Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 119-124).

Meagre and the greater amberjack are promising emerging species in aquaculture. This is due to their fast growth rate, large size, high processing yield and high quality fillet. However, little is known about the immune system of these fish and several potential pathogenic threats to sustainable culture of these fish have been identified. Therefore, this thesis has begun to characterise the immune response of these species in order to better combat pathogenic threats. The focus of this thesis is the identification, modulation and monitoring of key innate and adaptive immune genes. This is achieved by identifying conserved regions of target gene sequence and designing consensus primers to these in order to generate a partial sequence, which could then be used as a base from which RACE PCR could be performed to obtain full sequence. The identified sequence was then used to produce qPCR primers, anti-meagre IgM and anti-meagre IgT monoclonal antibodies and a functional synthetic greater amberjack piscidin active peptide. Using the developed qPCR primers the constitutive expression of target genes was determined in the gills, gut, head kidney and spleen. Changes in transcript expression were then monitored in these tissues in response to PAMP stimulation in vivo and in vitro in order to better understand how these genes are modulated by viral, bacterial and fungal stimuli. Furthermore, the meagre development of the immune system was monitored from 1 day post hatch (dph) until 120 dph, providing insights into when immune maturity is achieved. Monoclonal antibodies were also produced and their viability tested in a variety of assays including Western blot, Immunohistochemistry and ELISA. Finally, A synthetic greater amberjack piscidin was produced and the bacteriostatic capabilities of this peptide were tested and showed promising results against known bacterial fish pathogens, indicating a potential for future uses within and outwith aquaculture.

published_or_final_version / Ecology and Biodiversity / Master / Master of Philosophy

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The genus Seriola includes several important commercial fish species, yet the phylogenetic relationships between species have not been fully investigated to date. This study reports the first molecular phylogeny for this genus based on two mitochondrial (Cytb and COI) and two nuclear gene (RAG1 and Rhod) fragments for all extant Seriola species (nine species, n = 27). The phylogenetic patterns resolved three main lineages: a ((S. fasciata and S. peruana), S. carpenteri) clade, a (S. dumerili and S. rivoliana) clade and a (S. lalandi and S. quinqueradiata) clade. The closure of the Tethys Sea (12 - 20 MYA) coincides with divergence of the ((S. fasciata and S. peruana), S. carpenteri) clade from the rest of the Seriola species; while the uplifting of the Isthmus of Panama (± 3 MYA) played an important role in speciation between S. fasciata and S. peruana. The climate and water temperature fluctuation in the Pliocene played important roles during the divergence of the remainder of the Seriola species. This study is also the first to describe the evolutionary history of the commercially important species Seriola lalandi across its distribution range. Global patterns of genetic variation within S. lalandi (n = 190) were examined using three genes fragments (mitochondrial DNA COI, Cytb and nuclear RAG1). Three distinct clades were identified, corresponding to three different geographic regions (North-western Pacific - Japan, North-eastern Pacific - USA, and the southern hemisphere clade). These groupings correspond with the previously identified subspecies of S. lalandi (North-western Pacific – S. lalandi aureovittata, North-eastern Pacific – S. lalandi dorsalis, and the southern hemisphere clade - S. lalandi lalandi). AMOVA results and pairwise FST values revealed significant population differentiation between these groups. The population subdivision between these clades in all probability is maintained by biogeographic or oceanographic barriers (such as the equator and East Pacific Barrier) that disrupt gene flow. The southern hemisphere clade comprised of samples from the southern Pacific (AUS, NZL and Chile) and the southern Atlantic (SA). No haplotypes were shared between these areas in the southern hemisphere. This southern hemisphere clade was further investigated with six microsatellite markers. The analyses revealed the South African populations as genetically distinct from populations of the South Pacific oceans (AMOVA, FCA and STRUCTURE results). In summary, the South African and southern Pacific grouping could be the result of recent vicariant events during the Pleistocene glacial / interglacial periods and / or contemporary oceanographic forces acting on these populations. Further population differentiation was found within the South African samples, but not in the South Pacific. In the southern Pacific clade this lack of population structure is the result of high gene flow (analysed with MIGRATE) between the sampling localities. This is the first report on the genetic structure of this commercial important species for South African populations. Five sampling localities from the west- to the east coast of South Africa were sampled (n = 201). The microsatellite analyses revealed two potentially genetically distinct groups. AMOVA, FST and FCA results suggest small but significant differentiation between populations from the west coast and from the south- and east coast, suggesting a potential genetic break in the Cape Point region (BARRIER). However, the program STRUCTURE showed a high level of admixture along the South African coast and the migration results (MIGRATE and BAYESASS) also suggest a high degree of gene flow between these regions. / AFRIKAANSE OPSOMMING: Die genus Seriola bevat verskeie kommersieel belangrike vis spesies, tog is filogenietiese verwantskap tussen species is nog nie ten volle bestudeer nie. Hierdie studie is die eeste molekulêre filogenietiese studie vir die genus gebaseer op twee mitochondriale DNA (Cytb en COI) en twee nukleêre DNA fragmente (RAG1 en Rhod) vir al die bestaande Seriola spesies (nege spesies, n = 27). Drie beranglike filogenitiese patrone is geïdentifiseer: ‘n ((S. fasciata en S. peruana), S. carpenteri) groep, ‘n (S. dumerili en S. rivoliana) groep en ‘n (S. lalandi en S. quinqueradiata) groep. Die diversifikasie van die ((S. fasciata en S. peruana), S. carpenteri) groep van die ander Seriola spesies stem oor een met die sluiting van die Tethys See (12 - 20 MYA). Terwyl die opligging van die Isthmus van Panama (± 3 MYA) ‘n belangrike rol gespeel het in die spesiasie tussen S. fasciata en S. Peruana. Die veranderlike klimaat toestande en water temperature tydens die Pliocene help met die diversifikasie van die res van die Seriola spesies. Hierdie studie is die eerste om verslag te doen op die evolusionêre geskiedenes van kommersiele belangrike vis spesies Seriola lalandi oor sy hele verspreidings gebied. Die globale patrone van genetiese variasie binne S. lalandi (n = 190) is ondersoek deur gebruik te maak van mitokondriale (Cytb en COI) en nukleêre (RAG1) DNA volgorde data. Drie groepe geassosieer met geografie is geïdentifiseer (Noord-westelike Stille Oseaan - Japan, Noord-oostelike Stille Oseaan - FSA en die suidelike hemisfeer groep). Hierdie groepeerings stem oor een met voorheen geïdentifiseerde subspesies van S. lalandi (Noord-westelike Stille Oseaan - S. lalandi aureovittata, Noord-oostelike Stille Oseaan - S. lalandi dorsalis en die suidelike hemisfeer groep - S. lalandi lalandi). AMOVA en FST resultate bevestig die hoë graad van genetiese struktuur tussen groepe. Hierdie populasie groepeerings is moonlik die oorsaak van - en onderhou deur giogeografiese and oseaanografiese grense (soos the ewenaar en EPB) wat geen vloei ontwrig. Die suidelike hemisfeer groep kan verder verdeel word in ‘n suidelike Stille Oseaan (AUS, NZL en Chile) groep en ‘n suidelike Atlantiese groep (SA). Geen haplotiepes word gedeel deur hierdie twee groepe. Hiedie suidelike hemisfeer groep was verder ondersoek met ses mikrosatelliet merkers. Die analises bevestig dat die Suid Afrikaanse populasies geneties verskillend is van die suidelike Stille Oseaan groep (AMOVA, FCA and STRUCTURE). Verdere genetiese struktuur kan verkry word binne die Suid Afrikaanse monsters, maar nie in die suidelike Stille Oseaan nie. In die suidelike Stille Oseaan hiere gebrek aan populasie struktuur is as gevolg van die hoë geen vloei (MIGRATE) tussen die lokaliteite. Hierdie is ook die eerste studie oor die genetiese structure van S. lalandi vir Suid Afrikaanse populasies. Monsters (n = 201) was geneem by vyf lokaliteite vanaf wes tot oos kus van Suid Afrika. Die mikrosatelliet analises dui op twee moontlike genetiese groepe. AMOVA, FST en FCA dui ‘n klein maar betekenisvolle differensiasie tussen populasies van die wes kus en die van die suid en oos kus. Dit dui aan op moontlike breek in die Kaap Punt omgewing (BARRIER). STRUCTURE analises toon egter ‘n bymengsel van twee groepe langs die Suid Afrikaanse kus en migrasie resultate (MIGRATE en BAYESASS) toon ook ‘n hoë graad van gene vloei tussen hierdie gebiede.

Metazoan parasites threaten the development and expansion of yellowtail kingfish (Seriola lalandi) sea-cage aquaculture in Australia. There is international speculation that parasite transmission from farmed to wild fish leads to increased incidence of parasitism in wild fish. Conversely, transfer of parasites from wild fish to farmed fish can negatively impact upon the health of farmed fish. Baseline information on the parasite assemblage of wild S. lalandi in Australia will: 1) allow informed judgments to be made in order to responsibly monitor, and perhaps remedy, potentially negative impacts and; 2) enable identification of parasite species of potential harm to the Australian S. lalandi aquaculture industry. I collected wild Seriola spp. (Carangidae) throughout southern Australia and examined them for metazoan parasites. Fifty-six metazoan parasite species are identified, including one new species. A taxonomic listing is provided for the metazoan parasites found. Taxonomic descriptions are made for the blood fluke Paradeontacylix godfreyi n. sp. (Digenea: Sanguinicolidae) and a redescription is provided for the parasitic copepod Naricolax chrysophryenus (Cyclopoida: Bomolochidae). A qualitative risk assessment was devised for the metazoan parasite taxa identified for the sea-cage aquaculture of S. lalandi in South Australia. Risk was interpreted considering the likelihood and consequence of parasite establishment and proliferation. The monogeneans Benedenia seriolae and Zeuxapta seriolae were considered extremely likely to establish and proliferate. Benedenia seriolae also poses high potential negative consequences for cost-effective S. lalandi sea-cage farming. However, the absence of potential mitigation methods and parasite management for Paradeontacylix spp. (Digenea), Kudoa sp. and Unicapsula seriolae (Myxozoa) indicates that these species may also present high negative consequences for S. lalandi aquaculture in Australia. The nature of wild Seriola migrations is critical for an understanding of the potential impact of disease and parasite interactions between wild and farmed fish. A small-scale tagging programme of wild-caught S. lalandi and S. hippos in South Australia provided insight into the movements of these species. Recapture results indicate that large S. lalandi remain in, or return to, northern Spencer Gulf. S. lalandi also move past sea-cage farms in Fitzgerald Bay, northern Spencer Gulf, which is an important consideration in view of potential expansion of the S. lalandi sea-cage industry in Spencer Gulf. There is surprisingly little experimental assessment on parasite transmission from farmed fish to wild fish. Studies assessing parasite interactions between wild and cultured fish employ models to quantify parasite population levels of cultured, wild and escaped fish, while others carry out comparative surveys of parasite prevalence and intensity over time, in areas close to and distant from farming activity. I provide preliminary data on ectoparasite prevalence and intensity on wild S. lalandi in areas close to, distant from and where there is no sea-cage farming in southern Australia. I review methods employed in the northern hemisphere to assess sea-louse transfer between wild and farmed salmon and propose methods for assessing monogenean parasite transmission from farmed to wild S. lalandi in Australia. In summary, this thesis provides insight into the potential for parasite interactions between wild and farmed S. lalandi. I document the parasite assemblage of wild and farmed S. lalandi and wild S. hippos and provide baseline data on ‘natural’ parasite prevalence and intensity. I provide a taxonomic description of a new species of blood fluke. I indicate the likelihood of parasite transfer from wild fish to farmed S. lalandi, and identify parasite taxa with potentially negative consequences for sea-cage aquaculture. I provide the first firm data that wild S. lalandi move past one area where kingfish are farmed in sea-cages in South Australia. Finally, I propose procedures to better understand the potential for monogenean parasite transmission from farmed S. lalandi to wild fish. This thesis reports new information that is important when considering and managing expansion of the S. lalandi sea-cage aquaculture industry throughout Australia. It also provides baseline data on natural parasite levels to enable ongoing monitoring of the potential impacts of the industry on wild fish populations. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1294807 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007

Metazoan parasites threaten the development and expansion of yellowtail kingfish (Seriola lalandi) sea-cage aquaculture in Australia. There is international speculation that parasite transmission from farmed to wild fish leads to increased incidence of parasitism in wild fish. Conversely, transfer of parasites from wild fish to farmed fish can negatively impact upon the health of farmed fish. Baseline information on the parasite assemblage of wild S. lalandi in Australia will: 1) allow informed judgments to be made in order to responsibly monitor, and perhaps remedy, potentially negative impacts and; 2) enable identification of parasite species of potential harm to the Australian S. lalandi aquaculture industry. I collected wild Seriola spp. (Carangidae) throughout southern Australia and examined them for metazoan parasites. Fifty-six metazoan parasite species are identified, including one new species. A taxonomic listing is provided for the metazoan parasites found. Taxonomic descriptions are made for the blood fluke Paradeontacylix godfreyi n. sp. (Digenea: Sanguinicolidae) and a redescription is provided for the parasitic copepod Naricolax chrysophryenus (Cyclopoida: Bomolochidae). A qualitative risk assessment was devised for the metazoan parasite taxa identified for the sea-cage aquaculture of S. lalandi in South Australia. Risk was interpreted considering the likelihood and consequence of parasite establishment and proliferation. The monogeneans Benedenia seriolae and Zeuxapta seriolae were considered extremely likely to establish and proliferate. Benedenia seriolae also poses high potential negative consequences for cost-effective S. lalandi sea-cage farming. However, the absence of potential mitigation methods and parasite management for Paradeontacylix spp. (Digenea), Kudoa sp. and Unicapsula seriolae (Myxozoa) indicates that these species may also present high negative consequences for S. lalandi aquaculture in Australia. The nature of wild Seriola migrations is critical for an understanding of the potential impact of disease and parasite interactions between wild and farmed fish. A small-scale tagging programme of wild-caught S. lalandi and S. hippos in South Australia provided insight into the movements of these species. Recapture results indicate that large S. lalandi remain in, or return to, northern Spencer Gulf. S. lalandi also move past sea-cage farms in Fitzgerald Bay, northern Spencer Gulf, which is an important consideration in view of potential expansion of the S. lalandi sea-cage industry in Spencer Gulf. There is surprisingly little experimental assessment on parasite transmission from farmed fish to wild fish. Studies assessing parasite interactions between wild and cultured fish employ models to quantify parasite population levels of cultured, wild and escaped fish, while others carry out comparative surveys of parasite prevalence and intensity over time, in areas close to and distant from farming activity. I provide preliminary data on ectoparasite prevalence and intensity on wild S. lalandi in areas close to, distant from and where there is no sea-cage farming in southern Australia. I review methods employed in the northern hemisphere to assess sea-louse transfer between wild and farmed salmon and propose methods for assessing monogenean parasite transmission from farmed to wild S. lalandi in Australia. In summary, this thesis provides insight into the potential for parasite interactions between wild and farmed S. lalandi. I document the parasite assemblage of wild and farmed S. lalandi and wild S. hippos and provide baseline data on ‘natural’ parasite prevalence and intensity. I provide a taxonomic description of a new species of blood fluke. I indicate the likelihood of parasite transfer from wild fish to farmed S. lalandi, and identify parasite taxa with potentially negative consequences for sea-cage aquaculture. I provide the first firm data that wild S. lalandi move past one area where kingfish are farmed in sea-cages in South Australia. Finally, I propose procedures to better understand the potential for monogenean parasite transmission from farmed S. lalandi to wild fish. This thesis reports new information that is important when considering and managing expansion of the S. lalandi sea-cage aquaculture industry throughout Australia. It also provides baseline data on natural parasite levels to enable ongoing monitoring of the potential impacts of the industry on wild fish populations. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1294807 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007

The overall aim of this thesis was to determine the size and age compositions, growth and reproductive biology of Western Blue Groper (Achoerodus gouldii), Blue Morwong (Nemadactylus valenciennesi) and Yellowtail Flathead (Platycepahlus endrachtensis) in south-western Australian waters, in which these three species have divergent life cycle characteristics. As A. gouldii and N. valenciennesi are commercially and recreationally important in coastal waters and P. endrachtensis is one of the most recreationally important species in the Swan River Estuary, these biological data were then used to produce estimates of mortality and spawning stock biomass per recruit for each of these species. The biological data and stock assessment parameters were finally employed comparatively to ascertain whether any of the three species possessed characteristics that would make them particularly susceptible to the effects of fishing and whether there was evidence that any of the species is fully or even overexploited. Achoerodus gouldii typically uses reefs in protected inshore waters along the coast and around neighbouring islands as a nursery habitat and then, as it increases in size, moves to deeper, offshore reefs, where it spawns between early winter and mid-spring. The maximum total length and age of A. gouldii were 1162 mm and 70 years, the latter being the greatest age by far yet recorded for any species of labrid. However, most growth occurs in the first 20 years of life. Histological and demographic analyses demonstrated that all individuals begin life as females and, after attaining maturity, many become males, i.e. A. gouldii is a monandric protogynous hermaphrodite. The L50 at maturity and sex change were 653 and 821 mm, respectively, which correspond to ages of c. 17 and 37 years, respectively. As sex change took place over a narrower range in lengths (650 to 900 mm) than in ages (15 to 49 years), that change is apparently related more to size than age. Since sex change is typically accompanied by a change from green to blue, body colour can be used as a proxy for determining the length (L50) at which females change to males. von Bertalanffy growth curves fitted to the lengths at age of individuals of each sex of this hermaphroditic species using a novel technique demonstrated that, with increasing age, the lengths of males became increasingly greater than those of females. Thus, at ages 15, 30 and 60 years, the estimated lengths at age of females were c. 600, 670 and 680 mm, respectively, whereas those of males were c. 695, 895 and 975 mm, respectively. As A. gouldii is very long-lived and sexual maturity, and even more particularly sex change, occur late, this labrid is potentially very susceptible to overfishing. Thus, because the mortality estimates and per recruit analyses indicated that, at present, this species is close to or fully exploited, fisheries managers will need to take a precautionary and watchful approach to managing and thus conserving the stocks of this species. As with A. gouldii, N. valenciennesi moves to deeper, offshore waters as it increases in size and then matures and spawns in those waters. Although N. valenciennesi has a maximum length of nearly 1 m and thus, like A. gouldii, is moderately large, it has a far shorter life span, i.e. 19 vs 70 years. While female N. valenciennesi does not grow to as large a size as its males (max. lengths = 846 and 984 mm, respectively), the maximum age of both sexes was 19 years. From the growth curves, the females by ages 3, 6 and 10 years havd attained, on average, lengths of 435, 587 and 662 mm, respectively, compared with 446, 633 and 752 mm, respectively, for males. Both sexes grew little after 10 years of age. Juvenile N. valenciennesi < 400 mm in total length were found exclusively in shallow, coastal waters on the south coast, whereas their adults were abundant in offshore waters of both the south and lower west coasts. The females and males typically mature in offshore waters of the south coast at lengths of c. 600-800 mm and ages of c. 7-9 years. In contrast, the vast majority of females caught in offshore waters of the lower west coast (where they were of a similar length and age range to those in offshore waters on the south coast) became mature at lengths of 400-600 mm and 3-4 years of age. The attainment of maturity by N. valenciennesi at far lesser lengths and ages on the lower west coast than south coast suggests that the former coast provides better environmental conditions for the gonadal maturation and spawning of this species. Furthermore, the contrast between the almost total absence of the juveniles of N. valenciennesi in nearshore waters on the lower west coast and their substantial numbers in comparable waters on the south coast indicates that the larvae of this species produced on the lower west coast are transported southwards to the south coast, where they become juveniles. As spawning occurs between mid-summer and late autumn, the larvae, which spend a protracted period in the plankton, would be exposed, on the lower west coast, to the influence of the southwards-flowing Leeuwin Current at the time when that current is at its strongest. Although N. valenciennesi is caught by recreational line fishing and commercial gillnet fishing when they are as young as 3-4 years old, they do not become fully vulnerable to these fisheries until they are about 9 years old. Consequently, the individuals of this species can potentially breed over a number of years before they become particularly prone to capture by fishers. Mortality estimates and per recruit analyses suggested that N. valenciennesi in south-western Australia is not currently overfished. A greater resilience to fishing by N. valenciennesi than A. gouldii presumably reflects, in part, its far shorter lifespan, earlier maturity and possession of gonochorism rather than hermaphroditism. Platycephalus endrachtensis spawns in the Swan River Estuary between late spring and early autumn and completes the whole of its life cycle in this system. Although females attain a far larger length (615 mm) than males (374 mm), females and males were present in each age class. These data, together with a detailed examination of histological sections of a wide size and age range of individuals, demonstrated that this species, unlike some of its relatives, is not a protandrous hermaphrodite, i.e. it does not change from male to female with increasing body size. The combination of the presence of females and males in all age classes and the observation that all of the large number of individuals between 374 and 615 mm were females shows that the far greater length attained by that sex is largely related to its faster growth rate. The fact that females outnumbered males in each age class of P. endrachtensis in which the sample size was substantial, i.e. > 25, with the overall sex ratio being 2.7 females: 1 male, indicate that there has been strong selection for egg production in this species. As the minimum legal length for retention of P. endrachtensis is 300 mm, and relatively few males exceeded this length, the recreational fishery which targets this species is based largely on its females. The estimates of mortality and results of per recruit analyses provided no evidence that P. endrachtensis is currently overfished. From a management point of view, it is advantageous that the current size limit for this species exceeds the average length at which its females (259 mm) attain maturity. Furthermore, this species appears to be resilient to capture and release. The data presented in this thesis demonstrate that A. gouldii possesses biological characteristics which make it potentially more prone to the effects of fishing than is the case with either N. valenciennesi or P. endrachtensis. This presumably accounts, at least in part, for the indications that A. gouldii is the only one of these three species that is likely to be close to or at full exploitation.

Orientador: Rosicleire Veríssimo Silveira / Resumo: Peixes competem entre si em condições de escassez de recursos e por status em uma hierarquia de dominância. Os machos têm que superar potenciais rivais e o comportamento agressivo é a forma de alcançar esse objetivo, entretanto, isso introduz o risco de injúrias e pode levar a morte do animal. Diante disso, objetivou-se avaliar a influência da quantidade de fêmeas no desenvolvimento testicular e mortalidade dos machos de Astyanax altiparanae. Exemplares adultos, 248 machos e 72 fêmeas, foram submetidos a uma biometria inicial e final após 34 dias de experimento. O delineamento foi inteiramente casualizado com quatro tratamentos e quatro repetições, os tratamentos foram as proporções de: 0, 10, 30 e 50% fêmeas/machos. Foram analisados os dados biométricos, a mortalidade, o índice gonadossomático e as fases de maturação gonadal através da análise histológica em microscopia de luz. Os dados foram submetidos ao teste de análise de variância (ANOVA) a 5% de significância e as variáveis que sofreram efeito dos tratamentos foram submetidas ao teste t (LSD). O aumento na porcentagem de fêmeas nos tratamentos, levou a um aumento da mortalidade dos machos, como demonstrado em T0, T10 e T30, entretanto a relação de 1:1 macho/fêmea, influenciou na redução da agressividade e consequentemente na mortalidade dos peixes. Verificou-se que diferentes proporções de fêmeas não diferiram o IGS dos machos, e no tratamento com 50% de fêmeas foi possível ver uma continuidade da maturação testicular,... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Fish compete with each other in conditions of scarcity of resources and for status in a hierarchy of dominance. Males have to overcome potential rivals and aggressive behavior is the way to achieve this goal; however, this introduces the risk of injury and can lead to the death of the animal. The objective of this study was to evaluate the influence of the number of females on the testicular development and mortality of the males of Astyanax altiparanae. Adults, being 248 males and 72 females were submitted to an initial and final biometry after 34 days of experiment. The experimental design was completely randomized with four treatments and four replications, the treatments being the proportions of: 0, 10, 30 and 50% females/males. Biometric data, mortality, gonadosomatic index and gonadal maturation phases were analyzed through histological analysis under light microscopy. Data were submitted to the analysis of variance (ANOVA) at 5% of significance and the variables that underwent treatment effects were submitted to the t test (LSD). The increase in the percentage of females in the treatments led to an increase in the mortality of males, as demonstrated in T0, T10 and T30; however the ratio 1:1 male/female, influenced the reduction of aggressiveness and consequently mortality. It was verified that different proportions of females did not differ the IGS, and in the treatment with 50% of females it was possible to see a continuity of testicular maturation, showing that there... (Complete abstract click electronic access below) / Mestre

Submitted by ELIS MARINA DA SILVA CABRAL (elismarina989@gmail.com) on 2018-05-09T14:46:30Z No. of bitstreams: 1 Dissertação final_Elis Marina.pdf: 1978717 bytes, checksum: 9d56daa81d3c96634c39042f06952046 (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-05-09T17:34:56Z (GMT) No. of bitstreams: 1 cabral_ems_me_ilha.pdf: 1978717 bytes, checksum: 9d56daa81d3c96634c39042f06952046 (MD5) / Made available in DSpace on 2018-05-09T17:34:56Z (GMT). No. of bitstreams: 1 cabral_ems_me_ilha.pdf: 1978717 bytes, checksum: 9d56daa81d3c96634c39042f06952046 (MD5) Previous issue date: 2018-03-07 / Peixes competem entre si em condições de escassez de recursos e por status em uma hierarquia de dominância. Os machos têm que superar potenciais rivais e o comportamento agressivo é a forma de alcançar esse objetivo, entretanto, isso introduz o risco de injúrias e pode levar a morte do animal. Diante disso, objetivou-se avaliar a influência da quantidade de fêmeas no desenvolvimento testicular e mortalidade dos machos de Astyanax altiparanae. Exemplares adultos, 248 machos e 72 fêmeas, foram submetidos a uma biometria inicial e final após 34 dias de experimento. O delineamento foi inteiramente casualizado com quatro tratamentos e quatro repetições, os tratamentos foram as proporções de: 0, 10, 30 e 50% fêmeas/machos. Foram analisados os dados biométricos, a mortalidade, o índice gonadossomático e as fases de maturação gonadal através da análise histológica em microscopia de luz. Os dados foram submetidos ao teste de análise de variância (ANOVA) a 5% de significância e as variáveis que sofreram efeito dos tratamentos foram submetidas ao teste t (LSD). O aumento na porcentagem de fêmeas nos tratamentos, levou a um aumento da mortalidade dos machos, como demonstrado em T0, T10 e T30, entretanto a relação de 1:1 macho/fêmea, influenciou na redução da agressividade e consequentemente na mortalidade dos peixes. Verificou-se que diferentes proporções de fêmeas não diferiram o IGS dos machos, e no tratamento com 50% de fêmeas foi possível ver uma continuidade da maturação testicular, mostrando que não houve alterações no desenvolvimento dos testículos. Conclui-se que, o cultivo em grupos mistos, na proporção de 1:1, é, benéfico para esta espécie. / Fish compete with each other in conditions of scarcity of resources and for status in a hierarchy of dominance. Males have to overcome potential rivals and aggressive behavior is the way to achieve this goal; however, this introduces the risk of injury and can lead to the death of the animal. The objective of this study was to evaluate the influence of the number of females on the testicular development and mortality of the males of Astyanax altiparanae. Adults, being 248 males and 72 females were submitted to an initial and final biometry after 34 days of experiment. The experimental design was completely randomized with four treatments and four replications, the treatments being the proportions of: 0, 10, 30 and 50% females/males. Biometric data, mortality, gonadosomatic index and gonadal maturation phases were analyzed through histological analysis under light microscopy. Data were submitted to the analysis of variance (ANOVA) at 5% of significance and the variables that underwent treatment effects were submitted to the t test (LSD). The increase in the percentage of females in the treatments led to an increase in the mortality of males, as demonstrated in T0, T10 and T30; however the ratio 1:1 male/female, influenced the reduction of aggressiveness and consequently mortality. It was verified that different proportions of females did not differ the IGS, and in the treatment with 50% of females it was possible to see a continuity of testicular maturation, showing that there were no alterations in the development of testicles. In conclusion, the cultivation in mixed groups in the proportion of 1:1 is beneficial for this species.

Identifying the extent to which coral reef species are connected by dispersal is a fundamental challenge for developing marine conservation strategies. Many coral reef species are relatively sedentary as adults, yet have a pelagic larval phase where larvae can potentially be widely dispersed by ocean currents. This thesis focuses on the role of ocean currents in driving spatially explicit patterns of population connectivity among ecologically and commercially important coral reef species by combining research tools from population genetics, oceanography, and biophysical modeling. Despite the substantial differences among the life histories of each coral reef species in this thesis, some similarities in connectivity patterns were found among all species. The results of the kinship and genetic outlier analyses consistently found high levels of connectivity among distant populations separated by hundreds to thousands of kilometers. Despite the high levels of connectivity among distant populations, there was substantial variation in gene flow among the populations of each species. The findings of this thesis highlight the importance of international cooperation for the sustainable management of ecologically and commercially important coral reef species in the Caribbean. In conclusion, the findings of this thesis suggest that marine conservation strategies should conservatively plan for uncertainty, particularly since the many of ecological and physical drivers of connectivity among coral reef species in the Caribbean remain uncertain.