Processes occurring during the early life of marine fishes encompassing the larval, settlement, and juvenile stages can have important impacts on recruitment and subsequent population dynamics. Yet these life stages remain poorly understood, especially in coral reef-associated species of commercial and recreational fisheries interest. Two years (2003-2004) of monthly sampling of 17 stations along a transect spanning the east-west axis of the Straits of Florida revealed consistent spatiotemporal patterns in larval abundance, growth, and mortality of several snapper and barracuda species. Much of the species-specific variability in these patterns tracked adult life history, and spatial (several snapper species) and temporal (Sphyraena barracuda) patterns in larval growth were related to larval food availability. While no patterns were identified in larval mortality rates, tethering experiments examining relative rates of predation on late-stage Lutjanus griseus larvae in surface waters of the lower Florida Keys revealed that relative predation rate and probability of predation in oceanic areas seaward of the reef was significantly greater than over reef or nearshore seagrass/hardbottom habitats. The combined effects of mortality during these early stages in concert with variability in early life traits caused selective mortality to be pervasive throughout the early life stages of snappers and barracudas. Patterns in selective mortality were investigated by tracking and repeatedly sampling several cohorts of larvae in 2007 and 2008, and for the first time in tropical reef fishes, linking young pelagic larvae with settlement-stage fish and juveniles. In agreement with the growth-mortality hypothesis, large size-at-hatch and fast larval growth conveyed a survival advantage in most species examined, but several switches in the direction of selection with ontogeny and over time occurred, and were contrary to this hypothesis. Consistent patterns of trait-mediated selective mortality lower trait variability in the surviving population, while inconsistencies in these patterns may contribute to the high degree of variability that characterizes these early life stages. Results presented in this dissertation help fill knowledge gaps critical to the understanding and modeling of dispersal and connectivity in several economically valuable snapper and barracuda species. In addition, the identification of life history traits important to the survival of individuals through the larval and into the juvenile stage, has implications for future management of these ecologically and economically valuable species.

Abstract¡G The principal objectives of this research are to investigate the species composition and distribution of larval fish in relation to water temperature¡Bsalinity¡Bchlorophyll a and the abundance of copepods in Tapeng Bay and Kaoping coastal waters. Thirty-one species of the larval fish belonging to 29 genera and 16 families were identified in Tapeng Bay, with the mean numerical abundance of 22.9 ¡Ó40.7 ind./100m3 during the sampling period between June 1999 and December 2001. The trend of seasonal change in numerical abundance of the larval fish was not coincident interannually. The 7 most dominant species were Omobranchus sp., Tridentiger obscurus, Pterogobius Zonoleucus, Blenniidae gen. sp., Gobiidae gen. sp., Entomacrodus lighti and Engraulis japonicus, occupied 94% of the total larval fish abundance¡Famong these, the first two dominant species, Omobranchus sp. and T. obscurus contributed to 80% of the total count. One hundrad and eighty-four species of the larval fish belonging to 130 genera and 69 families were identified in Kaoping coastal waters, with the mean numerical abundance of 390.6¡Ó593.5 ind./100m3 during the sampling period between June 1999 and June 2001. Generally, the numerical abundance of the larval fish showed significantly seasonal changes, with lowest in winter and up to highest value in summer. The 10 most dominant species were Sillago japonica, Engraulis japonicus, Tridentiger obscurus, Gobiidae gen. spp., Pagrus major, Scomberoides lysan, Leiognathus nuchalis, Ceratoscopelus warmingi, Scatophagus argus and Diogenichthys laternatus, occupied 67% of the total larval fish abundance. The mean abundance, species number and species diversity index of the larval fish were obvious higher in Kaoping coastal waters than in Tapeng Bay. The dominant species of larval fish in Tapeng Bay were mostly sandy benthic species (Blenniidae and Gobiidae) and coastal epipelagic species (Engraulidae). The larval fish assemblage in Kaoping coastal waters was diverse, and dominated by benthic species (Sillaginidae), sandy bottom species (Blenniidae and Gobiidae), coastal epipelagic species (Engraulidae), mesopelagic species (Myctophidae) and coastal-migrant species (Scatophagidae).

No description available.

No description available.

Thesis (PhD (Biology))--University of Limpopo, 2010. / Digenean parasites are known to be a large and diverse group of parasites. Some of these parasites are free-living, a few are ecto-parasitic, while the majority are endo-parasitic in most invertebrates and vertebrates. Digenean parasites have always been known to be host specific. However, the degree to which these parasites are host specific, is determined by the number of hosts they are able to utilise and the parasitic stages they would currently be at. Morphologically the link between the cercarial and other parasitic stages such as metacercarial and adult stages, were found to be very difficult to establish, since different developmental stages utilise different types of hosts. For instance, cercariae may use the same or different hosts for their metacercarial stages. An example of this is in the case of freshwater snails where the cercariae re-penetrate the same snail and encyst as metacercariae, and then the snail hosts serve also as second intermediate hosts. Adult digenean parasites on the other hand utilise vertebrate hosts different from those serving as second intermediate hosts, as final or definitive hosts. Digenean trematodes like any other helminth parasites have been well researched for decades due to their widespread health-related diseases that they cause and their economic impact globally, especially in third world countries. Research in this field included aspects of species diversity, morphology, distribution, epidemiology and immunology. Despite all of these aspects, these parasites continue to thrive in the face of numerous strategies aimed at their control. Lately polymerase chain reaction (PCR) techniques have been employed to assist with parasite biology and identification, especially with regards to round- and flatworms. Several genome projects like the Schistosoma Genome Project (SGP) initiated in 1992, was established in an attempt to create gene banks and to allow researchers to utilise technology for genomic analysis in the study of organisms relevant to public health in developing countries. ABSTRACT________________________________________ The methods of gene discovery and their functional discovery have been accelerated significantly and are being progressively applied in numerous organisms of medical and veterinary importance. On the other hand parasitic helminths lag behind parasitic protozoa in the sense that in vitro cultivation systems have not been developed to support the entire life cycle of these helminth parasites, genomic databases are far from being complete and lastly there are no established methods for the highly efficient manipulation of endogenous genes within living worms. The present study was aimed at supplying morphological descriptions and additional information through PCR techniques to enable us later to complete the life cycles of the lesser known parasites experimentally. The study was achieved by collecting materials from six localities, namely Boekenhoutskloof farm dam, Supersand dam, Rietvlei dam, Kiewiet farm dam and Northern farm dam. All these five localities were located in the Gauteng Province, proximal to Tshwane. The sixth locality was Metsi-pepa in the North-West Province that was selected due to the unique eye source that feeds the Mooi River. The collected materials were then studied employing standard light and scanning electron microscopy techniques, as well as applying PCR techniques in order to identify and classify the digenean parasites collected during the study. Life cycle studies were also attempted through experimental infections of potential definitive hosts. Seven different types of snail species were collected during the research study, namely Bulinus africanus, Bulinus tropicus, Lymnaea natalensis, Gyraulus connollyi, Burnupia mooiensis, Biomphalaria pfeifferi and Ferrissia fontinalis. Of these, Lymnaea natalensis was found to be the most abundant snail of the entire snail species collected over a period of four years. Of the above-mentioned snail species only four types were found to be infected with various types of cercariae. ABSTRACT________________________________________ Lymnaea natalensis produced three different cercarial types: a) strigeid cercaria B with its characteristic three pairs of linear penetration glands and a very large sinous intestinal caeca, b) a xiphidio cercaria with three pairs of penetration glands, and c) an avian schistosome cercaria. Bulinus tropicus was found to produce two cercarial types: a) an echinostome cercaria with a collar consisting of 27-spines and b) strigeid cercaria A. The third infected snail species was B. africanus, found to be infected with only one type of cercaria, namely xiphidio cercaria B with its characteristic clustered penetration glands. The fourth infected snail species, G. connollyi, housed two types of monostome cercariae: a) monostome cercaria A possessing 3 pairs of linear penetration glands and b) a clinostomatid cercaria with its characteristic head membrane. Nine metacercarial types were collected from various second intermediate hosts. 27-spined echinostomatid metacercaria A and 43-spined metacercaria B were found encysted on the gills of the following fish hosts: Pseudocrenilabrus philander and Tilapia sparrmanii, as well as in the mantle of the snail hosts, L. natalensis and B. africanus. Two strigeid metacercarial types, a) strigeid metacercaria A encysted within a green cyst and b) strigeid metacercaria B with distinct fore- and hindbodies, were collected from the fish hosts, P. philander. Strigeid metacercaria A was sporadically also found in T. sparrmanii. Two diplostomatid metacercariae were collected from their fish hosts, a) diplostomatid metacercaria A from the cranial cavity of Clarias gariepinus and b) diplostomatid metacercaria B from the vitreous chamber of T. sparrmanii and P. philander. Two metacercarial types of the family Clinostomatidae, a) a clinostomatid metacercaria and b) an Euclinostomatid metacercaria, were collected from the buccal cavity and the muscle tissue of T. sparrmanii, respectively. The last metacercarial stages, namely xiphidio metacercariae, were collected from various hosts such as freshwater shrimps (branchial region), T. sparrmanii (gill filaments) and L. natalensis (mantle). This parasite was found to have developed sexually more in freshwater shrimps compared to the same stage in other infected second intermediate hosts. ABSTRACT________________________________________ Three adult parasites were also identified and described. They include an amphistome fluke of the genus Cotylophoron and the liver fluke, Fasciola gigantica. These two parasites were collected from the rumen and the hepatic ducts of a heifer at the Northern farm, respectively. The third fluke, Echinoparyphium elegans, was obtained from experimentally infected kittens. It was, however, difficult to link the different stages within the same family using only morphological characteristics. The morphological characterization of digenean parasites, especially the adult stages, has been well-documented over the past few decades worldwide. This has, however, not been the case with larval stages. Recent studies have shown that there were many attempts by researchers pertaining to molecular studies using PCR techniques. In most cases the studies were achieved by using matured (adult) stages of digenean parasites. These include the studies done on digenean parasites at species level, family level, superfamily level, suborder level and on general digeneans. Most of these phylogenetic studies were only conducted on medically and veterinary important digeneans. The present study focused more on the amplification of parasites at family level. The universal primers were used to target ITS-1, ITS-2 and LSU regions. Not all the specimens yielded desired amplicons. Only certain stages of the following four families; a) Clinostomatidae, b) Schistosomatidae, c) Echinostomatidae and d) Strigeidae were able to be amplified and sequenced. From this study, it is evident that in future, specific primers for specific digenean parasites need to be designed and used in order for us to achieve our desired goals (i.e. being able to amplify as many digenean specimens as possible including the lesser known trematodes). ABSTRACT________________________________________ The recent study also demonstrated that much more work needs to be done in order for us to understand parasite-host relationships in the localities studied. Experimental life cycle studies are therefore imperative in order to solve most of our cercaria, metacercaria and adult trematode questions raised during the present study.

Abstract The principal objectives of this research are to investigate the distribution of fish larvae in relation to environmental factors in Chiku lagoon and the coastal waters of Tainan, Southwestern Taiwan during the period from August 1998 to June 1999 and during August 13~14, 1997. Seventy-six species of the fish larvae belonging to 65 genera were identified in Chiku lagoon and the mean numerical abundance of the fish larvae was 29 ¡Ó44 inds./100m3 during the sampling period between August 1998 and June 1999; and the dominant species were Omobranchus fasciolaticeps¡BGobiidae gen. sp.¡BSillago maculata and Engraulis japonica. Seventy-two species of the fish larvae belonging to 66 genera were identified in the coastal waters off Chiku lagoon during two cruises of December 1998 and June 1999, with the mean numerical abundance of 35 ¡Ó24 inds./100m3 ; and the dominant species were Myctophidae gen. sp., Ceratoscopelus warming, S. maculata and E. japonica. Eighty-three species of fish larvae belonging to 73 genera were identified and the mean numerical abundance was 35 ¡Ó49 inds./100m3 during the cruise of August 13~14, 1997 at 6 stations along a transect from the coastal waters near Tsengwen River to the waters south of Penghu Island, and the dominant species were Bothidae gen. sp., Stomioidae gen. sp. and Mullidae gen. sp.. The abundance, species number and species diversity of fish larvae were usually higher in the coastal waters of Tainan than in Chiku lagoon. The larval fish assemblages of Chiku lagoon was significantly different from that of the coastal waters of Tainan. The dominant species of fish larvae in the coastal water of Tainan were mostly meso-epipelagic species¡]Myctophidae, C. warningi, Diaphus sp., and Carangidae¡^, while Chiku lagoon was dominated by sandy benthic species¡]Blenniidae¡^and estuarine species ¡]Gobiidae and Engraulidae¡^. The species number and abundance of fish larvae in the coastal water of Tainan were found higher in wet season¡]June¡^than in dry season¡]December¡^. The abundance of fish larvae was significantly different among stations and seasons, but did not different between tides in Chiku lagoon. The abundance of fish larvae was higher at night than during the day in August, 1998 and was usually higher in spring ¡]April¡^and lower at the middle station of Chiku lagoon. The abundance of fish larvae was not significantly correlated with water temperature and salinity, but higher abundance of fish larvae was always found when temperature was between 26¢Jand 30¢J, and in higher salinity ¡]34‰ ~36‰¡^. In the transect study, the abundance of fish larvae was significantly different between surface and deep tows¡]p<0.05¡^, but not among stations and between day and night (p>0.05).

No description available.

No description available.

VIANA, Sidarta Lopes. Avaliação da toxicidade da água residuária da usina de beneficiamento da casca do coco verde em girinos de Leptodactylus vastus (Amphibia, anura, leptodactylidae). 2010. 78 f. Dissertação (Mestrado em ecologia e recursos naturais)- Universidade Federal do Ceará, Fortaleza-CE, 2010. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-05-27T17:35:19Z No. of bitstreams: 1 2010_dis_slviana.pdf: 817917 bytes, checksum: 92c46a8430dd24028846f5b3adfcdb6b (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-05-27T20:41:24Z (GMT) No. of bitstreams: 1 2010_dis_slviana.pdf: 817917 bytes, checksum: 92c46a8430dd24028846f5b3adfcdb6b (MD5) / Made available in DSpace on 2016-05-27T20:41:24Z (GMT). No. of bitstreams: 1 2010_dis_slviana.pdf: 817917 bytes, checksum: 92c46a8430dd24028846f5b3adfcdb6b (MD5) Previous issue date: 2010 / Amphibians have several characteristics that make them particularly sensitive bioindicators for environmental quality. In this study, tadpoles of the anuran species Leptodactylus vastus A. Lutz, 1930 were used in bioassays to evaluate the toxicity of the liquid from the coconut shell (LCCV), a byproduct of the processing of the green coconut shell. It was analyzed acute effects as lethality and chronic effects as changes in the rate of metamorphosis, in the length of the larval period and in the mass of the tadpoles at metamorphosis. It was performed a total of six experiments, each lasting ninety days, using both LCCV extracted from fresh coconut shells still greenish and LCCV extracted from dry coconut shells that had already became yellowish. The first four experiments had seven treatments each, with concentrations of 0% (control), 0,1%, 0,2%, 0,3%, 0,4%, 0,5% and 0,6% of LCCV. The other two experiments had six treatments each, with concentrations of 0% (control); 0,3%; 0,6%; 0,9%; 1,2% and 1,5% of LCCV. Each treatment had three replicates with ten tadpoles each. The tadpoles were collected at Campus do Pici, Fortaleza, Ceará, in different places and days to avoid pseudo-replication in space and time. The LCCV had a toxic effect on the tadpoles of Leptodactylus vastus, causing an increase in mortality and a decrease in size at metamorphosis, in the highest concentrations tested. However, in some intermediate concentrations, the LCCV contributed to an increase in the mass of tadpoles during metamorphosis. Moreover, in the concentrations tested, the LCCV did not affect the ability of surviving tadpoles to complete metamorphosis or the length of the larval period. Tadpoles of L.vastus showed a positive correlation between mass at metamorphosis and length of the larval period, except in the highest concentrations tested. These results indicate that the LCCV can negatively affect the biota of aquatic environments, making necessary to determine safe parameters of its emission to the environment. The tadpoles of Leptodactylus vastus showed a good potential for use in ecotoxicological studies and as bioindicators of disturbance in aquatic environments, as L.vastus is a quite common species that it is not under threat or danger of extinction, and that produce conspicuous ovipositions with many eggs and larvae relatively large and easily manipulated as they do not require aeration or filtration of water or a special diet. / Os anfíbios apresentam algumas características que os tornam bioindicadores particularmente sensíveis da qualidade ambiental. No presente estudo, girinos da espécie de anuro Leptodactylus vastus A. Lutz, 1930 foram utilizados em bioensaios para avaliar a toxicidade do líquido da casca do coco verde (LCCV), subproduto do processo de beneficiamento da casca do coco verde. Foram analisados efeitos agudos como letalidade, e crônicos, como alterações na taxa de metamorfose, na duração da fase larval e na massa dos girinos por ocasião da metamorfose. Foi realizado um total de seis experimentos, cada um com duração de noventa dias, utilizando tanto LCCV extraído de cascas de coco mais frescas e que conservavam a coloração verde quanto LCCV extraído de cascas de coco mais secas cuja coloração tinha se tornado amarelada. Os quatro primeiros experimentos tiveram sete tratamentos cada, com concentrações de 0% (Controle); 0,1%; 0,2%; 0,3%; 0,4%; 0,5%; 0,6% de LCCV. Os outros dois experimentos tiveram seis tratamentos cada, com concentrações de 0% (Controle); 0,3%; 0,6%; 0,9%; 1,2%; 1,5% de LCCV. Cada tratamento teve três réplicas com dez girinos cada. Os girinos foram coletados no Campus do Pici, Fortaleza, Ceará, em locais e dias variados para evitar pseudo-replicação espacial e temporal. O LCCV apresentou um efeito tóxico sobre os girinos de Leptodactylus vastus, com aumento na letalidade e diminuição no tamanho na metamorfose, nas mais altas concentrações testadas. Entretanto, em algumas concentrações intermediárias, o LCCV contribuiu com um aumento na massa dos girinos por ocasião da metamorfose. Por outro lado, o LCCV nas concentrações testadas, não afetou a capacidade dos girinos sobreviventes de completar a metamorfose nem o tempo de duração da fase larval. Os girinos de L.vastus apresentaram uma correlação positiva entre massa por ocasião da metamorfose e duração do período larval, exceto nas mais altas concentrações de LCCV testadas. Os resultados indicam que o LCCV pode afetar negativamente as comunidades bióticas de ambientes aquáticos, se fazendo necessária a determinação de parâmetros seguros de sua emissão para o meio ambiente. Os girinos de Leptodactylus vastus mostraram um bom potencial de utilização em estudos ecotoxicológicos e como bioindicadores de perturbações em ambientes aquáticos, por sua espécie ser bastante comum e não se encontrar sob perigo ou ameaça de extinção, por suas fêmeas produzirem uma postura conspícua com grande número de ovos e larvas relativamente grandes e de fácil manipulação, e pelo fato destas larvas apresentarem fácil manejo em laboratório, não exigindo aeração ou filtração da água nem rações especiais.

No description available.