摘要:

The 24-h median lethal concentration of nitrite (NO2–) for striped bassMorone saxatiliswas 163 mg/L in static toxicity tests. Exogenous chloride ions increased the tolerance of the fish for NO2–; CaCl2was more than twice as effective as NaCl. Plasma NO2–, cortisol, and methemoglobin were correlated positively with environmental NO2–. Plasma NO2–and methemoglobin were correlated negatively with environmental Cl–, but cortisol was not reduced by the presence of environmental Cl–. Striped bass maintained NO2–in the plasma (0–45 mg NO2–/L) at concentrations below those in the environment (0–250 mg NO2–/L). However, striped bass were sensitive to NO2–that entered the plasma; methemoglobin levels greater than 60% and plasma NO2–, levels greater than 70 mg/L resulted in significant mortalities.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1991)120<0247:IONACC>2.3.CO;2

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Statolith growth and banding patterns were examined in larval sea lampreysPetromyzon marinuspreviously marked by oxytetracycline injection and held up to 20 months under constant and cycling temperature at either a natural or constant (15 h light: 9 h dark) photoperiod. Banding patterns were not influenced measurably by photoperiod, and statolith growth did not occur when larvae were held at a constant 8°C. Statolith growth at 12°C was even throughout the study and annuli did not form. Statoliths from larvae held at temperatures adjusted to mimic those of a typical sea lamprey stream formed annuli during the simulated winter and early-spring period. The shift in metabolism from protein synthesis to lipid storage that occurs during the final year of larval development did not alter the statolith banding pattern. An annulus was not formed during the nontrophic period of metamorphosis, which is completed by early winter, nor during the first few months of the juvenile period when low ambient temperatures inhibit feeding. Statolith growth increased rapidly in juveniles once active feeding on teleosts commenced. When larval southern brook lampreysIcthyomyzon gageiwere injected with oxytetracycline, and held at the same seasonally adjusted temperatures and photoperiods as larval sea lampreys, they showed the same statolith growth and annulus formation. Prior to marking and exposure to seasonal temperatures more extreme than those experienced in their usual habitat, southern brook lampreys had no annuli on their statoliths. This is consistent with the earlier observation of even larval growth throughout the year in their natal streams.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1991)120<0255:LSBPIR>2.3.CO;2

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Larval and juvenile striped bassMorone saxatiliswere mass-marked by oxytetracycline immersion as part of normal hatchery procedures. In 1988, 70% of samples of 1.2 million juveniles treated en route to stocking had a fluorescent mark in their otoliths. In 1989, all samples of 7 million larvae (6–9 d old) treated during transport to grow-out ponds had marked otoliths. Marks were retained for at least 5 and 7 months by larvae and juveniles, respectively. There was no significant difference between the mortality rates of marked and unmarked larvae to 30 d after hatch.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1991)120<0261:IMOLAJ>2.3.CO;2

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Ten of 735 adult red drumsSciaenops ocellatusinjected with oxytetracycline and released into Mosquito Lagoon and Upper Indian River Lagoon on the Atlantic coast of Florida during 1987–1988 were recaptured 358 to 564 d later. Each fish had deposited one opaque zone since being marked; zone formation probably occurred during the winter. These observations validate the use of otolith sections to determine the ages of red drums from 1 to 27 years old.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1991)120<0267:NDVOAD>2.3.CO;2

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659-120.2.270

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor