Spatial and temporal patterns in size and maturation of Loligo plei and Loligo sanpaulensis (Cephalopoda: Loliginidae) in southeastern Brazilian waters, between 23 degrees S and 27 degrees S

Patterns of population dynamics of Loligo plei and Loligo sanpaidensis in Southeastern Brazil were investigated with samples obtained from commercial catches and research cruises from 1999 to 2000 and from 2002 to 2003. Size and maturity Structure of the two species varied according to depth and season. Body size decreased with depth for L plei, whereas for L. sanpaidensis size increased with depth LIP to 100 m and decreased again in deeper areas. GSI and incidence of mature animals decreased with depth in both species. L. plei females matured at a larger size in summer, while size at maturity in L. sanpaulensis was greater in autumn. For L. plei, reproductive events Occurred in the late winter and spring, in depths up to 40 m, and during summer in inshore waters. L. sanpaidensis increased reproductive activity ill Summer, winter and spring between depths of 30 and 80 Ill. The presence of high proportions of immature Squid offshore Suggests that juveniles might develop in these areas and, upon maturation, migrate back to inshore waters to spawn, particularly in spring and Summer. However, differences found in aggregation patterns in different depth strata, as well as the seasonal differences found in the size structure of L. plei and L. sanpaidensis, Could ultimately be due to Changes in the water Column related to food availability. Considering that L. plei and L. sanpaidensis are both caught as by-catch by shrimp trawlers throughout file year, we also discuss hypotheses on the life cycle of the species and its implications for fishery management. We recommend measures to protect squid spawning grounds by creating spring and summer protected areas where trawling would be prohibited until 60 m depth, i.e. in the area and time of year when mature individuals concentrate.

Life cycle and reproductive traits of marine podonids (Cladocera, Onychopoda) in a coastal subtropical area

We studied the temporal distribution and reproductive biology of marine podonids during two consecutive years off Ubatuba, southeast coast of Brazil. Podonid specimens and their eggs and embryos were counted, measured and classified into categories. Pseudevadne tergestina was the most abundant species, and was more abundant in surface layers, in warm seasons, when the water column was stratified because of bottom intrusions of the cold and nutrient-rich South Atlantic Central Water (SACW) onto the inner shelf. Evadne spinifera had a similar temporal and vertical distribution, but with lower abundance and frequency. Pleopis schmackeri did not show a clear seasonal distribution, but preferred bottom layers. Pleopis polyphemoides and Podon intermedius occurred in low abundances, and only under SACW influence. Parthenogenetic females were dominant among all podonid species. Gamogenetic females of P. polyphemoides and P. intermedius were observed, but males of neither species occurred. This suggests that in tropical and subtropical regions, P. tergestina, E. spinifera and P. schmackeri reproduce through parthenogenesis during most of the year.

Allometric growth of a common Nassariidae (Gastropoda) in south-east Brazil

The allometric growth of two groups of Nassarius vibex on beds of the bivalve Mytella charruana on the northern coast of the State of Sao Paulo, was evaluated between September 2006 and February 2007 in the bed on Camaroeiro Beach, and from March 2007 to June 2007 at Cidade Beach. The shells from Camaroeiro were longer and wider and had a smaller shell aperture than those from Cidade; a principal components analysis also confirmed different morphometric patterns between the areas. The allometric growth of the two groups showed great variation in the development of individuals. The increase of shell width and height in relation to shell length did not differ between the two areas. Shell aperture showed a contrasting growth pattern, with individuals from Camaroeiro having smaller apertures. The methodology based on Kullback-Leibler information theory and the multi-model inference showed, for N. vibex, that the classic linear allometric growth was not the most suitable explanation for the observed morphometric relationships. The patterns of relative growth observed in the two groups of N. vibex may be a consequence of different growth and variation rates, which modifies the development of the individuals. Other factors such as food resource availability and environmental parameters, which might also differ between the two areas, should also be considered.

Recruitment and growth variation of Ophionereis reticulata (Echinodermata: Ophiuroidea)

Two growth patterns are recognized in shallow-water ophiuroids: (I) slow growth and early reproductive maturity over a long life span and (2) rapid growth with a short life span. For species with the first pattern, both growth and recruitment would reflect a reproductive pattern with long periods of resting and spawning concentrated in certain months of the year. To evaluate this hypothesis, the recruitment, population dynamics, and growth of the intertidal brittle star Ophionereis reticulata were analyzed from January 2001 to December 2002 at the Baleciro Isthmus on the southeast coast of Brazil. The species shows an annual gametogenic cycle with spawning taking place in summer. Densities varied from 0.46 to 9.46 individuals m(-2). Density variations and seawater temperature were not significantly correlated. The population structure of O. reticulata was polymodal, with at least four co-occurring cohorts. Recruitment events were recorded in March 2001, October 2001, January 2002, and September 2002. As indicated by the asymptote size (D(infinity)=11.47 mm +/- 1.46), growth constant (K=0.42 year(-1)+/- 0.12), and oscillation index (C=0.97 +/- 0.51), the growth pattern of O. reticulata seems to be based on high survivorship of juveniles and adults, where sexual maturity is reached at a small size with rapid growth in the first 2 years of life. A low level of settlement is to be expected based on these data; however, there must be a minimum successful survivorship and development for juveniles and adults. Another explanation for the lack of small individuals (disc diameter <1.0 mm) could be that recruitment is located in a different area and a post-settlement migration might be involved in the maintenance of the population.

Solanum americanum as a reservoir of natural enemies of the tomato red spider mite, Tetranychus evansi (Acari: Tetranychidae)

Brazilian populations of the pathogenic fungus Neozygites floridana (Weiser & Muma) Remaudiere & S. Keller (Entomophthoromycotina: Entomophthorales) and the predatory mite Phytoseiulus longipes Evans (Acari: Phytoseiidae) are potential candidates for introduction into Africa for classical biological control of the tomato red spider mite, Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae). The efficiency of these natural enemies against T. evansi has been demonstrated under laboratory conditions, but little is known about their performance on native Solanaceae in the field. The American nightshade, Solanum americanum Mill., is native to the Americas and may serve as an alternative host plant for T. evansi and its natural enemies in the absence of tomato plants. In this work, we studied the population dynamics of T. evansi and its natural enemies on S. americanum in a screen house, semi-field and field plots in Recife, Pernambuco, Brazil, to evaluate the potential of natural enemies for controlling T. evansi. Of the four natural enemies found in association with T. evansi, only N. floridana and P. longipes were clearly associated with the reduction of the populations of T. evansi. Neozygites floridana was observed in a screen house, semi-field and field plots, but P. longipes was only detected in the semi-field plots. Increases in the population of T. evansi were always followed by increases in the density of one of these natural enemies, suggesting that they were important factors regulating T. evansi populations on S. americanum. The presence of this host plant near the release sites in Africa thus might increase the chances for the permanent establishment of these natural enemies.

Reproductive biology of the ghost shrimp Lepidophthalmus bocourti (A. Milne-Edwards, 1870) (Decapoda: Axiidea: Callianassidae): A tropical species with a seasonal reproduction

Based on the hypothesis that reproduction is a continuous process in tropical habitats, we analysed reproductive periodicity and egg production in the callianassid ghost shrimp Lepidophthalmus bocourti, one of the most common species in mangrove systems along the Pacific coast of Central America. During one year (May 2008 to April 2009), individuals of L. bocourti (N = 499) were collected nearshore Gulf of Nicoya, Pacific coast of Costa Rica. Observations were made on presence or absence of incubated embryos, and gonad activity of females was analysed as gonadosomatic index (GSI). Our results revealed that L. bocourti has a marked seasonal breeding period, which contradicts previous reports regarding coastal marine decapods from the tropics. Ovigerous females were found only from June to August, while high GSI values were obtained from March to July. The increase of GSI and appearance of ovigerous females were associated with a concomitant decrease of salinity, but not with temperature. We assume that reproduction of L. bocourti is adapted to local changes of environmental conditions, and that a decrease in salinity during rainy season may serve as a triggering factor for ovarian development. Compared to other ghost shrimps, L. bocourti produced on average more (2002 +/- 1365) and smaller (0.87 +/- 0.109 mm) eggs, which seems to suggest that this species does not have an abbreviated larval development as reported for other species of genus. The deviation from the generalization of constant reproduction in the tropics for shallow water marine invertebrates and its probable cause are adequately discussed.

Does anti-hepatitis B virus vaccine make any difference in long-term number of liver transplantation?

Background: Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality worldwide. Chronic hepatitis B infection is associated with an increased risk of cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Our aim is to analyze, through a mathematical model, the potential impact of anti-HBV vaccine in the long-term (that is, decades after vaccination) number of LT. Methods: The model simulated that the prevalence of HBV infection was 0.5% and that approximately 20% of all the liver transplantation carried out in the state of Sao Paulo are due to HBV infection. Results: The theoretical model suggests that a vaccination program that would cover 80% of the target population would reach a maximum of about 14% reduction in the LT program. Conclusion: Increasing the vaccination coverage against HBV in the state of Sao Paulo would have a relatively low impact on the number of liver transplantation. In addition, this impact would take several decades to materialize due to the long incubation period of liver failure due to HBV.

Multiple Quaternary Refugia in the Eastern Guiana Shield Revealed by Comparative Phylogeography of 12 Frog Species

The Guiana Shield (GS) is one of the most pristine regions of Amazonia and biologically one of the richest areas on Earth. How and when this massive diversity arose remains the subject of considerable debate. The prevailing hypothesis of Quaternary glacial refugia suggests that a part of the eastern GS, among other areas in Amazonia, served as stable forested refugia during periods of aridity. However, the recently proposed disturbance-vicariance hypothesis proposes that fluctuations in temperature on orbital timescales, with some associated aridity, have driven Neotropical diversification. The expectations of the temporal and spatial organization of biodiversity differ between these two hypotheses. Here, we compare the genetic structure of 12 leaf-litter inhabiting frog species from the GS lowlands using a combination of mitochondrial and nuclear sequences in an integrative analytical approach that includes phylogenetic reconstructions, molecular dating, and Geographic Information System methods. This comparative and integrated approach overcomes the well-known limitations of phylogeographic inference based on single species and single loci. All of the focal species exhibit distinct phylogeographic patterns highlighting taxon-specific historical distributions, ecological tolerances to climatic disturbance, and dispersal abilities. Nevertheless, all but one species exhibit a history of fragmentation/isolation within the eastern GS during the Quaternary with spatial and temporal concordance among species. The signature of isolation in northern French Guiana (FG) during the early Pleistocene is particularly clear. Approximate Bayesian Computation supports the synchrony of the divergence between northern FG and other GS lineages. Substructure observed throughout the GS suggests further Quaternary fragmentation and a role for rivers. Our findings support fragmentation of moist tropical forest in the eastern GS during this period when the refuge hypothesis would have the region serving as a contiguous wet-forest refuge.

Production of Excirolana armata (Dana, 1853) (Isopoda, Cirolanidae) on an exposed sandy beach in southeastern Brazil

The somatic and gonad productions of the cirolanid isopod Excirolana armata were analyzed by taking monthly samples from December 2003 to November 2005 on Una beach, So Paulo state (24A degrees S), southeastern Brazil. Sampling was performed along three fixed transects established from the base of the foredunes to the waterline. Weight-specific growth rate was used to estimate the E. armata somatic production for 2004 and 2005, separately. The gonad production was estimated based on the monthly reproductive potential (mean number of eggs/embryos per female x monthly abundance of ovigerous females with near-release broods) for 2004. The annual somatic production of E. armata population varied from 15.57 to 17.25 g AFDW m(-1) year(-1) and the somatic production/biomass ratio (P (s)/B) from 3.55 to 3.14 year(-1) for 2004 and 2005, respectively. The P (s)/B ratios were higher for males (4.02 and 3.19 year(-1) for 2004 and 2005) than for females (3.10 year(-1) for both years). The annual gonad production (P (g) = 1.07 g AFDW m(-1) year(-1)) contributed about 15 and 6% to the total production (P (s) + P (g)) of females and the population, respectively. The proportion of gonad to somatic production of females (P (g)/P (s)) increased with individual size (ca 90% in the 7.5 mm size class), and the annual weight-specific gonad production (P (g)/B ratio) was estimated to 0.24 year(-1). The high P (s)/B ratios estimated for E. armata derive from the fast growth of individuals and show the importance of this population to the energy flow on Una beach ecosystem. However, the low percentage of juveniles verified in this population and in other studies of populations of the genus Excirolana is discussed as an important source of underestimation of P (s)/B ratio.

Phylodynamics and movement of Phycodnaviruses among aquatic environments

Phycodnaviruses have a significant role in modulating the dynamics of phytoplankton, thereby influencing community structure and succession, nutrient cycles and potentially atmospheric composition because phytoplankton fix about half the carbon dioxide (CO2) on the planet, and some algae release dimethylsulphoniopropionate when lysed by viruses. Despite their ecological importance and widespread distribution, relatively little is known about the evolutionary history, phylogenetic relationships and phylodynamics of the Phycodnaviruses from freshwater environments. Herein we provide novel data on Phycodnaviruses from the largest river system on earth-the Amazon Basin-that were compared with samples from different aquatic systems from several places around the world. Based on phylogenetic inference using DNA polymerase (pol) sequences we show the presence of distinct populations of Phycodnaviridae. Preliminary coarse-grained phylodynamics and phylogeographic inferences revealed a complex dynamics characterized by long-term fluctuations in viral population sizes, with a remarkable worldwide reduction of the effective population around 400 thousand years before the present (KYBP), followed by a recovery near to the present time. Moreover, we present evidence for significant viral gene flow between freshwater environments, but crucially almost none between freshwater and marine environments. The ISME Journal (2012) 6, 237-247; doi: 10.1038/ismej.2011.93; published online 28 July 2011

Effects of light intensity and temperature on Cylindrospermopsis raciborskii (Cyanobacteria) with straight and coiled trichomes: growth rate and morphology

Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju (Ordem Nostocales) is one of the most troublesome bloom-forming species in Brazil. Understanding the population dynamics of the different morphotypes of C. raciborskii (straight and coiled) could assist in the prediction of favourable conditions for the proliferation of this potentially toxin-producing species. The aim of the present study was to assess the effects of two different light intensities and temperatures on the growth rate and morphology of the trichomes of the straight and coiled morphotypes. For such, two non-toxin producing strains of C. raciborskii were used - one with a coiled trichome (ITEP31) and another with a straight trichome (ITEP28). The strains were cultured in BG-11 medium in a climatic chamber under controlled conditions. Two light intensities (30 and 90 mu mol.m(-2).s(-1)) were combined at temperatures of 21 and 31 degrees C and the growth rate and morphological changes were analysed. The morphotypes responded differently to the different temperatures and light intensities. Both strains exhibited faster growth velocities when submitted to higher light intensity and temperature. The lower temperature and higher luminosity hampered the development of both strains. Variations in cellular morphology and an absence of akinetes in both strains were related to the lower temperature (21 C). The coiled morphotype demonstrated considerable phenotype plasticity, changing the morphology of trichome throughout its growth curve. Although molecular analysis does not sustain the separation of the morphotypes as distinct species, their different eco-physiological responses should be considered further knowledge of extreme importance for the population control of these potentially toxic organisms.

Single-Nucleotide Polymorphism and Copy Number Variation of the Multidrug Resistance-1 Locus of Plasmodium vivax: Local and Global Patterns

Emerging resistance to chloroquine (CQ) poses a major challenge for Plasmodium vivax malaria control, and nucleotide substitutions and copy number variation in the P. vivax multidrug resistance 1 (pvmdr-1) locus, which encodes a digestive vacuole membrane transporter, may modulate this phenotype. We describe patterns of genetic variation in pvmdr-1 alleles from Acre and Amazonas in northwestern Brazil, and compare then with those reported in other malaria-endemic regions. The pvmdr-1 mutation Y976F, which is associated with CQ resistance in Southeast Asia and Oceania, remains rare in northwestern Brazil (1.8%) and its prevalence mirrors that of CO resistance worldwide. Gene amplification of pvmdr-1, which is associated with mefloquine resistance but increased susceptibility to CO, remains relatively rare in northwestern Brazil (0.9%) and globally (< 4%), but became common (> 10%) in Tak Province, Thailand, possibly because of drug-mediated selection. The global database we have assembled provides a baseline for further studies of genetic variation in pvmdr-1 and drug resistance in P. vivax malaria.

Genital morphology of the male South American fur seal (Arctocephalus australis) and biological implications

Male capacity for spreading genes to a great number of descendents and to determine population dynamics depend directly on the genital organs. Morphological studies in pinnipeds are scarce and the functional meaning of some characteristics has never been discussed. We hypothesized that Arctocephalus australis (A. australis) shows morphophysiological adaptations in order to guarantee the perpetuation of the species in the unique annual mating season. Seven males, dead from natural causes, had their genital organs collected and fixed for morphological description. Some features differ from other described mammalian males and are closely related to the biology and reproductive cycle of this species, as the scrotal epidermis, absence of glandular portion in the ductus deferens and spermatogenic epithelium suggest a recrudescent testis period. The corona glandis exhibits a singular arrangement: its erectile border looks like a formation of petals and its association with the os penis gives a "lily-flower" form to this region. We propose the name margo petaliformis to this particular erectile border of the corona glandis because of its similarity to a flower corola. The male genital organs of A. australis show morphological features compatible with adaptation to environment requirements and reproductive efficiency.

An insight into the populations of blainville's and curvier's beaked whales off El Hierro (Canary Islands)

Trabajo realizado por: Reyes, C., Schiavi, A., Aguilar del Soto,

Processo biotecnologico a cellule immobilizzate per la produzione di acidi grassi volatili da acque di vegetazione

Le acque di vegetazione (AV) costituiscono un serio problema di carattere ambientale, sia a causa della loro elevata produzione sia per l’ elevato contenuto di COD che oscilla fra 50 e 150 g/l. Le AV sono considerate un refluo a tasso inquinante fra i più elevati nell’ambito dell’industria agroalimentare e la loro tossicità è determinata in massima parte dalla componente fenolica. Il presente lavoro si propone di studiare e ottimizzare un processo non solo di smaltimento di tale refluo ma anche di una sua valorizzazione, utlizzandolo come materia prima per la produzione di acidi grassi e quindi di PHA, polimeri biodegradabili utilizzabili in varie applicazioni. A tale scopo sono stati utilizzati due bioreattori anaerobici a biomassa adesa, di identica configurazione, con cui si sono condotti due esperimenti in continuo a diverse temperature e carichi organici al fine di studiare l’influenza di tali parametri sul processo. Il primo esperimento è stato condotto a 35°C e carico organico pari a 12,39 g/Ld, il secondo a 25°C e carico organico pari a 8,40 g/Ld. Si è scelto di allestire e mettere in opera un processo a cellule immobilizzate in quanto questa tecnologia si è rivelata vantaggiosa nel trattamento continuo di reflui ad alto contenuto di COD e carichi variabili. Inoltre si è scelto di lavorare in continuo poiché tale condizione, per debiti tempi di ritenzione idraulica, consente di minimizzare la metanogenesi, mediata da microrganismi con basse velocità specifiche di crescita. Per costituire il letto fisso dei due reattori si sono utilizzati due diversi tipi di supporto, in modo da poter studiare anche l’influenza di tale parametro, in particolare si è fatto uso di carbone attivo granulare (GAC) e filtri ceramici Vukopor S10 (VS). Confrontando i risultati si è visto che la massima quantità di VFA prodotta nell’ambito del presente studio si ha nel VS mantenuto a 25°C: in tale condizione si arriva infatti ad un valore di VFA prodotti pari a 524,668 mgCOD/L. Inoltre l’effluente in uscita risulta più concentrato in termini di VFA rispetto a quello in entrata: nell’alimentazione la percentuale di materiale organico presente sottoforma di acidi grassi volatili era del 54 % e tale percentuale, in uscita dai reattori, ha raggiunto il 59 %. Il VS25 rappresenta anche la condizione in cui il COD degradato si è trasformato in percentuale minore a metano (2,35 %) e questo a prova del fatto che l’acidogenesi ha prevalso sulla metanogenesi. Anche nella condizione più favorevole alla produzione di VFA però, si è riusciti ad ottenere una loro concentrazione in uscita (3,43 g/L) inferiore rispetto a quella di tentativo (8,5 g/L di VFA) per il processo di produzione di PHA, sviluppato da un gruppo di ricerca dell’università “La Sapienza” di Roma, relativa ad un medium sintetico. Si può constatare che la modesta produzione di VFA non è dovuta all’eccessiva degradazione del COD, essendo questa nel VS25 appena pari al 6,23%, ma piuttosto è dovuta a una scarsa concentrazione di VFA in uscita. Questo è di buon auspicio nell’ottica di ottimizzare il processo migliorandone le prestazioni, poiché è possibile aumentare tale concentrazione aumentando la conversione di COD in VFA che nel VS25 è pari a solo 5,87%. Per aumentare tale valore si può agire su vari parametri, quali la temperatura e il carico organico. Si è visto che il processo di acidogenesi è favorito, per il VS, per basse temperature e alti carichi organici. Per quanto riguarda il reattore impaccato con carbone attivo la produzione di VFA è molto ridotta per tutti i valori di temperatura e carichi organici utilizzati. Si può quindi pensare a un’applicazione diversa di tale tipo di reattore, ad esempio per la produzione di metano e quindi di energia.