鱼塭产斑节对虾(Penaeus monodon)催熟繁殖技术研究

以综合催熟措施和移植精荚手术相结合的技术方法,解决了鱼塭产斑节对虾催熟效应期长,产卵率低,易蜕壳失去精荚等难题。使用 ２７８ 尾雌虾,催熟率达９０％ 以上,在４０ ｄ 内共产卵６０８ 尾次,卵量１８ ５３０ 万粒,孵出无节幼体１１ ９９８ 万尾,平均孵化率 ６４．７％ ,平均每尾雌虾孵出无节幼体 ４３．１ 万尾,育成商品虾苗 １ ０２８．５ 万尾,育苗平均成活率 １３．６％ ,试养成活率５７．１％     

斑节对虾苗和刀额新对虾苗对低盐度适应力的研究

取体长为11mm的斑节对虾苗和刀额新对虾苗体长为6．1mm,经暂养数天后,分别在不同盐度的水中进行试验。结果表明,这两种虾苗适应低盐度十分广泛。刀额新对虾苗可比斑节对虾苗适应更低的盐度。斑节对虾苗在从盐度23．18直接降至盐度6．21时,成活率仍可达70％。当虾苗饲养在盐度18．54时,直接放水至海水盐度5．1,成活率为85％。当虾苗在从盐度25．13逐渐淡化到盐度1时,成活率仍有20％～40％。但是,考虑到体重的增重率,虾苗最佳饲养盐度为13．8。刀额新对虾苗从盐度23．18的海水直接放入盐度2以下的海水中,成活率仍有56．7％～63．3％。如果逐渐淡化海水,可在盐度＜2时正常生长。在盐度8．96左右饲养,其体重增重率最佳。上述这两种虾适于河口低盐度地区养殖。在有条件的养成场适当降低盐度,有利其生长。     

Transcriptome Analysis Reveals New Insights into the Respiration Metabolism Mechanism of Different Feeding Rations of Sea Cucumber(Apostichopus japonicus)

Sea cucumber(Apostichopus japonicus) is an excellent model for investigating effects of bottom-dwellers on carbon migration and transformation. However, the molecular mechanism of respiratory metabolism process variation caused by feeding rations is poorly understood. In this study, treatment groups set as 1%(about 0.63 g), 3%, and 7% of total body weight(named F1, F3 and F7groups respectively). The potential molecular mechanisms behind the functions of respiratory tree and body wall were invest...     

Histological Assessment and Transcriptome Analysis Provide Insights into the Toxic Effects of Perfluorooctanoic Acid to Juvenile Half Smooth Tongue Sole Cynoglossus semilaevis

Perfluorooctanoic acid(PFOA) is a widespread synthetic persistent organic pollutant that may enrich along the food chain and affect the growth, development, reproduction, and lipid metabolism of aquatic organisms, particularly the benthic organisms. However, the toxic effects of PFOA on the half-smooth tongue sole Cynoglossus semilaevis, a commercial benthic fish in China, have rarely been reported. Because juvenile fish are sensitive to environmental pollutants, in the present study, histologic...     

Response of Soil Moisture to Rainfall Event in Black Locust Plantations at Different Stages of Restoration in Hilly-gully Area of the Loess Plateau,China

Precipitation plays an important role in the water supplies that support ecological restoration by sustaining large-scale artificial plantations in arid and semiarid regions, especially black locust(Robinia pseudoacacia) plantations(RP plantations), which are widely planted due to R. pseudoacacia being an excellent pioneer species. Characterizing the response of soil moisture to rainfall events at different stages of restoration is important for assessing the sustainability of restoration in RP plantations. In this study, we quantified the response of soil moisture to rainfall events at different years of restoration(15, 20 and 30 yr) representing different restoration stages in RP plantations in a typical hilly-gully area, i.e., the Yangjuangou Catchment, of the Loess Plateau, China. Over the growing season(June to September) of 2017, smart probes were placed at nine depths(10, 20, 40, 60, 80, 100, 120, 150, and 180 cm below the soil surface) to obtain volumetric soil water information at 30-min intervals in the three RP plantations. The advance of the wetting front was depicted, and the total cumulative water infiltration was measured. Soil moisture was mainly replenished by eight heavy rainfall events(mean rainfall amount = 46.3 mm), accounting for 88.7% of the rainfall during the growing season. The mean soil moisture content profiles of RP plantations at the three restoration stages were ordered as 30-yr(14.07%) 20-yr(10.12%) 15-yr(8.03%), and this relationship displayed temporal stability. Soil moisture was primarily replenished by rainfall at the 0-60 cm soil depth, and soil moisture remained stable below the 100-cm soil depth. The rainfall regime influenced the advancement of the wetting front. Here, a single rainfall event of 30 mm was the rainfall threshold for infiltration into the 60-cm soil layer. The total infiltration time ranged from 310.5-322.0 h, but no significant differences were found among RP plantations at different restoration stages. Young and old RP plantations had more total infiltration(more than 228.2 mm) and deeper infiltration depths(80-100 cm) than middle-aged plantations. The RP plantation at the intermediate restoration stage exhibited minimal total infiltration(174.2 mm) and a shallow infiltration depth(60 cm) due to the soil physical structure of the plot, which may have limited rain infiltration. More stand conditions that may affect infiltration should be considered for priority afforestation areas.