Interstitial annelids from the Caribbean Coast of Colombia / Anélidos intersticiales de la costa Caribe de Colombia

Abstract A total of 298 species of polychaetes have been recorded from Colombia. However, only the family Protodrilidae has been reported from the marine interstitial realm. We here aim at identifying the interstitial annelids inhabiting the sandy beaches in Santa Marta region to the most accurate taxonomic level based on light microscopy examinations. Our samples, collected from the intertidal zone at three touristic beaches in the department of Magdalena (Santa Marta Bay, Rodadero Bay, and Taganga Bay), yielded a total of 83 specimens, which we assigned to five families, ten genera and nine species. From those, two families, eight genera, and the species Hesionides gohari, Neogyptis mediterranea, Neopetitia amphophthalma, Westheidesyllis gesae, and Syllis beneliahuae represent new records for the Colombian fauna. This survey should be considered as a first step towards a complete knowledge of the Colombian diversity of interstitial annelids, and our results significantly contribute to fill the gap of our current knowledge, suggesting a high diversity of species comparable to this in better-known areas of the Caribbean and the Atlantic coasts of Brazil. A brief diagnosis, comments on distribution and ecology, and remarks are provided for each record, in order to facilitate the re-identification of the species. Rev. Biol. Trop. 66(2): 658-673. Epub 2018 June 01.

Resumen Un total de 298 especies de poliquetos han sido registradas para Colombia. Sin embargo, solo la familia Protodrilidae ha sido reportada para el medio marino intersticial. El objetivo de este estudio fue identificar los anélidos intersticiales que habitan en playas arenosas de la región de Santa Marta hasta la categoría taxonómica más precisa, basados en observaciones al microscopio de luz. Las muestras fueron recolectadas en la zona intermareal de tres playas turísticas en el departamento del Magdalena (La bahía de Santa Marta, bahía de Rodadero y bahía de Taganga), resultando un total de 83 especímenes, los cuales fueron asignados a cinco familias, diez géneros y nueve especies. De estos, dos familias, ocho géneros y las especies Hesionides gohari, Neogyptis mediterranea, Neopetitia amphothalma, Westheidesyllis gesae y Syllis beneliahuae representan nuevos registros para la fauna de Colombia. Este trabajo debería ser considerado como el primer paso hacia el conocimiento de la diversidad de anélidos intersticiales en Colombia y los resultados contribuyen significativamente a llenar el vacío de información en el tema, sugiriendo una alta diversidad de especies comparable con la de áreas mejor conocidas del Caribe y de la costa atlántica de Brasil. En este trabajo se provee una breve diagnosis, comentarios sobre la distribución y ecología, y anotaciones para cada registro, con el propósito de facilitar la re-identificación de las especies.

The geographic distribution of Costa Rican velvet worms (Onychophora: Peripatidae)

Abstract:Velvet worms, "peripatus" or onychophorans, are "living fossils" that were geographically widespread in Cambrian seas but now occur exclusively on terrestrial habitats. The only extant species studied in some detail are those from Costa Rica, but their real geographic distribution was in urgent need of revision. To solve this problem we visited the localities mentioned in all the original taxonomic descriptions and redescriptions. These visits covered a 25 year period (1988-2014) and included interviews with local residents. We also examined all Costa Rican collections, and checked the information in old maps and books. Here we critically review geographic data, correct errors, assign neotype localities, report on the survival of populations after heavy volcanic eruptions or urbanization, and present the correct geographical distribution for the seven currently described Costa Rican species. Rev. Biol. Trop. 64 (4): 1401-1414. Epub 2016 December 01.

Resumen:Los gusanos aterciopelados, también llamados onicóforos o peripatos son "fósiles vivientes" de amplia distribución en los mares cámbricos pero que actualmente sólo viven en hábitats terrestres. Las únicas especies estudiadas en algún detalle son las de Costa Rica, pero su distribución geográfica real necesitaba una revisión urgente. Para resolver este problema visitamos las localidades mencionadas en las descripciones taxonómicas originales y en las redescripciones. Estas visitas cubren un periodo de 25 años (1988-2014) e incluyen entrevistas a residentes. También examinamos todas las colecciones costarricenses (INBio, UNA y UCR); la información recopilada en mapas y libros viejos en las bibliotecas universitarias, y consultamos a expertos. Aquí revisamos críticamente la información geográfica, corregimos errores, designamos localidades de neotipo, y ubicamos poblaciones sobrevivientes después de fuertes erupciones volcánicas y procesos de urbanización de sus hábitats naturales, ofreciendo a futuros investigadores la distribución correcta geográfica de las siete especies de onicóforos descritas en Costa Rica.

Improvement of erectile dysfunction by the active pepide from urechis unicinctus by high temperature/pressure and ultra - wave assisted lysis in streptozotocin induced diabetic rats

ABSTRACT Introduction: We investigate the effect of active peptide from Urechis unicinctus (UU) by high temperature/pressure and ultra-wave assisted lysis on erectile dysfunction in streptozotocin-induced diabetic rats. Materials and Methods: Forty 12-week-old Sprague-Dawley rats were used in this study. Diabetes was induced by a one-time intraperitoneal injection of streptozotocin (50mg/kg). One week later, the diabetic rats were randomly divided into four groups: normal control, untreated diabetes control, and groups treated with 100 or 500mg/kg/d UU peptide. Rats were fed with UU peptide by intragastric administration for 8 weeks. After 8 weeks, penile hemodynamic function was evaluated in all groups by measuring the intracavernosal pressure after electrostimulating the cavernous nerve. Nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) activities were measured and endothelial nitric oxide synthase (eNOS) and neuronal NOS (nNOS) protein expression was determined by Western blot. Results: Maximum intracavernosal pressure in diabetic control rats decreased significantly compared to normal control rats, and was increased significantly compared to untreated diabetic rats after UU peptide supplementation. Treatment with the higher dose of UU peptide significantly increased the NO and cGMP levels compared with the diabetic control group. Decreased activity and expression eNOS and nNOS were found in the diabetic rats compared with the normal control group. Decreased eNOS and nNOS in diabetic rats were improved by UU peptide administration. Conclusions: Active peptide from UU ameliorates erectile function in a streptozotocin induced diabetic rat model of erectile dysfunction.

Effect of water temperature, stocking density and feeding cycle on growth of juvenile Poecilobdella manillensis / 中国中药杂志

The effect of water temperature, stocking density and feeding cycle on the growth of Poecilobdella manillensis juvenile was conducted P. manillensis was conducted respectively under different conditions: water temperatures(18, 22, 26, 30,34, 38 degrees C and CT), stocking density (75, 125, 200, 275, 350 individual/L) and feeding cycle(2, 4, 6, 8, 12, 16 d). After 30 days, survival rate, weight gain rate, specific growth rate were measured. There was a significant correlation between water temperature and specific growth rate (γ = -0.066x2 + 3.543 1x -38.09, R2 = 0.837 9). Based on the regression equation, the specific growth rate of P. manillensis achieved the maximum (9.461 4) at 26.84 degrees C. And the most optimal water temperature was 26-30 degrees C. Meanwhile, the survival rates of P. manillensis was 0 at 38 degrees C in 3 d. There was significant negative correlation between density and specific growth rate (γ = -0.005 7x + 9.197 3, R2 = 0.998 3) and between feeding cycle and specific growth rate (γ = -0.468 2x + 10.574, R2 = 0.998 8).

Caracterización de la comunidad bacteriana aerobia en sanguijuelas (Hirudinea), Haementeria sp. (Glossiphoniidae) y Oxytychus ornatus (Macrobdellidae) de El Bagre, Antioquia / Characterization of the aerobic bacterial community in leeches Haementeria sp (Hirudinea: Glossiphoniidae) y Oxytychus ornatus (Hirudinea: Macrobdellidae) de El Bagre, Antioquia

Se ha incrementado el uso terapéutico de las sanguijuelas y se ha demostrado que ellas pueden inocular bacterias causantes de infecciones en el 20% de los pacientes. El hallazgo en Antioquia de dos especies de sanguijuelas promisorias para hirudoterapia motivó este estudio para identificar las bacterias en la superficie, la probóscide y el intestino de estos anélidos y evaluar su sensibilidad a antibióticos. Las sanguijuelas estudiadas se identificaron como Haementeria sp., y Oxytychus ornatus. Muestras de la superficie, boca e intestino de ambos anélidos se inocularon en agar sangre, agar sangre con ampicilina y agar eosina azul de metileno. La identificación de las bacterias y su sensibilidad a antibióticos se evaluaron por el método automatizado Vitek (Biomerieux®). Se hicieron en total 26 aislamientos pertenecientes a 12 especies de nueve géneros. Enterobacter cloacae fue la especie más frecuente en ambos anélidos. Las bacterias fueron sensibles a los antibióticos comúnmente empleados en las infecciones causadas por este tipo de microorganismos. Se sugiere hacer profilaxis con antibióticos en los pacientes que reciban terapia con los anélidos investigados e implementar los protocolos estandarizados para el lavado de los animales antes de su uso y para el aseo de los acuarios en donde se los mantenga.

Therapeutic use of leeches (hyrudotherapy) has increased, and it has been shown that they can transmit bacteria associated with infections in 20% of patients. Two species of leeches have been found in Antioquia, Colombia, apparently promising for such therapy. This study was done to identify bacteria in the surface, mouth and intestine of these species and to test the antibiotic sensitivity of the isolates. The studied species were Haementeria sp., and Oxytychus ornatus. Specimens were obtained from their surface, mouth and intestine. Blood agar, blood agar with ampicillin, and eosine-methylene blue agar were used as culture media. Identification and sensitivity tests were carried out with the Vitek (Biomerieux®) automated method. A total of 26 isolates was obtained belonging to 12 species and nine genera. Isolates were sensitive to the commonly used antibiotics. We suggest to do antibiotic prophylaxis in patients undergoing hyrudotherapy, and to implement standardized protocols to disinfect the animals before use and for the cleaning of the aquarium where they are kept.

Reasonable and safe application of Shuxuetong injection and intravenous medication's combined application in acute cerebral infarction's therapy / 中国中药杂志

Shuxuetong injection is a kind of compound injection which is made from traditional Chinese medicine Hirudo and Pheretime, which has a clear anticoagulant, fibrinolytic promoting, blood rheology improving, blood lipids regulating and cell protecting effect, and the injection has been widely used in clinical. Especially, the injection has often been combined with other Chinese and modern medicine in the treatment of cerebral infarction disease. However, there are still many non-standard and irrational aspects in clinical practice so as to make a more reasonable and safer use of Shuxuetong injection. In order to avoid the occurrence of adverse reactions to provide a reference for regulating the use of the injection,the paper systematically expounds the Shuxuetong injection's main clinical problems and the reasonable combination.

Polidiariose em ostras Crassostrea gigas cultivadas na praia da Ponta do Sambaqui, Florianópolis, Santa Catarina, Brasil / Polydiariosis in cultured oyster Crassostrea gigas from Ponta do Sambaqui, Florianópolis, Brasil

A infestação por poliquetas do gênero Polydora em ostras C. gigas de cultivo foi acompanhada por meio de coletas mensais enquanto os parâmetros físico-químicos da água do mar foram monitorados semanalmente. Foi determinada a área total ocupada pelas bolhas e tubos na superfície interna das valvas, observando os possíveis danos às principais características fisiológicas da ostra. Houve prevalência do anelídeo Polydora sp. (Polychaeta: Spionidae) em todos os meses amostrados, chegando a 100% no período de águas mais frias. As análises histológicas mostraram que os tecidos e órgãos estavam intactos, ocorrendo a formação de gametas. Nas ostras severamente infestadas, foi possível observar intensa fibrose na região do manto, mostrando reparo do tecido.

The infestation of polychaetes Polydora in oyster C. gigas within cultivation was accompanied by monthly samples whereas the physical and chemical parameters of seawater were monitored weekly. The total area occupied by bubbles and tubes in the inner surface of the valve was determined, indicating the possible damage to the main physiological characteristics of oysters. It was observed prevalence of annelid Polydora sp. (Polychaeta: Spionidae) in all samples each month, reaching 100% in the period of cooler waters. The histological analysis showed that the tissues and organs were intact, occurring the formation of gametes. In oysters severely infested, it was possible to observe intense fibrosis in the mantle, showing repair of the tissue.

Oligochaeta (Annelida: Clitellata) em córregos de baixa ordem do Parque Estadual de Campos do Jordão (São Paulo - Brasil) / Oligochaeta (Annelida: Clitellata) in headwater streams of the Parque Estadual de Campos do Jordão (São Paulo - Brazil)

O objetivo desse artigo foi inventariar as espécies de oligoquetos limnícolas que habitam córregos do Parque Estadual de Campos do Jordão (PECJ). As amostras revelaram 2302 indivíduos, distribuídos em três famílias (Naididae, Enchytraeidae, Tubificidae). Foram inventariadas 17 espécies, sendo elas: Achaeta sp., Allonais paraguayensis, Chaetogaster diastrophus, Nais communis, Nais variabilis, Pristina biserrata, Pristina leidyi, Pristina proboscidea, Pristinella jenkinae, Pristinella longidentata, Pristinella minuta, Pristinella notopora, Pristinella osborni, Pristinella sima, Aulodrilus limnobius, Botrioneurum sp. e Limnodrilus hoffmeisteri. O número total de espécies encontrado representa 24 por cento de todas as espécies de oligoquetos registrados em diversos ambientes aquáticos no Brasil (70), evidenciando a importância deste trabalho, visto que há ainda grandes lacunas no conhecimento da fauna de oligoquetos límnicos no Brasil.

This study inventoried stream oligochaetes of the Campos do Jordão State Park (CJSP), São Paulo, Brazil. A total of 2302 individuals of three families (Naididae, Enchytraeidae, Turbificidae) were obtained. Seventeen species were inventoried: Achaeta sp., Allonais paraguayensis, Chaetogaster diastrophus, Nais communis, Nais variabilis, Pristina biserrata, Pristina leidyi, Pristina proboscidea, Pristinella jenkinae, Pristinella longidentata, Pristinella minuta, Pristinella notopora, Pristinella osborni, Pristinella sima, Aulodrilus limnobius, Bothrioneurum sp., and Limnodrilus hoffmeisteri. The total number of species found represents 24 percent of all oligochaetes species (70) recorded in diverse aquatic environments in Brazil, making this inventory very important given the poor knowledge of this group in Brazil.

Occurrence of Naididae (Annelida: Oligochaeta) from three gastropod species in irrigation fields in southeastern Brazil / Ocorrência de Naididae (Annelida: Oligochaeta) em três espécies de gastrópodes em campos irrigados no sudeste do Brasil

In the present study we report the occurrence of three Naididae species from three gastropod mollusk species. The species Dero (Dero) righii was found from mollusks of the genus Biomphalaria. Nais communis was found from Biomphalaria sp. and Aplexa rivalis. Chaetogaster limnaei was found from Biomphalaria sp., Aplexa rivalis and Lymnaea columella. In Brazil, previous studies have reported the occurrence of Chaetogaster limnaei from Biomphalaria solely, while Nais communis have been found from Pomacea bridgesii and Dero (Dero) righii in the sediment of aquatic habitats in Mato Grosso do Sul. Our results indicate that, due to their locomotion, naidids are capable of colonizing different substrates in aquatic environments.

No presente estudo, relatamos a ocorrência de Dero (Dero) righii associada a moluscos do gênero Biomphalaria. Nais communis foi encontrada associada a Biomphalaria sp. e Aplexa rivalis. A espécie Chaetogaster limnaei esteve associada à Biomphalaria sp., Aplexa rivalis e Lymnaea columella. No Brasil, estudos anteriores registraram Chaetogaster limnaei associada somente à Biomphalaria, Nais communis à Pomacea bridgesii e Dero (Dero) righii ao sedimento de ambientes aquáticos no Mato Grosso do Sul. Os resultados obtidos confirmam que, devido à capacidade de se deslocar na coluna d'água, os oligoquetos naidideos apresentam habilidade de colonizar diferentes substratos presentes nos ambientes aquáticos.

Oligochaeta (Annelida, Clitellata) of lotic environments at Parque Estadual Intervales (São Paulo, Brazil) / Oligochaeta (Annelida, Clitellata) de ambientes lóticos do Parque Estadual Intervales (São Paulo, Brasil)

Studies on benthic macroinvertebrates of lotic environments usually focus on the occurrence, distribution, and richness of aquatic insects and decapod crustaceans. Only rarely these studies include the Oligochaeta. The aim of the present study was to examine the occurrence and species richness of Oligochaeta in different substrata patches of lotic environments. The studied included seven stream sites at Parque Estadual Intervales (São Paulo, Brazil). Stream sites differed in size and ranged from first to fourth order. In each stream, qualitative collections were made using a D-type net sampler with 0.21 mm mesh. Measures of pH, electrical conductivity, dissolved oxygen, temperature and water turbidity were taken in the studied sites during collections of Oligochaeta. Specimens of the Tubificidae (including Naidinae) and Enchytraeidae families were collected. The Tubificidae Aulodrilus limnobius, Limnodrilus neotropicus and Limnodrilus hoffmeisteri were associated with low-flow habitats containing fine organic material. The most representative species among the Naidinae, Nais communis, was predominantly associated with rocky substrates present in fast current locations. The two other Naidinae species, Pristina osborni and Amphichaeta leydigi, presented low frequency in the studied streams. The Enchytraeidae family was present in only one of the sampled habitats.

Estudos sobre macroinvertebrados bentônicos de ambientes lóticos geralmente focam na ocorrência, distribuição e riqueza de insetos aquáticos e de crustáceos decápodos. Tais estudos apenas raramente incluem Oligochaeta. O objetivo do presente estudo foi examinar a ocorrência e riqueza de espécies de Oligochaeta de diferentes substratos em ambientes lóticos. O estudo incluiu sete riachos do Parque Estadual Intervales (São Paulo, Brasil). Os riachos estudados variaram em tamanho desde primeira até quarta ordem. Em cada ambiente, foram realizadas coletas qualitativas utilizando amostrador do tipo rede em D com malha 0,21 mm. Simultaneamente às coletas de Oligochaeta foram tomadas medidas do pH, condutividade elétrica, oxigênio dissolvido, temperatura e turbidez da água dos ambientes. Foram coletados exemplares das famílias Tubificidae (incluindo Naidinae) e Enchytraeidae. Os Tubificidae Aulodrilus limnobius, Limnodrilus neotropicus e Limnodrilus hoffmeisteri estiveram associados à habitats com pouca correnteza e substrato contendo material orgânico fino. Nais communis espécie mais representativa entre os Naidinae, esteve predominantemente associada a substratos rochosos presentes em locais de correntes rápidas. As duas outras espécies de Naidinae, Pristina osborni e Amphichaeta leydigi apresentaram baixa freqüência nos córregos analisados. A família Enchytraeidae esteve presente somente em um dos ambientes amostrados.

First occurrence of the family Paralacydoniidae (Annelida: Polychaeta) in the South Atlantic Ocean / Primeira ocorrência da família Paralacydoniidae (Annelida: Polychaeta) no Oceano Atlântico Sul

Paralacydoniid polychaetes belonging to the genus Paralacydonia Fauvel 1913 were collected during the REVIZEE Program/South Score/Benthos ("Avaliação do Potencial Sustentável dos Recursos Vivos na Zona Econômica Exclusiva") on the outer shelf and continental slope off the south-southeastern coast of Brazil between 156 and 400 m depth. This new report extends the known geographic distribution of the family, which had previously been recorded in the North Atlantic as far as the Gulf of Mexico. Paralacydonia is here treated as monotypic; P. mortenseni Augener 1924 and P. weberi Horst 1923 are considered synonyms of Paralacydonia paradoxa Fauvel 1913.

Poliquetas paralacidoniídeos pertencentes ao gênero monotípico Paralacydonia Fauvel 1913 foram coletados durante o Programa REVIZEE/Score Sul/Bentos ("Avaliação do Potencial Sustentável dos Recursos Vivos na Zona Econômica Exclusiva") na plataforma externa e talude continental na costa sul-sudeste do Brasil entre 156 e 400 m de profundidade. Esta nova ocorrência amplia grandemente a distribuição geográfica dos representantes da família, a qual tinha sido previamente registrada no Atlântico Norte até o Golfo do México. Paralacydonia é tratado aqui como monotípico; P. mortenseni Augener 1924 e P. weberi Horst 1923 são considerados sinônimos de Paralacydonia paradoxa Fauvel 1913.

Glyceridae Grube 1850 (Annelida: Polychaeta) from Southern and Southeastern Brazil, including a new species of Glycera / Glyceridae Grube 1850 (Annelida: Polychaeta) da região sudeste e sul do Brasil, incluindo uma nova espécie de Glycera

This systematic study of the polychaete species of the family Glyceridae is part of a broader program to inventory and determine parameters for conservation and sustainable use of the marine biodiversity off the southeastern and southern coast of Brazil. The material studied was collected from intertidal sandy beaches, the inner continental shelf (<50 m depth) off the northern coast of the state of São Paulo, and the outer continental shelf and part of the continental slope (depths from 60 to 808 m) off the state of Rio de Janeiro south to Rio Grande do Sul (22º S - 34º 40' S). The descriptions of several species were improved, adding new and important taxonomic characters, mainly related to proboscideal papillae. A key for identification of the glycerid species from southeastern and southern Brazil is also provided. Eight species of Glyceridae were identified: Glycera americana Leidy 1855; Glycera brevicirris Grube 1870; Glycera dibranchiata Ehlers 1868; Glycera lapidum Quatrefages 1866; Glycera oxycephala Ehlers 1887; Glycera tesselata Grube 1863; Hemipodia californiensis (Hartman 1938); Hemipodia simplex (Grube 1857); and a previously unknown species of Glycera.

O estudo sistemático das espécies da família Glyceridae é parte de um amplo programa de inventariamento e determinação de parâmetros abióticos para conservação e uso sustentável da biodiversidade marinha ao largo da costa sudeste e sul do Brasil. O material estudado foi coletado desde a região entremarés de praias arenosas até a plataforma interna (<50 m prof.) na costa norte de São Paulo, e da plataforma externa ao talude superior (profundidades entre 60 e 808 m) desde a costa sul do Rio de Janeiro até a o sul do Rio Grande do Sul (22º S - 34º 40' S). As descrições de algumas espécies foram ampliadas, com a adição de novos e importantes caracteres taxonômicos, principalmente relacionados às papilas proboscidiais. Uma chave de identificação para as espécies de glicerídeos da região sudeste e sul do Brasil é fornecida. Oito espécies de Glyceridae foram identificadas: Glycera americana Leidy 1855; Glycera brevicirris Grube 1870; Glycera dibranchiata Ehlers 1868; Glycera lapidum Quatrefages 1866; Glycera oxycephala Ehlers 1887; Glycera tesselata Grube 1863; Hemipodia californiensis (Hartman 1938); Hemipodia simplex (Grube 1857); além de uma espécie previamente desconhecida de Glycera.

Nephtyidae (Annelida: Polychaeta) from São Paulo State, Brazil, including a new record for the Brazilian coast / Nephtyidae (Annelida: Polychaeta) do Estado de São Paulo, Brasil, incluindo um novo registro para a costa brasileira

In the present study, four species of Nephtyidae, Aglaophamus juvenalis (Kinberg 1866), Nephtys acrochaeta Hartman 1950, Nephtys californiensis Hartman 1938 and Nephtys squamosa Ehlers 1887, were found from the intertidal zone to the shallow sublittoral (<50 m) off São Paulo, Brazil, during the program BIOTA/FAPESP Marine Benthos. Descriptions and notes on each of them are provided. Nephtys californiensis is a new record for the Brazilian coast. Keys to genera and species of Nephtyidae recorded from Brazil are given.

Neste estudo, quatro espécies de Nephtyidae: Aglaophamus juvenalis (Kinberg 1866), Nephtys acrochaeta Hartman 1950, Nephtys californiensis Hartman 1938 e Nephtys squamosa Ehlers 1887 foram coletadas desde a região entremarés até o sublitoral raso (<50 m) da costa de São Paulo, Brasil, durante o Programa BIOTA/FAPESP Bentos Marinho. Descrições e comentários são fornecidos para cada uma delas. Nephtys californiensis é um novo registro para a costa brasileira. Chaves para gêneros e espécies de Nephtyidae registrados no Brasil são fornecidas.

New record of Laeonereis acuta (Treadwell, 1923) (Nereididae: Polychaeta) in Northeast coast of Brazil / Novo registro de Laeonereis acuta (Treadwell, 1923) (Nereididae: Polychaeta) na costa nordestina do Brasil

In the present study, we report the presence of the nereidid polychaete Laeonereis acuta near to the estuarine areas of Parnaíba River, extending its distribution towards the north of the northeastern Brazilian coast.

No presente estudo, nós relatamos a presença do poliqueta nereídídeo Laeonereis acuta próximo à região estuarina do rio Parnaíba, ampliando sua distribuição para o litoral norte do nordeste brasileiro.

Variation in worm assemblages associated with Pomacea canaliculata (Caenogastropoda, Ampullariidae) in sites near the Río de la Plata estuary, Argentina

Pomacea canaliculata is a common gastropod in freshwater habitats from Central and Northern Argentina, extending northwards into the Amazon basin. Several Platyhelminthes have been reported associated to P. canaliculata, sharing an intimate relationship with this gastropod host. The objectives of this study were to describe the symbiotic species assemblages associated to P. canaliculata in the study area, and to disclose differences among them. Samples were taken in three typical small streams and one artificial lentic lagoon, all connected with the Rio de la Plata estuary. The 81.53% were infested with different symbiotic (sensulato) species. Among the Platyhelminthes, the commensal Temnocephala iheringi Haswell, 1893 was highly prevalent in all samples, always in the mantle cavity. Four trematode taxa were recognized: (a) metacercariae of Echinostoma parcespinosum Lutz, 1924 in the mantle cavity and sporocysts in the digestive gland; (b) metacercariae of Dietziella egregia (Dietz, 1909) in the pericardial cavity; (c) unidentified xiphidiocercariae and (d) unidentified sporocysts and furcocercariae in the digestive gland. Nematode larvae and oligochaetes were found in two localities in the mantle cavity. Among the Annelida, Helobdella ampullariae Ringuelet, 1945 was found in the mantle cavity and lung of snails only from one locality. Our results show that although some of the symbionts are present in all localities, others are restricted to some particular ones, whether in their absolute numbers or in their relative abundance. Thus, eachhosting population at the studied localities may be defined by the particularcombination of symbionts that bears.

Efecto de sedimentos naturales enriquecidos con zinc, en modelos aislados y en microcosmos, sobre tres especies de invertebrados bentónicos / Effect of zinc-enriched sediments, in open and isolated systems, on three species of benthonic invertebrates

Availability of toxics in aquatic bodies is limited by the physicochemical characteristics of sediments and water, as well as by the interactions between the different xenobiotics and inhabits species. The aim of this work was to relate the effect produced by zinc (Zn) spiked in sediments of the Ignacio Ramirez dam (PIR), in isolated and microcosms models, on ATP concentration of three benthic organisms with the metal biodisponibility. The selected species were a crustacean, an annelid and a mollusk: Hyalella azteca (Amphipoda: Hyalellidae), Limnodrilus hoffmeisteri (Oligochaeta: Tubificidae) and Stagnicola attenuata (Basommatophora: Lymnaeidae), species that are found at high proportions in the reservoir and use different spaces in the benthos. Samples of sediments and organisms were collected from the PIR during the dry season (February of 1999). Metal concentration (Zn, Fe, Cu and Ni), pH, texture, particle size, total nitrogen and organic matter were determined in sediments. Sublethal studies were carried out using two types of static systems (organisms isolated and in microcosms). Both models contained PIR sediments enriched with Zn (nominal concentration of 0.8129 mg/kg) and synthetic water in a proportion of 1:4. The test organisms were added to the systems once the equilibrium was reached (2 hr) considering the biomass quantity with respect to volume (1.0 g of organism by each 100 ml of water:sediment). After 0, 12, 24, 36, 48 and 72 hr of exposure, samples of sediment and hydrobionts were taken, and Zn content was quantified by atomic absorption. ATP concentration was also determined in organisms. The effect produced by natural sediments spiked with Zn is increased by the presence of more than one specie in the system (microcosm). With respect to Zn levels, two of the organisms tend to lose this metal in isolated and microcosm models, probably as a regulation strategy in its accumulation, as well as Fe presence in the reservoir sediments. Therefore...

En los cuerpos acuáticos la disponibilidad de los tóxicos es limitada por las características fisicoquímicas de los sedimentos y agua, así como por las interacciones entre los diversos xenobióticos y entre las especies que los habitan. Por lo anterior, el objetivo del presente trabajo fue relacionar el efecto producido por el zinc (Zn) sembrado en sedimentos del embalse Ignacio Ramírez (PIR), en modelos aislados y en microcosmos, sobre el ATP de res organismos bentónicos con la biodisponibilidad del metal. Las especies seleccionadas fueron: Hyalella azteca, Limnodrilus hoffmeisteri y Stagnicola attenuata, dado que se encuentran en altas proporciones en el embalse y ocupan espacios diferentes en el bentos. Las muestras de sedimentos y organismos se colectaron en la estación de sequía (febrero de 1999). A los primeros se les determinó el pH, textura, tamaño de partícula, nitrógeno total, materia orgánica y concentración de metales (Zn, Fe, Cu y Ni). Posteriormente se realizó un estudio de toxicidad subletal utilizando dos tipos de sistemas estáticos (organismos aislados y en microcosmos). Ambos modelos contenían sedimentos de la PIR enriquecidos con Zn (concentración nominal de 0.8129 mg/kg) y agua sintética en una proporción de 1:4. Los organismos de prueba fueron adicionados una vez alcanzado el equilibrio (2 hr) considerando la cantidad de biomasa con respecto al volumen (1.0 g de organismo por cada 100 ml de agua:sedimento). Después de 0, 12, 24, 36, 48 y 72 hr de exposición se tomaron muestras del sedimento y de los hidrobiontes, a los cuales se les cuantificó el contenido de Zn por absorción atómica. A los organismos también se les determinó la concentración de ATP. Los resultados obtenidos muestran que el efecto producido por los sedimentos naturales enriquecidos se ve potenciado por la presencia de más de una especie en el sistema (microcosmos). Con respecto a los niveles de Zn, dosde los organismos (L. hoffmeisteri y S. attenuata) tienden a...

Annelids of a west African estuarine system.

Annelids collected from eight stations in the western part of Lagos Lagoon between May, 1996 and February, 1998 were reported. Rainfall, salinity and sediment type influenced distribution of annelids, which were either dry season species, wet season species or euryhaline species. A total of fifty-five species were collected, thirty-one not recorded in earlier studies. Pollution indicators, Polydora sp., Capitella capitata, Nereis sp. and Tubifex sp. were collected in both dry and wet seasons.

Experimental taphonomy of velvet worms (Onychophora) and implications for the Cambrian "explosion, disparity and decimation" model

Experimental preservation of velvet worms (phylum Onychophora), a very rare but evolutionarily important group that has existed for more than 500 million years, showed that the absence of bucal parts, adhesive-expelling organs, gonopore, eyes, legs, claws, annulation and papillation in fossils may not represent absence in the living animals. In fossils, leg thickness and claw orientation can be unreliable. The experiments indicate that not only absence, but even presence of certain structures can simply be the result of tissue decomposition. Computer-aided photorealistic reconstructions of fossi onychophorans are presented. We recommend future researchers to conduct taphonomy experiments specially before analysing unusual fossils

Marine biodiversity of Costa Rica: the phyla Sipuncula and Echiura

Fourteen species of Sipuncula belonging to 9 genera have been reported from Costa Rican waters, mostly from the Pacific coast. Three of these species are new records for Costa Rica (Phascolion strombus (Montagu 1804), Aspidosiphon (Aspidosiphon) muelleri Diesing 1851, and Aspidosiphon (Aspidosiphon) gracilis schnehageni (W. Fisher 1946)). One species of Echiura, Thalassema steinbecki Fisher 1946, in the order Echiuroinea, has been reported from the Pacific coast of Costa Rica.