Avaliação da toxicidade de florações naturais e de cultura de cianobactérias: efeitos sobre Ceriodaphnia silvestri (Crustacea, Cladocera)

The incidence of toxic cyanobacterial blooms is one of the important consequences of eutrophication in aquatic ecosystems. It is a very common phenomenon in reservoirs and shrimp ponds in the State of Rio Grande do Norte (RN), Brazil. Cyanobacterias produce toxins which can affect aquatic organisms and men trough the food chain. Aiming to contribute to the studies of cyanobacterias in RN, we propose: a) to evaluate the toxicity of isolated cyanobacterias in important fresh-water environments; and b) to verify the effects of both natural and cultured blooms occurred in reservoirs for human supply and in the cladoceran Ceriodaphnia silvestrii. This study was carried out using samples of natural blooms occurred between March and October of 2004 in Gargalheiras Dam (08º L e 39º W), in July of 2004 in Armando Ribeiro Gonçalves Dam (06o S e 37o W) and in commercial shrimp ponds (Litopenaeus vannamei) located in fresh-water environments. The samples were collected with plankton net (20µm.) for identification, isolation and obtaining of phytoplanktonic biomass for liophilization and later toxicity bioassays. The toxicity of cultured samples and natural blooms was investigated through bioassays in Swiss mice. Quantification of cyanobacteria in samples was conducted following the Ütermol method, with 300mL samples fixed with lugol. The toxicity test with Ceriodaphnia silvestrii followed ABNT, 2001 recommendations, and were accomplished with natural hepatotoxic bloom s samples and cultured samples of both non-toxic and neurotoxic C. raciborskii. In this test, five newborns, aged between 6 and 24 hours, were exposed to different concentrations (0 a 800 mg.L-1) of crude cyanobacterial extracts during 24 and 48 hours. Three replicates were used per treatment. The pH, temperature and dissolved oxygen at the beginning and after 24 and 48hours from the test were measured. We estimated the CL50 through the Trimmed Spearman-Karber method. The blooms were constituted by Microcystis panniformis, M. aeruginosa, Anabaena circinalis, Cylindrospermopsis raciborskii and Planktothrix agardhii, producers of mycrocistin-LR confirmed with HPLC analysis. Samples of hepatotoxic blooms registered toxinogenic potential for C. silvestrii, with CL50-24h value of 47.48 mg.L-1 and CL5048h of 38.15 mg.L-1 for GARG samples in march/2005; CL50-24h of 113,13 mg.L-1 and CL5048h of 88,24 mg.L-1 for ARG July/2004; CL50-24h of 300.39 mg.L-1 and CL50-48h of 149.89 mg.L-1 for GARG October/2005. For cultured samples, values of CL50-24h and CL50-48h for C. raciborskii toxic strains were 228.05 and 120.28 mg.L-1, respectively. There was no mortality of C. silvestrii during the tests with non-toxic C. raciborskii strain. The toxicity test with C. silvestrii presented good sensitivity degree to cyanotoxins. The toxicity of natural hepatotoxic blooms samples (microcystins) and cultured neurotoxic saxitoxins producer samples analyzed in this study give us strong indications of that toxin s influence on the zooplanktonic community structure in tropical aquatic environments. Eleven cyanobacteria strains were isolated, representing 6 species: Anabaenopsis sp., Cylindrospermopsis raciborskii, Chroococcus sp., Microcystis panniformis, Geitlerinema unigranulatum e Planktothrix agardhii. None presented toxicity in Swiss mice. The strains were catalogued and deposited in the Laboratório de Ecologia e Toxicologia de Organismos Aquáticos (LETMA), in UFRN, and will be utilized in ecotoxicológical and ecophysiological studies, aiming to clarify the causes and control of cyanobacterial blooms in aquatic environments in RN. This state s reservoirs must receive broader attention from the authorities, considering the constant blooms occurring in waters used for human consumption

Estudo do crescimento, eficiência de biofiltração e cinética de absorção de nutrientes (N-NH, N-NO e P-PO4³) da macroalga Gracilaria cervicornis (Turner) J. Agardh

The objective of this study was to examine the growth of Gracilaria cervicornis cultured in a shrimp (Litopenaeus vannamei) pond and to determine the absorption efficiency and the kinetics parameters (Vmax, Ks e Vmax:Ks) of this macroalgae for the nutrients N-NO3-, N-NH4+ and P-PO4-3, aiming at its use as bioremediatory of eutrophicated environments. For this study, two experiments (field and laboratory) were developed. In the field study, the seaweed was examined in relation to the growth and the biomass. In the laboratory experiment, the absorption efficiency of G. cervicornis was measured through the monitoring of the concentration of the three nutrients (N-NO3-, N-NH4+ e P-PO4-3) during 5 hours and the kinetic parameters were determined through the formula of Michaelis-Menten. The results obtained in this study demonstrated that G. cervicornis benefited from the available nutrients in the pond, increasing 52.4% of its biomass value after 30 days of culture. It was evidenced that the variability of the biomass could be explained through the salinity, availability of light (transparency and solid particle in suspension) and concentration of N-NO3- in the environment. In the laboratory experiment, the highest absorption efficiency was found in the treatments with low concentration (5 µmol.L-1), being evidenced a reduction of up to 85,3%, 97,5% and 81,2% of N-NH4+, N-NO3- and P-PO43-, respectively. Regarding the kinetic parameters, G. cervicornis presented better ability in absorbing N-NH4+ in high concentrations (Vmax = 158,5 µmol g-1 dry wt h-1) and P-PO43- in low concentrations (Ks = 5 µmol.L-1 e Vmax:Ks = 10,3). The results of this study show that G. cervicornis could be cultivated in shrimp ponds, presents a good capacity of absorption for the tested nutrients and is a promising candidate for biorremediation in shrimp pond effluent

Characterisation of soluble components and PAH in PM10 atmospheric particulate matter in Brisbane

Fours sets of PM10 samples were collected in three sites in SEQ from December 2002 to August 2004. Three of these sets of samples were collected by QLD EPA as a part of their regular air monitoring program at Woolloongabba, Rocklea and Eagle Farm. Half of the samples were used in this study for the analysis of water-soluble ions, which are Na+, K+, Mg2+, Ca2+, NH4 +, Cl-, NO3 -, SO4 2-, F-, Br-, NO2 -, PO4 -3 and the other half was retained by QLD EPA. The fourth set of samples was collected at Rocklea, specifically for this study. A quarter of the samples obtained from this set of samples were used to analyse water-soluble ions; a quarter of the sample was used to analyse Pb, Cu, Al, Fe, Mn and Zn; and the rests were used to analyse US EPA 16 priority PAHs. The water-soluble ions were extracted ultrasonically with water and the major watersoluble anions as well as NH4 + were analysed using IC. Na+, K+, Mg2+, Ca2+ Pb, Cu, Al, Fe, Mn and Zn were analysed using ICP-AES while PAHs were extracted by acetonitrile and analysed using HPLC. Of the analysed water-soluble ions, Cl-, NO3 -, SO4 2-, Na+, K+, Mg2+ and Ca2+ were high in concentration and determined in all the samples. F-, Br-, NO2 -, PO4 -3 and NH4 + ions were lower in concentration and determined only in some samples. Na+ and Cl- were high in all samples indicating the importance of a marine source. Principal Component Analysis (PCA) was used to examine the temporal variations of the water-soluble ions at the three sites. The results indicated that there was no major difference between the three sites. However, comparing the average concentrations of ions and Cl-/Na+ it was concluded that Woolloongabba had more marine influence than the other sites. Al, Fe and Zn were detected in all samples. Al and Fe were high in all samples indicating the significance of a source of crustal matter. Cu, Mn and Pb were in low concentrations and were determined only in some samples. The lower Pb concentrations observed in the study than in previous studies indicate that the phasing-out of leaded petrol had an appreciable impact on Pb levels in SEQ. This study reports for the first time, simultaneous data on the water-soluble, metal ion and PAH levels of PM10 aerosols in Brisbane, and provides information on the most likely sources of these chemical species. Such information can be used alongside those that already exist to formulate PM10 pollution reduction strategies for SEQ in order to protect the community from the adverse effects of PM pollution.

Preparation, characterization of surfactants modified clay minerals and nitrate adsorption

Organic surfactants modified clay minerals are usually used as adsorbents for hydrophobic organic contaminants remediation; this work however has shown organoclays can also work as adsorbents for hydrophilic anionic contaminant immobilization. Organoclays were prepared based on halloysite, kaolinite and bentonite and used for nitrate adsorption, which are significant for providing mechanism for the adsorption of anionic contaminants from waste water. XRD was used to characterize unmodified and surfactants modified clay minerals. Thermogravimetric analysis (TG) was used to determine the thermal stability and actual loading of surfactant molecules. Ion chromatography (IC) was used to determine changes of nitrate concentration before and after adsorption by these organoclays. These organoclays showed different removal capacities for anionic ions from water and adsorption mechanism was investigated.

Development of analytical techniques for studies on dispersion of actinides in the environment and characterization of environmental radioactive particles

Radioactive particles from three locations were investigated for elemental composition, oxidation states of matrix elements, and origin. Instrumental techniques applied to the task were scanning electron microscopy, X-ray and gamma-ray spectrometry, secondary ion mass spectrometry, and synchrotron radiation based microanalytical techniques comprising X-ray fluorescence spectrometry, X-ray fluorescence tomography, and X-ray absorption near-edge structure spectroscopy. Uranium-containing low activity particles collected from Irish Sea sediments were characterized in terms of composition and distribution of matrix elements and the oxidation states of uranium. Indications of the origin were obtained from the intensity ratios and the presence of thorium, uranium, and plutonium. Uranium in the particles was found to exist mostly as U(IV). Studies on plutonium particles from Runit Island (Marshall Islands) soil indicated that the samples were weapon fuel fragments originating from two separate detonations: a safety test and a low-yield test. The plutonium in the particles was found to be of similar age. The distribution and oxidation states of uranium and plutonium in the matrix of weapon fuel particles from Thule (Greenland) sediments were investigated. The variations in intensity ratios observed with different techniques indicated more than one origin. Uranium in particle matrixes was mostly U(IV), but plutonium existed in some particles mainly as Pu(IV), and in others mainly as oxidized Pu(VI). The results demonstrated that the various techniques were effectively applied in the characterization of environmental radioactive particles. An on-line method was developed for separating americium from environmental samples. The procedure utilizes extraction chromatography to separate americium from light lanthanides, and cation exchange to concentrate americium before the final separation in an ion chromatography column. The separated radiochemically pure americium fraction is measured by alpha spectrometry. The method was tested with certified sediment and soil samples and found to be applicable for the analysis of environmental samples containing a wide range of Am-241 activity. Proceeding from the on-line method developed for americium, a method was also developed for separating plutonium and americium. Plutonium is reduced to Pu(III), and separated together with Am(III) throughout the procedure. Pu(III) and Am(III) are eluted from the ion chromatography column as anionic dipicolinate and oxalate complexes, respectively, and measured by alpha spectrometry.

Metal doped nanosized titania used for the photocatalytic degradation of rhodamine B dye under visible-light

Metal-doped anatase nanosized titania photocatalysts were successfully synthesized using a sal gel process. Different amounts of the dopants (0.2, 0.4, 0.6, 0.8 and 1.0%) of the metals (Ag, Ni, Co and Pd) were utilized. The UV-Vis spectra (solid state diffuse reflectance spectra) of the doped nanoparticles exhibited a red shift in the absorption edge as a result of metal doping. The metal-doped nanoparticles were investigated for their photocatalytic activity under visible-light irradiation using Rhodamine B (Rh B) as a control pollutant. The results obtained indicate that the metal-doped titania had the highest activity at 0.4% metal loading. The kinetic models revealed that the photodegradation of Rh B followed a pseudo first order reaction. From ion chromatography (IC) analysis the degradation by-products Rhodamine B fragments were found to be acetate, chloride, nitrite, carbonate and nitrate ions.

Estudo preliminar da determinação de amônio por cromatografia de íons e sua remoção em lixiviados de resíduos sólidos utilizando argilas

A quantidade de resíduos gerados tem crescido rapidamente, sendo maior que a taxa de crescimento populacional, indicando um aumento na geração per capita. Este fato torna preocupante a maneira como é realizada a disposição final de resíduos e o impacto ambiental gerado com isso. Dentre os impactos está a produção de chorume, um poluente de elevada carga orgânica com altas concentrações de amônio e forte coloração, produzido pela decomposição química e microbiológica dos resíduos sólidos depositados em um aterro. Em locais de destino como aterros sanitários, este chorume é drenado para tratamento a fim de não impactar o local onde foi implantado o aterro. Porém, no Brasil, em grande parte dos casos, este tratamento não acontece, deixando o ambiente mais suscetível à contaminação. Este trabalho teve como finalidade determinar a quantidade de amônio presente em amostras de chorume do aterro de Gramacho no Rio de Janeiro, utilizando a cromatografia de íons para a sua quantificação, além de estudar a remoção de amônio por processos de adsorção em materiais como argilominerais. As amostras de chorume in natura apresentaram valores de pH em torno de 8,0 e concentrações de amônio entre 1665,0 e 2788,8 mg.L-1. Nas amostras analisadas após a destilação do chorume foram encontrados valores de pH entre 8,6 e 9,7 e concentrações de amônio de até 6362,3 mg.L-1, verificando que a maior concentração deste íon é arrastada nos primeiros 50 mL da destilação. Os testes de adsorção obtiveram um potencial de remoção de até 47 % do total de amônio. A metodologia aplicada se mostrou eficiente para determinação de amônio, uma vez que o tratamento prévio minimiza a ação de interferentes. Os baixos valores de remoção de amônio reforçam a necessidade de maior aprofundamento deste estudo, o que seria uma alternativa interessante para minimizar a ação deste poluente no meio ambiente

Avaliação da remoção do íon cádmio em solução aquosa utilizando processos de osmose inversa e nanofiltração

Os efluentes contendo cádmio podem ser gerados dos por várias indústrias. A aplicação de ambas as tecnologias osmose inversa (OI) e nanofiltração (NF) para o tratamento de efluentes contendo o íon cádmio para reduzir a degradação ambiental foram estudadas no presente trabalho. Amostras sintéticas contendo o íon cádmio em várias concentrações foram preparadas e submetidas aos tratamentos por OI e NF em escala laboratorial. Assim, dividiu-se o processo de remoção em três etapas: 1- analisou-se os processos de osmose inversa e nanofiltração em termos da rejeição do íon cádmio, onde se correlacionou e avaliou os principais parâmetros de processos (concentração da solução alimentação, fluxo de permeado e pressão) e comparou-se os sistemas entre si. Nas etapas 2 e 3 avaliou-se os efeitos da salinidade utilizando os contra-íons zinco e sódio respectivamente, sobre a rejeição do íon cádmio no sistema de osmose inversa em soluções aquosas contendo misturas de sulfato de cádmio e sulfato de zinco, e sulfato de cádmio e sulfato de sódio. Mediu-se as concentrações de cádmio e zinco por espectroscopia de absorção atômica e as concentrações de sulfato e sódio por cromatografia de íons. Os resultados obtidos na primeira etapa dos experimentos mostram que a osmose inversa e nanofiltração são eficientes na remoção de cádmio, onde se obteve as taxas médias de rejeição de 92,4% e 96,6% respectivamente, sendo esses valores iguais em magnitude, tendo em vista os valores da incerteza padrão relativa associada a esses resultados. Em ambos os sitemas, os fluxos de permeado e as rejeições não sofreram influência do aumento da concentração de cádmio na solução alimentação.Na etapa 2, os resultados mostraram a diminuição da rejeição de cádmio com o aumento da concentração de sulfato de zinco na alimentação, sendo esse fenômeno atribuído a semelhança existente entre os íons Cd2+ e Zn2+ associados aos seus raios iônicos de hidratação e as energias de hidratação. Foram observadas as quedas do fluxo de permeado e das rejeições com o aumento da concentração de alimentação provavelmente devido ao efeito da polarização. Na etapa 3, a rejeição do íon cádmio não foi afetada pelo aumento da concentração de sulfato de sódio na alimentação, assim como os fluxos de permeado. Outro aspecto relacionado à rejeição é que a difusão do sódio através da membrana é favorecida frente à difusão do cádmio, sendo atribuído ao menor raio de hidratação do sódio

Avaliação do tratamento de efluentes sintéticos com glifosato por osmose inversa

O presente trabalho avaliou a capacidade do sistema de osmose inversa de bancada na remoção de glifosato, em soluções de efluente aquoso sintético, empregando membrana de poliamida. Os parâmetros empregados para esta avaliação foram a pressão, o fluxo de alimentação, o tempo de operação, o pH e a concentração de glifosato na solução de alimentação em que os mesmos foram variados de modo a se ter um comparativo entre diferentes níveis. O sistema de osmose inversa teve em todos os experimentos uma boa resposta quanto a rejeição de glifosato em que a mesma variou entre 74,2% a 98,6 %, sendo a máxima atingida em condições de pressão em 30 bar, fluxo de alimentação 1 L.min-1 e pH 11 da solução de alimentação. A resposta do sistema foi avaliada quanto ao fluxo de permeado, de rejeição percentual e concentração de glifosato no permeado. O efeito da variação de concentração sobre a rejeição de glifosato foi pouco efetiva, mas apresentou grande influência quanto à variação de concentração deste no permeado. Ainda foi avaliada a remoção do ácido aminometilfosfônico (AMPA), pelo sistema de osmose inversa, obtendo-se uma boa resposta quanto à rejeição atingindo valores em torno de 95%. Uma solução combinada de AMPA e glifosato foi preparada e processada no sistema de osmose inversa, obtendo-se resposta similar quanto à concentração de permeado e rejeição para ambos os compostos. A quantificação de AMPA e glifosato se deu por cromatografia de íons, onde esta técnica se mostrou robusta e simples para quantificar ambos os compostos em meio aquoso, em baixas concentrações

Analytical strategies to solve problems in industrial and official laboratories

210 p.

STUDY OF THE CHLORINATION REACTION OF Li2CO3 WITH NH4Cl

The chlorination reaction of Li2CO3 with NH4Cl has been studied in detail by a series of thermal analysis methods. When NH4Cl/Li2CO3 mole ratio equals 4, Li2CO3 can be transformed into LiCl quantitatively in a stream of Ar gas flow. All residual NH4Cl is decomposed completely at 400 degrees C and carried away from the reaction cell by Ar gas.Analysis by X-Ray diffraction and Ion Chromatography show that there are almost no NH4Cl remained in The LiCl product. It is interested that the chlorination reaction can be applied to the determinations of phase diagram by thermal analysis method and the preparation of Al-Li alloy by electrolysis in molten salt.

蚯蚓作为饲料成分对对虾生长及其免疫指标的影响

本文以鲜活饵料赤子爱胜蚓（Eisenia foetida）为研究对象，从营养学和免疫学的角度研究探讨了蚯蚓对对虾生长和抗病力的影响，为目前虾病问题的解决进行了有益的探索，为蚯蚓在规模化养殖生产中的推广应用提供了参考和依据。主要研究结果如下： 1、以鲜活饵料赤子爱胜蚓为主，双齿围沙蚕（Perinereis aibuhitensis）和人工配合饵料为对照，比较研究了凡纳滨对虾（Litopenaeus vannamei���摄食不同饵料的生长和免疫指标的差异。结果表明：沙蚕和蚯蚓单独投喂或与人工饵料配合投喂都可显著提高凡纳滨对虾的生长速率，提高对虾肌肉蛋白的营养价值，但用沙蚕单独投喂的对虾成活率较低。在增强对虾的免疫功能方面，蚯蚓和沙蚕与人工饵料配合投喂优于蚯蚓和沙蚕单独投喂，同时蚯蚓的饵料效果优于沙蚕。 2、采用鲜活饵料赤子爱胜蚓和人工配合饵料的不同配比投喂处于健康状态下的中国明对虾（Fenneropenaeus chinensis）幼虾，研究了其生长和免疫特征。结果表明：在人工饵料中配合投喂1/4的蚯蚓（干重）可显著加快中国明对虾的生长速率，增加对虾肌肉蛋白质含量，提高对虾肌肉蛋白的营养价值，减少脂肪含量，但对处于健康状态下的中国明对虾幼虾免疫功能的增强无明显效果。 3、考虑到对虾规模化养殖的可行性，采用冰冻蚯蚓赤子爱胜蚓和人工饵料的不同配比投喂处于非健康状态下的凡纳滨对虾，测定分析对虾的生长、营养成分和免疫指标，结果表明：蚯蚓投喂量（干重）占日投喂量的1/4时可以显著提高对虾的生长速率，增加对虾营养，增强对虾免疫功能，提高对虾成活率。 我国蚯蚓资源丰富，来源广泛，研究证实，以蚯蚓作为对虾饵料可增加对虾营养，促进对虾生长，提高机体免疫力，是对虾规模化养殖生产中的优质绿色动物性饵料。

软甲纲动物和星虫动物线粒体基因组特征及分子进化研究

在过去的几十年间，利用线粒体基因组序列探讨后生动物深层次的系统发育关系已取得初步进展。这主要得益于，线粒体基因组与其它分子标记相比具备诸多优势。迄今为止，超过1,200个后生动物的线粒体基因组已被测定，然而所获得的数据分布极不均衡。 软甲纲历来是甲壳动物分类学和系统发育学研究的重要类群，在形态学特征和分子生物学各方面取得广泛的发展。尽管软甲纲本身作为单系群已得到大多数甲壳动物学家认可，但是软甲纲内部各个类群之间的系统发育关系迄今仍颇有争议。本文报道了凡纳滨对虾Litopenaeus vannamei���中国明对虾Fenneropenaeus chinensis、脊尾白虾Exopalaemon carinicauda、太平洋磷虾Euphausia pacifica和采自南极普里兹湾南极磷虾Euphausia superba的线粒体基因组，其长度分别为15,989 bp、16,004 bp、15,730 bp、16,898 bp和15,498 bp以上（部分非编码区没有测定）。 本研究发现凡纳滨对虾、中国明对虾、脊尾白虾和太平洋磷虾的线粒体基因组包含后生动物线粒体基因组典型的基因组成（13个蛋白质编码基因、22个转运RNA、2个核糖体RNA和一个非编码的AT富含区）；然而，南极磷虾与后生动物线粒体基因组典型的基因组成相比，存在1个trnN基因的重复。与泛甲壳动物线粒体基因组的原始排列相比，凡纳滨对虾和中国明对虾线粒体基因组的基因排列完全一致；脊尾白虾的线粒体基因组发生罕见的trnP和trnH易位，从而说明在真虾下目中线粒体基因组的基因排列并不保守；太平洋磷虾线粒体基因组的基因排列出现3个转运RNA的重排 （trnL1、trnL2和trnW）；南极磷虾线粒体基因组的基因排列除了出现太平洋磷虾具有的这3个转运RNA重排之外，还有1个trnN的重复和1个trnI基因的重排。另外，在太平洋磷虾线粒体基因组最大的非编码区中存在一个154 bp×4.7的串连重复区域，如此大片段的串联重复区域（>150 bp）在软甲纲动物线粒体基因组中是首次报道。 目前所获得的线粒体基因组数据强有力地支持口足目、对虾科、真虾下目和短尾下目为单系群。通过比较基因排列及蛋白质编码基因核苷酸和氨基酸序列的系统发育分析得知真虾类和龙虾类为腹胚亚目的原始类群，并支持“（（Penaeus＋Fenneropenaeus）＋Litopenaeus）＋Marsupenaeus”的系统发育关系。此外，线粒体基因组的数据也强有力地支持磷虾目为单系群。但对于磷虾目在软甲纲中的分类地位及与其它类群的系统发育关系存在一些分歧：基于蛋白质编码基因核苷酸和氨基酸数据的贝叶斯分析强有力地支持磷虾目和十足目近缘，这个结果和传统的分类系统完全一致；然而，基于核苷酸序列的邻接法、氨基酸序列的邻接法和最大似然法均强有力地支持磷虾类和对虾类亲缘关系较近，从而破坏了十足目的单系性，与传统的认识并不一致，但由于自展值的支持率非常高，所以深层次的分析需要进一步加强。 星虫动物属于海洋生物中的一个小门类，自1555年被记载以来，其在后生动物中的分类地位就备受争议。本研究测定了星虫动物门的第一条线粒体基因组：革囊星虫Phascolosoma esculenta的线粒体基因组，全长为15,494 bp，包含13个蛋白质编码基因、22个转运RNA、2个核糖体RNA和1个非编码的AT富含区，所有37个基因在同一条链上编码。与后生动物线粒体基因组的典型组成相比，存在一个trnR基因的缺失和一个trnM基因的重复。比较星虫动物和其它后生动物的线粒体基因组，可以得到以下结论：1）星虫动物和环节动物（包括螠虫动物）的线粒体基因组有相近的基因排列，而且所有基因都在同一链上编码；2）基于蛋白质编码基因的系统发育分析强有力地支持星虫动物和环节动物（包括螠虫动物）组成一个单系群，而将软体动物排除在外。因此，本研究认为以前许多星虫动物和软体动物“共享”的特征，包括发育特征和缺乏分节等，需要重新考虑。