Kaohsiung harbor is the biggest one in Taiwan. Many previous researches revealed that the pollution of organotin was usually serious in harbors. TBT contained in the antifouling paint of vessels would release into the seawater and contaminate the harbor area. In this study, shrimps (Acetes intermedius) and water samples were collected from Xinbin wharf and the second port entrance in Kaohsiung harbor. After pretreatment, ethylated with sodium tetraethylborate and extracted by hexanes, contents of organotin compounds were analyzed by GC-FPD. The results showed that TBT and DBT were the predominant organotin species in Kaohsiung harbor. In seawater, the concentration of DBT ( 98-257 ng/L ) was higher than TBT ( 17-133 ng/L). In shrimps, the concentration of TBT ( 228-480 ng/g ) was higher than DBT ( 98-257 ng/g). The concentration of TBT in shrimps decreased with the increased wet weight. There was no significant variation for the organotin concentrations in the shrimp samples collected from the second port entrance during the period from September 2002 to May 2003. The bioconcentration factor (BCF) of TBT ranged between 6700-17900. The organotin concentrations in shrimps collected from Xinbin wharf also showed no significant variation from August 2002 to May 2003. The BCF values of TBT were between 2200-8300. The ability of shrimps to concentrate organotin compounds was between that of fishes and neogastropods. There were significant differences for the organotin concentrations in shrimps sampled from different sampling area. The shrimps sampled from Kaohsiung harbor were significantly higher in organotin concentration than Tungkang. According to the risk assessment, shrimps from Tungkang were much lower than the tolerable daily intake, however, the shrimps from Kaohsiung harbor were well beyond the dangerous level . In order to understand the toxicity of organotin compounds to the shrimps, experiments on acute toxicity test were conducted. The 72-h LC50 of TBT was 47£gg/L. After toxicity test, live shrimps which were exposed to organotin for 72 hours were assayed. The concentration of TBT in shrimps increased with the exposure concentrations. DBT which was the degradation product of TBT also showed the same trend. The 72-h LC50 of DBT was 225£gg/L. After toxicity test period, the concentration of DBT and its metabolite MBT in shrimps also increased with the increased exposure concentrations. The accumulation rate of the shrimps at 30£gg/L TBT was 17ng/g-h and the elimination rate was 8.8 ng/g-h. The accumulation rate of the shrimps at 100£gg/L DBT was 12 ng/g-h and the elimination rate was 4.2 ng/g-h.

Abstract Acetes is a kind of macroholozooplankton. We can use the "genetic analysis to know its evolution, zooplankton population structure and taxa. The step is :ampified the 16S rDNA of the mitochondrial DNA and the COI fragment DNA in Acetes, and then sequence. We get the genetic distance between species of the 16S rDNA is 2.65~13.16%, and it's 1.43~25.42% of the COI fragment gene in Acetes. These results show that the diversity of COI fragment DNA in Acetes is more than the 16S rDNA of the mitochondria DNA. If we translated the COI gene DNA to amino acid sequence, the genetic distance between species of the amino acid sequence is about 1.83%~8.97%. By the way, we know that the genetic distance between species of the amino acid sequences are clearly less then the DNA sequences. Using the genetic data, we constructure a phylogenetic tree. The tree divided the Acetes into two group : Japonicus group and Erythraeus group, we can find the Acetes japonicus is the most permitive species and the A. erythraeus is the last specation species in the Acetes under the DNA sequences. But under the tree which was made from the amino acid sequence, we found the Acetes erythraeus is the most permitive species in the Acetes. The genetic distance between A. intermedius and A. erythreaus were 5.44% and 18.01% of the 16S rDNA and COI gene which indicated that the A. intermedius is true species. The population of A. japonicus between Japon Sea and Taiwan showed 0.24% and 2.36% of the 16S rDNA and COI gene that reveled two population should have gene-flow. The populations diversity of the A. intermedius in Taiwan showed the same way which had no different and the populations in Taiwan should be a single population.

The planktonic shrimp Acetes intermedius is an ecologically and commercially important species. Since it was described by Omori(1975) as a new species, there have been relative few studies focused on the reproduction of this species. The aim of this study is to examine the spawning, egg hatching, larval development of A. intermedius and the related environmental factors. The newly released eggs of Acetes intermedius were round, 200 um in diameter in average, transparent, demersal and were usually green in color. The cleavage pattern of developing egg is holoblastic. Larval stages could be divided into four stages: nauplius, protozea, zoea and postlarva. Nauplius, protozoea and zoea can be further divided into 4, 3 and 2 substages, respectively. At water temperature 30 ¢J and salinity 25 psu, hatching of nauplius was around 10-11 h after spawning while protozoea, zoea and postlarva occurred around 29h, 5-6 and 7 days after spawning, respectively. Newly released eggs were introduced directly into different temperature-salinity combinations. The results revealed that eggs failed to hatch at 15¢J at all salinities tested and at salinities 0 to 10 psu at all temperatures examined. Hatching success started to decrease at salinity 15 psu at 30¢J and at 20 psu at both 25¢J and 20¢J. When salinity was not lower than 25 psu, the hatching success reaches nearly 90 % in average and is generally similar among temperatures tested. Hatching started at about 10, 14 and 28h after spawning at temperatures 30, 25, 20¢J, respectively. At salinity 25 psu, hatching time was the shortest at both 25 and 30¢J, whereas it was similar among salinities at 20¢J. Eggs and nauplii I hatched at 30 ¢J, 30 psu were incubated in the different temperature-salinity combinations. It took eggs incubated at salinities ranging from 20 to 35 psu about 28, 45 h and 5 days to develop into protozoea I at 30, 25 and 20 ¢J, respectively. Nauplii usually started to metamorphose earlier at 25 and 30 psu than at 35 and 20 psu at 25 and 30¢J while no significant trend in metamorphosis time was found among different salinities at 20¢J. Nearly 90% of nauplii metamorphosed into protozoea I at 25 and 30¢J while the metamorphosis rate of nauplii was greatly reduced at 20¢J. The metamorphosis rate was usually higher around 20-25 psu and lower at 15 and 35 psu in all temperatures examined. While spawning, the gravid females swam near the water surface and were rapidly beating pleopods. The eggs were directly released into water. Spawning usually took place at night but the timing is generally peaked around midnight. The gravid females spawned in the early spring before midnight while they spawned after midnight in summer. The spawning timing is delayed at low temperature (24¢J) while it is not affected by high temperature (30¢J). The salinity did not show any effects on spawning but the hatching success of eggs released at 15 and 35 psu was significantly lower than those at 20-30 psu. The gravid females were tended to be endogenous timed to spawn in the night since spawning was not affected by absence of presence of light.

The assemblage composition, biomass and dynamics of zooplankton and epibenthos were examined in a commercial prawn pond in southeast Queensland over two seasons. Physico-chemical characteristics of the pond water were measured concurrently. Numbers and biomass of zooplankton in the surface tows (140 micrometre mesh) varied from 8 ind. L-1 (44 micrograms L-1) to 112 ind. L-1 (324 micrograms L-1) in the first season, with peaks in biomass corresponding to peaks in numbers. In the second season the zooplankton numbers varied from 12 to 590 ind. L-1, but peaks in numbers did not correspond with peaks in biomass, which varied from 28 to 465 micrograms L-1. This was due to differences in the size of the dominant taxa across the season. Although this occurred in both seasons, the effect on biomass was more pronounced in the second season. In both seasons, immediately after the ponds were stocked with prawn postlarvae there was a rapid decline in zooplankton numbers, particularly of the dominant larger copepods. This was probably due to predation by the postlarvae. Subsequent peaks in zooplankton numbers were principally due to barnacle nauplii. The largest peaks in zooplankton numbers occurred before stocking in the first season, but the largest peaks were in the middle of the second season. While changes in abundance and biomass of the zooplankton assemblage were not correlated with physico-chemical characteristics in the first season, there were correlations between zooplankton numbers and temperature, dissolved oxygen, pH and secchi disk readings in the second season. No correlations were found with zooplankton biomass and physico-chemical characteristics in the second season. The correlations in the second season were mainly due to the high prevalence of barnacle nauplii through the middle part of the season, and may reflect suitable conditions for barnacle reproduction. Epibenthic faunal abundance in the beam trawls (1 mm mesh) peaked at 14 ind. m-2 and 7 ind. m-2 in the first and second seasons respectively and the biomasses at 0.8 g m-2 and 0.7 g m-2. Peaks in abundance of epibenthos did not correspond to peaks in biomass. This was due to large differences in the size of the taxa across the seasons. Sergestids (Acetes sibogae) and amphipods were the most abundant taxa in beam trawl samples. Amphipods were only abundant in the first season, with their numbers increasing towards the end of the grow out period. Acetes were abundant in both seasons, but were dominant in the second season. Correlations between physico-chemical parameters and epibenthos numbers were found to be strongly influenced by the dominant taxa in each season. In the first season, negative correlations were found between epibenthos abundance and pH and temperature. These relationships may reflect an effect on the growth of macroalgae in the pond, with which the amphipods were strongly associated, rather than a direct effect on the epibenthos. In the second season, a positive correlation existed between temperature and epibenthos abundance, however this was strongly influenced by the very high abundance of Acetes in the last sampling period. No correlations were found between epibenthic fauna biomass and physico-chemical parameters. Abundances of epibenthic fauna were not related to zooplankton densities indicating this source of food was not likely to be a limiting factor. Neither the pond water exchange regime nor moon phase could explain changes observed in abundances of zooplankton or epibenthos assemblages in the first season, however the sampling regime was not designed to specifically investigate these effects. In the second season water exchanges were sampled more rigorously. The density of zooplankton in the outlet water was from 2 to 59% of the density of zooplankton in the pond, and the zooplankton density of the inlet water was from 9 to 50% of the outlet water. The number of zooplankton recruited into the pond from the inlet water, after the prawns were stocked, was negligible and contributed little to changes observed in zooplankton assemblages. Reproduction of barnacles within the pond appeared to play the most important role in changes in the assemblage. Water exchange did, however, appear to play a greater role in the changes observed in epibenthic fauna assemblages. In the last season of sampling the feeding of the dominant epibenthic species, Acetes sibogae, was examined using a combination of gut content and stable isotope analysis. Acetes gained little nutrition directly from the pelleted feed, probably relying primarily on zooplankton as their direct food source. Other dietary items such as macroalgae also played a role in the nutrition of the Acetes. If Acetes numbers were high at the beginning of a season they may compete with the newly stocked prawns for the zooplankton resource. However, they will not compete with the prawns later in the season when the prawns are gaining most of their nutrition from the pelleted feed. Overall it appears that zooplankton are important to the nutrition of the prawns at the beginning of the season when the assemblage is usually dominated by copepods. Later in the season the assemblage is dominated by barnacle nauplii which are recruited from within the pond. The establishment of an abundant assemblage of suitable zooplankton species before stocking prawn postlarvae would appear to be beneficial, if not essential. The assemblage of epibenthic fauna changes throughout the season as new recruits are brought in from outside the pond. Epibenthic faunal assemblages in ponds from southeast Queensland are dominated by Acetes which are not likely to adversely affect the production of prawns unless they are particularly abundant early in the grow out season when the prawns would be utilising the same food resources as Acetes.

Submitted by Irvana Coutinho (irvana@ufpa.br) on 2012-06-13T12:20:41Z No. of bitstreams: 2 Dissertacao_AntComposicaoCentesimal.pdf: 857530 bytes, checksum: 1c1d2ed288e685c30c18f545d000f2d1 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Irvana Coutinho(irvana@ufpa.br) on 2012-06-13T12:21:01Z (GMT) No. of bitstreams: 2 Dissertacao_AntComposicaoCentesimal.pdf: 857530 bytes, checksum: 1c1d2ed288e685c30c18f545d000f2d1 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2012-06-13T12:21:01Z (GMT). No. of bitstreams: 2 Dissertacao_AntComposicaoCentesimal.pdf: 857530 bytes, checksum: 1c1d2ed288e685c30c18f545d000f2d1 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2007 / A espécie Acetes marinus Omori, 1975, possui total aproveitamento alimentar constituindo-se em uma espécie de grande importância nutritiva para a população regional onde ocorre, porém, é muito pouco estudada. Visando contribuir com um melhor aproveitamento deste recurso foram realizadas coletas mensais de A. marinus durantes os meses de janeiro de 2006 a junho de 2007, em duas praias, próximas da cidade de Cametá, no baixo Tocantins. Foram determinadas a composição centesimal (%) e o teor de colesterol (mg/100g) relacionado aos parâmetros ambientais: pH, temperatura e material em suspensão da sub-superfície da água. A caracterização do desenvolvimento ovariano, baseado nas modificações macro e microscópicas. Para essas duas praias o pH médio anual foi de 7,52 ± 0,71, a temperatura foi de 26,57°C ± 1,26, e o material em suspensão foi de 73mg/L ± 65,53. Para a composição centesimal do A. marinus obteve-se: 87,1 % ± 1,1- umidade; 9,8% ±1,3-cinzas; 71% ± 1,8-proteínas; 5,4% ± 2,9-lipídios; 13,7% ± 2,6- carboidratos; 387,6% ± 13,2 Kcal-valor calórico. O teor de colesterol foi de 374,87mg/100g ± 207,08. Foi revelado um grande potencial nutricional, principalmente protéico, desta espécie, porém esta é rica em colesterol. E para o desenvolvimento ovariano foram descritos três estágios de maturação, baseados em quatro diferentes tipos de ovócitos. / The specie Acetes marinus Omori, 1975, have full use as food constituting themselves into a kind of nutritional importance to the regional population, however, it is few studied. To contribute to a better use of this resource were conducted monthly collections of A. marinus during the months of January 2006 to June 2007, in two beaches, near of the Cametá town in low Tocantins river. They were certain the composition centesimal (%) and the content of cholesterol (mg/100g) relating to environmental parameters: pH, temperature and material in suspension of the subsurface water. The characterization of ovarian development, were based on the macro-and microscopic changes. For these two beaches the annual average pH was 7.52 ± 0.71, the temperature was 26.57 ° C ± 1.26, and the material in suspension was 73mg / L ± 65.53. For the composition centesimal of A. marinus got itself: 87.1% ± 1.1- moisture; 9.8% ± 1.3-ash, 71% ± 1.8-protein, 5.4% ± 2.9-lipids; 13.7 % ± 2,6- carbohydrates; 387.6% ± 13.2 kcal - calorific value. The content of cholesterol was 374.87 mg/100g ± 207.08. Was revealed a large potential nutrition, especially protein, for this species, but it is rich in cholesterol. And for developing ovarian were described three stages of maturation, based on four different types of oocytes.