Comparative Nutritional Analysis on Fish Meal and Meat and Bone Meal of Harmless Treatment of Dead Pig Carcass

In order to explore the resource utilization of the harmless treatment product(pork meat and bone meal,abbreviated PM)of pigs died of non-communicable diseases,the general nutritional components and amino acid composition of PM and fish meal were determined and compared.The results showed that the contents of moisture,crude protein,crude fat and ash in PM and fish meal were 3.25%and 8.92%,66.65%and 66.67%,13.52%and 8.23%,18.25%and 21.50%,respectively.The contents of essential amino acids(EAA)in PM and fish meal were 19.94%and 22.35%,respectively.For PM and fish meal,the first limiting amino acid was Met(methionine)+Cys(cysteine),and the second limiting amino acid was Lys(lysine);their essential amino acid indexes(EAAI)were 66.60 and 77.04,respectively;and their delicious amino acid(DAA)contents were 26.89%and 23.15%,respectively.In summary,the meat and bone meal of pigs died of non-communicable diseases has the characteristics of high protein and low ash contents,and has certain development and utilization potential as a recycled waste resource,especially in aquatic feed to replace fish meal.

Temporal Distribution of Fish Community Structure in Dongting Lake Estuary

The Dongting Lake Estuary is migration pathways for some river-lake migratory and semi-migratory fishes. In the present study, an annual survey of fish was conducted from January to November 2018 covering a total of 6 sites in Dongting Lake Estuary. A total of 57 freshwater species and subspecies belonging to 5 orders and 10 families were recorded. The catches at the Dongting Lake Estuary were mainly composed of Lake settled fish. The biomass of Cyprinus (Cyprinus) carpio Linnaeus was the highest, accounting for 25.53% of the total catches, followed by Hypophthalmichthys molitrixs, Culter alburnus Basilewsky and Ctenopharyngodon idellus, accounting for 10.41%, 8.99% and 7.10% of the total catches, respectively. The four major domestic carps accounted for 26.13% of the total catch. The range of richness of species varied between 40 and 51 species. The trend was fewer species in spring, with the arrival of summer and autumn gradually increasing, peaking at the turn of summer and autumn, and then gradually decreasing with the arrival of winter, to the lowest in spring. The Shannon, Simpson, Pielou and Margalef indices showed the consistent trends with richness of species.

DNA Extraction from Formalin Fixed <i>Coilia macrognathos</i>Fin Tissues

Approximately 200 mg of fin tissue from each specimen was cut into pieces and treated with a gradient of ethanol (65%, 70%, 75%, 80%, 85%, 90%, 95% and 100%) and then DNA was extracted from formalin fish fin tissues. Agarose gel visualization of the DNA confirmed DNA extracted. MtDNA cyt b gene banding pattern of samples with agarose gel was clearly visible and could be used to be sequenced. In terms of DNA purity, the 260/280 ratio of 87.5% samples ranged between 1.8 and 2.0, indicating that DNA of the majority of the samples was pure. The developed DNA extraction procedure from formalin fish fin tissues by pretreatment with a gradient of ethanol system will be a useful tool to study the genetic structure and phylogenesis of endangered fish, by specimens preserved formalin-fixed in museum and herbarium.

An Evaluation of Artificial Fish Nest for Assessment Enhancement Effects of Fishery Resources of in Xiangjiang River

Artificial fish nests are set in Lukou section and Hengyang section of Xiangjiang River from March 20 to May 10, 2019. The structure of artificial fish nest is bamboo frame, with the size of 2.5 m × 5.0 m × 4 and a unit frame area of 60 m2. A total of 58,201 eggs were collected by 24 monitoring times, of which 30,441 were from Lukou and 27,760 from Hengyang. 3831 fish eggs identify 8 fish species using morphological or molecular biological methods. The results showed that the number of eggs peaked from the 8th day to the 24th day after the nest entered the water, and then decreased rapidly. There was significant negative correlation between egg number in per m2 fish nest and days of fish nest (P < 0.01). The economic benefits of artificial fish nests were RMB 11.81 million. The artificial fish nest can not only increase the population of fish, but also has significant economic benefits.

Strong Genetic Differentiation of <i>Glytothorax zanaensis</i>(Wu et al. 1981) in Nu River, China

The Nu River Project comprised of 13-dam cascade is one of the biggest hydropower development projects yet conceived in China. However, hydropower development will inevitably result in the local ecological environment and biological material impact, particularly the effects on fish. Glyptothorax zainaensis is weak in swimming with suction cup and is extremely sensitive in the hydrological characteristics and water quality changes, so that it can be considered as a water quality monitor of indicator organism. Currently, with the need for conservation, fishery restoration and so on, there is a great demand for genetic information on Glyptothorax zainaensis. Fourty microsatellite loci were isolated, characterized and evaluated from Glyptothorax zainaensis. A total of 91 different alleles were observed in the 303 wild Glyptothorax zainaensis, and the percentage of polymorphic bands ranged from 41.8% to 66.7%, with an average of 90.1%. The genetic diversity value was significantly huge with the expected heterozygosity ranging from 0.578 to 0.706, the observed heterozygosity value ranging from 0.923 to 0.980 and PIC value ranging from 0.418 to 0.644, which showed that the wild Glyptothorax zainaensis population had a high level of genetic diversity. Analysis of molecular variance (AMOVA) and pairwise Fst showed a significant level of genetic differentiation (P < 0.01) among the populations accounting for 40.2% of the total variance. Additionally, results derived from different statistical techniques with different software packages included cluster analysis on NJ tree. Apart from such molecular approaches, we opposed four ways to strengthen the effective resources protection.

Genetic Structure of <i>Spinibarbus caldwelli</i>Based on mtDNA D-Loop

Spinibarbus caldwelli was an endemic species to China, and its germplasm protection and resources utilization had become more and more concerned. To know its genetic diversity and differentiation, the mitochondrial DNA D-loop was amplified and sequenced for 148 individuals from four regions of Pearl River and Yangtze River Basin. Altogether 9 variable nucleotide sites existed among the aligned sequences of 748 bp, and 8 haplotypes were found within 148 individuals. The average nucleotide diversity (Pi) was high 0.00297, while haplotype diversity (Hd) was 0.706. The average genetic distance was 0.00298, most value occurred between LJ and CL populations, and small value occurred between HJ and QZ populations.