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731.
The early life history of the black anglerfish, Lophius budegassa was investigated by otolith (lapilli) increment analysis. Samples of demersal juvenile L. budegassa ranging from 54 to 196 mm total length were collected during bottom trawl surveys in the central Adriatic Sea. By counting increments presumed to be deposited daily in the lapillar otoliths, 88 specimens of L. budegassa were successfully aged. Age estimates of juveniles ranged between 79 and 204 days, indicating that probably the pelagic phase of this species is relatively short and settlement occurs at less than 3 months of life. The analysis of check marks in the core area of lapilli enabled us to determine the period of endogenous feeding, which would last between 15 and 24 days after hatching. Back-calculated hatching dates and, consequently, the spawning season of L. budegassa in the Adriatic Sea was spread over a long period, lasting at least from February to June. The length at age relationship gave an estimate of mean growth rate of approximately 0.8–1.02 mm/day, indicating a faster growth rate of 0+ juveniles L. budegassa than previously thought. The implications of these findings on age estimates discrepancies between previous ageing studies on L. budegassa carried out using different calcified structure (sagittae or illicia) are discussed. 相似文献
732.
Effect of L‐tryptophan supplemented diets on serotonergic system and plasma cortisol in Totoaba macdonaldi (Gilbert, 1890) juvenile exposed to acute stress by handling and hypoxia
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Miguel Cabanillas‐Gámez Lus M López Mario A Galaviz Conal D True Ulises Bardullas 《Aquaculture Research》2018,49(2):847-857
Brain serotonin and cortisol play a central role in integrating the neuroendocrine response to stress. Previous studies in aquatic species show that dietary supplementation with the 5‐HT precursor L‐tryptophan amino acid is able to modulate this response. The aim of this study was to evaluate the effect of dietary tryptophan (Trp) on the serotonergic system and acute stress response in Totoaba macdonaldi. Four groups of fish were fed with one of four isonitrogenous and isocaloric diets formulated with different Trp content: 0.5% (1X TRP, control diet), 1.1% (2X TRP), 1.7% (3X TRP) and 2.3% (4X TRP). After a feeding period of 21 days, groups were exposed to acute stress by handling with a net or hypoxia. Feeding with Trp‐enriched diets resulted in increased 5‐HT content in telencephalon of undisturbed fish. Handling increased the 5‐hydroxyindole acetic acid (5‐HIAA) and serotonin turnover (5‐HIAA/5‐HT) in telencephalon of fish fed with 1X TRP and 2X TRP but was not significant for the fish fed 3X TRP and 4X TRP, and no significant increase was observed by hypoxia in both telencephalon and hypothalamus in any of the diets. An inverted U‐shaped response was observed in plasma cortisol increasing with 2X TRP after both handling and hypoxia and decreasing with diets rich in Trp, 3X TRP and 4X TRP. A higher increase was observed in haematocrit, plasma glucose and lactate in hypoxia than the handling groups. Our results indicate that Trp supplementation modulated cortisol response and mediated negative feedback of 5‐HT system in telencephalon after acute stress. 相似文献
733.
Gretel Frangipane Mario Pistolato Emanuela Molinaroli Stefano Guerzoni Davide Tagliapietra 《水产资源保护:海洋与淡水生态系统》2009,19(1):24-33
- 1. Loss on ignition (LOI) is a widely used method to estimate organic matter (OM) in the sediment of marine and freshwater ecosystems. Thermogravimetric‐differential thermal analysis (TG‐DTA) of organic species provides information on thermal reactions, the amount and properties of clay structural water, organic species and carbonates.
- 2. The accuracy of LOI compared with that of TG‐DTA was evaluated in 33 sediment samples from the Lagoon of Venice (Italy).
- 3. In all tests conducted with TG‐DTA the mass loss of OM and the loss of clay structural water (LCSW) from oxidized samples were measured. The mass loss of OM at 350°C (TG‐DTA 350 OM) and the total extraction of organic matter at 567°C (TEOM) calculated from the difference between natural state samples and oxidized samples highlight the presence of both thermally labile and thermally stable substances.
- 4. The grain size data of sediment samples from the Lagoon shows a variable distribution between slightly muddy sand and mud. Loss of clay structural water at 350°C (LCSW 350) and total extraction of clay structural water at 567°C (TECSW) both estimated by TG‐DTA on oxidized samples, were found to correspond approximately to 6% and 10%, respectively of the clay fraction (<4 µm). This percentage may be used to correct LOI measurements of OM in sediments with high clay content.
- 5. LOI 350 (loss on ignition at 350°C) and LOI 550 (loss on ignition at 550°C) proved to be ~80% and ~200%, respectively, of total extraction of mass loss at 350°C (TG‐DTA 350 tot) and at 567°C (TEML) estimated by TG‐DTA on natural samples, meaning that the LOI 550 value represents a significant overestimate. The difference between the LOI 550 and TEML values indicates that the mass loss excess (MLE) may be accounted for by losses due to breakdown of carbonates.
734.
Kraisiri Khidkhan Saranya Poapolathep Sittinee Kulprasertsri Rattapong Sukkheewan Paphatsara Khunlert Mario Giorgi Amnart Poapolathep 《Journal of veterinary science (Suw?n-si, Korea)》2022,23(6)
Domestic poultry are among the non-target species of exposure to fipronil, but limited information is available on the metabolic effects of fipronil exposure in avian. We investigated the comparative capacity of in vitro biotransformation of fipronil among chicken, duck, quail, goose, and rat. Interspecies differences in kinetic parameters were observed; the clearance rate calculations (Vmax/Km) indicated that chicken and duck are more efficient in the cytochrome P450-mediated metabolism of fipronil to sulfone than quail, goose and rat. The lower hepatic clearance of fipronil in quail, goose and rat, suggested that fipronil sulfone may serve as a biomarker to indicate fipronil exposure in these species. 相似文献