High-resolution velocity measurements were undertaken over a series of redds and riffles on a gravel-bed stream to quantify the hydrodynamics preferred by spawning brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) for redd-site selection. On each riffle studied, over 6,000 velocity measurements per day were acquired to quantify the velocity, depth, Reynolds number, Froude number, bed shear, and turbulent kinetic energy per unit area of streambed in attempts to relate fluid properties to redd-site selection, relative to remaining riffle structures. Results showed that velocity, Reynolds number, and Froude number vary widely at the redd- and riffle-scale with no apparent correlation to spawning location preference. Turbulent kinetic energy per unit area consistently demonstrated a strong correlation with redd locations whereby the metric maintained low values (i.e., unidirectional flow with little turbulence) where redds and attempted redds were observed. Habitat suitability indices were applied at the reach-, riffle-, and redd-scale using the results of the high-resolution velocity measurements. Findings demonstrated that habitat suitability indices, which are based on reach-scale hydraulics, were adequately represented at the reach scale. However, by decreasing the scale to the riffle- or redd-scale, where increasing heterogeneity in the flow regime is revealed, habitat suitability indices failed to adequately reflect the habitat conditions preferred by the spawning fish.

This collection of studies was designed to understand the mechanisms and consequences of competition among early life stages of red drum (Sciaenops ocellatus), with a special attention to asymmetric competition and multiple-breeding strategy of parents. The overall hypotheses were that (1) red drum larvae show behavioral interactions, and the magnitude of these interactions is explained by the sizes of the competing individuals, (2) red drum larvae compete for food and habitat use, and the competition is asymmetric as determined by size and behavioral interactions, and (3) the parents can reduce negative effects of competition among larvae and increase larval survival by altering their multiple-spawning traits. The laboratory experiments showed the existence of sociality in red drum larvae. The magnitudes of aggressive behavior, vigilant behavior and shoaling behavior were explained by a combination of absolute and relative phenotypes of competing individuals, such as body lengths and body condition. A new method of combining the laboratory experiments and the foraging theory disentangled interference competition for food from exploitative competition, revealing that both absolute and relative body lengths of competing individuals influence feeding efficiencies. In addition, vigilant behavior decreased feeding efficiency regardless of body sizes. The competitor size and behavioral interactions between individuals had different effects on competition for habitat use: the existence of larger individuals prevented the newly settled larvae from entering preferred habitats, whereas the aggressive behavior from the occupants of preferred habitats moved newly settled larvae to the unpreferred habitats. Finally, computer simulations using an individual-based model revealed that as interference competition among larvae increased, the number of spawning events and the spawning interval of the parents increased to lessen competition and maximize total survival of offspring. / text

During the last two hundred years many wetlands and streams in Sweden have been lowered to provide land for agriculture and forestry. Some of the coastal wetlands and streams probably served as spawning sites for certain species of fish in the Baltic Sea, but the present situation is not well known. As standardized methods to monitor fish in running waters are carried out during late summer or autumn, there is a need for methods to sample spring-spawning fish in these streams. The aim of this study was to survey the lower kilometer stretch of Hammerstaån in Stockholm, to investigate the extent to which the stream is used by spring-spawning fish. Furthermore, the study aims to evaluate a new type of survey fishing gill net called strömöversiktsnät (SÖN). This was done by comparing the catch of fish by SÖN with that of fyke nets. The comparison of the types of gear included number of fish caught, on a catch per unit effort (CPUE) basis, number of species and the size distributions. The study included 14 days with one gill net and one fyke net at two sites, in total 28 net-days. The inventory yielded in total seventeen species among which only trout (Salmo trutta), perch (Perca fluvitalis), roach (Rutilus rutilus), burbot (Lota lota), eel (Anguilla anguilla) and pike (Esox lucius) were previously known to occur. Six spawning species, smelt (Osmerus eperlanus), vimba bream (Vimba vimba), perch (Perca fluvitalis), roach (Rutilus rutilus), bream (Abramis brama) and white bream (Blicka bjoerkna) were caught in more than 60 individuals, which was set as a limit for comparisons of size distributions. There was no significant difference in CPUE between SÖN and fyke nets. Also length distribution did not differ between SÖN and fyke nets except for the species perch and white bream were the nets caught significant smaller perch and bigger white bream than the fyke nets. The results show that investigations with SÖN or fyke nets during springtime can be of great importance to increase our knowledge about spring-spawning fish in Swedish streams and the coastal areas of the Baltic Sea.

During the last two hundred years many wetlands and streams in Sweden have been lowered to provide land for agriculture and forestry. Some of the coastal wetlands and streams probably served as spawning sites for certain species of fish in the Baltic Sea, but the present situation is not well known. As standardized methods to monitor fish in running waters are carried out during late summer or autumn, there is a need for methods to sample spring-spawning fish in these streams. The aim of this study was to survey the lower kilometer stretch of Hammerstaån in Stockholm, to investigate the extent to which the stream is used by spring-spawning fish. Furthermore, the study aims to evaluate a new type of survey fishing gill net called strömöversiktsnät (SÖN). This was done by comparing the catch of fish by SÖN with that of fyke nets. The comparison of the types of gear included number of fish caught, on a catch per unit effort (CPUE) basis, number of species and the size distributions. The study included 14 days with one gill net and one fyke net at two sites, in total 28 net-days. The inventory yielded in total seventeen species among which only trout (Salmo trutta), perch (Perca fluvitalis), roach (Rutilus rutilus), burbot (Lota lota), eel (Anguilla anguilla) and pike (Esox lucius) were previously known to occur. Six spawning species, smelt (Osmerus eperlanus), vimba bream (Vimba vimba), perch (Perca fluvitalis), roach (Rutilus rutilus), bream (Abramis brama) and white bream (Blicka bjoerkna) were caught in more than 60 individuals, which was set as a limit for comparisons of size distributions. There was no significant difference in CPUE between SÖN and fyke nets. Also length distribution did not differ between SÖN and fyke nets except for the species perch and white bream were the nets caught significant smaller perch and bigger white bream than the fyke nets. The results show that investigations with SÖN or fyke nets during springtime can be of great importance to increase our knowledge about spring-spawning fish in Swedish streams and the coastal areas of the Baltic Sea.

Darbo tikslas buvo ištirti ir palyginti Žeimenos lašišinių žuvų veislyne augintų (I grupė), pavasarį išleistų ir rudenį sugautų Šventosios ir Siesarties upėse (II gupė) ir laukinių, sugautų Žeimenos upėje (III grupė) lašišų jauniklių morfofiziologinę ir fiziologinę būklę, įvertinat morfologinius, morfofiziologinius, kepenų morfopatologinius ir biocheminius bei hematologinius rodiklius. Tyrimo rezultatai parodė, kad lašišų mailiaus išleisto pavasarį ir rudenį sugautų jauniklių Siesarties upėje morfologiniai (Q, L), morfofiziologiniai rodikliai (įmitimo koeficientas, Q/L), kepenų morfopatologinė būklė (kepenų somatinis indeksas, spalva ir konsistencija, riebalų kiekis kepenyse) patikimai skyrėsi nuo veislyne augusių jauniklių ir buvo artimi natūraliai augusių jauniklių Žeimenos upėje rodikliams. Lyginant veislyne augintų lašišų jauniklių hematologinius rodiklius su laukinių lašišų jauniklių rodikliais, matyti ženklūs hematokrito ir leukocitų koncentracijos kraujyje skirtumai. Tačiau eritrocitų ir hemoglobino koncentracijos kraujyje rodo, kad veislyne augintų lašišų jauniklių organizme vyksta intensyvūs kraujodaros ir normalūs medžiagų apykaitos procesai. Remiantis tyrimų rezultatais bus tobulinamos lašišų jauniklių auginimo sąlygos veislyne, tuo pačiu gerės jų funkcinė būklė, imuninis atsparumas ligoms, didės jų galimybė greitai prisitaikyti prie besikeičiančių natūralių aplinkos sąlygų bei išgyventi gamtoje. / The aim of the present study was to investigate and compare salmon juveniles [reared in the Žeimena hatchery (I group), released in the spring and caught in autumn in the Siesartis River (II group), and wild salmon juveniles caught in the Žeimena River (III group)] morphophysiological and physiological state, and the evaluation of morphological, morphophysiological, liver morphopatological and biochemical, haematological parameters. The results of the study showed that salmon fry released in spring and juveniles caught in autumn in the Siesartis River morphological (Q, L), morphophysiological (condition factor, Q/L), liver morphopatological (liver somatic index, color and consistency, and the amount of fat in the liver) statistically differed from the juveniles reared in the Žeimena hatchery (I group), and was close to wild juveniles from the Žeimena River (III group). Comparing the haematological parameters of juveniles reared in the Žeimena hatchery (I group) with wild juveniles from the Žeimena River (III group) we saw the significant differences of hematocrit and leukocyte concentrations in blood. However, red cell and haemoglobin concentration in blood of salmon juveniles reared in hatchery indicates that in the organism is the intensity of blood and normal metabolic processes. Based on the results of our research salmon juveniles rearing conditions in the hatchery will be improved, as well as their functional status, immune resistance to diseases, and their ability... [to full text]

Copies of author's previously published articles inserted. / Bibliography : leaves 201-217. / ix, 216 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Concentrates on the settlement and nursery stages of the life history of Panaeus latisulcatus over a seven year history. Key nursery areas within the Gulf of St. Vincent were monitored between October 1989 and June 1996. It was determined that the best sampling technique was the use of a fully enclosed jet net. A mean index of abundance calculated from these trawls was used to estimate the relative abundance in the area sampled. No particular trend in post larval settlement patterns and juvenile abundance was obvious. A longer time frame may be required to observe significant changes in this species. / Thesis (Ph.D.)--University of Adelaide, Dept. of Environmental Biology, 1999

Copies of author's previously published articles inserted. / Bibliography : leaves 201-217. / ix, 216 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Concentrates on the settlement and nursery stages of the life history of Panaeus latisulcatus over a seven year history. Key nursery areas within the Gulf of St. Vincent were monitored between October 1989 and June 1996. It was determined that the best sampling technique was the use of a fully enclosed jet net. A mean index of abundance calculated from these trawls was used to estimate the relative abundance in the area sampled. No particular trend in post larval settlement patterns and juvenile abundance was obvious. A longer time frame may be required to observe significant changes in this species. / Thesis (Ph.D.)--University of Adelaide, Dept. of Environmental Biology, 1999

A lek-breeding cichlid fish Pseudocrenilabrus philander was studied experimentally. Females in choice-chamber experiments showed no active choice for male size and colour, or for other male attributes, but preferred males which courted most actively. In a laboratory lek, the significant determinants of the strongly skewed mating success in males were territory size, side-shake and female chasing frequency. Together these three variables explained 79% of the variation in male mating success, with territory size alone accounting for 75% of the variation and the other two variables each accounting for 2% of the remaining variation. As there was no difference in territory quality in the laboratory lek, territory size became the principal measure of the effect of male-male competition since it was directly related to dominance. Both side-shake and female chasing could be identified as the basic factors influencing female choice, as they had an immediate effect on the display-response mating system of females. Thus, the relative importance of these three variables indicated that sexual selection in this particular lek mating species operated chiefly through the agency of intrasexual competition for dominance. However, both female behaviour and their requirement for a prolonged pre-spawning courtship had the effect of promoting male rivalry and favouring mating with dominant males. Although the intense male competition excluded subordinate males from practising normal courtship behaviour, competitively inferior males might "make the best of a bad situation" by facultatively adopting an alternative sneaking tactic to gain access to females. Spawning intrusions by females to steal freshly-laid eggs also occurred frequently. However, territorial males appeared to be relatively more tolerant of female intruders than male sneakers. Interference during spawning could lead to a longer pre-spawning courtship and even multiple-mating by females. The results of the present study and the behavioural evidence shown by males and females did not support the ʺrunaway selection modelʺ of the mating pattern in terms of sexual selection in leks, but conformed to the rival ʺwar propaganda modelʺ

Made available in DSpace on 2014-06-11T19:32:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-27Bitstream added on 2014-06-13T21:05:27Z : No. of bitstreams: 1 signor_a_dr_botfmvz.pdf: 560532 bytes, checksum: 83329148a6a5185429d5e4c31d176bfc (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / A composição nutricional da levedura a destaca como alimento funcional. O presente trabalho objetivou avaliar a ação da levedura (Saccharomyces cerevisiae) nas respostas reprodutivas de fêmeas de tilápia do Nilo. No Estudo-I 105 fêmeas da linhagem GIFT foram distribuídas em 15 aquários de 500L (três tratamentos e cinco repetições com sete peixes/aquário). No Estudo-II foram utilizados 63 fêmeas e 21 machos da linhagem GIFT distribuídos em três aquários com capacidade de 7000L de água/cada (21 fêmeas e sete machos/aquário). Em ambos os Estudos, os reprodutores foram alimentados ad libitum com dietas isoprotéica e isoenergética contendo 2,0% de levedura íntegra, 2,0% de levedura autolisada ou ausente de inclusão. O Estudo-I foi realizado na UNESP – AquaNutri, Campus de Botucatu e o Estudo-II foi conduzido no Caunesp - Tilapilcultura Campus de Jaboticabal. Avaliou-se nas fêmeas o desempenho produtivo, status nutricional e composição química das gônadas e, o desempenho reprodutivo e o desenvolvimento inicial das larvas. Os dados foram submetidos à análise de variância e quando significativo aplicou-se o teste de comparações múltiplas de médias. A suplementação de levedura íntegra ou autolisada na dieta das reprodutoras, não melhorou o desempenho produtivo e não influenciou o desempenho reprodutivo das fêmeas. Entretanto, melhorou o desenvolvimento larval 72h após eclosão, com melhor desenvolvimento nas larvas dos reprodutores alimentados com a dieta suplementada com 2,0% de levedura íntegra. / The nutritional composition yeast detach how functional food. The research present objective evaluates the action yeast (Saccharomyces cerevisiae) in the response reproductive of females of Nile tilapia. In Study-I 105 females of GIFT lineage was randomized in 15 500L-aquarius (three treatments and five repetition with seven fish/aquarium). In Study-II was utilized 63 females and 21 males of GIFT lineage was randomized in three 7000L-aquarium (21 female and seven male for aquarium). The spawning was feed ad libitum with diet isoproteic and isoenergetic with 2,0% whole yeast and autolised yeast or supplementation absent. In Study-I were realize in UNESP – AquaNutri Campus de Botucatu and Study-II in Caunesp – Tilapicultura Campus de Jaboticabal. Was evaluation in female productive performance, nutritional status and chemistry composition of gonad (Study-I) and reproductive performance of spawning and development larvae (Study-II). The data was submitted variance analyses and multiple comparison test of mean. The supplemented whole yeast or autolised yeast in diet of spawning didn’t improvement productive performance and didn’t influence reproductive performance of female. Therefore improved of development larvae at 72h after eclosion with improved development in larvae of spawning feed with diet 2,0% whole yeast.

Resumo: A composição nutricional da levedura a destaca como alimento funcional. O presente trabalho objetivou avaliar a ação da levedura (Saccharomyces cerevisiae) nas respostas reprodutivas de fêmeas de tilápia do Nilo. No Estudo-I 105 fêmeas da linhagem GIFT foram distribuídas em 15 aquários de 500L (três tratamentos e cinco repetições com sete peixes/aquário). No Estudo-II foram utilizados 63 fêmeas e 21 machos da linhagem GIFT distribuídos em três aquários com capacidade de 7000L de água/cada (21 fêmeas e sete machos/aquário). Em ambos os Estudos, os reprodutores foram alimentados ad libitum com dietas isoprotéica e isoenergética contendo 2,0% de levedura íntegra, 2,0% de levedura autolisada ou ausente de inclusão. O Estudo-I foi realizado na UNESP - AquaNutri, Campus de Botucatu e o Estudo-II foi conduzido no Caunesp - Tilapilcultura Campus de Jaboticabal. Avaliou-se nas fêmeas o desempenho produtivo, status nutricional e composição química das gônadas e, o desempenho reprodutivo e o desenvolvimento inicial das larvas. Os dados foram submetidos à análise de variância e quando significativo aplicou-se o teste de comparações múltiplas de médias. A suplementação de levedura íntegra ou autolisada na dieta das reprodutoras, não melhorou o desempenho produtivo e não influenciou o desempenho reprodutivo das fêmeas. Entretanto, melhorou o desenvolvimento larval 72h após eclosão, com melhor desenvolvimento nas larvas dos reprodutores alimentados com a dieta suplementada com 2,0% de levedura íntegra. / Abstract: The nutritional composition yeast detach how functional food. The research present objective evaluates the action yeast (Saccharomyces cerevisiae) in the response reproductive of females of Nile tilapia. In Study-I 105 females of GIFT lineage was randomized in 15 500L-aquarius (three treatments and five repetition with seven fish/aquarium). In Study-II was utilized 63 females and 21 males of GIFT lineage was randomized in three 7000L-aquarium (21 female and seven male for aquarium). The spawning was feed ad libitum with diet isoproteic and isoenergetic with 2,0% whole yeast and autolised yeast or supplementation absent. In Study-I were realize in UNESP - AquaNutri Campus de Botucatu and Study-II in Caunesp - Tilapicultura Campus de Jaboticabal. Was evaluation in female productive performance, nutritional status and chemistry composition of gonad (Study-I) and reproductive performance of spawning and development larvae (Study-II). The data was submitted variance analyses and multiple comparison test of mean. The supplemented whole yeast or autolised yeast in diet of spawning didn't improvement productive performance and didn't influence reproductive performance of female. Therefore improved of development larvae at 72h after eclosion with improved development in larvae of spawning feed with diet 2,0% whole yeast. / Orientador: Luiz Edivaldo Pezzato / Coorientador: Margarida Maria Barros / Coorientador: Teresa Cristina Dias Ribeiro Koberstein / Doutor