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Journal

Aquaculture and Fisheries

2007

Articles 1 - 8 of 8

Full-Text Articles in Life Sciences

Developmental Reproductive Effects Of Exposure To Pharmaceutical Steroids In The Aquatic Environment: Studies On Mosquitofish (Gambusia Affinis Affinis),Roach (Rutilus Rutilus) And Medaka(Oryzias Latipes), Taisen Iguchi, Yoshinao Katsu, Hiroshi Urushitani, Anke Lange, Charles R. Tyler Oct 2007

Developmental Reproductive Effects Of Exposure To Pharmaceutical Steroids In The Aquatic Environment: Studies On Mosquitofish (Gambusia Affinis Affinis),Roach (Rutilus Rutilus) And Medaka(Oryzias Latipes), Taisen Iguchi, Yoshinao Katsu, Hiroshi Urushitani, Anke Lange, Charles R. Tyler

Journal of Marine Science and Technology

Pharmaceutical androgens and estrogens discharged into the aquatic environment are now known to induce adverse effects in fish and are a health concern for wildlife. Mosquitofish (Gambusia affinis) exposed to a pharmaceutical androgen, trenbolone, used to enhance cattle growth and found to pollute waters below feedlots in the USA, has been shown to alter the development of the anal fin of the females and disrupt gonopodium development in fry. In our work, we showed that altered gonopodium development was associated with disruption in the normal patterns of expression of 2 cloned androgen receptors. Furthermore, exposure to trenbolone at 1 µg/L …

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Effects Of Elevated Seawater Co2 Concentration On The Meiofauna, Haruko Kurihara, Atsushi Ishimatsu, Yoshihisa Shirayama Oct 2007

Effects Of Elevated Seawater Co2 Concentration On The Meiofauna, Haruko Kurihara, Atsushi Ishimatsu, Yoshihisa Shirayama

Journal of Marine Science and Technology

An increase in atmospheric CO2 concentration leads to a rise in CO2 concentrations and a decrease in pH of the ocean surface water due to continuous gas exchange between air and seawater, which may have serious impacts on neritic marine organisms. In this study, we assessed the impacts of elevated CO2 concentrations on meiobenthic organisms by exposing them to seawater equilibrated with air (control: CO2 concentration 380 ppm) or CO2-enriched air (2,000 ppm higher than control, CO2 concentration predicted by the year 2300) for 56 days in microcosms. We observed no significant differences in the abundance of total meiofauna, nematodes, …

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Adaptation To Deep-Sea Hydrothermal Vents: Some Molecular And Developmental Aspects, Florence Pradillon, Françoise Gaill Oct 2007

Adaptation To Deep-Sea Hydrothermal Vents: Some Molecular And Developmental Aspects, Florence Pradillon, Françoise Gaill

Journal of Marine Science and Technology

Alvinella pompejana is a polychaetous annelid inhabiting the surface of deep sea hydrothermal chimneys along the ridge of the east part of the Pacific ocean. The main characteristic of this emblematic species is its habitat, which is very aggressive considering its temperature. The exceptional thermotolerance of this species (up to 80°C) has been the subject of much controversy. This review is focused on the thermal adaptation of this worm regarding molecular data relative to its extracellular matrix and life history traits.

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Neuroendocrinology Of Fish Metamorphosis And Puberty: Evolutionary And Ecophysiological Perspectives, Sylvie Dufour, Karine Rousseau Oct 2007

Neuroendocrinology Of Fish Metamorphosis And Puberty: Evolutionary And Ecophysiological Perspectives, Sylvie Dufour, Karine Rousseau

Journal of Marine Science and Technology

Metamorphosis and puberty are two major events of the postembryonic development in Vertebrates. Based on some examples from fish species, we review the definition, role and regulation of these events, analyze their common and different features, as well as their impact on the evolution and diversity of life cycles. The term of puberty, firstly defined in humans, has been subsequently extended to the first acquisition of the capacity to reproduce in all mammalian and non-mammalian vertebrates as well as in invertebrates. By definition, puberty occurs only once in the life cycle. However, some similarities may be found with other events, …

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Simulated Migration Of European Silver Eel; Swim Capacity And Cost Of Transport, Guido Van Den Thillart, Arjan Palstra, Vincent Van Ginneken Oct 2007

Simulated Migration Of European Silver Eel; Swim Capacity And Cost Of Transport, Guido Van Den Thillart, Arjan Palstra, Vincent Van Ginneken

Journal of Marine Science and Technology

An important aspect of the reproduction of European silver eels is the huge distance (ca 6000-km) they have to swim to reach their spawning grounds. So, obviously endurance swimming is a major requirement for successful reproduction. As migrating eels don’t feed, two major questions should be asked: 1) what are the energy costs to cross the Atlantic Ocean, 2) How much fat do eels need to cover the expenses. From swim tunnel experiments run for days till even 6 months we could determine the cost of transport (COT): 0.5 kJ km-1 kg-1. This amount is about 5 times lower than …

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Role Of Sex Hormones In Sex Change Of Grouper, Masaru Nakamura, Mohammad Ashraful Alam, Yasuhisa Kobayashi, Ramji Kumar Bhandari Oct 2007

Role Of Sex Hormones In Sex Change Of Grouper, Masaru Nakamura, Mohammad Ashraful Alam, Yasuhisa Kobayashi, Ramji Kumar Bhandari

Journal of Marine Science and Technology

Groupers are commercially important coral reef fishes because of their excellent flavor and high price. Due to their sex changing nature, commercial aquaculture operations have not yet been developed for groupers. Sex steroids play a critical role in the initiation of sex change, but their exact function and mechanism of action are unknown. We have investigated the role of sex steroids in protogynous sex change using the honeycomb grouper, Epinephelus merra, for a number of years. Our studies have shown that sex steroids play a major role in sex change. In this review, we integrate our findings to better understand …

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Reproductive Cycles Of The Pearl Oysters, Pinctada Fucata (Gould) And Pinctada Margaritifera (Linnaeus) (Bivalvia: Pteriidae) In Southwestern Taiwan Waters, Jiuan-Jiuan Hwang Apr 2007

Reproductive Cycles Of The Pearl Oysters, Pinctada Fucata (Gould) And Pinctada Margaritifera (Linnaeus) (Bivalvia: Pteriidae) In Southwestern Taiwan Waters, Jiuan-Jiuan Hwang

Journal of Marine Science and Technology

The reproductive cycles of the pearl oysters Pinctada fucata (Gould) and Pinctada margaritifera (Linnaeus) were examined based on 339 and 284 specimens, collected in southwestern Taiwan. Except for the month of December 2002, Pinctada fucata were collected during the periods from March 2002 to September 2003. Pinctada margaritifera were collected over two periods: from March 2002 to November 2002 and from June 2003 to September 2003. Histological observations on gonadal development indicated that Pinctada fucata and Pinctada margaritifera were protandrous hermaphrodites, and both species exhibited different annual cyclical patterns, in which maturity peaked in May and October for Pinctada fucata, …

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Gymnothorax Shaoi, A New Species Of Moray Eel (Anguilliformes: Muraenidae) From Southeastern Taiwan, Hong-Ming Chen, Kar-Hoe Loh Apr 2007

Gymnothorax Shaoi, A New Species Of Moray Eel (Anguilliformes: Muraenidae) From Southeastern Taiwan, Hong-Ming Chen, Kar-Hoe Loh

Journal of Marine Science and Technology

A new species of moray eel, Gymnothorax shaoi, is described here based on ten specimens collected in southeastern Taiwan. The new muraenid is distinct from its most similar species, Gymnothorax fimbriatus, in the character combinations of having brown body color, dark brown spots in at least three rows on body side and spots on posterior dorsal and caudal fin not forming oblique streaks; paler rictus, jaws, and inner mouth; fins without pale margins; no bend in lower jaw; fewer total vertebrae; and smaller in maximum body size. G. shaoi’s eyes have yellow to orange irises, body with dark reddish brown …

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