Orientador: Ivan Sazima / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-04T14:13:24Z (GMT). No. of bitstreams: 1 Bonaldo_RobertaMartini_M.pdf: 942939 bytes, checksum: 402f5af12cb6d33685ef9a23b2692f1c (MD5) Previous issue date: 2005 / Resumo: Os peixes-papagaio (Perciformes: Scaridae) são importantes componentes das guildas de herbívoros e detritívoros de recifes tropicais e subtropicais. Estes peixes são hermafroditas seqüenciais protogínicos e geralmente apresentam fases dicromáticas seqüenciais, denominadas inicial (fêmeas ou machos) e terminal (somente machos). Este estudo caracterizou o forrageamento de Sparisoma amplum, S. axillare e S. frondosum, espécies sintópicas de Scaridae no Arquipélago de Fernando de Noronha, Pernambuco. As três espécies diferiram na seleção e preferência de substrato usado para forrageio, mas indivíduos iniciais e terminais de mesma espécie apresentaram preferência e seleção de substrato semelhante, exceto S. amplum. O padrão de distribuição das taxas de forrageamento ao longo do dia foi semelhante entre indivíduos de mesma espécie, mas diferente entre indivíduos de espécies distintas. Indivíduos em fase inicial apresentam maior freqüência de forrageamento que indivíduos terminais e apenas indivíduos de fase inicial forragearam agrupados em locais rasos, nos quais os indivíduos terminais defendiam territórios. Indivíduos em fase terminal das três espécies de Sparisoma sp. forragearam em grupo em áreas de maior profundidade. As três espécies também se associaram a outras espécies recifais, como o budião-de-Noronha (Thalassoma noronhanum), que segue os peixes-papagaio durante o forrageamento e os limpa quando interrompem momentaneamente seu forrageamento. As três espécies também procuraram estações fixas de limpeza. Indivíduos em fase inicial foram seguidos mais freqüentemente pelo budião e procuraram menos as estações de limpeza, que os de fase terminal. Indivíduos em fase inicial possivelmente foram seguidos com maior freqüência, por T. noronhanum, porque forragearam com maior freqüência. Como os indivíduos em fase inicial são limpos durante o forrageamento, não precisam procurar as estações de limpeza com tanta freqüência como fazem os indivíduos em fase terminal / Abstract: Parrotfishes are important components of the herbivore and detritivore guilds of tropical and subtropical reefs. These fishes are protogynous hermaphrodites which change colour and sex, from initial phase females or males (IP) to terminal phase males (TP). The foraging of Sparisoma amplum, S. axillare and S. frondosum was studied at Fernando de Noronha Archipelago, tropical West Atlantic, where these parrotfishes are syntopic. The three species differed in substrate selection and preference, but IP and TP individuals of the same species preferred the same substrate type, except for S. amplum. Feeding rates of IP individuals were higher than those of TP ones but the distribution of feeding frequencies throughout the day of IP and TP individuals of the same species was similar. Initial phase individuals of all three species foraged in groups at shallow sites, whereas terminal phase ones defended territories there. Terminal phase individuals of S. amplum and S. frondosum were recorded foraging in groups at deeper sites. The suggestion is made that for TP individuals, shallow sites are mostly reproductive areas and deeper sites are foraging areas. The three parrotfish species also associate with other reef species, such as the Noronha-wrasse (Thalassoma noronhanum), a fish that follows the scarids during the foraging and cleans them when they interrupt momentarily their feeding. At the study site, the parrotfishes are also cleaned at fixed cleaning stations of gobies, wrasses and shrimps. Initial individuals were followed more often by the Noronha wrasse and posed at fixed cleaning stations less frequently than the terminal ones. Initial phase fishes probably are followed more often by the Noronha wrasse because they forage more than the terminal ones. Since the IP individuals were cleaned by T. noronhanum while foraging, they have no need to stop this activity to pose at cleaning stations as the TP individuals have to do / Mestrado / Ecologia / Mestre em Ecologia

Orientadores: Fosca Pedini Pereira Leite, Sergio Ricardo Floeter / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-16T19:50:45Z (GMT). No. of bitstreams: 1 Krajewski_JoaoPaulo.pdf: 9575479 bytes, checksum: 263e857c27328008c50d4b577be61438 (MD5) Previous issue date: 2010 / Resumo: Os recifes proporcionam abrigo e alimento para diversas espécies de peixes e, portanto, pode haver uma relação entre a distribuição e comportamento de peixes recifais e a composição de substratos do recife. Fatores físicos, especialmente o hidrodinamismo e profundidade, também parecem ter grande influência sobre a distribuição e comportamento de algumas espécies de peixes recifais. No presente estudo a relação entre a distribuição e atividade de espécies de peixes, especialmente as que se alimentam de invertebrados bentônicos (zoobentivoras), e a composição de substratos do recife, hidrodinamismo e profundidade foi estudada em recifes do arquipélago de Fernando de Noronha, Pernambuco. As principais espécies zoobentivoras de Fernando de Noronha forrageiam principalmente sobre substratos compostos por algas filamentosas verdes e vermelhas e algas pardas cobertas de sedimento, e sua atividade alimentar não é distribuída proporcionalmente à abundância relativa dos diferentes substratos. Ainda, para algumas espécies, o uso de substrato pode variar entre recifes. A dieta principal dos zoobentívoros mais abundantes em Fernando de Noronha são poliquetas e crustáceos. Quatro espécies foram estudadas quanto à variação de sua atividade entre diferentes recifes. Haemulon chrysargyreum, Halichoeres radiatus, e Cephalopholis fulva em geral parecem evitar nadar na coluna d'água quando há maior batimento de ondas. Por outro lado, Thalassoma norohhanum não varia seu comportamento em função do hidrodinamismo. A presença de distúrbio no substrato também pode influenciar o comportamento dos peixes recifais de Fernando de Noronha, uma vez que experimentalmente foi demonstrado que espécies carnívoras oportunistas são atraídas por distúrbios causados no substrato não consolidado. Em geral, o hidrodinamismo é o principal fator que influencia a distribuição e comportamento de peixes recifais em Fernando de Noronha, especialmente os planctívoros e alguns herbívoros. A abundância e biomassa de peixes em geral foi maior em recifes com menor hidrodinamismo, mais fundos (>10m) e maior cobertura de corais. Os peixes zoobentívoros de Fernando de Noronha, porém, aparentam ser generalistas na escolha de substrato de forrageamento e habitat e, portanto, parece não haver relação entre sua abundância e a disponibilidade de seus principais substratos de forrageamento. / Abstract: Reefs provide shelter and food for several fish species and, thus, there may be a correlation between the abundance and behaviour of fishes and the reef bottom composition-Physical factors, such as water movement and depth, may also have a profound impact in species distribuiton and activity on reefs. Here, the possible relationship between the distribution and activity of reef fishes, mainly benthic carnivores, and reef bottom composition, water movement and depth was studied in the Fernando de Noronha Archipelago, off Northeast Brazil. The main benthic carnivorous fishes at the archipelago forage mostly on substrata composed by filamentous and brown algae covered by sediments, and the different types of substrata present on reefs were used disproportionaly to their availability. Some studied species also varied their foraging substratum selection between nearby reefs. The main items in the diet of the benthic carnivorous fishes were polychaetes and crustaceans. We also studied the local variation in the activity of four fish species, and Haemulon chrysargyreum, Halichoeres radiatus, e Cephalopholis fulva tended to avoid swimming in the water column when there was higher water movement. On the other hand, Thalassoma noronhanum did not vary its activity with diferent degres of water movement. We also recorded that the presence of substratum disturbance on soft sediments may alter the activity of opportunistic carnivorous fishes, since they were attracted by disturbance on the bottom caused experimentaly and started to forage in the area where the substratum was disturbed. In general, water movement was the main factor influencing the fish communities in Fernando de Noronha, especially of herbivorous and planktivorous fishes. Abundance and biomass of fishes in general were greater in reefs with less water movement, deeper (>10m) and whith more coral cover. The benthic carnivorous fishes of Fernando de Noronha, however, were mostly versatile in their habitat use and foraging substratum selection and its distribution seem not to be influenced by the avalability of their main foraging substratum. / Tese (doutotrado) - Universida / Ecologia / Doutor em Ecologia

Aspects of the life history of Myxus capensis which were likely to be most affected by man-induced habitat changes, were studied in the eastern Cape. Myxus capensis was found to be specialized for a catadromous life history. The fry migrate into freshwater reaches of rivers within a few months of being spawned at sea and return to an estuarine or marine environment when maximum size has been attained and large energy reserves necessary for spawning have been accumulated. Myxus capensis penetrates considerable distances up eastern Cape rivers and although present in the upper reaches of some estuaries, is only common in freshwater-dominated systems. Myxus capensis has adapted its life history style in a number of ways to overcome the constraints associated with the spatial separation of the freshwater feeding areas and the marine spawning grounds in a region prone to droughts and erratic river flow. Research on the more estuarine-dependent Mugil cephalus, which is also found in the freshwater reaches of eastern Cape rivers, enabled useful comparisons to be drawn. As the latter species is not dependent on a freshwater phase in its life cycle, it is subject to different selection pressures. This comparative approach gave insights into the adaptive significance of the life history tactics of Myxus capensis. Myxus capensis displays a number of life history tactics characteristic of migratory fish species which are thought to increase population fecundity by increasing the number of large females and hence maximizing egg production. These include a sex ratio in favour of females, faster female growth, females remaining longer in the freshwater feeding areas and reaching a larger ultimate size. Possible adaptations to the periodic isolation of the feeding and spawning areas include: (i) the development of ripe gonads only in estuarine or marine areas when access to the spawning grounds is ensured; (ii) year-round spawning and hence recruitment which enables the erratic floods to be used at any time for downriver spawning migrations and reduces the chances of total recruitment failure due to short-term adverse environmental conditions and (iii) a relatively wide range of size and age at first (and final) sexual maturity (2+ to 5+ years); this tends to ensure successful reproduction and recruitment in spite of a series of poor years, as well as dampen population fluctuations after long periods of isolation in fresh water. The dependence of Myxus capensis on the freshwater reaches of eastern Cape rivers makes this species vulnerable to man-induced habitat changes. The erection of barriers to migration has cut off large stretches of suitable habitat and almost completely eliminated Myxus capensis from certain rivers. This detrimental effect has been largely responsible for the recent inclusion of this species on the Red Data list of endangered fish species in South Africa. This study demonstrated the considerable fisheries potential of both mullet species and this should ensure that their conservation and wise utilization be given high priority. Management proposals include: (i) the netting and lifting of Myxus capensis over barriers to migration; (ii) the construction of fish ladders when feasible and (iii) the artificial propagation of this species to enable large-scale stockings of existing man-made impoundments as well as natural habitats to be carried out. It is predicted that the life history characteristics of Myxus capensis, which evolved in response to an erratic freshwater environment, should ensure that when man-induced habitat changes are rectified, this species will again flourish in eastern Cape rivers.

Goatfishes inhabit inshore reefs and corals and are commercially important across their distribution in the Western Indian Ocean (WIO). The biogeography of these species in the WIO has not been explored with regards to their levels of diversity and relationships among regions. The genetic connectivity and differentiation of three goatfishes of the genus Parupeneus (P. barberinus, P. macronemus and P. rubescens) was studied using two mitochondrial genes (ND2 and 16S rRNA) and one nuclear gene (RAG1) using specimens from East and southern Africa, islands around the Mascarene plateau, Oman, Maldives and the Red Sea. Haplotype diversities, networks and AMOVA were used to measure genetic variance among localities and defined regional groups. There were high haplotype (HD > 0.9) and low nucleotide diversities (< 0.006) among all species for all gene regions, suggesting high levels of genetic differentiation among different areas, except for the mtDNA 16S data for P. macronemus and P. rubescens. For all three species, the FST population pairwise values revealed significant differentiation in all datasets for most population pairwise comparisons with the Maldives and genetic connectivity with haplotypes being shared among other localities. The 16S and RAG1, AMOVA for P. barberinus revealed a significant (P < 0.05) strong genetic structure among groups, for example P = 0.00 was estimated in the 16S data for four groups (the Maldives, WIO islands, Kenya and eastern mainland). This study found evidence for regional differentiation within the WIO for these three species supporting the presence of genetic breaks among areas. This differentiation could be either due to the historical isolation among areas or due to geographic and oceanic barriers such as the Mascarene Plateau and the Agulhas Current eddies in the Mozambique Channel. The effects of oceanographic features and physical barriers in the species distribution range and the dispersal potential based on the life history features of the species can have an influence on the genetic structuring of a population. It is also important to note that the length of the pelagic larval phase is just one factor affecting dispersal in marine organisms that can also explain the difference in genetic population structure. Unfortunately there is no specific information on the larval dispersal of these three goatfish. Therefore, studies are needed to be conducted on the specific biology and life history strategies of each Parupeneus species. These results suggest the importance of other factors, such as currents, and larval retention that may cause strong differentiation. These factors should also be considered when observing larval dispersal and its effect on population genetic structure. This study support the hypotheses that physical factors, processes (geographic barriers and oceanographic characteristics) and life history parameters need to be studied to understand the genetic differentiation of these Parupeneus reef fishes.