Portland State University PDXScholar Dissertations and Theses Dissertations and Theses 1980 Storage and use of glycogen by juvenile Carcinonemertes errans D. Mitchell Wolgamott Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Part of the Biology Commons, and the Developmental Biology Commons Let us know how access to this document benefits ou.y Recommended Citation Wolgamott, D. Mitchell, "Storage and use of glycogen by juvenile Carcinonemertes errans" (1980). Dissertations and Theses. Paper 2970. https://doi.org/10.15760/etd.2966 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. AN ABSTRACT OF THE THESIS OF D. Mitchell Wolgamott for the Master of Science in Biology presented February 29, 1980. Title: Storage and Use of Glycogen by Juvenile Carcinonemertes er rans. APPROVED BY MEMBERS OF THE THESIS COMMITTEE: David T. Clark, Chairperson Juvenile ~ errans do not feed on particulate matter and· yet they can survive, apparently unchanged, for several months before maturing into the adult stage which feeds on the eggs of Cancer magister. The significance of glycogen as an energy source for maintenance of the juvenile form was investigated. Glycogen was shown to be present and to be confined largely to the columnar cells of the gastrodermis. When animals were 2 maintained 30 days in filtered sea water at 10 C there was no detecta- ble change in .glycogen content on a per worm basis. But when the oxy- gen tension of the environment was lowered to zero over .an eight hour period, the glycogen content of the worms increased 60% in the first four hours. Worms were shown to be capable of surviving at least 21 days of complete anaerobiosis. Iodoacetate at a concentration of O.SmM greatly reduced tolerance to anoxia. The findings of this study indicate that glycogen is not essen- tial to the aerobic maintenance of the worm. However, if the oxygen tension is lowered, juvenile £!.. errans can rapidly increase their glycogen content. They can then survive long periods of anoxia by relying on anaerobic glycolysis.as an.energy source. STORAGE AND USE OF GLYCOGEN BY JUVENILE CARCINONEMERTES ER.RANS by D. Mitchell Wolgamott A thesis submitted in partial fulfillment .of the requirements for the degree of MASTER OF SCIENCE in BIOLOGY Portland State University 1980 TO THE OFFICE OF GRADUATE STUDIES AND RESEARCH: The members of the Committee approve the thesis of D. Mitchell Wolgamott presented February 29, 1980. David T. Clark, Chairperson Leonard Simpson Stanley s.~Hillman APPROVED: w. Herman Stanley Studies and Research ACKNOWLEDGMENTS I would like to extend thanks to Dr. David Clark, my advisor, and the other members of-my Committee for their help and criticism; Dr. Paul Rudy, Director of the Oregon Institute of Marine Biology, for introducing me to Carcinonemertes and for allowing me to work at OIMB; Drs. Robert Terwilliger and Charles Holiday for their enthusiasm and for allowing me to collect worms from crabs they had collected for other purposes at OIMB. Thanks also to Sue E. Orlaske for her criticism and moral support when it was severely needed. TABLE OF CONTENTS PAGE ACKNOWLEDGMENTS • iii LIST OF TABLES v LIST OF FIGURES • vi INTRODUCTION l LITERATURE REVIEW • 3 ~TERIALS AND METHODS 10 Localization of Glycogen 12 Quantitative Determination of Glycogen 13 Determination of Effects of Metabolic Inhibitors 16 RESULTS • • • • • • 19 Localizatio~ of Glycogen 19 Quantitative Determination of Glycogen i·e Effects of Metabolic Inhibitors 22 DISCUSSION AND CONCLUSIONS • • • • • • a • • • • • • 28 LITERATURE CITED . 34 APPENDIX 37 LIST OF TABLES TABLE PAGE I Measurements <µm} of Component Parts of Proboscis Armature of various Species of Carcinonemertes 11 LIST OF FIGURES FIGURE PAGE 1. Standard Curve1 Relation of NADPH Fluorescence and Glycogen Concentration • • 15 2. Tissue Sections of Juvenile C. errans Stained by the PAS Method •• . 20 3. Seasonal Variation in Glycogen Content of Juvenile C. errans . 21 4. Effect of Decreasing Environmental Oxygen on Glycogen Content of Juvenile c. errans 23 5. Glycogen Content of Juvenile f.!_ errans During Long Term Anaerobic Incubation 23 6. Percent ~urvival of Juvenile ~ errans Incubated with Iodoacetate in Anaerobic and Aerobic Conditions 24 7. Effect of Iodoacetate on Oxygen Consumption by Juvenile ~ errans • .• • • • • 26 8. Effect of Sodium Cyanide on Oxygen Consumption by Juvenile c. errans • 27 INTRODUCTION The Rhynchocoelan genus Carcinonemertes Coe, 1902, consists of 1 five species which live symbiotically with various species of marine crabs where the adult worms feed on the host eggs. Among those crab species infested by the worms are the economically important Cancer magister Dana, 1852, and Callinectes sapidus Rathbun, 1906. Recently, there have been indications that the newly described species, Carcinone- mertes errans Wickham, 1978, may play a role in the declining crab fishery along the coast of Northern California (Wickham 1979a). Host eggs appear to be the only food of adult Carcinonemertes (Kuris 1978, Humes 1942). Juveniles are found on both male and female crabs where they apparently do ·not feed on particulate matter. For this reason they are considered to be phoretic on the host (Kuris 1978). The energy source for maintenance of the juvenile form, until it is stimulated to mature and begin feeding (when the host undergoes ovaposition), is not known. The stimulus for maturation also is not understood. This study was undertaken to evaluate the significance of glyco- gen as an energy source for maintenance of juvenile Carcinonemertes. To do this, the glycogen content of juvenile worms.was localized and quantified. The effects of aerobic and anaerobic maintenance on glycogen content of the worms was determined. And the effects, on 1 symbiosis, as used in this Thesis, refers to any close asso­ ciation between organisms .of different species (Pennak 1964). 2 the intact animal, of the metabolic inhibitors iodoacetate (an inhibi- tor of glycolysis) and sodium cyanide {an inhipitor of electron trans- port) were determined. I lt i l I LITERATURE REVIEW The genus Carcinonemertes was established by Wesley Coe who described its members as "parasitic nemerteans living on various species of Crustacea" (Coe 1902). This is the only genus included in the family Carcinonemertidae. There are currently five recognized species, one of which is divided into varieties: ~ carcinophila var. carcinophila (Kolliker 1845) Coe, 1902, from the South Atlantic Coast of North America, Italy, Belgium, and France; C. Carcinophila var. irnrninuta, Humes, 1942, from the Atlantic Coast of North America; f.!_ epialti Coe, 1902, from the Pacific Coast of North America; .£:. mitsukurii Takakura, 1910, from Japan; f!_ coei Humes, 1942, from the East Coast of Africa; and c. errantia Wickham, 1978, from the Pacific Coast of North America. Coe· (1902) felt that these worms are true parasites feeding on hemolymph from the gills of male and non-ovigerous female hosts and feeding on crab embryos when the host is an ovigerous female. However, Humes (1942) could find no evidence that the worms feed on hemolymph or damage the gills in any other way (except possibly by impeding oxygen exchange when the infestation is severe}. He referred to the worms as ectohabitants rather than parasites. He also implied that crab embryos are the only source of nourishment for the worms. Scrocco and Fabianek (1970) also found no evidence that the worms feed on hemolyrnph or any other tissue of the host. Kuris (1978) has referred to Carcinonemertes as being egg predators. 4 Regardless of whether the species of Carcinonemertes are consi­ dered to be commensals or true parasites, they d~ display several structural and behavioral modifications related to their symbiotic mode of life. These include: reduction in number of eyes as compared to many free~living nemertean species, increase in number of gonads, reduced proboscis, absence of cephalic grooves or other cerebral sense organs, excessive development of cephalic glands, positive photaxis of the larvae (Humes 1942, Gibson 1972). The juvenile or non-sexual phase of Carcinonemertes is found encysted in mucoid capsules in the branchial chamber, on the gills, or on the exoskeleton of the host crab (Humes 1942, Kuris 1978) with the possible exception of f..=...errans which, according to Wickham (1978a), does not build mucous sheaths and is never found on the gills. The worms begin their feeding, growing, sexual phase upon ·receiving some signal.at the time of extrusion of the egg mass by a female crab. At ~his time the worms leave their capsules and migrate to the abdomen of the host where they take up residence in or near the egg mass. Here they begin a period of rapid growth and maturation. When mucous tubes are constructed, individuals usually inhabit separate tubes, but occasionally a male and female are found together in the same tubes. After mating, the femal~ deposits her eggs in the closed end of her mucous tube. The eggs hatch as free-swimming larvae which eventually escape from the mucous tube. Roe (1979) has shown for c. eoialti that not all larvae from a particular tube hatch at once. Instead, they hatch a few at a time over a period of several days. The larvae may represent a dispersal stage which must settle on the 5 same or on a new host to survive. Once a suitable substrate is located, the larvae presumably lose their swimming cilia and become juvenile worms. Host-to-host transmission of juvenile worms has been shown to occur under experimental conditions (Humes 1942, Kuris 1978). Crabs of both sexes become.infested with juveniles, but the life cycle can only be completed on an ovigerous female. Hopkins (1947) has reported that the spawning history of female Callinectes sapidus can be determined by the presence or absence of mature Carcinonemertes in the gills.