Effect of the parasitic isopod,Catoessa boscii(Isopoda,Cymothoidae),a buccal cavity parasite of the marine fish,Carangoides malabaricus

Objective:To examine the effect of isopod parasite Catoessa boscii(C.boscii)on Carangoides malabaricus(C.malabaricus).Methods:The host fish C.malabaricus infested by C.boscii were collected directly from the trawlers landed at Parangipettai coast during December 2008 to November2009.Data regarding the total length,width,weight and sex of the host fish were recorded.Effect of infestation on C.malabaricus,the length and weight data were analysed and host specificity of isopods was also examined.Results:During the sampling period,585 C.malabaricus were examined.Among them,218 specimens were found to carry 243 parasites.Three pairs of isopods(one male with one female)were recorded from the host fish and each pair was attached to the tongue in the buccal cavity of the host.Another pair was also found where the male and male,female and female isopod had settled on the tongue in the buccal cavity.Gross lesions observed in the buccal cavity of infested fish showed small pin-holes in the tongue region,through which dactyls of pereopod's penetrating claws dig into the host tissues.The maximum weight loss was reported in females(5.43%)than in males(3.75%)of C.malabaricus.Due to infestation of different isopod parasites in both male and female fish,the effects on the length-weight relationship of C.malabaricus were compared.The rate of increased growth in weight in uninfested female fish was found to be higher than that of the infested.The weight gain is faster in uninfested fish than in the infested fish.Conclusions:From the above mentioned observations,it is clear that the worst of fish on account of the infestation of isopods are the C.malabaricus succumbed to the attack of isopod parasites.Although,the infestation did not cause immediate death,it had affected the normal growth of the host fish.

First record of three giant marine Bathynomids(Crustacea,Isopoda,Cirolanidae) from India

Three species, Bathynomus decemspinosus, B. doederleini and B. kensleyi （Crustacea, Isopoda, Cirolanidae）, are reported for the first time from the Parangipettai coastal waters, Southeast coast of India. Several Trilasmis （Temnaspis） tridens （Cirripedia Thoracica, Lepadomorpha） were attached to the pleopods of some individuals. So, five bathynomid species are currently reported from India.

Substrate selection and seasonal variation in abundance and size composition of isopod Lirceus fontinalis in Ontario streams, Canada

The abundance and size composition of stream isopods Lirceusfontinalis were investigated from April 2001 to August 2002 in 3 streams in southem Ontario, Canada. Effects of current speed was released from the analysis by choosing slow flowing water. The effects of substrate, season and water depth on the abundance, distribution and size composition of the isopods were analyzed. It was found that substrate and season influence isopods the most. The rocky substrate with attached filamentous macro-algae contains an isopod abundance 7.05 times that of bare rock substrate and 14.6 times that of free-sand and mud substrate. There was a large variation with respect to seasonali .ty in both abundance and size composition of the isopods, with the highest abundance occumng in summer and the lowest in winter and spring; individual isopods also tend to be larger in the winter and spring. In all substrates, shallow areas tend to support higher densities of isopods than deeper areas.

A NEW SPECIES OF THE GENUS NEROCILA (ISOPODA: CYMOTHOIDAE) FROM THE EAST CHINA SEA

A new species of cymothoid Isopoda, Nerocila donghaiensis , collected from the body of a sciaenid fish, Johnius sp., is described in the present paper. The new species can be distinguished from the other species of genus Nerocila by its endopod of uropods with deep notch, sharply serrated on the lateral margin and strongly serrated on the medial margin; antennule with 1st article swollen; dactyli of pereopods I, II, IV, V swollen.

Characterization of the Dominant Bacterial Communities Associated with Terrestrial Isopod Species Based on 16S rDNA Analysis by PCR-DGGE

From the marine environment, woodlice gradually colonized terrestrial areas benefiting from the symbiotic relationship with the bacterial community that they host. Indeed, they constitute the only group of Oniscidea suborder that has succeed to accomplish their lives in terrestrial even desert surfaces. Herein they play an important role in the dynamic of ecosystems and the decomposition of litter. So to enhance our understanding of the sea-land transition and other process like decomposition and digestion of detritus, we studied the bacterial community associated with 11 specimens of terrestrial isopods belonging to six species using a Culture independent approach (DGGE). Bands sequencing showed that the cosmopolitan species Porcellionides pruinosus has the most microbial diversity. Screening demonstrated the predominance of Proteobacteria followed by members from Actinobacteria, Firmicutes and Cyanobacteria phyla. In fact we detected some symbionts like Wolbachia, Mycoplasma and Spiroplasma for the first time in a terrestrial isopod species.

Review on Possible Factors for Outbreak of Wood Boring Isopod, Sphaeroma spp. Which Causes Destructive Impact on Mangrove Forest in China

The tropical and subtropical mangrove biomes form the foundation of a highly productive and biologically rich ecosystem providing essential goods and services to human beings. Despite its values, the stability and survival of mangroves are consistently threatened by anthropogenic activities and their associated degradation, resulting in their disappearance. After realizing their ecological importance, in recent years, rehabilitation and restoration programs for mangrove forests have been launched globally. Unfortunately, most mangrove restoration efforts yielded negative results and failed to re-establish mangrove forests because of technical and social failures. Besides, the continued outbreak of wood borer, Sphaeroma spp., in mangrove forests has become one of the destructive causes of natural and restored mangrove forests in some nations including China. However, few studies on the biology of Sphaeroma spp. found in Chinese mangrove ecosystem have been done, and little is known concerning the factors affecting their outbreak in China. In this review, we discussed the possible factors that affect the rapid growth and recruitment of Sphaeroma spp. in the mangrove ecosystem by examining the information of the wood borer Sphaeroma spp. from the scattered pieces of literature with great regard. We discussed the relationship between the recruitment of Sphaeroma spp. and the tide and flow of water, food availability from the surrounding water and water quality including salinity, temperature, and the pollution of water. In addition to these factors, the reduced biodiversity of restored mangrove forest could be one of the main reasons for the outbreak of isopod. We also discussed the destructive impact of the isopod’s outbreak and the possible ways to control their outbreak in mangrove forest.

Color change in a marine isopod is adaptive in reducing predation

Although background matching is a common form of camouflage across a wide diversity of animals, there has been surprisingly little experimental work testing the fitness consequences of this camouflage strategy, especially in marine ecosystems. In this study, we tested whether color camouflage enhances survival of the intertidal marine isopod Pentidotea （Idotea） wosnesenskii, quantified patterns of camouflage in different algal habitats, and examined how algal diet affected color change and growth using laboratory assays. In the field, isopods collected from two differently colored algal habitats （the brown alga Fucus distichus and the red alga Odonthaliafloccosa） matched the color of their respective algal habitats, and also differed significantly in body size： smaller red isopods were found on red algae, while larger brown isopods were found on brown algae. Predation ex- periments demonstrated these color differences had fitness benefits： brown isopods that matched their brown algae habitats sur- vived at higher rates than red unmatched isopods. Surprisingly, despite the propensity of isopods to match their algal habitats, algal diet had no effect on color change in color change experiments. Instead, isopods in all treatments turned browner, matching the color of the algal habitat that many isopods are found on as adults. In summary, our data supported our hypothesis that back- ground matching serves an adaptive function in reducing predation, with important evolutionary implications for explaining the wide variation in color change mechanisms in idoteid isopods [Current Zoology 61 （4）： 739-748, 2015].

Experimental evidence of Wolbachia introgressive acquisition between terrestrial isopod subspecies

Wolbachia are the most widespread endosymbiotic bacteria in animals.In many arthropod host species,they manipulate reproduction via several mechanisms that favor their maternal transmission to offspring.Among them,cytoplasmic incompatibility(Cl)promotes the spread of the symbiont by specifically decreasing the fertility of crosses involving infected males and uninfected females,via embryo mortality.These differences in reproductive efficiency may select for the avoidance of incompatible mating,a process called reinforcement,and thus contribute to population divergence.In the terrestrial isopod Porcellio dilatatus,the Wolbachia wPet strain infecting the subspecies P.d.petiti induces unidirectional Cl with uninfected individuals of the subspecies P.d.dilatatus.To study the consequences of Cl on P.d.dilatatus and P.d.petiti hybridization,mitochondrial haplotypes and Wolbachia infection dynamics,we used population cages seeded with different proportions of the 2 subspecies in which we monitored these genetic parameters 5 and 7 years after the initial setup.Analysis of microsatellite markers allowed evaluating the degree of hybridization between individuals of the 2 subspecies.These markers revealed an increase in P.d.dilatatus nuclear genetic signature in all mixed cages,reflecting an asymmetry in hybridization.Hybridization led to the introgressive acquisition of Wolbachia and mitochondrial haplotype from P.d.petiti into nuclear genomes dominated by alleles of P.d.dilatatus.We discuss these results with regards to Wolbachia effects on their host(Cl and putative fitness cost),and to a possible reinforcement that may have led to assortative mating,as possible factors contributing to the observed results.

Invasion of parasitic isopods in marine fishes

Objective:To carry out a detailed three-year observation study on isopod parasites infestation in fish.Methods:Fish samples were collected from different localities in various landing centers along the Tamil Nadu coastal area.The prevalence and mean intensity were calculated.The proximate composition of infestation and uninfestation were studied in different marine fishes.A comparative analysis of bacteria and fungi in the infected and uninfected regions of fishes were analysed.Results:Tweenty six species including 12 genera of isopods(Cymothoidae)distributed in 39 species of marine fishes along the Tamil Nadu coast.The isopod parasites were attached in three different microhabitats in host fishes viz.,buccal,branchial and body surfaces.They exhibited host and site specific occurrence.Maximum prevalence 17.11%was recorded in March 2010 and minimum 0.27%in Febuary 2010.The intensity ranged from 1 to 1.7 parasites per fish during the different months from Decmber 2008 to November 2011.There was a decrease in the protein,carbohydrate and lipid content in the infested fishes compared to uninfected fishes.A comparative analysis of bacteria and fungi in the infected and uninfected region of fishes were analysed.It revealed that infected portions had dense bacterial load as observed in the lesions of infected fishes than uninfected fishes.Conclusion:Factors which are able to induce parasitic manifestation are stock quality,stocking density,environmental conditions,biological and physiological characteristics of parasite,zoo technical measures,food quantity,feeding strategies,etc.

Histopathological changes in the skins and gills of some marine fishes due to parasitic isopod infestation

Objective:To study the histopathological symptoms owing to cymothoid isopod that were categorised as gross lesions.Methods:Nature of damage fish tissues and gills were taken from the parasite attachment area of infested and uninfested fishes which were cut out in fresh condition fixed in 10%buffered neutral formalin.Fresh and recently preserved tissues and gills were washed in tap water and dehydrated using alcohol series.The tissues gills were then cleaned in methylbenzoate and benzene and embedded in paraffin wax.The serial sections cutting 4 to 5 m thickness,were stained with Erlich’s haematoxylin and Eosin for histopathological analysis.Results:In normal muscle tissue,the tensile strength of muscle fibers with extra cellular matrix collagen was extensively tight associated.This gave a rigid musculature pattern to the tissues.Infested fish exhibited histopathological anomalies such as tissue reactions,primarily associated with the formation of granulomas consisted of macrophages and epitheleioid cells,which were occasionally surrounded by a thin rim of fibroblasts.The infestations such as lipofibrosis,hyperaemia,haemorhagic lesions and penetration of dactylus usually pressure atrophy often accompanied by the presence of parasites.Lesions had well developed granulomas that underlined in the muscle or overlying subcutaneous tissue,form these spread to underlying organs.Conclusions:It could be concluded that the infection studies of parasite that attaches or settles on the host body,at first,causes localized inflammatory changes,but with time,assuring a different or diffused character.The changes always begin with hyperaemia in the angles between adjacent sides at the site of attachment and then move towards deeply situated area.

中国红树林蛀木团水虱危害分析研究

【目的】蛀木团水虱是近年来危害中国红树林的一个新情况,已导致海南和广西部分红树林的死亡。为了防控团水虱,本文总结团水虱对中国红树林的危害情况,分析团水虱爆发的可能原因,提出一些管理策略。【方法】在海南和广西三处红树林团水虱危害地实地调查资料及生石灰消杀与鱼类捕食控制实验的基础上进行分析。【结果】调查表明,2010至2013年海南东寨港受团水虱攻击而死亡的红树林面积的平均连年增长率为66.4%。危害中国红树林的蛀木等足类生物主要为有孔团水虱和光背团水虱,前者是危害海南东寨港红树林的关键物种。受害的红树林都分布于人为干扰强烈且有机污染严重的海区。生长在污染物扩散通道潮沟边缘或污染物沉积区中的林子是团水虱的集中攻击对象。处于地带性演替后期、相对高大的成熟林易遭受团水虱危害。团水虱对红树植物的选择性攻击序列为:海莲、木榄>尖瓣海莲、角果木>白骨壤、秋茄>桐花树。由于潮差不同,中国大陆沿海红树林可受团水虱攻击的地上部高度为海南岛的2倍以上。在实验室中,1∶1配比的石灰水90min就可达到50%的团水虱消杀效果。中华乌塘鳢单位时间的吞食量较稳定,24h内平均可捕食42只团水虱。【结论】推测在海区环境退化的背景下放养家鸭,虾塘排放有机物和消毒剂,人为捕获经济动物很可能是团水虱爆发的触发因子,建议将红树林团水虱危害纳入相关的海洋生态环境监测与评价体系,建立以化学手段为应急,物理措施为辅助,生态保育为长效的红树林团水虱防控机制。

长江下游陆生等足目的研究(Ⅰ)江苏沿海陆生等足目记述

本文报导江苏沿海（包括连云港、南通、盐城三市）陆生等生足目共６个种：海蟑螂（ＬｉｇｉａｅｘｏｔｉｃａＲｏｕｘ）、普通卷甲虫（Ａｒｍａｄｉｌｌｉｄｉｕｍｖｕｌｇａｒｅ（Ｌａｔｒｅｉｌｌｅ））、具粉腊鼠妇（Ｐｏｒｃｅｌｌｉｏｎｉｄｅｓｐｒｕｉｎｏｓｕｓ（Ｂｒａｎｄｔ））、光滑鼠妇（ＰｏｒｃｅｌｌｉｏｌａｅｖｉｓＬａｔｒｅｉｌｌｅ）、快捷气管虫（Ｔｒａｃｈｅｌｉｐｕｓｒａｔｈｋｅｉ）（Ｂｒａｎｄｔ））和方鼻卷甲虫（ＡｒｍａｄｉｌｌｉｄｉｕｍｎａｓａｔｕｍＢｕｄｄｅＬｕｎｄ）并将其分类性状、生活习性及地理分布分别予以记述，其中快捷气管虫和方鼻卷甲虫为我中国新记录种．

广东贺江水域野生鲮鱼体表寄生虫典型海弯水虱的种群动态

近年来,广东贺江暴发了由等足类寄生虫引起的严重的鱼类外寄生虫病,给当地网箱养殖和野生鱼类资源造成了严重危害。根据虫体的口器、触角、腹肢等形态学特征将其鉴定为等足目(Isopoda)、扇肢亚目(Flabellifera)、纺锤水虱科(Aegidae)、海弯水虱属(Alitropus)的典型海弯水虱(Alitropus typus)。为了弄清典型海弯水虱对贺江内野生鱼类资源的危害及其种群季节动态变化规律,作者从2006年5月份到2007年4月份,用刺网定时定点捕获野生鲮鱼(Cirrhina molitorella),检查典型海弯水虱的寄生状况。结果发现:典型海弯水虱对鲮鱼的感染率、感染强度和平均密度均从2006年5月份开始上升,至7月份达到高峰,然后逐渐下降,于次年的2月份达到最低点,从3月份开始有所回升。典型海弯水虱种群在不同月份及不同体长鲮鱼中均为聚集性分布,且聚集强度随着平均密度的增加而增加。典型海弯水虱种群在鲮鱼中的感染参数与水温呈显著的正相关,而与宿主的体长无明显的相关性。周年种群结构动态变化分析表明:典型海弯水虱1年只繁殖1次,繁殖受水温的影响,6、7月份是其繁殖高峰期。

珠江水系2种鱼虾寄生性等足类新种的发现和初步观察

对国内新发现的江河等足类寄生虫病病原的外部形态、生活习性及寄生特性进行了初步观察与描述.该病病原为2种,1种寄生于鱼类鳃腔、胸鳍基部及体表,为纺锤水虱科(Aegidae)海弯水虱属(Alitropus)种类(Alitropus sp.),另1种寄生于虾体表或甲壳内,偶见于鱼类体表、鳃腔与口腔,为珊瑚水虱科(Corallanidae)的种类.此2种寄生虫均属淡水或低盐度型底栖类,可短时间自由游泳、具暂寄生性,4～10月为其繁殖期.Alitropus sp.以吸食宿主体液和组织为生,对宿主无专一选择性,群袭特性明显,未见洞穿宿主体壁现象.由该病原引起的疾病流行高峰季节为7～10月.珊瑚水虱则主要危害软壳及抱卵的宿主,致使其附肢残缺、卵块脱落,或因无法游泳上浮而缺氧死亡.

长江下游陆生等足目研究（Ⅲ）

报导宜兴陆生等足目共６种，分别隶属４个科、５个属，其中三刺湖蟑螂Ｌｉｇｉｄｉｕｍｔｒｉｓｐｉｎｏｓｕｓｓｐ．ｎｏｖ．和列齿鼠妇Ｐｏｒｃｅｌｌｉｏｓｅｅｒａｔｕｓｓｐ．ｎｏｖ．两种为新种，并对其形态特征进行详细描述．

陆生等足目第二触角鳞片的超微结构

通过对５种陆生等足目（隶属４科４属）第二触角扫描电镜的观察，尤其对触鞭的观察，发现第二触角覆被鳞片、其鳞片按其外形可分为长条形、三角形、椭圆形、近方形、扇形、铲形、长矛形等７种；按其鳞片表面是否光滑可分为光滑型和具肋型，后者又可分为整体具肋型和边缘具肋型．

Hourly and monthly variations in the surface activity patterns of Hemilepistus reaumurii in arid environments of Tunisia

Life in desert ecosystems drives animals to adapt their surface locomotor activity according to environmental conditions. In this study, the hourly and monthly variations in the surface activity patterns of the terrestrial crustacean Hemilepistus reaumurii were investigated. The surface activity of H. reaumurii at the population scale was observed by collecting the hourly active individuals from the sunrise to the sunset of the studied day in each month of 2013 in the Bchachma locality, Tunisia. The collected active individuals were put in perspex boxes（on which we labeled the hourly time interval in which the individuals were collected） in the field and then transported to the laboratory for analysis. Individuals were counted, sexed, and measured in the laboratory. Despite desert conditions in the studied site, H. reaumurii was characterized by a diurnal surface activity, showing a bimodal pattern during the warm months（i.e., May to October）. However, it exhibited a unimodal surface activity pattern in the cold months（i.e., February, March, and November）. The surface activity was significantly correlated with sunrise and sunset. Moreover, a significant quadratic effect of temperature on the surface activity of H. reaumurii was observed. Furthermore, the study showed that the most important surface activity was recorded in March. The daily exploitation of the temporal niches was significantly different as a function of months. The body size of males was larger than that of females, and the body size of active individuals changed with months. All these behavioural changes in the surface activity represent an adaptive strategy of life in the arid environment.

Occurrence of double parasitism on black-barred halfbeak fish from the southeast coast of India

A double parasitism(isopod Cymothoidae and copepod Pennellidae) on black-barred halfbeak fish,Hemiramphus far,was recorded from Pazhayar coastal waters(southeast coast of India) during September 2008.This is the first report from this region and the infection is discussed in relation to environmental and biological parameters.

陆生等足目第一触角的超微结构

对海蟑螂（Ｌｉｇｉａｅｘｏｔｉｃａ）、光滑鼠妇（Ｐｏｒｃｅｌｉｏｌａｅｖｉｓ）、糙皮鼠妇（Ｐｏｒｃｅｌｉｏｓｃａｂｅｒ）、普通卷甲虫（Ａｒｍａｄｉｌｉｄｉｕｍｖｕｌｇａｒｅ）、美丽卷甲虫（Ａｒｍａｄｉｌｉｄｉｕｍｐｉｃｔｕｍ）和普通卷甲虫红色变形体等陆生等足目的第一触角，进行了扫描电镜观察、比较．陆生等足目第一触角由４节组成，即底节、基节、中节和顶节．从而纠正了一百多年来公认的２～３节的描述．底节小，且被基节所遮挡，故有时不易见到．顶节具感觉刺，可能是第一触角的鞭节或退化了的鞭节．第一触角存在着种间差异性和种内稳定性。