Hatchability of gemmules of two Neotropical freshwater sponges (Porifera: Spongillida)

Inland waters experience extreme environmental conditions determining the evolution of several adaptive strategies of the fauna to these variable conditions. Freshwater sponges produce resisting bodies called gemmules that contain totipotent cells and specialized spicules (gemmuloscleres). Completely formed gemmules exhibit low metabolic rates and may become dormant during periods of environmental stress. Until now, few species had their hatchability tested against different environmental conditions. The purpose of the present study was to test the capacity of hatching gemmules of two freshwater sponge species (Heteromeyenia cristalina Batista, Volkmer-Ribeiro & Melão, 2007 and Radiospongilla inesi Nicacio & Pinheiro, 2011) from inland waters from different localities. Five assays were tested (A): A1 (water of sponge collection site); A2 (Pirangi River water); A3 (Araraquara Pond water); A4 (mineral water) and A5 (A1 after drying gemmules). For each assay, three replicates with 30 gemmules were used. The gemmules were observed daily during 30 days. Data analysis was performed using ANOVA and a posteriori Tukey test. Results showed that gemmules from both species submitted to A3 have not hatched, probably due to its very high conductivity. There was a significant difference between assays (A1, A2 and A4) and between species (F2, 12 = 77.2; P 0.001). Comparison between A1 and A5 showed significant differences between both assays and species (F1, 8 = 27.5; P 0.001). Radiospongilla inesi presented high hatching rate at all assays, while H. cristalina had a high hatching rate only on A1 and A5. Results clearly show that each species has a different capacity of hatching.(AU)

Ambientes de águas continentais estão suscetíveis a condições ambientais extremas, determinantes à evolução de várias estratégias adaptativas para estas condições variáveis. As esponjas de águas continentais produzem corpos resistentes chamados gêmulas, que contêm células totipotentes e espículas especializadas (gemoscleras). As gêmulas completamente formadas exibem baixas taxas metabólicas e podem tornar-se dormentes tipicamente durante períodos de estresse ambiental. Até agora, poucas espécies tiveram sua capacidade de eclosão testada frente diferentes condições ambientais. O objetivo do presente estudo foi testar a capacidade de eclosão de gêmulas para duas espécies (Heteromeyenia cristalina Batista, Volkmer-Ribeiro & Melão, 2007 e Radiospongilla inesi Nicacio & Pinheiro, 2011) de esponjas de águas continentais em águas de diferentes localidades. Foram realizados cinco ensaios (A): A1 (água do local da coleta das esponjas); A2 (água do Rio Pirangi); A3 (água da Lagoa Araraquara); A4 (água mineral) e A5 (água do local da coleta das esponjas). Para cada ensaio, três réplicas com 30 gêmulas foram usadas. As gêmulas foram observadas diariamente durante 30 dias. A análise de dados foi conduzida usando ANOVA e o teste aposteriori Tukey. Os resultados mostraram que gêmulas de ambas espécies submetidas ao A3 não eclodiram, provavelmente devido à alta condutividade. Há diferenças entre os ensaios (A1, A2 e A4) e entre espécies (F2, 12 = 77.2; P 0.001). Ao comparar A1 e A5, houve diferenças significativas entre ambos os ensaios e espécies (F1, 8 = 27.5; P 0.001). Radiospongilla inesi apresentou alta taxa de eclosão em todos os ensaios enquanto que Heteromeyenia cristalina teve uma alta taxa de eclosão apenas no ensaio com água do seu ambiente natural. Os resultados mostram claramente que cada espécie tem diferente capacidade de eclosão.(AU)

Hatchability of gemmules of two Neotropical freshwater sponges (Porifera: Spongillida)

Inland waters experience extreme environmental conditions determining the evolution of several adaptive strategies of the fauna to these variable conditions. Freshwater sponges produce resisting bodies called gemmules that contain totipotent cells and specialized spicules (gemmuloscleres). Completely formed gemmules exhibit low metabolic rates and may become dormant during periods of environmental stress. Until now, few species had their hatchability tested against different environmental conditions. The purpose of the present study was to test the capacity of hatching gemmules of two freshwater sponge species (Heteromeyenia cristalina Batista, Volkmer-Ribeiro & Melão, 2007 and Radiospongilla inesi Nicacio & Pinheiro, 2011) from inland waters from different localities. Five assays were tested (A): A1 (water of sponge collection site); A2 (Pirangi River water); A3 (Araraquara Pond water); A4 (mineral water) and A5 (A1 after drying gemmules). For each assay, three replicates with 30 gemmules were used. The gemmules were observed daily during 30 days. Data analysis was performed using ANOVA and a posteriori Tukey test. Results showed that gemmules from both species submitted to A3 have not hatched, probably due to its very high conductivity. There was a significant difference between assays (A1, A2 and A4) and between species (F2, 12 = 77.2; P 0.001). Comparison between A1 and A5 showed significant differences between both assays and species (F1, 8 = 27.5; P 0.001). Radiospongilla inesi presented high hatching rate at all assays, while H. cristalina had a high hatching rate only on A1 and A5. Results clearly show that each species has a different capacity of hatching.

Ambientes de águas continentais estão suscetíveis a condições ambientais extremas, determinantes à evolução de várias estratégias adaptativas para estas condições variáveis. As esponjas de águas continentais produzem corpos resistentes chamados gêmulas, que contêm células totipotentes e espículas especializadas (gemoscleras). As gêmulas completamente formadas exibem baixas taxas metabólicas e podem tornar-se dormentes tipicamente durante períodos de estresse ambiental. Até agora, poucas espécies tiveram sua capacidade de eclosão testada frente diferentes condições ambientais. O objetivo do presente estudo foi testar a capacidade de eclosão de gêmulas para duas espécies (Heteromeyenia cristalina Batista, Volkmer-Ribeiro & Melão, 2007 e Radiospongilla inesi Nicacio & Pinheiro, 2011) de esponjas de águas continentais em águas de diferentes localidades. Foram realizados cinco ensaios (A): A1 (água do local da coleta das esponjas); A2 (água do Rio Pirangi); A3 (água da Lagoa Araraquara); A4 (água mineral) e A5 (água do local da coleta das esponjas). Para cada ensaio, três réplicas com 30 gêmulas foram usadas. As gêmulas foram observadas diariamente durante 30 dias. A análise de dados foi conduzida usando ANOVA e o teste aposteriori Tukey. Os resultados mostraram que gêmulas de ambas espécies submetidas ao A3 não eclodiram, provavelmente devido à alta condutividade. Há diferenças entre os ensaios (A1, A2 e A4) e entre espécies (F2, 12 = 77.2; P 0.001). Ao comparar A1 e A5, houve diferenças significativas entre ambos os ensaios e espécies (F1, 8 = 27.5; P 0.001). Radiospongilla inesi apresentou alta taxa de eclosão em todos os ensaios enquanto que Heteromeyenia cristalina teve uma alta taxa de eclosão apenas no ensaio com água do seu ambiente natural. Os resultados mostram claramente que cada espécie tem diferente capacidade de eclosão.

Hatchability of gemmules of two Neotropical freshwater sponges (Porifera: Spongillida)

ABSTRACT Inland waters experience extreme environmental conditions determining the evolution of several adaptive strategies of the fauna to these variable conditions. Freshwater sponges produce resisting bodies called gemmules that contain totipotent cells and specialized spicules (gemmuloscleres). Completely formed gemmules exhibit low metabolic rates and may become dormant during periods of environmental stress. Until now, few species had their hatchability tested against different environmental conditions. The purpose of the present study was to test the capacity of hatching gemmules of two freshwater sponge species (Heteromeyenia cristalina Batista, Volkmer-Ribeiro & Melão, 2007 and Radiospongilla inesi Nicacio & Pinheiro, 2011) from inland waters from different localities. Five assays were tested (A): A1 (water of sponge collection site); A2 (Pirangi River water); A3 (Araraquara Pond water); A4 (mineral water) and A5 (A1 after drying gemmules). For each assay, three replicates with 30 gemmules were used. The gemmules were observed daily during 30 days. Data analysis was performed using ANOVA and a posteriori Tukey test. Results showed that gemmules from both species submitted to A3 have not hatched, probably due to its very high conductivity. There was a significant difference between assays (A1, A2 and A4) and between species (F2, 12 = 77.2; P 0.001). Comparison between A1 and A5 showed significant differences between both assays and species (F1, 8 = 27.5; P 0.001). Radiospongilla inesi presented high hatching rate at all assays, while H. cristalina had a high hatching rate only on A1 and A5. Results clearly show that each species has a different capacity of hatching.

RESUMO Ambientes de águas continentais estão suscetíveis a condições ambientais extremas, determinantes à evolução de várias estratégias adaptativas para estas condições variáveis. As esponjas de águas continentais produzem corpos resistentes chamados gêmulas, que contêm células totipotentes e espículas especializadas (gemoscleras). As gêmulas completamente formadas exibem baixas taxas metabólicas e podem tornar-se dormentes tipicamente durante períodos de estresse ambiental. Até agora, poucas espécies tiveram sua capacidade de eclosão testada frente diferentes condições ambientais. O objetivo do presente estudo foi testar a capacidade de eclosão de gêmulas para duas espécies (Heteromeyenia cristalina Batista, Volkmer-Ribeiro & Melão, 2007 e Radiospongilla inesi Nicacio & Pinheiro, 2011) de esponjas de águas continentais em águas de diferentes localidades. Foram realizados cinco ensaios (A): A1 (água do local da coleta das esponjas); A2 (água do Rio Pirangi); A3 (água da Lagoa Araraquara); A4 (água mineral) e A5 (água do local da coleta das esponjas). Para cada ensaio, três réplicas com 30 gêmulas foram usadas. As gêmulas foram observadas diariamente durante 30 dias. A análise de dados foi conduzida usando ANOVA e o teste aposteriori Tukey. Os resultados mostraram que gêmulas de ambas espécies submetidas ao A3 não eclodiram, provavelmente devido à alta condutividade. Há diferenças entre os ensaios (A1, A2 e A4) e entre espécies (F2, 12 = 77.2; P 0.001). Ao comparar A1 e A5, houve diferenças significativas entre ambos os ensaios e espécies (F1, 8 = 27.5; P 0.001). Radiospongilla inesi apresentou alta taxa de eclosão em todos os ensaios enquanto que Heteromeyenia cristalina teve uma alta taxa de eclosão apenas no ensaio com água do seu ambiente natural. Os resultados mostram claramente que cada espécie tem diferente capacidade de eclosão.

The effects of plastic bags presence on a macrobenthic community in a polluted estuary.

The damaging effects of marine debris on wildlife are often noted through the observation of animals that ingest and/or become entangled in debris. Yet, few studies have evaluated the effects of marine litter on benthic habitats. The aim of this study was to investigate if the presence of plastic bags has any effect on benthic macrofauna in an estuary located in an urban area in North-eastern Brazil. Biogeochemical and macrofauna samples were obtained from 10 different deposition locations (location factor), under, border and distant (treatment factor) from plastic bags. The results did not show any significant alterations in the biogeochemical parameters of the sediment due to treatment effect except for summed microphytobenthic pigments. The macrobenthic community structure responded to treatment. The greatest dissimilarity (34%) was between samples that were under and distant. Effects occurred despite the high dynamics of deposition-resuspension of plastic bags and the dominance of opportunistic species. Changes in community structure are a complex result of plastic bags effects on species ecological interactions in the polluted estuarine environment, attracting deposit feeders, diminishing suspension feeders and providing mechanical protection against predation by seabirds.

Evaluation of Meiofauna in the Hyporheic Zone of the Beberibe River, Pernambuco, Brazil.

The hyporheic environment is composed of a rich meiofauna that depends on water flow, organic matter, and oxygen. The concentration of meiofauna varies spatially (horizontal and vertical) and temporally. Several processes occur at this interface (groundwater and surface water), including biogeochemical processes involving meiofauna. A study of the hyporheic meiofauna community in the sediments of the Beberibe River, in Brazil, was conducted. Meiofauna attained peak densities of 942.8 organisms/10 cm2, with organisms distributed over six taxa, with 98% of them represented by rotifers, nematodes, and annelids. Density was higher in the dry season with an average of 653.1 organisms/10 cm2, and in more superficial sediments with an average of 739.6 organisms/10 cm2. Greater densities were found in coarser sediment with a higher percentage of organic matter. A river bank filtration (RBF) pilot project has been installed, with good results in the attenuation of contaminants and pathogens.

Foraging with finesse: A hard-fruit-eating primate selects the weakest areas as bite sites.

OBJECTIVES: Fruit husks are rarely uniformly hard, varying in penetrability via sulci and changes in thickness. We tested whether a hard-food specialist primate i) bites randomly on food fruit husk surfaces to access seeds, or ii) selects areas most easily penetrated by canines. We consider this would occur so as to minimize deployed mechanical force, energetic expenditure and risk of dental breakage when feeding. METHODS: A sulcus is the natural line of weakness where a dehiscent fruit breaks open. Using fruits dentally opened for seeds by golden-back uacaris (Cacajao ouakary) we: 1) analysed bite mark distribution on surface of four fruits types (hard-with-sulcus, soft-with-sulcus, hard-no-sulcus, soft-no-sulcus); 2) quantified the force needed to penetrate hard and soft fruits at sulci and elsewhere on fruit surface; 3) measured fruit wall thickness and correlated it with bite-mark distribution in all four categories of fruit. RESULTS: 1) Bite marks were distributed at random only on surfaces of soft fruits. For other fruits types, bite locations were concentrated at the thinnest areas of husk, either over the entire surface (non-sulcate fruits), or at sulci (sulcate fruits). 2) For hard-husked fruits, areas where uacaris concentrated their bites were significantly easier to penetrate than those where they did not. CONCLUSIONS: This hard-fruit feeding specialist primate is not biting at random on the surface of diet fruits. To access seeds they are focusing on those areas requiring less force to penetrate. This may be to save energy, to minimize the risk of breaking teeth used in food processing, or a combination of both. The study shows, for the first time, the subtlety by which these powerfully-jawed animals process their diet items.

Estuarine macrofauna responses to continuous in situ nutrient addition on a tropical mudflat.

A field experiment to assess the effects of continuous nutrient addition on the macrobenthic community was carried out on an estuarine mudflat on the northeast coast of Brazil. The experiment began on 5 October 2005 and ended on 8 February 2006. Macrofauna was compared at approximately four-week intervals in triplicate plots with three levels (Control - C, Low Dose - LD and High Dose - HD) of weekly fertilizer additions for 17 weeks. Inorganic fertilizer (N-P-K) was applied on nine randomly defined quadrangular plots (4m(2) each). All measurements were calculated from species abundances. Multivariate analyses as well as the univariate indices (richness, abundance and Shannon-Wiener index) showed statistically significant differences between the enriched and control areas during the period of the experiment. The expected gradual response based on the succession model of Pearson and Rosenberg was not observed. The nutrient doses used were high enough to cause severe decreases in abundance, richness and evenness, and an increase in dominance.

Macrobenthic community for assessment of estuarine health in tropical areas (Northeast, Brazil): review of macrofauna classification in ecological groups and application of AZTI Marine Biotic Index.

The aim of the present study was to investigate the ecological quality of tropical estuaries on the northeastern coast of Brazil using the AMBI. Macrofauna classification based on ecological groups was reviewed using the Indicator Value (IndVal) coefficient. The results indicate that the ecosystems exhibit some level of disturbance. Most sites are situated between slightly-moderately disturbed boundaries due to the higher proportion of Nematoda (assigned here as Ecological Group I) and of Oligochaeta and Tubificidae (both classified as Ecological Group V). The AMBI proved efficient in evaluating environmental status, although the applicability of this index requires adjustments regarding some species in ecological groups. The present study also highlights the merits of the IndVal method for examining the assignments of species/taxa to an ecological group and demonstrates the validity of this coefficient is an assessment tool. Moreover, the complementary use of different methods is recommended for the assessment of ecosystem quality.

Recovery of macrobenthos in defaunated tropical estuarine sediments.

In the estuarine environment, hypoxia and/or anoxia have become a major cause of benthic defaunation and are strongly associated with increased eutrophication. Mesoscale field experiments were carried out to examine the recolonization and recovery time of macrobenthos after defaunation. Azoic sediments were achieved by covering four areas with polyethylene sheeting. Temporal changes and depth distribution of macrobenthos within the defaunated sediments were compared with those in undisturbed natural sediments at the same site. Within 3 days, annelids appeared as the first immigrants. After 153 days, the process of recovery had not yet been completed in terms of species richness. Whereas diversity and evenness showed no significant differences between treatments during the entire experiment, multivariate analyses proved that differences between treatments were still significant 93 days after the start of the experiment.

Assessing the severity of disturbance for intertidal and subtidal macrobenthos: the phylum-level meta-analysis approach in tropical estuarine sites of northeastern Brazil.

The phylum-level meta-analysis approach was applied to assess the status of disturbance of intertidal and subtidal macrobenthos in two estuaries in northeastern Brazil that are subject to different sources of pollution. Previously published estuarine data were included in the body of knowledge considered in the meta-analysis, to improve the reliability of the assessment of the Brazilian samples. Further multivariate and distributional techniques were applied to discriminate differences between estuaries and assess the pollution status of each. Phylum-level multivariate comparisons based on community attributes succeeded in discriminating the estuaries, and species distributions against abundance separated the estuaries in terms of pollution status. The meta-analysis indicated an almost indistinguishable moderate pollution status for both systems. Addition of new comparative data to the meta-analysis did not improve its sensitivity. Although the meta-analysis yielded satisfactory results in detecting disturbance in tropical estuaries, the method is not very sensitive to differences in sources of pollution.

Ideal width of transects for monitoring source-related categories of plastics on beaches.

Although there is a consensus on the necessity of monitoring solid wastes pollution on beaches, the methods applied vary widely. Therefore, creating, testing and recommending a method that not only allows comparisons of places and periods, but also the detection of source signals, will be important to reach the objectives of the source-prevention principle. This will also allow the optimisation of time, resources, and processing of samples and data. A classification of the items found into specific categories was made according to their most probable source/use (fisheries, food packaging, hazardous, sewage/personal hygiene, beach user, general home). This study tested different widths of sampling transects to be used in the detection of plastics contamination on beaches, until all the categories were significantly represented. Each transect had its total width (50m) sub-divided into eight intervals of 0-2.5m; 2.5-5m; 5-10m; 10-15m; 15-20m; 20-30m; 30-40m; and 40-50m. The accumulated number of categories in the 50m (up to 2.5m; up to 5m and so on) was used to determine the minimal width necessary to qualitatively characterize the area regarding plastics contamination. The diversity of the categories was directly related to the area of the sampling transect. These results indicate that a significant increase in the number of categories in the first intervals tend to stabilize from 15-20m onwards.