Spawning and parental care in the pink variety of Cichlasoma nigrofasciatum (Gunther) was studied from September 1970 to May 1971. The objectives of the study were to determine: (1) the spawning behavior of C. nigrofasciatum when isolated as pairs; (2) the spawning behavior of a pair when sharing an aquarium with other cichlid species. The study was conducted in two parts.In Part 1 three aquaria were set up, each containing a pair of sexually mature pink convicts. Twelve different pairs were observed over a period of 120 days. Pre-spawning and post-spawning activities were noted. These were recorded in a pictograph form developed by the author. Eight of these activities were observed in the pre-spawning period and 46 were observed during the days following spawning. The interactions between the members of any one pair differed very little from the interactions of any other pair.One spawning was observed from start to finish and every egg placement was recorded. The eggs appeared to be deposited in an irregular pattern, but form a relatively compact mass when the spawning is completed. When a pair is isolated the female cares for both the eggs and the wigglers. The male takes an active role in the care of the fry when they are just starting to swim. The male becomes the more ardent parent once the fry are free swimming and spends much of his time keeping the female in close proximity to the young.In Part 2 the presence of other fishes in the aquarium changed the male's behavior appreciably. He became much more involved in the early post-spawning stages, actively involved in the defense of the eggs and wigglers. These changes were not limited to the male; the female's behavior also changed. She was a much more conscientious parent in the later stages of fry care. The male spent very little time driving the female toward the fry. Both parents became more attentive in Part 2.Six aquaria were used in Part 2. This section placed the pink convicts in aquaria with six other species. The interspecific activity was the prime observation. All of the species observed acted alike. The spawning of several of the species was observed, as was the activity of caring for the young of a different species. The most notable observation here was the similarity of behavior of the cichlids representing three different genera.In both parts all pairs spawned in or on a flowerpot provided. The egg and fry care was almost the same for all of the fishes. The interspecific interactions were as intense as most of the intraspecific. The level of intensity observed declined in the following order: (1) same sex same species; (2) same sex related species; (3) different sex same species; and (4) different sex different species.All of the species in Part 2 that spawned used the same behavioral displays used by the convicts in Part 1. All display with lateral weaving, erected fins, flared opercula, and lowered branchiostegals. All of the spawning pairs attempted to occupy a large territory, but none insisted on more than 5t of their spawning tank. Generally the pairs observed in this study established pair bonds and spawned within two weeks of their introduction to the aquarium.The pink convict lends itself well to this kind of behavioral study because it is a hardy, easy to spawn species large enough to observe easily. They tolerate laboratory conditions very well. The pink variety of C. nigrofasciatum is much less aggressive and more attractive than the native variety.

Loma salmonae is a microsporidian parasite that infects economically important Chinook salmon (Oncorhynchus tshawytscha) farmed in British Columbia, Canada. Here a variety of research efforts aimed at improving early detection and diagnostic tools, developing preventative strategies, and increasing understanding of the parasite/host interactions are presented. First, the development of chicken-derived polyclonal antibodies (IgY) specific for L. salmonae is described. These antibodies have proven useful for immunohistochemical detection of parasites very early in the infection process. Next, the immune-modulating effects of intra-peritoneal β-glucan inoculation of Chinook salmon are presented. Intensity of L. salmonae infection was significantly reduced in fish inoculated with β-glucan 3 weeks prior to parasite exposure, although prevalence was not reduced in these fish. Gene expression analysis of head kidney from glucan-inoculated fish measured at 1, 2 and 3 weeks post-inoculation (PI) revealed that the majority of differential expression occurred at 1 week. Pathways related to antioxidant defence, innate immune responses, antigen presentation, as well as oxidative metabolism were up-regulated in glucan-inoculated fish at 1 week PI. Finally, temporal gene-expression analysis on gill and kidney tissue from Chinook salmon infected with L. salmonae is described. Analysis at 4 weeks post-exposure (PE) in the gill revealed an early up-regulation of gas transport, whereas numerous pathways including oxidative metabolism, antioxidant defences, monooxygenases and immune receptors were down-regulated in the gill at the same time point. Similarly, oxidative metabolism, antioxidant defences, and monooxygenases were down-regulated in the kidney at 4 weeks PE. However, there is evidence for a developing immune response over time. Antigen processing and presentation pathways were up-regulated in the kidney at 4 weeks and in both tissues at 8 weeks PE. In addition a number of immune receptors and genes involved with innate immune functions were also up-regulated at 4 and 8 weeks PE in the kidney. / Graduate / 0306

Digenean eye-flukes of the genus <i>Diplostomum </i>(Family:  Diplostomatidae) are common in the eyes of freshwater fishes.  <i>Diplostomum </i>spp. infections can lead to severe detrimental deformities and even death to both farmed and wild fish species.  Identification of <i>Diplostomum</i> spp. in the fish host (metacercaria) is challenging because species are morphologically indistinguishable.  Since <i>Diplostomum</i> spp. are difficult to identify the literature is confounded by synonymy and as a result, the taxonomic status of the genus remains unclear.  Thus, it is difficult to ascertain the pathological status, diversity and geographical distribution of this economically important group of parasites. The purpose of this study was to define operational taxonomic units (OTU) using morphometric and molecular data collected from <i>Diplostomum </i>spp. metacercaria in the U.K.  Data was collected from ten fish species and four host locations:  lens humor retina and brain.  Four OTU were defined by host location using morphometric analysis.  Hence the morphometric analysis proved metacercaria from the four host locations were different in size and shape. Four OTU were discriminated using PCR-RFLP and sequence analysis.  However, with the exception of brain parasites, those in the fish eye (lens, humor and retina) could not be differentiated by host location.  Therefore, although parasites in the three fish eye locations were different in size and shape, they were not genetically different.  The OTU ITS1 sequence data was compared to published <i>Diplostomum</i> spp. sequences and the following genetic similarity was revealed:  OTU1 showed 99.4% similarity to <i>D. mergi</i>;  OTU2 99.7% similarity to <i>D. baeri</i> and OTU3 99.7% similarity to <i>D. paracaudum/D. spathaceum.  </i>OTU4 in the fish brain has previously been described as <i>D. phoxini.</i> The molecular approach was subsequently used in a temporal study to assess <i>Diplostomum </i>spp. metacercaria infections over the course of a year in a rainbow trout farm.

This study examined three aspects of the processes of host location and initial attachment of the infective copepodid stage of the sea louse, <i>Lepeophtheirus salmonis</i> Krøyer 1838, to its host Atlantic salmon, <i>Salmo salar </i>(L.). The role of host and non-host odours and derived chemicals in modifying copepodid behaviour was identified in laboratory bioassays. Seasonal and stage-specific changes in the energetics of the eggs and the free-living larval stages were investigated through respiration experiments and chemical analyses. The influence of realistic physical factors, light intensity, salinity and host swimming speed, on determining the sites of initial copepodid attachment were identified in flowing water conditions, by the use of flume studies. Exposure to original odours and extracts of host odours resulted in significant changes in non-oriented behaviour and movement patterns which would increase the probability of host encounter, whilst exposure to original and extracts of host odour gave near-significant levels of oriented movement to the odour source. The host-derived chemicals isophorone and 1-octen-3-ol appeared to induce activated and limited arrested behaviours in the copepodid, respectively. During all stages of embryonic and larval development a gradual reduction in weight and energy content with developmental stage of larvae was noted, as lipid and protein stores were preferentially catabolised to provide energy for morphological changes and increased locomotion of the later larval stages, as revealed by an observed increase in respiration rates with developmental stage. Seasonal changes in embryonic dry weight, energy and biochemical composition were masked by the presence of seasonally variable proteinaceous egg cases. The free living stages showed a mixed trend in reproductive strategy, similar to previous studies of <i>L. salmonis </i>eggs in response to seasonal changes in temperature and photoperiod, but also similar to trends observed in food-unlimited holopelagic copepod species. Light intensity, salinity and host swimming speed independently and interactively altered the distribution and total initial attachment of <i>L. salmonis</i> copepodids on host Atlantic salmon smolts.

Isolates of Yersinia ruckeri were obtained from Europe, North America, Australia and South Africa. The biochemical and serological characteristics of the isolates were investigated. Biochemically the isolates were extremely uniform although motile, Tween positive isolates could be differentiated from non-motile, Tween negative isolates; these were designated biotypes 1 and 2 respectively. With the exception of two isolates, biotype 2 isolates were confined to the U. K. Five 0-serotypes were recognised and an O-serotyping scheme is proposed; the relation of this scheme to previously described schemes is discussed. The geographic distribution of the different serotypes is also discussed. The lipopolysaccharide (LPS) and outer membrane protein (OMP) profiles of isolates were analysed by SDS-PAGE and Western-blotting using both rabbit and rainbow trout antisera. The relation of LPS-type to 0- serotype, as well as variation within LPS-types, is discussed. Based on interstrain variation in the molecular weight of a heat-modifiable protein and of peptidoglycan-associated (porin) proteins, an OMP-typing scheme was developed. Three major OMP-types comprised 95% of the isolates studied. Variation in biotype, serotype and OMP-type was used as an epizootiological tool, and six serotype 01 clonal groups were recognised which differed in their geographic distribution. The production of iron-regulated OMPs and siderophores was investigated. Four iron-regulated OMPs were produced in all of the isolates examined; siderophores appeared not to be produced by any of the isolates. Production of iron-regulated OMPs was not an important virulence determinant and appears to be a chromosomally-mediated factor. Resistance to the bactericidal effects of normal rainbow trout serum and virulence were also investigated. Serum-resistance was associated principally with two serotype 01 clonal groups and virulence was associated with the same two clonal groups. Other serotype 01 clonal groups and other serotypes were iii generally serum-sensitive and avirulent. Thus, serum-resistance is an important virulence determinant in this organism. The role of outer membrane components in serum-resistance and virulence is discussed.

Graduation date: 1986

Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 174-184) / Microfiche. / xiii, 184 leaves, bound ill. 29 cm

Typescript. / Thesis--University of Hawaii, 1963. / Bibliography: leaves 189-194. / xv, 194 leaves ill. (part mount. and col.) diagrs., tables

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1966. / Bibliography: leaves [180]-199. / xxiv, 297 l illus. (part mounted), tables

Aspects of the growth, reproduction and diet of Chaetodon miliaris, the millet-seed butterflyfish, were studied in an effort to characterize populations of fish exploited by the aquarium fish industry. Age determinations were accomplished by examination of daily growth rings within otoliths. Age estimates were corroborated by growth experiments, analysis of a size-frequency distribution, and the determination of the onset of reproductive maturity. Estimates of the duration of the larval tholichthys stage were also obtained from study of the otoliths. The sex ratio of £. miliaris was 1:1 and individuals matured after one year of growth. The spawning season extended from November through Hay but peaked in February and March. No lunar influence on spawning was found. Estimates of fecundity were high and indicated a relatively large investment in reproduction. Chaetodon miliaris is broadly opportunitistic in its diet, however it feeds principally on zooplankton in the water column. The diet of individual fish varied as a function of the time of year, the collection location and the size of the fish. Individuals from Kaneohe Bay, Oahu, were small and appeared to be reproductively inactive when compared to fish from other areas. Dietary deficiencies are postulated as causing these differences. The overexploitation of populations of the millet-seed butterflyfish as a fisheries resource is improbable due to its fast growth, high fecundity, and the existence of refuge populations. / Thesis for the degree of Master of Science (University of Hawaii at Manoa). Typescript. Bibliography: leaves [93]-102.