Sonic-tagged flannelmouth suckers made long distance and local movements; 12.5% of fish moved ≥ 98 km downstream and 40% stayed within Glen Canyon. Motivation for long distance movements could be spawning or food related. A controlled flood of 1,274 m³/sec did not displace flannelmouth suckers downstream or interrupt spawning. The majority (62%) of fish moved into the impounded mouth of the Paria River. Spawning occurred as evidenced by capture of adults over spawning areas and collection of young-of-year (YOY) in spring and summer. From May-September 1996, YOY flannel mouth suckers were captured in the impounded mouth of the Paria River. Successful rearing of YOY fish was attributed to the presence of a warm, slackwater area in the mouth. Formation of this area is dependent upon antecedent Colorado and Paria river flows and their effect on sediment deposition in the mouth of the Paria River.

<p> In Arctic Alaska, Dolly Varden <i>Salvelinus malma </i> is highly valued as a subsistence fish; however, little is known about oceanic dispersal or ecology. This study addresses this knowledge gap, by using a fisheries independent method, pop-up satellite archival tags (PSATs). In spring of 2012 and 2013, we attached 52 PSATs to Dolly Varden in a river in northwestern Alaska, which flows into the Arctic Ocean, to examine the marine dispersal, behavior and habitat occupancy of this species. Tagged Dolly Varden demonstrated two types of dispersal, including offshore and nearshore dispersal. The offshore type was the first documented northwesterly dispersal and occupancy of Outer Continental Shelf (OCS) areas of the Russian Chukchi Sea. While occupying this area, tagged Dolly Varden demonstrated affinity for the first 5 m of the water column, diel patterns in depth occupancy, and dive depths of up to 50 m, while experiencing a thermal environment of generally 3&ndash;7&deg;C. During the nearshore dispersal type, Dolly Varden transited in coastal areas of northwest Alaska, likely returning to their natal rivers to spawn. While in nearshore areas, tagged Dolly Varden always occupied shallow waters (&lt; 6 m), and experienced a rapidly changing thermal environment (&plusmn; 15&deg;C), including some waters temperatures cooler than -1&deg;C. This study demonstrates that PSATs offer an alternative and effective platform with which to study several aspects of large adult Dolly Varden dispersal and ecology in areas where it is not practical or feasible to capture these fish, such as in coastal and offshore regions of Arctic Alaska. Additionally, the results of this study have increased our knowledge of the summer marine distribution, behavior and thermal environment of Dolly Varden in Arctic regions of Alaska, and this knowledge is important to several stake holders for the conservation of this important subsistence species.</p>

<p> Arctic Grayling (<i>Thymallus arcticus</i>) are widely distributed on the Arctic Coastal Plain (ACP) of Alaska, and are one of the few upper level consumers in streams, but the trophic pathways and food resources supporting these fish are unknown. Grayling migrate each summer into small beaded streams, which are common across the landscape on the ACP, and appear to be crucial foraging grounds for these and other fishes. I investigated prey resources supporting different size classes of grayling in a beaded stream, Crea Creek, where petroleum development is being planned. The specific objectives were to measure terrestrial prey subsidies entering the stream, quantify prey ingested by Arctic Grayling and Ninespine Stickleback (<i>Pungitius pungitius </i>), determine if riparian plant species affect the quantity of terrestrial invertebrates ingested by grayling, and determine if prey size and type ingested were a function of predator size. Results indicated that small grayling (&lt; 15 cm fork length (FL)) consumed mostly aquatic invertebrates (caddisflies, midges, and blackflies) early in the summer, and increasing quantities of terrestrial invertebrates (wasps, beetles, and spiders) later in summer, while larger fish (> 15 cm FL) foraged most heavily on stickleback. Riparian plant species influenced the quantity of terrestrial invertebrates entering the stream, however these differences were not reflected in fish diets. This study showed that grayling can be both highly insectivorous and piscivorous, depending upon fish size class, and that both aquatic and terrestrial invertebrates, and especially stickleback, are the main prey of grayling. These results highlight the importance of beaded streams as summer foraging habitats for grayling. Understanding prey flow dynamics in these poorly studied aquatic habitats, prior to further petroleum development and simultaneous climate change, establishes essential baseline information to interpret if and how these freshwater ecosystems may respond to a changing Arctic environment. </p>

Cholla Lake is a cooling reservoir for the coal-fired Cholla electrical generating plant. The lake provides recreational fishing and water contact recreation. The fish populations are self-sustaining. I collected water, sediment, and whole body fish samples to be analyzed for levels of some possibly toxic inorganic constituents. I also measured dissolved oxygen, pH, Secchi disk transparency. I compared current fish population structure, fish stomach contents, and the frequency of occurrence of benthos, with those same parameters in previous studies. Water temperature and turbidity have increased; catfish and bluegill have increased in their relative abundance; and the density of benthic invertebrates has decreased. Aquatic insects occur most commonly in the stomach contents of bluegill and filamentous algae in the stomachs of catfish. Selenium levels in all matrices exceed national averages and are above levels in a nearby reservoir unaffected by the power station.

In 1995, Squaw and Flash creeks were renovated with Antimycin-A to eradicate non-native fish. After renovation, 129 Apache trout from Flash Creek were introduced into Squaw Creek. Two years later, all size classes were present. Apache trout above a natural barrier on Flash Creek were allowed to repopulate the renovated section. Three years later, 45 Apache trout were found below the natural barrier. In both streams, adults selected deep, slow moving areas. Juveniles selected shallow areas with fast currents. Both size classes selected open areas exposed to sunlight with surface turbulence and other forms of instream cover. Apache and Gila trout were experimentally PIT-tagged in the: (1) pelvic girdle; (2) abdominal cavity; and (3) dorsal musculature to determine the best tagging location. Fish tagged in the dorsal musculature had 0% tag loss and 98% survival. The minimum size Apache and Gila trout could be tagged was 90 mm TL.

The synthesis of RNA in isolated nuclei from two sea urchin species was studied. Isolated nuclei from sea urchin embryos synthesize a variety of RNAs in vitro. Two small RNAs, 5S rRNA and N1 RNA, made in isolated nuclei are identical to the small RNAs detected in vivo by hybridization selection with specific cloned sea urchin DNAs. RNAs complementary to DNA clones for histone mRNAs and rRNAs were also detected among the in vitro transcripts. The rRNAs appear to initiate and terminate transcription in the isolated nuclei near the correct DNA sequences. Synthesis of these four RNAs faithfully in the isolated nuclei encompasses the activities of all three RNA polymerases. / The addition of cell extracts modifies the activity of the RNA polymerases in the isolated embryo nuclei. Extracts from sea urchin eggs specifically inhibit RNA polymerase III activity in the isolated nuclei. This activity was purified from the crude egg extracts approximately fifty fold. The inhibition of RNA polymerase III does not appear to be due to a nonspecific activity in the egg extract. The partially purified inhibitor from the egg extract also inhibits RNA polymerase III in DNA dependent transcription assays from mouse and Drosophila. The inhibitor probably interferes with RNA polymerase III initiation by an unknown triphosphate dependent mechanism. / The activity of the inhibitor is destroyed within thirty minutes of fertilization. The rapid destruction of the inhibitor activity by fertilization suggests that this activity is biologically relevant. The inactivation of the inhibitor may be at least partially due to the ionic changes associated with fertilization. The activity of the inhibitor may be related to a 135,000 molecular weight protein which can be detected in preparations from eggs but not in parallel preparations from embryos which lack the inhibitor. / This dissertation demonstrates in an in vitro assay a possible control mechanism for RNA polymerase III activity in sea urchin development. It is conceivable that such a mechanism is operative in other organisms as well. / Source: Dissertation Abstracts International, Volume: 43-09, Section: B, page: 2884. / Thesis (Ph.D.)--The Florida State University, 1982.

A series of experiments has demonstrated that selection of prey by predators was determined by prey accessibility rather than predator preferences. The caridean shrimp Toxeuma carolinense is one of the numerically dominant invertebrates in subtropical seagrass meadows. However, feeding analyses of dominant fishes have shown that few fish consume Tozeuma. Predator-preference experiments revealed that Tozeuma was underrepresented in the diet of Lagodon rhomboides, the dominant epibenthic predatory fish, and that large Tozeuma were preferred over small individuals. / I examined the influence of prey behavioral responses, microhabitat shifts and cryptic coloration on prey accessibility with a combination of field observations and laboratory experiments. Tozeuma's behavior and habitat choice were extremely similar in both the field and laboratory and were tightly coupled to the seagrasses Tozeuma inhabits. In the presence of predatory fishes, Tozeuma exhibited a significant increase in the proportion of time spent in certain rare behaviors and a significant decrease in certain common behaviors. Laboratory experiments revealed that Tozeuma's behavioral responses to predators resulted in a significant increase in shrimp survival and, thus, are adaptive. In addition, Tozeuma changed its microhabitat in response to predators; individuals that did not respond were often consumed. These experiments demonstrate that prey behavior and microhabitat choice reduced Tozeuma's accessibility to predatory fishes and hence, increased its survival. / Source: Dissertation Abstracts International, Volume: 44-11, Section: B, page: 3292. / Thesis (Ph.D.)--The Florida State University, 1983.

My research was designed (1) to examine the role of predatory decapods as an organizing force in grassbed prey distribution and abundance patterns, and (2) to compare the importance of vegetation as a prey refuge with its importance in providing increased living space for prey populations in seagrass meadows. My approach was first to catalogue the feeding ecology of the larger shrimps and crabs in Apalachee Bay, Florida. This study revealed great overlap among trophic niches of the 14 decapod species examined, nine feeding categories based on different proportions of prey consumed by 25 age-related ontogenetic trophic groups, trophic niche similarity that was unrelated to taxonomic similarity, and that living plants, especially algal epiphytes, are more important in diets than has been realized. The pink shrimp, Penaeus duorarum, was clearly the most important predatory decapod. / After evaluating the predator-exclusion effectiveness of a new cage design by defaunating and monitoring faunal recruitment into cages during a 2-mo period of high predator densities, I initiated a 1-mo manipulative field experiment designed to test the refuge hypothesis. Replicate predator inclusion (treatment) and exclusion (control) cages were established across a vegetation gradient and Penaeus duorarum were enclosed in treatment cages. Cages successfully excluded larger decapods and fishes and a significant predation effect was detected for total densities of all major prey taxon groups in a simple (low plant biomass) habitat. The general consequence of increasing microhabitat complexity on the outcome of predator-prey interactions was a reduction in Penaeus effects on total prey densities across the vegetation gradient. Vegetation provided more protection for amphipods and mollusks than for decapods and polychaetes. These results extend the premise that vegetation affords protection for prey from the laboratory to nature. These experiments also reveal that living space (on vegetation) alone can account for microhabitat distributions of some grassbed fauna without invoking predation as a causal mechanism. / Source: Dissertation Abstracts International, Volume: 44-07, Section: B, page: 2041. / Thesis (Ph.D.)--The Florida State University, 1983.

TEM observations of holotrich nematocysts in catch tentacles of the sea anemone Haliplanella luciae reveal that capsule wall formation occurs by means of a self-assembly of proteins from a Golgi-derived pool within the capsule interior. Wall growth results from precipitation of material onto the wall, as indicated by an increase in wall thickness throughout development. Wall maturation is characterized by wall thinning. Such thinning was reversed by performic acid treatment, suggesting that disulfide bond formation within the wall causes thinning. Nematocyst thread walls stain with the sulfur stain, alcian blue, both before and after performic acid treatment, while capsule walls are stained only after such treatment, suggesting that the thread has "free" sulfur groups that are absent from the capsule. / Occurring simultaneous with wall development, is a Golgi-deposition of calcium into the developing nematocyst, as evidenced by potassium pyroantimonate deposits in the Golgi and nematocyst interior that were removed by EGTA. Tube inversion is accompanied by an apparent increase in antimonate concentration within the nematocyst, along with an increase in fluids in the cytoplasm, suggesting that a dehydration of nematocyst contents occurs at the time of tube inversion. / The mature nematocyst moves to the cell surface (in preparation for discharge) by apparent microtubule disassembly between the capsule and dense bodies located at the cell surface. / Nematocyst discharge begins with the opening of the capsule tip apical flaps. The flaps are sealed by subunit-lined seams that separate upon discharge, suggesting that the subunits hold the flaps together. / The everted thread is lined on both sides by subunits that might bind together to hold the uneverted thread in its folded configuration. Thread eversion could follow subunit uncoupling. / Nematocyst discharge is accompanied by a calcium-mediated contraction of supporting cell microfilament bundles. Such contraction causes the capsule to become recessed beneath these bundles, possibly anchoring the capsule in the tentacle. Because extracellular fibrous network connections occur between the cnidocyte cell surface and the supporting cell stereocilia, it was proposed that supporting cell contraction (which changes supporting cell shape) might initiate nematocyst discharge. / Source: Dissertation Abstracts International, Volume: 44-10, Section: B, page: 3013. / Thesis (Ph.D.)--The Florida State University, 1983.

Atya innocous occurs in permanent and temporary freshwater streams in Panama. Its microhabitat distribution depends in part on the presence of congeners. The propodus and dactylus of each cheliped of A. innocous bear about 300 setae modified for specific functions in food collection. These setae may be divided into three basic types: chemoreceptors, scrapers, and filtering setae. The latter two types also function as mechanoreceptors. The cheliped setae are probably extended by hemocoelic pressure, producing an efficient filtering fan. Mechanosensory and chemosensory bipolar neurons innervate the cheliped setae, presumably providing the shrimp with the ability to detect current velocity, particulate load and food sources. The external morphology and ultrastructure of these sensilla are described. / The peropods are also used to groom body parts and brooded embryos. Super-8 cine films show the role mouthparts play in grooming. The third maxillipeds groom the antennae and antennules of the prawn, with the distal endite of the second maxillipeds freeing lodged debris from pereopods one and two. The pectinate comb of the fifth pereopod grooms the dorsal surface of the abdomen and pleopods. / Electron microscopy showed pores leading to unicellular glands within the epidermis. Three gland types were observed and their respective functions described. / Adaptations for a lotic habitat seem to have dominated atyid evolution. With the exception of lake species, most atyid shrimp have a wide array of morphological modifications for life in running water. / The mouthparts, mandibles and foregut of Atya innocous and another atyid Potimirim glabra are compared to test the hypothesis that these structures are related to diet. Potimirim glabra inhabits quiet pools scraping periphyton from leaf surfaces and decaying organic detritus. The feeding appendages of both species are modified for handling fine food. The mandible of these shirmp have a strong incisor and molar process but are not utilized for crushing large food items. The primitive nature of the mandibles and foregut suggest the placement of the family Atyidae at the base of the caridean evolutionary tree. / Source: Dissertation Abstracts International, Volume: 43-12, Section: B, page: 3877. / Thesis (Ph.D.)--The Florida State University, 1982.