Effects of different feeding rations on the CO2 fluxes at water-air interface and energy budget of sea cucumber Apostichopus japonicus (Selenka)

Feeding ration is one of the most important factors that directly affect growth and physiology progress of sea cucumber Apostichopus japonicus. In present study, a 32-day experiment was carried out to investigate the effects of feeding ration (1%, 3%, and 7% of total body weight, named F1, F3 and F7, respectively) on growth performance, carbon allocation, energy budget and CO2 fluxes at water-air interface. Results showed the maximum specific growth rate was observed at F3, while F7 showed negative growth. And F3 exhibited the highest enzyme activities associated with respiration in respiratory tree and body wall. Carbon intake, nitrogen intake and energy intake were significantly affected by feeding ration, while energy allocation between F1 and F3 on growth and excretion were no significant difference, suggesting that increased feeding ration slightly increased the digestive burden. Compared to F1, food conversion efficiency and fecal energy of F3 were reduced, while respiration metabolizable energy was increased. Mean CO2 flux at water-air interface of F3 was significantly higher than that of F1 at noon and dusk, and mean CO2 flux of F7 was significantly lowest than other groups at all sample times. Our results revealed that feeding rations influence CO2 fluxes at water-air interface by altering physiological status, carbon content, and energy allocation for respiration metabolizable of sea cucumber. Our study provides a theoretical basis for promoting the development of efficient low-carbon aquaculture technology for sea cucumber and sustainable development of the industry

Crosstalk between Growth and Osmoregulation of GHRH-SST-GH-IGF Axis in Triploid Rainbow Trout (<i>Oncorhynchus mykiss</i>)

Smolting is an important development stage of salmonid, and an energy trade-off occurs between osmotic regulation and growth during smolting in rainbow trout (Oncorhynchus mykiss). Growth hormone releasing hormone, somatostatin, growth hormone and insulin-like growth factor (GHRH-SST-GH-IGF) axis exhibit pleiotropic effects in regulating growth and osmotic adaptation. Due to salmonid specific genome duplication, increased paralogs are identified in the ghrh-sst-gh-igf axis, however, their physiology in modulating osmoregulation has yet to be investigated. In this study, seven sst genes (sst1a, sst1b, sst2, sst3a, sst3b, sst5, sst6) were identified in trout. We further investigated the ghrh-sst-gh-igf axis of diploid and triploid trout in response to seawater challenge. Kidney sst (sst1b, sst2, sst5) and sstr (sstr1b1, sstr5a, sstr5b) expressions were changed (more than 2-fold increase (except for sstr5a with 1.99-fold increase) or less than 0.5-fold decrease) due to osmoregulation, suggesting a pleiotropic physiology of SSTs in modulating growth and smoltification. Triploid trout showed significantly down-regulated brain sstr1b1 and igfbp2a1 (p igfbp1a1 (~2.61-fold, p = 0.057) and igfbp2a subtypes (~1.38-fold, p igfbp5a subtypes (~6.62 and 7.25-fold, p = 0.099 and 0.078) and significantly down-regulated igfbp5b2 (~0.37-fold, p igfbp6 subtypes patterns (p < 0.05) potentially indicated trout triggered energy redistribution in brain and kidney during osmoregulatory regulation. In conclusion, we showed that the GHRH-SST-GH-IGF axis exhibited pleiotropic effects in regulating growth and osmoregulatory regulation during trout smolting, which might provide new insights into seawater aquaculture of salmonid species

Transcriptional Signatures of Immune, Neural, and Endocrine Functions in the Brain and Kidney of Rainbow Trout (<i>Oncorhynchus mykiss</i>) in Response to <i>Aeromonas salmonicida</i> Infection

Rainbow trout (Oncorhynchus mykiss) serves as one of the most important commercial fish with an annual production of around 800,000 tonnes. However, infectious diseases, such as furunculosis caused by Aeromonas salmonicida infection, results in great economic loss in trout culture. The brain and kidney are two important organs associated with “sickness behaviors” and immunomodulation in response to disease. Therefore, we worked with 60 trout and investigated transcriptional responses and enrichment pathways between healthy and infected trout. We observed that furunculosis resulted in the activation of toll-like receptors with neuroinflammation and neural dysfunction in the brain, which might cause the “sickness behaviors” of infected trout including anorexia and lethargy. We also showed the salmonid-specific whole genome duplication contributed to duplicated colony stimulating factor 1 (csf-1) paralogs, which play an important role in modulating brain immunomodulation. Enrichment analyses of kidneys showed up-regulated immunomodulation and down-regulated neural functions, suggesting an immune-neural interaction between the brain and kidney. Moreover, the kidney endocrine network was activated in response to A. salmonicida infection, further convincing the communications between endocrine and immune systems in regulating internal homeostasis. Our study provided a foundation for pathophysiological responses of the brain and kidney in response to furunculosis and potentially offered a reference for generating disease-resistant trout strains

Erratum to: Performance evaluation of operational atmospheric correction algorithms over the East China Seas (Chinese Journal of Oceanology and Limnology, (2017), 35, 1, (1-22), 10.1007/s00343-016-5170-6)

Unfortunately for all articles of Vol. 35 No. 1 the future journal title “Journal of Oceanology and Limnology” was used instead of the current journal title “Chinese Journal of Oceanology and Limnology”. All articles in the issue are affected. Please make sure to cite the articles with the following Vol. and No. info: Chinese Journal of Oceanology and Limnology, Vol. 35 No. 1, [page range]

Erratum to : Performance evaluation of operational atmospheric correction algorithms over the East China Seas (Chinese Journal of Oceanology and Limnology, (2017), 35, 1, (1-22), 10.1007/s00343-016-5170-6)

Unfortunately for all articles of Vol. 35 No. 1 the future journal title “Journal of Oceanology and Limnology” was used instead of the current journal title “Chinese Journal of Oceanology and Limnology”. All articles in the issue are aff ected. Please make sure to cite the articles with the following Vol. and No. info: Chinese Journal of Oceanology and Limnology, Vol. 35 No. 1, [page range]