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Abstract: There were 75 families, 119 genera and 182 species of ichthyoplankton found in the adjacent areas of Kaohsiung and Liuchiu Yu Island. Fifty families, 82 genera and 111 species were collected in the surface waters, and 37 families, 54 genera and 68 species were collected in oblique tows to 100m with an open 1 m net, while 41 families, 48 genera and 73 species were collected by a multiple opening-closing net. Engraulis japonicus was the most dominant species, and was found all year round; other dominant species included coastal fish species (Apogonidae and Pomacentridae), anadromous species (Scombridae), oceanic species (Engraulidae and Myctophidae), and demersal species (Gobiidae). There were only 3 species of ichthyoplankton belonging to 3 genera and 2 families found in the Tapong Bay, all these species are benthic species. The coastal waters of Kaohsiung and Liuchiu Yu Island might be influenced both by the river and the topography of Kaping Trench, and thus the hydrological conditions of this area were more complex, and the ichthyoplankton was more diverse. On the other hand, the hydrological conditions of the semi-closed Tapong Bay changed less than that of the estuary of Kaoping river, thus the species composition of larval fish was simple and less diverse. Overall, the highest abundance of the ichthyoplankton in the adjacent areas of Kaohsiung and Liuchiu Yu Island was found in the wet season(June), with an average of 108¡Ó 116 ind./100 m3. E. japonicus was the most abundant in February, revealed that might be the breeding season of this species. Other dominant species (eg. Bregmaceros japonica and Tridentiger sp.) also showed significant seasonal variation. Higher abundance of ichthyoplankton was usually found in the entrance of Kaohsiung first harbor(St.1) and the estuary of Kaoping river(ie. St.4~6). No significant diel vertical migration of the ichthyoplankton was observed in this study. Most ichthyoplankton were found in the water column above 100 m during both day and night.

A simple design of automatic counting system for fish larvae Chien-hua Huang Advisor: Dr. Sun-chio Fong Institute of Marine Biology, National Sun Yat-sen University, Kaohsiung 804,Taiwan, R.O.C. The purpose of this study is to develop a portable-computer system for automatic counting of fish larvae. It was intended as an economical, fast and accurate tool for the general fish farmers. The basic principle of the system is to use gray level value of the three prime colors (red, green and blue) as an indicator to separate and estimate fish larvae within the CCTV image. The hardware part includes a CCTV camera which hooks up to an IBM compatible laptop computer. Images of fish in a tank were captured and stored for future counting process. Program was written in True Basic language for taking the average number of pixel for individual fish, and system optimization for estimating the total number of fishes within tank. Regression analytical methods were also employed for estimating and correction of bias and errors. In an experiment using the present system to estimate known numbers (100, 300, 500, 700 and 900) of larval Paracheirodon innesi in a 60-liter tank as the testing material, the estimated fish numbers were 132, 259, 495, 799 and 1054 respectively. The group of 500 fishes (standard deviation equals to 88) gave the best result. The total percentage of error ranged between 0.9% and 32%. Application of this system on other species of fishes is yet to be tested. It was safe to suggest that the current version of the system works only onto the same species of fishes under similar conditions (less than 1000 fishes of similar sizes, water depth of 25 cm etc.). For different target fishes under different type of container, a new set of error-correcting formula would be needed. However, the present results when compared with published reports of other system, are no less accurate. This system however is more economical and works more conveniently than do most others.

This study was based on samples taken from 7 cruises between February 2004 and November 2004 and intended to investigate the effects of hydrographic conditions on the spatiotemporal variations of fish larvae assemblage in the waters surrounding Taiwan. The cold, low salinity, and nutrient-rich waters were usually found in the seas northwest of Taiwan in winter, probably due to the invasion of China Coastal Current (CCC). While the dominance of warm and saline waters in the Taiwan Strait in summer and in the waters south and east of Taiwan throughout the year implied that the waters of these areas might be controlled by Kuroshio Current (KC) and South China Sea Waters. In total, 622 fish larvae taxa belonging to 295 genera and 138 families were identified by this study with an overall mean abundance of 760.52 ¡Ó 75.63 ind./1000m3. No significant difference in abundance was found among seasons. The 10 predominant taxa, which constituted 32% of the total number of fish larvae, were Engraulis japonicus, Benthosema pterotum, Scomber japonicus, Vinciguerria nimbaria, Encrasicholina punctifer, Sigmops gracilis, Auxis sp., Trichiurus lepturus, Bleekeria mitsukurii, and Maurolicus sp.. The distribution patterns of fish larvae showed a close relationship with the water masses, higher abundance and lower species richness of fish larvae were always found in the northwestern and northern waters of Taiwan where the CCC prevails, and lower abundance and higher species diversity were present in the eastern waters of Taiwan where the KC dominates. Results of cluster analysis distinguished three station groups, the western, transitional, and eastern groups, and the distribution patterns of these station groups were also corresponded with hydrographic conditions. Furthermore, two seasonal groups of fish larvae assemblages were also recognized, spring-summer group and autumn-winter group. Results of correlation coefficients showed that total abundance of fish larvae and the most dominant taxa were positively related to zooplankton abundance but negatively related to phytoplankton abundance, and suggested that food source might be a key factor to determine the abundance and distribution of fish larvae in the waters surrounding Taiwan. Results of indicator species analysis designated Engraulis japonicus the indicator species of the CCC, and Vinciguerria nimbaria, Maurolicus sp., and Sigmops gracilis the indicator species of the KC.

The main objectives of this study is to :¡]1¡^probe into relationship of larval fish communities and environmental water factor in Tan-sui River Estuary, and observe assemblages of larval fish within different time scale¡F¡]2¡^to compare the results of DNA barcode with mophorlogical identification in larval and juvenile¡F¡]3¡^conjecture the recruit phase & the early life cycles of DNA indentified fish groups associated estuaries in Tan-sui. It shows that recruitment family, such as Scorpaenidae, Engraulidae, Sciaenidae, Sillaginidae and Gobiidae are the main fish have significant differences between larval fish community and the four seasons in Tan-sui estuary. Besides, statistical informations show community distribution and most environmental factors have significant differences, but temperature is the most. We compare the communities of twenty years ago, spring, autumn or summer are the opportune time of recruitment, 72 and 31 families of fish larvae were collected over past five and twenty years ago respectively, it shows that Tan-sui estuarine environment have been improved. We used 96 COI sequences in DNA indetification. Comparing the results of specimens identification between DNA barcoding and different morphological resolution power, DNA barcoding could up to the lower level than the tradiontional way. And after counting, the success rate of DNA identification was higher than different morphological resolving power¡Fthe numbers of mophological type are higher than the taxa after DNA indetification, it means that many morphological characters are not constant in early developmental stage, and DNA barcoding can be a useful tool to assist in promoting the success rate of the traditional way. Comparing with references, 34 indentified by DNA Barcode can conjecture recruit phase & early life cycles, most of these specimens are categorized to¡unondependent marine fish¡v, and the others are¡udependent marine fish¡v, but in fact, some of¡utrue estuarine¡v¡B¡ufeshwater¡vand ¡udiadromous¡vspecies can be indetified by morphology, it was due to the incompletion of the sequence database or sampling error. We should be able to understand the early life history of fish and the role of local habitat for the resources conservation and managenment in the future as long as we collect more complete COI database.

This study investigates the tempo-spatial distribution in species composition and abundance of planktonic pteropods in relation to hydrography in the waters around Liu-chiu Yu Island, southwestern Taiwan from February 2006 to October 2007. In total, we recognized 25 pteropod species belonging to 12 genera and six families, with a mean abundance of 7348 ¡Ó 994 ind./ 1000m3. The five most dominant species were Limacina inflata, Creseis virgula var. conica, Creseis acicula, Limacina trochiformis and Creseis clava, together they accounted for 78.7 % of the total pteropods. The surface sea water temperature, salinity, and phytoplankton concen- tration in the waters around Liu-chiu Yu Island were significantly higher in 2006 than in 2007. Pteropod abundance was higher in spring than in other seasons, and higher in deeper waters than in surface waters. Species number of pteropods was significantly higher in 2007 than in 2006, generally higher in summer and lower in autumn, and higher in deeper waters than in surface waters. Species diversity index of pteropods was generally higher in summer and lower in autumn. Cluster analysis of hydrography included 4 clusters (e.g., 2007 summer, summer and autumn, spring and winter, spring), the 2007 summer cluster was different from other seasons. Pteropod assemblage showed apparent difference between seasons, the variation of pteropod assemblages between stations in spring was higher than other seasons. Linear regression showed that the species number (p < 0.01) and diversity index (p < 0.05) were positively correlated with abundance of fish larvae. Abundance of most dominant species of pteropods was significantly and positively correlated with abundance of fish larvae (e.g., Limacina inflata; Creseis virgula var. conica and Limacina trochiformis) and significantly and negatively correlated with phytoplankton abundance (e.g., Limacina inflata, p < 0.001). In addition to the hydrographic factors, the distribution of pteropods might also be affected by predatory fish larvae and phytoplankton supplement.

O principal objetivo desse trabalho foi analisar a influência das condições ambientais na higidez das larvas de engraulidídeos da plataforma continental ao largo de Santos (24o49\'S - 23o49\'S e 46o55\'W - 45o24\'W). As coletas foram realizadas em dois cruzeiros oceanográficos (setembro de 2005 e março de 2006). Verificou-se diferença nas condições hidrográficas entre as duas campanhas de coletas, sendo que em setembro de 2005 houve maior influência de descarga de águas estuarinas na plataforma, enquanto em março de 2006 houve intrusão da Água Central do Atlântico Sul. As duas situações geraram estratificação vertical e favoreceram a entrada de nutrientes no sistema, o que gera enriquecimento da zona eufótica e beneficia as cadeias tróficas locais. Para avaliar a condição de higidez das larvas, foram utilizados indicadores morfológicos (relação massa-comprimento, fator de condição, altura do corpo da larva, relação entre altura da cabeça e diâmetro do olho) e bioquímicos (quantidade de proteína e relação proteína/DNA). Os indicadores apontaram melhor condição relativa, para as larvas coletadas em março de 2006, que pode ser conseqüência da ocorrência de uma intensa estratificação vertical na coluna de água e de uma maior estabilidade gravitacional em março de 2006, proporcionando maior concentração de nutrientes e ocasionando aumento na densidade e melhora na condição das populações planctônicas. / The aim of this study was to analyze influence of environmental conditions on health of engraulidid larvae of the continental shelf off Santos (24º49´S - 23º49´S e 46º55´W - 45º24´W). Samples were collected during two oceanographic cruises (September 2005 and March 2006). Differences among hydrographic conditions were verified between surveys: in September there was a major influence of the estuarine water discharge in the inner shelf, whereas in March there was an intrusion of the South Atlantic Central Water (SACW) in the region. The two conditions generated vertical stratification and improved the pelagic food web, in which fish larvae participate. Morphological (weight-length relation, condition factor, larvae body height, head height-eye diameter relation) and biochemical (protein quantity and protein/DNA relation) indicators were used to evaluate the larvae health condition. Results showed better relative condition of larvae collected in March 2006 that can be a consequence of the intense water column vertical stratification and gravitational stability in March 2006, providing higher nutrients concentration, increasing density of organisms and improving condition of planktonic populations.

A primary goal of marine ecology is to understand the physical and biological mechanisms that drive patterns of larval dispersal and population connectivity. The larvae of many marine organisms develop in the pelagic environment before settling on benthic habitat. Early efforts to predict dispersal patterns assumed that larvae are passive particles dispersed by currents for 10s to 100s of kilometers (km). However, recent studies using parentage analyses to observe dispersal patterns reveal that peak dispersal occurs within 1 – 2 km, and declines exponentially with increasing distance from the natal reef. This gap between predicted and observed dispersal patterns suggests that other factors, such as larval behavior, may play an important role in shaping patterns of dispersal. However, due to challenges associated with obtaining larvae early in development, there is little information on the ontogeny of behavior from hatching through settlement. In this dissertation, I begin to address these challenges by developing a protocol for rearing the larvae of two species of sponge-dwelling neon gobies, Elacatinus lori and E. colini. Using lab-reared specimens, I provide the first description of larval development for both species. Then, I investigate the ontogeny of swimming ability in larvae of E. lori, E. colini and the model species Amphiprion percula. Remarkably, A. percula were capable of swimming twice as fast and three orders of magnitude longer than E. lori near settlement. Relating swimming speed to published dispersal patterns for E. lori, A. percula and another species Plectropomus leopardus, I show there is a positive association between swimming speed and the median and maximum dispersal distance. This finding suggests that swimming abilities may influence the extent of long distance dispersal. Finally, I investigate the role of habitat preferences and post-settlement persistence in establishing the distribution of E. lori settlers on sponge habitat. I demonstrate that E. lori settlers are more abundant, persist longer, and prefer to settle on large Aplysina fistularis, suggesting that settling E. lori choose sponge habitats that confer the highest relative fitness. This dissertation indicates the importance of larval and settler behaviors in determining the dispersal patterns and distribution of fishes on coral reefs.

O principal objetivo desse trabalho foi analisar a influência das condições ambientais na higidez das larvas de engraulidídeos da plataforma continental ao largo de Santos (24o49\'S - 23o49\'S e 46o55\'W - 45o24\'W). As coletas foram realizadas em dois cruzeiros oceanográficos (setembro de 2005 e março de 2006). Verificou-se diferença nas condições hidrográficas entre as duas campanhas de coletas, sendo que em setembro de 2005 houve maior influência de descarga de águas estuarinas na plataforma, enquanto em março de 2006 houve intrusão da Água Central do Atlântico Sul. As duas situações geraram estratificação vertical e favoreceram a entrada de nutrientes no sistema, o que gera enriquecimento da zona eufótica e beneficia as cadeias tróficas locais. Para avaliar a condição de higidez das larvas, foram utilizados indicadores morfológicos (relação massa-comprimento, fator de condição, altura do corpo da larva, relação entre altura da cabeça e diâmetro do olho) e bioquímicos (quantidade de proteína e relação proteína/DNA). Os indicadores apontaram melhor condição relativa, para as larvas coletadas em março de 2006, que pode ser conseqüência da ocorrência de uma intensa estratificação vertical na coluna de água e de uma maior estabilidade gravitacional em março de 2006, proporcionando maior concentração de nutrientes e ocasionando aumento na densidade e melhora na condição das populações planctônicas. / The aim of this study was to analyze influence of environmental conditions on health of engraulidid larvae of the continental shelf off Santos (24º49´S - 23º49´S e 46º55´W - 45º24´W). Samples were collected during two oceanographic cruises (September 2005 and March 2006). Differences among hydrographic conditions were verified between surveys: in September there was a major influence of the estuarine water discharge in the inner shelf, whereas in March there was an intrusion of the South Atlantic Central Water (SACW) in the region. The two conditions generated vertical stratification and improved the pelagic food web, in which fish larvae participate. Morphological (weight-length relation, condition factor, larvae body height, head height-eye diameter relation) and biochemical (protein quantity and protein/DNA relation) indicators were used to evaluate the larvae health condition. Results showed better relative condition of larvae collected in March 2006 that can be a consequence of the intense water column vertical stratification and gravitational stability in March 2006, providing higher nutrients concentration, increasing density of organisms and improving condition of planktonic populations.

The processes influencing larval fish survival in the low-latitude open ocean are poorly understood, especially with regard to feeding. As part of a large-scale study that included two years of monthly sampling in the Straits of Florida (SOF), the objectives of this dissertation were to elucidate the larval fish feeding behaviors and strategies of 1) istiophorid billfishes, 2) tunas, and 3) coral reef fishes, while also 4) characterizing the feeding environment, synthesizing the dominant trophic pathways to fish larvae, and reviewing the literature for evidence of latitudinal distinctions in larval fish trophodynamics. Larval billfishes exhibited highly selective feeding, and their diets were numerically dominated (90%) by two genera of crustaceans, Farranula copepods and Evadne cladocerans. These prey were consumed throughout early larval ontogeny, from first-feeding through piscivorous lengths (> 5 mm), until piscivory became exclusive near 12 mm. High feeding incidence (0.94) and rapid digestion (~3.5 hrs) suggests frequent and successful feeding by billfish larvae. For tunas, nearly all larvae examined (>98%) contained prey. Thunnus spp. exhibited a mixed diet, while skipjack, little tunny, and Auxis spp. nearly exclusively consumed appendicularians. All four tuna taxa co-occurred in the western SOF where prey was more abundant, while in the central and eastern SOF (where prey availability was lower), only Thunnus spp. and skipjack were present. Additionally, these two taxa exhibited significantly different vertical distributions. Estimates of predatory impact indicated the potential for depletion of resources in the absence of the spatial and dietary niches of larval tunas. Coral reef fish families examined included Serranidae, Lutjanidae, Mullidae, Pomacentridae, Labridae, Scaridae, and Acanthuridae. Feeding incidences were high (0.94 to 1.0) for all taxa except scarids (0.04), and diets were narrow and predator-specific. Cluster analysis yielded clear groupings based on the selective feeding exhibited by the taxa, while within taxa, canonical correspondence analysis illustrated the change in diet with a variety of variables. The physical and biological environment varied markedly across the SOF, largely influenced by the Florida Current. Characteristics examined included thermocline depth, fluorescence, and abundances of total plankton and copepod nauplii. The feeding ecologies of the 21 taxa of fish larvae in this work were synthesized into qualitative and quantitative webs that illustrate the variable trophodynamic strategies of larvae in the SOF and the levels of community reliance upon zooplankton prey types. A review of 170 investigations on larval fish feeding revealed notable distinctions between high- and low-latitude regions, highlighting the substantial variability across environments in the role of larval fishes within the planktonic food web.