三种油葫芦鸣声节律谱图比较

采用长时间连续采样的方法研究了黄脸油葫芦Teleogryllus emma(Ohmachi et Matsumura)、北京油葫芦Teleogryllus mitratus(Burmeister)和黑脸油葫芦Teleogryllus occipitalis(Serville)等3种油葫芦的鸣声节律特征谱图,分析其特点及其在鸣声分类中的意义.     

油葫芦的营养价值(英文)

本研究旨在确定油葫芦Gryllus testaceus Walker的主要营养成分和营养价值。研究发现油葫芦体内主要含有蛋白质、脂类和几丁质三类物质,它们的含量(干重比)分别是58.3％,10.3％和8.7％。其中必需氨基酸的含量除了半胱氨酸和蛋氨酸外,非常符合FAO／WHO所确定的人体对氨基酸需求标准。脂肪酸分析显示,不饱和脂肪酸的含量很高,仅油酸、亚油酸和亚麻酸的含量就占总脂肪含量的77.51％。油葫芦的甲壳素含量为8.7％,而且从该虫提取甲壳素／壳聚糖的品质在甲壳素色泽及残留灰分含量、壳聚糖粘度等方面比常规甲壳素原料虾蟹壳的好。因此,油葫芦可以作为很好的食品或饲料添加剂,或医药原料。     

NUTRITIONAL VALUE OF THE FIELD CRICKET (GRYLLUS TESTACEUS WALKER)

Abstract The chemical composition and the nutritional quality of protein, fatty acids and chitin of adult field cricket Gryllus testaceus Walker were investigated. The adult insect contained: crude protein 58.3 %; fat 10.3 %, chitin 8.7 % and ash 2.96 % on dry matter basis respectively. The essential amino acid profile compared well with FAO/WHO recommended pattern except for cysteine and methionine. The fatty acid analysis showed unsaturated acid of the field cricket to be present in high quantities, and the total percentage of oleic acid, linolic acid and linolenic acid was 77.51%. The chitin content of the insect was 8.7% with a better quality than the commercial chitin that was prepared from shells of shrimp and crab. Therefore the chemical composition of the field cricket indicates the insect to be a good supplement to nutrition for food and feed, even a raw material for medicine.     

A NEW SOUND TRAP,AND OBSERVATIONS ON THE MIGRATORY AND ACOUSTIC BEHAVIOUR OF THE FIELD CRICKET TELEOGRYLLUS COMMODUS (WALKER)

ABSTRACT

A new sound trap for capturing male and female crickets attracted to the calling song of the male is described. Major advantages of the trap are its portability and effectiveness. It was designed to operate in conjunction with a previously described cricket-song generator. The trap is compared with other designs and the acoustic and migratory behaviour of crickets revealed by sound trapping are discussed.     

INFECTIOUS DISEASES OF MAZZAELLA LAMINARIOIDES (RHODOPHYTA): CHANGES IN INFECTION PREVALENCE AND DISEASE EXPRESSION ASSOCIATED WITH SEASON,LOCALITY, AND WITHIN-SITE LOCATION1

This study addresses the issues of infection prevalence and disease expression in two wild populations of the red algal host Mazzaella laminarioides and their variability associated with locality, season, and spatial location of the host in the intertidal zone. Our results demonstrated that Endophyton ramosum is the most frequent infective pathogen affecting M. laminarioides in Matanzas and Pucatrihue. This situation prevailed through the year and across the high-to-low intertidal gradient. Although there was a general trend for lower levels of infection in late winter and early spring, only in a few, cases was well-defined seasonality detected. Furthermore, clear seasonal patterns, as displayed by deformative disease in the high intertidal zone of Pucatrihue, were attenuated in the middle and lower intertidal zones. Differences in levels of infection in M. laminarioides between the high intertidal zones of Matanzas and Pucatrihue diminished toward the low intertidal zone. Thus, effects of seasonality and locality on infection prevalence may be influenced, at least in part, by the position of the hosts an the intertidal zone. Spatial distribution of the diseased individuals also varied along the beach. This pattern was consistent between the two sites and seemed related to wave exposure and the specific pathogen. Comparisons of the size distribution of noninfected fronds with their infected counterparts showed that infections by Endophyton ramosum and Pleurocapsa sp. more frequently affected medium-and large-sized fronds. This pattern was consistent temporally and similar in the two localities. Finally, a clear association between maturity and prevalence of infection was detected. This association resulted in most fronds of the noninfected segment of the host population being immature, whereas most mature fronds were infected. In conclusion, infectious diseases affecting the red alga Mazzaella laminarioides are a persistent phenomenon in wild populations of the host, although only a small segment of the infected populations displays the full expression of the disease. In spite of the suggested role of factors such as season, latitude, and spatial location of the host on disease prevalence and expression, additional studies are needed to understand fully the dynamics of infectious diseases in wild populations of algal hosts.     

EFFECTS OF AN OFFSHORE OIL DEVELOPMENT ON LOCAL ABUNDANCE AND DISTRIBUTION OF RINGED SEALS (PHOCA HISPIDA) OF THE ALASKAN BEAUFORT SEA1

This study investigates how densities of ringed seals were affected by construction and oil production activities at Northstar, an artificial island built in the nearshore Alaskan Beaufort Sea. Intensive and replicated aerial surveys of seals on landfast ice were conducted during six spring seasons: for three seasons before island construction began (1997–1999); after a winter of intensive island construction (2000); and after more limited construction plus drilling (2001) and drilling plus oil production (2002). A Poisson regression model was used to examine seal densities relative to distance from Northstar after allowance for environmental covariates. Post hoc power analysis indicated that the study design and Poisson regression approach had high power to detect small‐scale changes in seal densities near Northstar if such changes had occurred. However, seal densities during spring were not significantly affected by proximity to Northstar in 2000–2002. Habitat, temporal, and weather factors did have significant effects on seal densities. This study shows that effects of the Northstar oil development on local distribution of basking ringed seals are no more than slight, and are small relative to the effects of natural environmental factors. An understanding of environmental effects is essential when assessing potential impacts of industrial activity on ringed seals.     

STUDIES ON POLYSACCHARIDES FROM THREE EDIBLE SPECIES OF NOSTOC (CYANOBACTERIA) WITH DIFFERENT COLONY MORPHOLOGIES: COMPARISON OF MONOSACCHARIDE COMPOSITIONS AND VISCOSITIES OF POLYSACCHARIDES FROM FIELD COLONIES AND SUSPENSION CULTURES

Hot water-soluble polysaccharides were extracted from field colonies and suspension cultures of Nostoc commune Vaucher, Nostoc flagelliforme Berkeley et Curtis, and Nostoc sphaeroides Kützing. Excreted extracellular polymeric substances (EPS) were isolated from the media in which the suspension cultures were grown. The main monosaccharides of the field colony polysaccharides from the three species were glucose, xylose, and galactose, with an approximate ratio of 2:1:1. Mannose was also present, but the levels varied among the species, and arabinose appeared only in N. flagelliforme. The compositions of the cellular polysaccharides and EPS from suspension cultures were more complicated than those of the field samples and varied among the different species. The polysaccharides from the cultures of N. flagelliforme had a relatively simple composition consisting of mannose, galactose, glucose, and glucuronic acid, but no xylose, as was found in the field colony polysaccharides. The polysaccharides from cultures of N. sphaeroides contained glucose (the major component), rhamnose, fucose, xylose, mannose, and galactose. These same sugars were present in the polysaccharides from cultures of N. commune, with xylose as the major component. Combined nitrogen in the media had no qualitative influence on the compositions of the cellular polysaccharides but affected those of the EPS of N. commune and N. flagelliforme. The EPS of N. sphaeroides had a very low total carbohydrate content and thus was not considered to be polysaccharide in nature. The field colony polysaccharides could be separated by anion exchange chromatography into neutral and acidic fractions having similar sugar compositions. Preliminary linkage analysis showed that 1) xylose, glucose, and galactose were 1→4 linked, 2) mannose, galactose, and xylose occurred as terminal residues, and 3) branch points occurred in glucose as 1→3,4 and 1→3,6 linkages and in xylose as a 1→3,4 linkage. The polymer preparations from field colonies had higher kinematic viscosities than those from correspondingsuspension cultures. The high viscosities of the polymers suggested that they might be suitable for industrial uses.