"A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Title from PDF of title page (Georgia Southern University, viewed on April 5, 2010). Stephen P. Vives, major professor; Sophie B. George, Risa A. Cohen, committee members. Electronic version approved: December 2009. Includes bibliographical references (p. 37-40).

Populations of a marine invertebrate symbiont were found on the outer surface and internal spaces of a keratose sponge from a shallow bay in the Florida Keys in May 2014. A total of 24 specimens of the seagrass and reef-dwelling sponge were collected between May 2014 and August 2015 to provide material to identify both host and symbiont, and elucidate information on the nature of the association. Based on a morphological analysis via light microscopy, histology, and scanning electron microscopy (SEM), and 99% similarity in aligned partial sequences from 28S and 18S nuclear ribosomal genes (rDNA), the symbiont was identified as the solitary entoproct Loxosomella vivipara Nielsen, 1966 (Entoprocta: Loxosomatidae). A partial sequence from the Internal Transcribed Spacer Region 2 (ITS2) of L. vivipara was registered to GenBank for the first time. The identity of the host sponge, based on a morphological investigation, is resolved as “velvet sponge” Hippospongia cf. gossypina Duchassing and Michelotti, 1864 (Demospongiae: Spongiidae). This is the first report of an entoproct commensal from Hippospongia cf. gossypina, a sponge that formerly had great commercial value when it was abundant throughout the Bahamas, Florida Keys and Gulf of Mexico. Other common sponge species at the study site were collected to investigate the host specificity of L. vivipara. Evidence that L. vivipara favorably selects the sponges Hippospongia cf. gossypina and Chondrilla nucula over other potential host sponges at the study site is provided. Commensalism is the most plausible justification for this relationship: L. vivipara is dependent on sponges for protection and food particles, while the sponges are unaffected by its presence. Further evidence of host-specific inquilinism is provided for L. vivipara associated with Hippospongia cf. gossypina, but not for L. vivipara associated with C. nucula. An inquilinistic association between an entoproct and sponge is a rare discovery only mentioned in one previous study. Sponge aquiferous qualities such as aperture and canal size, canal and choanocyte chamber arrangement, seawater pumping rate, and food particle size selection are likely factors that inhibit or enable inquilinism in sponge-entoproct associations – a potential topic for future researc / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Thesis (M. Phil.)--University of Hong Kong, 1987.

The benthos of Lake Sibayi, Lake Nhlange, Lake Shengesa and Lake Sifungwe has been sampled by means of a van Veen grab of bite area 0.225m². Except for Lake Shengesa, the substrates of the lakes have been investigated visually by SCUBA divers. Some quantitative sampling, using underwater techniques, has been carried out in Lake Sibayi. In general, the substrate of the lakes consisted of two types, either fine sand with an average particle size of 3.2 phi, or mud with a median phi value of less than 6. The sandy substrata was usually rich in fauna, and the mud usually poor. Lake Sibayi , which is freshwater (135 ppm Cl¯) has estuarine and freshwater species in the benthos. Some of the species, notably Grandidierella lignorum and Apseudes digitalis, show an uneven pattern of distribution with respect to depth. Lake Nhlange is a brackwater lake (3.4‰ salinity) and has mainly an estuarine fauna. Many of the species are different from those found in Lake Sibayi. There is some evidence that the benthic fauna of the lake has increased its range in depth in the years following a flood in January 1966. Only chironomid larvae were found in the benthos of Lake Shengesa. The greater part of the substrate of this lake consisted of a highly organic mud mainly derived from burnt grassland around the periphery of the lake. Lake Sifungwe, which is connected to Lake Nhlange, has a halocline at about 9 metres. The fauna of the benthos has more species than lake Nhlange. There is some evidence to suggest that LGC fauna invades deeper water in summer, and is driven into shallower water in winter because of the fluctuating level of anaerobic conditions below the discontinuity layer. The benthic fauna of the lakes has been compared with that of the estuaries reported on by the Cape Town Ecological Survey. experimental studies on G. lignorum, a species present in Lake Sibayi, suggested that the physiological responses of material from an estuary normally at 35‰ salinity (Kowie River estuary) and from lakes which are normally of low salinity (Groenvlei 2.5‰ salinity, Lake Sibayi) were not different. Studies on substrate choice, and pressure, indicated that these factors do not affect the distribution pattern of G. lignorum in the substrate. Studies on light orientation responses and the effects of rates of carbon dioxide increase of about 20 mm HgC0₂/hr or more, suggest that these may be the principle factors affecting the distribution of G. lignorum in the benthos of Lake Sibayi. Some supporting evidence for the presence of changing pC0₂ has been found. A discussion of the importance of dynamic events at the substrate/water interface is given.

This paper investigates a means of detecting the reaction of aquatic vertebrates to environmental change by recording behavioral patterns within the diurnal activity. An apparatus measuring the activity of Jordanella floridae, Goode and Bean, using a photoelectric sensor system is described. Individual sensors monitored specific areas of the test aquarium that had special significance to the fish in the way of a particular behavioral category. An event recorder documented the breakage of light beams, giving continuous and accurately timed data of activity. Two distinct patterns of activity were recognized; a control, or typical, pattern, and a pattern resulting from the administration of a large (10°C) change in environmental temperature. Modifications in the diurnal behavior were consistent with reactions that could be adaptive for the species under similar conditions in nature.

<p>Aquatic macroinvertebrates of channelized headwater streams in agricultural landscapes are exposed to alterations in chemistry and physical characteristics of benthic sediments. These habitat alterations are known to influence communities of aquatic macroinvertebrates. Benthic sediments can have a wide range of impacts and influences on aquatic macroinvertebrates. I hypothesized that sediments would play a significant role in determining macroinvertebrate community structure within agriculturally dominated headwater streams. I evaluated the influences of sediment chemistry characteristics and physical characteristics on aquatic macroinvertebrate communities in Cedar Creek, Indiana and Michigan, and the Upper Big Walnut Creek, Ohio, during 2017 and 2018. Macroinvertebrates were collected twice per year using artificial substrate and leaf pack samplers and identified to the family level. Sediments were sampled two times per year and analyzed for seven physical characteristics and twenty sediment chemistry characteristics. Principle component analyses were used to create axes that are indicators of gradients of sediment chemistry and physical characteristics that occur among the samples. Macroinvertebrate community metrics used in the analyses included abundance, Shannon Diversity Index, Hilsenhoff Biotic Index scores, Invertebrate Community Index scores, percentage of collector-filters, percentage of scrapers, percentage of Chironomidae and a Berger-Parker Reciprocal Index of dominance. Linear Mixed Effect Model analyses revealed that both sediment chemistry and physical characteristics influence macroinvertebrate community metrics. Aquatic macroinvertebrate abundance was negatively correlated with increasing concentrations of simazine and decreasing concentrations of calcium. Percentages of Chironomidae were positively correlated with increasing percentages of sand and decreasing percentages of clay and decreasing diversity of sediment particle sizes. My data supported the hypothesis that benthic sediments play an important role in determining aquatic macroinvertebrate community structure in headwater streams of agriculturally dominated landscapes. Gradients of chemical characteristics containing simazine and calcium were observed to be negatively correlated with macroinvertebrate abundance. Gradients of physical characteristics including percentages of sand and clay along with the diversity of particle sizes were observed to be positively correlated with percentage of chironomids. My research increases the knowledge that benthic sediments, chemically and physically, can lead to alterations in aquatic macroinvertebrate communities within Midwestern headwater streams. </p>

Wastewater effluent is a major source of aquatic pollution, discharging a continuous and complex mix of contaminants into the environment. The physiological impacts of exposure to individual contaminants are well characterized in fish, but less is known about the consequences of complex mixtures that typify wastewater effluent in the environment. This thesis explores the metabolic and respiratory effects of in situ wastewater exposure on bluegill sunfish (Lepomis macrochirus). By assessing multiple levels of biological organization, I provide evidence that wastewater exposure invoked a metabolic cost in bluegill, which was associated with physiological adjustments to enhance oxygen uptake, delivery, and utilization. These findings broaden our understanding of how fish tolerate life in effluent-dominated waters and support the emergence of metabolic and respiratory physiology as biomarkers in ecotoxicology. / Thesis / Master of Science (MSc)

Experiments on the colonization of artificial substrates by stream benthos were conducted in upper Chingmei Stream, Taiwan. The artificial substrates were colonized by stream benthos for periods of 3, 6 12, 21, 30 and 42 days.The two experiments were designed for different purposes. Experiment I from December 15, 1990 to January 29, 1991 investigated the colonization patterns of stream benthos at two sites: a polluted site caused by coal mining activities (Site 1) and a recovery site further downstream of the polluted site (Site 2). Experiment II from March 14, 1991 to April 28, 1991 tested the effect of two different sizes of substrate (cobble and gravel) on the colonization patterns of stream benthos at Site 2. In Experiment I, the total number of individuals and taxa were significantly affected by exposure period of experimental substrates and sites which indicate the occurrence of succession and the detrimental effect of coal mining activities on the benthic community. At Site 1, only Caenis sp., Euphaea sp. and Chironomidae occurred on all sampling dates and were abundant. The other taxa may just continue to drift away from the site. The chironomid larvae were most abundant. They accounted for over 90% of the colonizing individuals from day 12 to day 42. At Site 2, Baetis spA and Chironomidae were most abundant. They accounted for over 80% during the experiment, except on day 21. The relative abundance shifted from Baetis sp.A to Chironomidae with an increase in colonization time. Association analysis was performed on the abundance of taxa pairs within the same functional feeding group at Site 2. The results suggest that filter-feeders and predators have concordant colonization patterns. The relationship between taxa and abundance at the two sites also was tested by lognormal distribution to determine the degree of equilibrium of the community. In Experiment II, the substratum types influenced only the total number of individuals colonizing baskets. The gravel substrate provides more surface area for stream benthos and supports more individuals. Baetis sp.A and chironomid larvae were abundant; they accounted for over 84% of the individuals from day 6 to 42 on both gravel and cobble. The chironomid larvae comprised 36% of the fauna on the gravel substrate and 35 - 79% of the fauna on the cobble substrate. The results of association analysis on the abundance of taxa pairs within the same functional feeding group showed that there were more taxa pairs with significant associations on cobble than on gravel. The negatively significant associations also occurred more on the cobble substrate. This indicates that biological interactions may be important in determining the development of community on the cobble substrate. Disturbance caused by floods influenced the colonization patterns, especially on the gravel substrate. It reset the artificial substrates back to earlier conditions. This study only suggests that competition may occur in the subtropical Taiwanese stream and further experimentation is needed to demonstrate whether competition occurs. / Graduation date: 1992

Hydrologic Information Systems (HIS) have emerged as a means to organize, share, and synthesize water data. This work extends current HIS capabilities by providing additional capacity and flexibility for marine physical and chemical observations data and for freshwater and marine biological observations data. These goals are accomplished in two broad and disparate case studies – an HIS implementation for the oceanographic domain as applied to the offshore environment of the Chukchi Sea, a region of the Alaskan Arctic, and a separate HIS implementation for the aquatic biology and environmental flows domains as applied to Texas rivers. These case studies led to the development of a new four-dimensional data cube to accommodate biological observations data with axes of space, time, species, and trait, a new data model for biological observations, an expanded ontology and data dictionary for biological taxa and traits, and an expanded chain-of-custody approach for improved data source tracking. A large number of small studies across a wide range of disciplines comprise the “Long Tail” of science. This work builds upon the successes of the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) by applying HIS technologies to two new Long Tail disciplines: aquatic biology and oceanography. In this regard this research improves our understanding of how to deal with collections of biological data stored alongside sensor-based physical data. Based on the results of these case studies, a common framework for water information management for terrestrial and marine systems has emerged which consists of Hydrologic Information Systems for observations data, Geographic Information Systems for geographic data, and Digital Libraries for documents and other digital assets. It is envisioned that the next generation of HIS will be comprised of these three components and will thus actually be a Water Information System of Systems. / text

<p>As the human population increases and the demand for aquaculture increases, aquaculturists are coming up with new ways to mitigate stress in fish to increase their production. Cannabidiol (CBD) is an up and coming nutraceutical that may have potential to reduce stress in not only humans but also other vertebrates such as fish. In this project the effect of CBD on the stress physiology and immunology of Nile tilapia was evaluated both <i>in-vitro</i> and <i>in-vivo</i>. In the <i>in-vitro</i> study, spleen cell proliferation was conducted to observe the effect of CBD on fish T and B cells and were compared to mouse T and B cell proliferation. In the <i>in-vivo</i> study, the fish were reared in a recirculating aquaculture system. The effect of CBD on the stress physiology of the fish in short term and long term were evaluated. Based on the short-term acute study, a longer chronic study was designed where tilapia were fed with and without CBD (0.001% of feed weight) and with and without hydrocortisone stress hormone (0.01% of body weight) every day for four weeks. This experiment compared the various growth and feed utilization parameters as well as physiological and immunological parameters such as, plasma cortisol, blood glucose and protein levels, liver and spleen somatic indices (HSI and SSI, respectively), and lysozyme activity of the fish. From our current research, CBD shows potential in stress modulation and in immune modulation. It may have different effects based on the species, whether they need to enhance their immune response or reduce inflammation to be healthy. It also seems to have had different effect on different parts of the immune system. Hematological parameters were not significantly affected by acute stress. CBD did not make any substantial difference in growth. However, in the presence of stress, CBD was able to lower lysozyme activity down to the normal control levels. By administering the proper dosage of CBD on a case by case basis, health benefits can be achieved. Further investigation into the matter may not just be useful in stress mediation in aquatic organisms but may also have implications in human medicine as well.</p>