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Effects of dietary oxidized fish oil on the growth performance, intestinal health, and antioxidant capacity of zebrafish
Get PDFThis study aimed to investigate the effects of oxidized fish oil (OFO) on growth performance, intestinal health, and antioxidant function and to determine the minimum concentration of oxidized fish oil to cause irreversible damage to the intestinal tissue structure of zebrafish. A 30-day feeding trial on zebrafish (average weight 0.054 g) was conducted in triplicate groups of fish fed four test diets containing different concentrations of OFO: 0% OFO (OFF, blank control), 2% OFO (OF1), 4% OFO (OF2), and 6% OFO (OF3). The body weight gain (WG), specific growth rates (SGR), feed conversion ratio (FCR), survival rate (SR), and antioxidant function {glutathione peroxidase (GSH-PX), total superoxide dismutase (T-SOD), catalase (CAT), and malondialdehyde (MDA)} were recorded. The intestinal structure was observed at the end of the trial. After the 14-day experimental period, Final body weight (FBW), WG, and SGR decreased significantly with the increase in the concentration of feed OFO (P < 0.05), while FCR showed a downward trend. The activity of T-SOD decreased significantly, the activities of GSH-PX and CAT, and the MDA content increased significantly with the increase in the concentration of feed OFO (P < 0.05). The intestinal morphological damage score showed an upward trend with the increase in the concentration of OFO, and it was significantly higher in group OF2 and OF3 than in group OF1 (P < 0.05). After the 28-day test period, the experimental indexes and intestinal antioxidant function trends were the same as those on 14 days. The increased OFO concentration significantly increased the intestinal morphological injury score (P < 0.05). These results demonstrated that adding 4% OFO to the feed for 14 days could induce irreversible damage to the intestinal tissue structure, weaken the antioxidant function, and decrease the growth performance of zebrafish
Manchuria : AMS L542, Index Map
No full textScale 1:250,000. Approximately 200 maps : color ; 47 x 72 cm or smaller. Relief shown by contours and spot heights. "Prepared by the Army Map Service (AM), Corps of Engineers, U.S. Army, Washington D.C." Contains various editions of some sheets, e.g.: Edition 1-AMS -- Edition 2-AMS -- Edition 3-AMS. Map in English and Chinese
Replacement of fishmeal by common cricket (<em>Acheta domesticus</em>) meal in diets for juvenile tilapia (<em>Oreochromis niloticus</em>)
No full textThe present study was to substitute fishmeal with domestic cricket (Acheta domesticus) meals in diets for tilapia (Oreochromis niloticus) farming. Productive performance was evaluated by two diets based on Pearson's square, the treatment T1 with 20% inclusion and treatment T2 with 35%, respectively, and a control T3 (commercial feed) performed in triplicate. Each treatment had ten organisms weighing 9+5 gr for 40 days. Initial biometry was performed, and after this, every five days until the end of the bioassay. The production and survival variables were evaluated; Finally, a proximal analysis of moisture, ash, lipids, and protein was carried out. According to the weight gain, the performance of the diets presented significant differences between the three diets. T2 diet results were similar to T3 (Control) due to tilapia being omnivorous and having excellent resistance and adaptability to different types of food. Therefore, the possible use of this food can be considered, favoring its economic impact on tilapia crops
Effect of ginger, <em>Zingiber officinale</em> extract on growth performance, digestive enzyme and stress tolerance of whiteleg shrimp, <em>Litopenaeus vannamei</em> juveniles
No full textThis study evaluated the effects of ginger extract as a feed additive on the growth performance, digestive enzymes, and resistance to environmental stress of the whiteleg shrimp, *Litopenaeus vannamei*. 1200 juveniles were randomly allocated into four groups with three replicates. Shrimps were fed diets supplemented with 0 (T0-control), 0.5 (T1), 1 (T2), and 1.5 g kg^-1^ of ginger extract (T3) for 56 days. The results indicated that shrimp fed with ginger extract had a lower feed conversion ratio (FCR) than the control. In addition, shrimp fed with 0.5 g kg^-1^ of ginger extract had significantly greater weight gain and protease activity in the intestine than those in the control group. However, dietary supplementation with ginger extract did not significantly affect survival rates. After 56 days of culture, shrimp fed with 0.5 and 1 g kg^-1^ of ginger extract had higher survival rates than the controls after 72 -- 96 h exposure to high ammonia stress (40 mg L^-1^). Based on the study's findings, ginger extract could be recommended for shrimp feed to enhance growth and resistance against stress factors, and the optimal level is 0.5 g kg^-1^
Population genetics analysis of the black rockfish <em>Sebastes schlegelii</em> in Northern China based on 2b-RAD simplified genome sequencing
Get PDFThe black rockfish Sebastes schlegelii is an important fishery species in Japan, South Korea, and China. Overfishing has severely depleted the natural resources of S. schlegelii in recent years, leading to the initiation of programs aimed at enhancing fish stock. However, the genetic structure of northern populations remains elusive, posing challenges in collecting and preserving germplasm resources. In this study, a total of 191 S. schlegelii individuals from seven populations, including one cultured population (Changdao: CDYZ) and six wild populations (Lianyungang: LYG; Qingdao: QD; Weihai: WH; Changdao: CDYS; Beidaihe: BDH) sequenced by 2b-RAD method and their population genetics was analyzed using 27,064 SNPs obtained. The results indicated low genetic diversity in both wild and cultured populations (PIC Ho: 0.174-0.273, He: 0.173-0.234), with the cultured population exhibiting higher diversity than the wild ones. Moderate genetic differentiation existed between the cultured population and six wild populations (0.05 Fst Fst Nm > 1). This study provides a theoretical basis for conserving and rationalizing germplasm resources for S. schlegelii
Study on the Realization of Freshwater Ecosystem Services from the Perspective of Consumer Willingness to Pay in China
Get PDFThe realization of freshwater ecosystem services value plays a vital role in the survival of human beings and the sustainable development of fisheries, and this process is inseparable from the support of consumers. This paper decomposes freshwater ecosystem services in multiple dimensions. From the perspective of consumers' willingness to pay for ecosystem services, using the survey data of 821 consumers in China, the influence of various dimensions of freshwater ecosystem services on consumers' willingness is explored by the structural equation model. The results show that: (1) consumers already have a certain awareness of freshwater ecosystem services, but the proportion of consumers willing to pay extra for them is not high; (2) the individual characteristics (age, gender, education, and income ) affect consumers’ willingness to pay for freshwater ecosystem services value, but the impact degree is not high; (3) regulating, cultural, and provisional servers functions of freshwater ecosystem services significantly affect consumers’ willingness to pay, especially freshwater ecosystem services’ role on regulating carbon emissions, controlling algal biomass, enhancing local fishery culture and improving leisure and leisure entertainment services. This study is helpful to deeply understand consumers' willingness to pay for various dimensions of freshwater ecosystem services and provide more targeted and detailed guidance for realizing it
The vitellogenesis-inhibiting hormone (SpVIH) of the crab Scylla paramamosain is not likely to have a vitellogenesis-inhibiting function in the ovary
Get PDFThe function and molecular characterization of the previously reported crab (Scylla paramamosain) vitellogenesis inhibiting hormone SpVIH is still unclear. In this experiment, SpVIH’s bioinformatic and functional characterizations were analyzed. Sequence analysis showed SpVIH was clustered with several type II MIH/GIHs of the Brachyura. The expression of SpVIH in the eyestalk was low in the early ovarian developmental stage I and increased with the advancement of ovary maturation. Interestingly, the SpVIH transcript was still at a high level in the ovary of females at the middle to late maturation stage. SpVIH’s function was studied according to the expression of vitellogenin (Vg) and vitellogenin receptor (VgR) in the ovary and hepatopancreas after incubation with SpVIH-dsRNA and recombinant SpVIH protein (rSpVIH). In vitro assay results indicated that rSpVIH has a significant stimulative effect on the expression of Vg in the hepatopancreas in the middle stage of vitellogenesis and in the ovary of each vitellogenesis stage. However, SpVIH-dsRNA has no significant effect on the expression of Vg when SpVIH-dsRNA is introduced to the ovary and hepatopancreas at the early, middle, and late stages of vitellogenesis. Furthermore, the co-incubation experiment result indicated that the eyestalk consists of factor(s) that can significantly up-regulate the expression of Vg in the ovary, with a further combination of dsVIH and eyestalk under incubation, the significant increase of Vg-mRNA expression levels were also found in the ovary of four ovarian development stages of S. paramamosain. Contrary to the previous reports, SpVIH does not possess a vitellogenesis-inhibiting function but can promote vitellogenesis in the ovary and hepatopancreas
Serial Verb Constructions in Papuan Malay: Forms, Functions and Indeterminacy
Get PDFThis paper describes serial verb constructions in Papuan Malay, an eastern Malay language, spoken in coastal West Papua, on the island of New Guinea. Papuan Malay employs serial verb constructions to encode complex events by means of verb sequences, or to express grammatical categories. However, the identification of Papuan Malay verb sequences as monoclausal serial verb constructions is often less than straightforward. This is due to the structure of Papuan Malay which is characterized by little productive morphology, no inflectional morphology, and the pervasive use of syntactic argument elision. In consequence, Papuan Malay multiverb constructions often have an indeterminate status; they could be interpreted as monoclausal serial verb constructions or as multiclausal chaining constructions with elided subject arguments. It is suggested here that the interpretation of such indeterminate verb sequences needs to be pragmatically inferred
