The study of organism level energetics in conjunction with ecosystem level energetics can lead to a better understanding of the structure and function of stream ecosystems. The purpose of this study was to calculate energy budget equations for a net-spinning caddisfly, Hydropsyche venularis Banks, and to develop, or modify, methods used to determine consumption and growth in the field. The method used to determine consumption rate was a modification of the procedure used by Ladle et al. (1972). Growth rate was determined by mark-recapture and metabolic rate was determined in a Gilson respirometer. Egestion rate was determined by a new method. Consumption rate was found to be higher than other values reported for hydropsychids. Growth and metabolic rate were similar to that reported by McCullough et al. (1979) for H. occidentalis. Egestion was much lower than would be predicted from consumption and cast doubt as to the usefulness of the new method. Energy budgets were calculated from regression equations relating the various processing rates to body weight and temperature for 1, 8, and 15 mg larvae at 15 to 25°C. The overall energy budget was: C - 0.53 cal/mg/hr, G - 0.01 cal/mg/hr, R - 0.01 cal/mg/hr, AE - 8%, NGE - 56%, GGE - 5%. Egestion was constant at 0.01 cal/mg/hr. The high consumption rate of H. venularis, above that necessary for growth and maintainence may be significant in the processing of energy in Little River. Feces produced by H. venularis are larger than the particles ingested. The fecal pellets are then available to other filter-feeders and deposit feeders. Higher consumption rates may therefore increase the efficiency of the ecosystem. / Master of Science

Larvae of Cheumatopsyche analis and Hydropsyche betteni produce a water soluable silk fiber in an aquatic environment. Study of the morpholocial characteristics of the silk gland cells would provide valuable information of where the components of the fiber and associated adhesive secretions are produced and preliminary data on their chemical composition. The silk glands of Cheumatopsyche analis and Hydropsyche betteni were examined with specific histochemical stains for lipids, proteins, nucleic acids, mucopolysaccharides and carbohydrates. Whole mounts indicate a high degree of polymorphism of the nuclei throughout the gland. In both Cheumatopsyche analis and Hydropsyche betteni typical cellular organelles, invaginating plasma membranes and microvilli are present. Serial sections indicate immediate deposit of both fiber and adhesive secretions beginning at the blind end of the gland and continues proximally through the "manufacturing" portion to the "excretory" portion.The highly proteinaceous fiber demonstrates a lack of acid mucopolysaccharides and a prevalance of carbohydrates and some polymers containing glucose, galactose and/or glucosamine. The adhesive secretion in the "manufacturing" portion is a homogenous layer surrounding the fiber. It is comprized of large amounts of carbohydrates, mucopolysaccharides and a small amount of glycoprotein which increases slightly as it followed proximally. Light staining vacuoles of similar characteristics to the fiber punctuate the coating adhesive layer and to be continuous with the fiber. In the "excretory" portion the coating adhesive layer is not found. Fiber staining intensifies greatly and similar characteristics of the adhesive section are assumed by the fiber. Cells of this portion have long microvilli and demonstrate bands of carbohydrate and mucopolysaccharides within the cytoplasm. Possible material absorbtion is indicated.Ball State UniversityMuncie, IN 47306

Stream ecology is dominated by studies that describe the distribution of invertebrate populations and communities. Many of these studies make untested assumptions about the various ecological processes that influence these distributions. The most common assumption, which is often unstated, is that distribution patterns reflect habitat selection by individual animals. However, very few studies have directly tested the relative importance of this process or considered other processes that may also affect the distribution of stream invertebrates. In this thesis I use a correlative survey in combination with manipulative field experiments and behavioural observations to investigate the factors and ecological processes that are associated with the distribution of hydropsychid caddisfly larvae in rocky upland streams in southeastern Australia.

Thesis (M. Ed.)--Kutztown University of Pennsylvania, 1990. / Source: Masters Abstracts International, Volume: 45-06, page: 3051. Typescript. Includes bibliographical references (leaves 42-46).

No description available.

No description available.

Thesis (M. Sc.)--Memorial University of Newfoundland, 1997. / Restricted until November 1998. Bibliography: leaves 172-179.

The incidence of parasitism by Bunodera mediovitellata in Trichoptera in Tin Can Creek was investigated. Larvae of Lepidostoma roafi had a low incidence of infection , while Psychoglypha alascensis larvae had a high incidence of infection. The encapsulation reactions of these Trichoptera larvae to internal Epon implants, and metacercariae of the parasite encysted within the silk glands, were examined in vivo to determine the details of the cellular encapsulation reactions of Trichoptera to foreign objects in both of these sites, and to determine which hemocytes are involved in the reaction. The hemocytes of larvae of P. alascensis were capable of encapsulating Epon implants within the hemocoele; the reaction took approximately twenty days longer than those of other insects that have been maintained at 20°C. The hemocytes of larvae of P. alascensis are also capable of encapsulating the metacercariae of their natural parasite B. mediovitellata in the silk glands despite the normal absence of hemocytes from the silk gland lumen. The hemocyte capsules around both the non-living and living objects was typical of the 'ordinary encapsulation reaction' described by Salt (1970). The capsule consisted of an inner layer of flattened cells which were densely packed and an outer layer of cells which were not flattened to the same extent as those of the inner layer. The hemocytes which took part in both capsules around implants and capsules around parasites were flattened elongated hemocytes which probably correspond to plasmatocytes or granulocytes. However, the production of a Summary Fate Map of free circulating hemocytes demonstrated that hemocyte types are stages in the development of a number of lines of hemocyte types. It appears that the hemocytes taking part in the encapsulation reactions belong to two of these lines of hemocyte types. / Science, Faculty of / Zoology, Department of / Graduate

No description available.

Life histories, trophic dynamics , abundances, and microdistrubution of Trichptera were investigated in the Flathead River, Montana, from January 1977 through August 1979. Thirty-six Trichoptera species representing 9 families were collected from 5th order tributaries and the 6th order Mainstream River.