基于计算机视觉的大黄鱼体尺测算与体质量估测

鱼类的体重、体长等表型性状是水产养殖和遗传育种中非常重要的经济性状,为了避免人工测量的不确定性、误差随机性和效率低下的问题,本研究开发出一种基于Mask Region Convolutional Neural Network (Mask R-CNN) 的自动化、无侵入式鱼类图像分割和表型性状测量的装置。该装置包括图像采集装置和控制软件两部分,其中图像采集装置可以测量不同规格鱼类 (体长1~40 cm)。基于Mask R-CNN的控制软件,可以对图片进行目标性状的训练和预测,实现目标数据的测量、存储和管理。本研究利用该装置对477尾3月龄大黄鱼进行了图像采集和基于大黄鱼图像的体长、体高、体重性状预测。研究表明,利用该装置测量的大黄鱼体长和体高的平均相对误差均小于4%。基于体长、体高、体表面积的多元回归模型对体重进行拟合,测量值与真实体重的相关系数为0.99,平均相对误差为4%,对每张图片的平均处理时间为3 s,测量速率是人工的8倍。该系统可以实现自动化、高效、准确地获取大黄鱼体型与体重性状,为大黄鱼种质资源评价、良种选育和种质创新提供更加便捷高效的表型测评工具。     

Diversification of shrimp products in the Japanese and US markets during the 1990s

Abstract

During the 1990s the major producers of farmed shrimp in the world included countries such as Thailand, Ecuador, Indonesia, China and India. These countries exported shrimp products in frozen form. The major importers were Japan, the United States and European Union countries. This study reports changes in the trend of exported shrimp products of 10 countries by using the ‘revealed comparative advantage’ method. The selected producers were 10 shrimp exporters to the Japanese and US markets. The results of the study showed that there was a gradual increase in the export quantity of shrimp‐exporting countries such as Thailand, Indonesia and China. These countries have developed processing technology with the advantage of low production costs, as well as abundant and inexpensive labour.     

Use of GIS and machine learning to predict disease in shrimp farmed on the east coast of the Mekong Delta,Vietnam

Diseases in shrimp farms in the Mekong Delta of Vietnam cause significant crop losses and are therefore of great concern to producers. Once a pond becomes infected, it is difficult to prevent spread of the disease to nearby shrimp farming areas. Thus, predicting the occurrence of disease is an essential part of reducing the risk for shrimp farmers. In this study, we applied an integrated geographic information system and machine learning system to predict three serious diseases of shrimp, namely, acute hepatopancreatic necrosis, white spot syndrome disease, and Enterocytozoon hepatopenaei infection, based on data collected from shrimp farms in the Tra Vinh, Bac Lieu, Soc Trang, and Ca Mau provinces of Vietnam. We first constructed a map showing the distribution of these diseases using the locations of affected farms, and then we conducted spatial analysis to acquire the geographical features of the affected locations. This latter information was combined with environmental factors and clinical signs to form the set of independent variables affecting the outbreak of diseases. The neural network model outperformed the logistic regression, random forest, and gradient boosting methods in terms of predicting infection to estimate the probability of disease occurrence in farmed areas. Acute hepatopancreatic necrosis disease infected farms downstream of the Co Chien and Hau Rivers of Tra Vinh and west of Ca Mau. Enterocytozoon hepatopenaei infection is distributed in Soc Trang Province, while white spot syndrome virus has spread to the coastal districts of Soc Trang and Bac Lieu Provinces, where it is highly associated to water from a complex canal system.

     

Implicit price of mussel characteristics in the auction market

This study explores desired and undesired characteristics of mussels in wholesale market by applying hedonic price analysis. Transaction data in auction market in Yerseke, the Netherlands, was used to estimate linear and semi-log price models. Meat content and size count, which are measured as the ratio of the weight of cooked meat to the total weight and the number of mussel per kg of raw mussels, respectively, are the most important characteristics determining the price. At the sample mean, if the meat content increases by 1%, farmers can get a premium price of 5.5 eurocents kg^?1 of raw mussel. Mussel lots with size counts below 50 pieces kg^?1 can command the highest implicit price of size. Processors prefer mussel lots in which the size of mussels is more or less heterogeneous. The impurity of mussel lots, which is measured by the percentage of tare, the amount of barnacles and limpets per kg of raw mussels are significant discounting factors on the price. The study also investigates the impact of farming locations and seasons on the price and the price trend during the period of 2002–2009.     

The use of machine learning to predict acute hepatopancreatic necrosis disease (AHPND) in shrimp farmed on the east coast of the Mekong Delta of Vietnam

Fisheries Science - Predicting the outbreak of disease is essential when managing shrimp farms. Acute hepatopancreatic necrosis disease (AHPND) caused by Vibrio parahaemolyticus is a serious...     

Nondestructive evaluation of fish meat using ultrasound signals and machine learning methods

In this study, we propose a new method for the nondestructive measurement of the fat content and texture of fish meat using machine learning and the bag of features approach. We employed two machine learning methods, that is, a self-organizing map (SOM) and radial basis function (RBF) network. The SOM was applied to symbolize the pattern of the frequency spectrum extracted from ultrasound signals and to generate key features for the bag of features technique. The RBF network was applied to estimate the fat content and texture of fish meat from the bag of features histogram. We verified the accuracy of the fat content and texture estimations given by the proposed method through a series of experiments. The results showed that the fat content and texture of fish meat was estimated more accurately using the proposed method than by the conventional approach.     

Export performance of major cultured shrimp producers in the Japanese and US markets

Increase in shrimp farming was stimulated by growth in world market for high-value shrimp products in the 1980s. The major cultured shrimp producers are located in Asia-Pacific and Latin American regions. The revealed comparative advantage (RCA) method is used to provide insights into the export performance of nine selected shrimp producers in the Japan and United States markets, separately. Shrimp is marketed in a wide variety of product forms, and prices vary according to various product attributes including species, size, taste, quality and origin. The results show that vertical product differentiation concerning different varieties of a good in terms of both quality and price plays an important role on the relative export competition of shrimp products among major shrimp-exporting countries. As a result of the geographical advantage, Asia-Pacific producers enjoy comparative advantage in the Japanese imported shrimp market. Joint ventures with the United States provide great benefits to Ecuador and Mexico in exporting fresh shrimp into the United States market.     

From Atlantic to Pacific: Price links in the US wild and farmed salmon market

Abstract

In 1990, the US International Trade Commission stated that Atlantic and Pacific salmon species did not share a substitute relationship in any of the product forms. This result is contrary to economic demand studies that show a substitute relationship for Atlantic and Pacific salmon species. Time‐series results reported in this paper are consistent with the earlier demand studies and show evidence of an equilibrium price system that includes Atlantic, chinook and coho salmon species for the US market. For these three salmon species a substitute relationship cannot be rejected. However, we observe only weak price links across the three different species in the different US regional markets.     

The feasibility of using primary shrimp hemocyte culture to screen herbal immunostimulants

An analysis of the immune activity of herbal extract in vivo and in vitro assays was performed to explore the feasibility of using primary shrimp hemocyte culture to screen herbal immunostimulants. In vitro experiment was conducted by adding herbal extract into the medium of primary cultured hemocytes and incubating for 24h. In vivo experiment was carried out by feeding shrimp with diets incorporated with herbal extract for 21 days. Challenge test can be used to directly reflect comprehensive immune capacity of organisms. Four immune indexes, total hemocyte counts (THC and lysozyme, phenoloxidase (PO), and phagocytic activity were examined both in vitro and in vivo. The results showed that effects of herbal extract on THC or lysozyme activity were different between in vitro and in vivo. On the contrary, effects of herbal extract on PO activity and phagocytic activity in vitro and in vivo showed a strong correlation. Herbal extract, which enhanced PO activity and phagocytic activity in vitro, had ultimate immune-promoting function in vivo. Therefore, it was feasible to use primary hemocyte culture to screen herbal immunostimulants by determining the effects of herbal immunostimulants on PO and phagocytic activities.     

对虾虾头、虾壳副产品综合利用的研究概况

对虾在加工过程中会产生大量的虾头及虾壳等副产品,其副产品中含有丰富的营养物质.近年来,随着对虾产量的递增,其副产品的产量也越来越多,但产生的副产品大多被低值化利用或直接被废弃.既浪费资源又对环境造成了污染.为解决这一问题,本文就虾副产品在食品、化工、医学等方面的综合利用作简要概述,以期为对虾食品加工企业提高虾的综合利用...     

免疫增强剂-肽聚糖在对虾养殖中的应用

概述肽聚糖的来源、结构组成，以及肽聚糖被利用后对提高生物多种免疫因子活力，增强抗病力所表现出的生物活性。分析了对虾免疫系统在防御病原入侵过程中，免疫细胞与体液免疫因子的功能特点，从对病原的防御，消除及损伤修复等方面阐明肽聚糖提高对虾非特异性免疫力的作用机理。     

Using machine learning algorithms to analyse the scute structure and sex identification of sterlet Acipenser ruthenus (Acipenseridae)

Sturgeons are valued as specialty black caviar, which is very expensive. Only females are used in the technology of caviar aquaculture. Universal method of sex determination has not yet been developed. Most of known methods are not sufficiently accurate, or used at a relatively late age, or difficult to use. Perfect early determination of sex is considered to be impossible. Because of the dark colour of most sturgeons and important morphological differences, which fish of almost all ages have, were overlooked. We first found that the scute structure of sterlet sturgeon depends on the sex. The found dependencies with the help of machine learning algorithms open a possibility for creation of sex determination equipment using the artificial intelligence. Our results open a perspective for creation of sex determination methods for other 23 sturgeon species, which can increase the efficiency of caviar aquaculture and restoration of sturgeons in natural waters.     

对虾养殖中的清塘及养殖期间水体消毒药物使用的探讨

养虾池塘的塘底和养殖水体常因环境变异而滋生细菌,病毒以及附生物,导致虾病发生。养殖对虾放养前的清塘及养殖过程中的水体消毒,是关系到养虾成功或失败的一项重要工作。常用于清塘和消毒的药物十几种。放养前清塘常用的有生石灰、茶麸、敌百虫、强氯精等药物。养殖期间常用的有生石灰、强氯精、二氧化氯,高锰酸钾、新洁尔灭等药物。 本文只就养虾过程中的放养前清塘及放养后的水体消毒使用药物问题作一些探讨。 一、他们及水体消毒的目的 在养虾池塘中,从大海进入的海水,会带进鱼类、甲壳类和各种原生动物、有害细菌及病毒。鱼类是…     

南美白对虾淡化高产养殖试验

凡纳滨对虾（（Litopennaeus vannamei Boone1931）亦称白脚虾,俗称南美白对虾,属节肢动物门,有鳃亚门,甲壳纲、软甲壳纲,十足目,游泳亚目、对虾科、对虾属。为广盐、广温的热带虾类,主要分布在秘鲁北部至墨西哥桑诺拉一带,以厄瓜多尔沿岸最多。     

关于对虾的养殖技术之二 如何控制青苔在虾池内的生长

随着海洋污染的恶化,海区内的海水富营养化,致使近年海水围塘养殖虾池内青苔大量滋生,严重影响了虾池养殖.笔者通过几年来的生产实践,采取了一些对策,在控制青苔生长方面取得比较好的效果. 我们采取的虾池养殖模式是以贝类为生,虾类稀养,鱼蟹套养的生态健康养殖模式.     

Prenursery of the Pacific white shrimp in a biofloc system using different artificial substrates

This study evaluated different artificial substrates during pre-nursery of Pacific white shrimp in a biofloc system. Post-larvae (PL 5–80 PL L⁻¹) were raised in 60 L tanks filled with 52 L of chlorinated seawater (35‰) and 6 L of the microalga Chaetoceros muelleri. Four treatments were performed, including control (no artificial substrate), Bidim^® (geotextile), mosquito net screen (2 mm mesh) and Needlona^® (polyester fiber). The total surface area of artificial substrate comprised 100% of the tank area (0.89 m²). PLs were fed nine times a day using commercial feed. Molasses was added in all treatments four times a day at an average carbon:nitrogen ratio of 14.7:1. The experiment was carried out until the PLs reached PL20, and during this time, water quality, survival, weight gain and survival to salinity stress were all evaluated. Water quality parameters remained within the accepted levels for shrimp rearing, with the exception of total suspended solids (TSS) in mosquito net screen and control, which had the highest values (507 ± 5.50 mg L⁻¹ and 565 ± 23.46 mg L⁻¹, respectively). Using Needlona^® as artificial substrate increased the survival rate (91 ± 11.6%) and reduced TSS (42%) when compared to the control. No significant differences were observed in final weight and survival to salinity stress. Among the different substrates, Needlona^® was the most suitable for application in Pacific white shrimp prenursery in the biofloc system, essentially because it could maintain levels of solids suspended in water without the use of clarifiers or water exchange, resulting in higher survival.     

Toxicity of some chemical therapeutics to the commercial shrimp,Penaeus californiensis

Information is presented concerning the toxicity of methylene blue, copper sulfate, cutrine, potassium permanganate, formaline-malachite green, and hyamine to Penaeus californiensis Holmes.     

硒酵母的培养及其养虾效果

对五株假丝酵母菌株进行利用淀粉废水和转化硒元素的筛选试验,其中CY-173菌株所得的蛋白质含量和蛋白态硒总量最多.对其进行耐高温试验,在33～45℃范围内,菌株都能生长,但超过40℃生长速度开始减缓,45℃时明显受到抑制.在6L标准发酵罐内进行pH与温度条件试验,pH在3～5之间,菌株生长差异不显著;在33～40℃范围内,菌株都能较好生长,但以37℃的蛋白质含量与蛋白态硒总量为最高.将所得的硒酵母替代部分鱼粉用于养殖中国对虾,结果三组硒酵母饲料(含10%、20%、30%硒酵母)的养殖效果均优于对照饲料,其中10%硒酵母添加量的饲料(含硒0.6×10-6),其饵料系数最低,为2.56,比对照组的2.95减少了13.3%.     

Use of high‐protein brewer’s yeast products in practical diets for the Pacific white shrimp Litopenaeus vannamei

Two 6‐week growth trials and a digestibility trial were conducted to evaluate the effects of brewer's yeast in practical shrimp feeds. In the first growth trial, graded levels (0, 60, 120, 180 and 240 g/kg) of a brewer's yeast (BY50) were used to replace fishmeal and soybean meal, referred to as Diet DBY0, DBY6, DBY12, DBY18, DBY24 and Diet LFM0, LFM6, LFM12, DBY18 and LFM24, respectively. The results showed that there were no significant differences in final biomass, survival, protein retention efficiency and feed conversion ratio; however, limited differences in final weight and weight gain were shown in the FM replacement series. There was no significant difference on the growth performance in the SBM replacement series. The second growth trial was conducted with Diet DBY0, DBY12, DBY18, DBY24, LFM0 and a low‐FM diet containing 20 g/kg of BY with 700g/kg (?) protein (Diet DBY70). Shrimp fed with Diet DBY0 exhibited significantly higher final mean weight and weight gain than those offered the Diet DBY24. Nutrient availability of BY50 and BY70 was similar to SBM and significantly higher than FM. Results indicated that 180–240 g/kg BY50 can be effectively used in shrimp diets as a replacement for FM, or up to 240 g/kg when replacing SBM.