, or environmental managers feel that sufficient research has now been conducted to justify eliminating further funding of chlorination effects studies. This paper examines the salient aspects of the topics discussed during the conference with the hope of addressing the question: Where do we go from here?

Melius, P. and D.L. Elam. 1983. Mixed Function Oxidase in Sea Catfish. In: Polynuclear Aromatic Hydrocarbons: Formation, Metabolism and Measurement: Proceedings of the 7th International Symposium. Battelle Press, Columbus, OH. Pp. 877-895. (ERL,GB X586).

Sea catfish can metabolize and oxidize benzo(a)pyrene, a model polynuclear aromatic hydrocarbon (PAH), to similar metabolites as observed in the rat, trout, mullet, and other fish. This paper describes studies using sea catfish treated with 0.5, 10, 20, and 40 mg 3-methylcholanthrene/kg (3-MC/kg). Results demonstrated an increse in liver/body mass ratios that was linearly dependent on 3-MC dosage. At the 20 mg 3-MC/kg body mass dose level, at least 5 days were necessary to observe a significant change in liver/body mass ratio. At high dose levels (40 mg 3-MC/kg body mass), the response, S. typhimurium TA98 reversion rate, was no longer directly proportional to dose levels. Possibly some cell toxic effects begin to occur, or the capacity of induction is maximum at the 20 mg 3-MC/kg body mass level. Results of Ames mutagenicity test indicate that one or more of the metabolites formed by the hepatic preparations of 3-MC are mutagenic to sea catfish.