Pelagic behavior of adult Greenland halibut (Reinhardtius hippoglossoides)

It is evident from several field experiments with vertical longlines and archival tags, as well as concurrent studies of predator-prey relationships, that adult specimens of the deep-water flatfish Greenland halibut (Reinhardtius hippoglossoides) make regular excursions several hundred meters through the water column. The distribution of longline catches within the water column is confined to a well-defined depth layer overlapping with the distribution of blue whiting (Micromesistius poutassou), an important prey species, and depth recordings from archival tags overlap with Atlantic herring (Clupea harengus), the other major fish prey. The degree of pelagic use varies with fish size as well as seasons. Smaller individuals are found further off the bottom, and pelagic activity is greatest during early autumn. Interaction with pelagic prey species can influence results from bottom trawl surveys.

How much does the fishery at Apo Island benefit from spillover of adult fish from the adjacent marine reserve?

The contribution of the no-take marine reserve at Apo Island, Philippines, to local fishery yield through “spillover” (net export of adult fish) was estimated. Spatial patterns of fishing effort, yield, and catch rates around Apo Island were documented daily in 2003−2004. Catch rates were higher near the reserve (by a factor of 1.1 to 2.0), but fishing effort was often lowest there. Higher catch rates near the reserve were more likely due to spillover than to low fishing intensity. Lower fishing effort near the reserve may have been due to 1) weather patterns, 2) traditional importance of other fishing grounds, 3) high variability in catch rates, 4) lower market value of target species, and 5) social pressures. The yield taken near the reserve was only 10% of the total yield, but the actual spillover contribution was probably much less than this. This study is one of the few to estimate the spillover contribution to overall yield and to document the responses of fishermen to spil

Abundance of adult horseshoe crabs (Limulus polylphemus) in Delaware Bay estimated from a bay-wide mark-recapture study

Estimates of the abundance of American horseshoe crabs (Limulus polyphemus) are important to determine egg production and to manage populations for the energetic needs of shorebirds that feed on horseshoe crab eggs. In 2003, over 17,500 horseshoe crabs were tagged and released throughout Delaware Bay, and recaptured crabs came from spawning surveys that were conducted during peak spawning. We used two release cohorts to test for a temporary effect of tagging on spawning behavior and we adjusted the number of releases according to relocation rates from a telemetry study. The abundance estimate was 20 million horseshoe crabs (90 % confidence interval: 13−28 million), of which 6.25 million (90% CI: 4.0−8.8 million) were females. The combined harvest rate for Delaware, New Jersey, Virginia, and Maryland in 2003 was 4% (90% CI: 3−6%) of the abundance estimate. Over-wintering of adults in Delaware Bay could explain, in part, differences in estimates from ocean-trawl surveys. Based on fecundity of 88,000 eggs per female, egg production was 5.5×1011 (90% CI: 3.5×1011, 7.7×1011), but egg availability for shorebirds also depended on overlap between horseshoe crab and shorebird migrations, density-dependent bioturbation, and wave-mediated vertical transport.

Influence of Extracellular Matrix Components on the Expression of Integrins and Regeneration of Adult Retinal Ganglion Cells

Purpose Retinal ganglion cells (RGCs) are exposed to injury in a variety of optic nerve diseases including glaucoma. However, not all cells respond in the same way to damage and the capacity of individual RGCs to survive or regenerate is variable. In order to elucidate factors that may be important for RGC survival and regeneration we have focussed on the extracellular matrix (ECM) and RGC integrin expression. Our specific questions were: (1) Do adult RGCs express particular sets of integrins in vitro and in vivo? (2) Can the nature of the ECM influence the expression of different integrins? (3) Can the nature of the ECM affect the survival of the cells and the length or branching complexity of their neurites? Methods Primary RGC cultures from adult rat retina were placed on glass coverslips treated with different substrates: Poly-L-Lysine (PL), or PL plus laminin (L), collagen I (CI), collagen IV (CIV) or fibronectin (F). After 10 days in culture, we performed double immunostaining with an antibody against beta III-Tubulin to identify the RGCs, and antibodies against the integrin subunits: alpha V, alpha 1, alpha 3, alpha 5, beta 1 or beta 3. The number of adhering and surviving cells, the number and length of the neurites and the expression of the integrin subunits on the different substrates were analysed. Results PL and L were associated with the greatest survival of RGCs while CI provided the least favourable conditions. The type of substrate affected the number and length of neurites. L stimulated the longest growth. We found at least three different types of RGCs in terms of their capacity to regenerate and extend neurites. The different combinations of integrins expressed by the cells growing on different substrata suggest that RGCs expressed predominantly alpha 1 beta 1 or alpha 3 beta 1 on L, alpha 1 beta 1 on CI and CIV, and alpha 5 beta 3 on F. The activity of the integrins was demonstrated by the phosphorylation of focal adhesion kinase (FAK). Conclusions Adult rat RGCs can survive and grow in the presence of different ECM tested. Further studies should be done to elucidate the different molecular characteristics of the RGCs subtypes in order to understand the possible different sensitivity of different RGCs to damage in diseases like glaucoma in which not all RGCs die at the same time.

Weed control by adult and juvenile tilapia Tilapia rendalli in rainfed ponds

Two studies were conducted in consecutive years over the time period 14 January to 1 July to determine whether labor-savings and fish growth enhancement could be achieved by stocking Tilapia rendalli directly into ponds containing weeds left from a dry period. Six replicates 200 sq. m ponds located at the Malawi National Aquaculture Centre, Domasi were drained, left dry for 63 days and natural growth of weeds was allowed. All ponds were stocked with 200 T. rendalli fingerlings (study 1) or adults (study 2) averaging 4.6 g (40 mm TL) and 47.7 (130 mm TL), respectively. For T. rendalli juveniles, final standing stock, growth and offspring production were significantly (P<0.05) better in fed than in weedy ponds. Average weight of fingerlings were significantly (P<0.05) different between the two treatments. For T. rendalli adults, final standing stock, growth and offspring production were not affected by the presence of weeds.

Proteomic Analysis of the Ubiquitin Landscape in the Drosophila Embryonic Nervous System and the Adult Photoreceptor Cells

Background Ubiquitination is known to regulate physiological neuronal functions as well as to be involved in a number of neuronal diseases. Several ubiquitin proteomic approaches have been developed during the last decade but, as they have been mostly applied to non-neuronal cell culture, very little is yet known about neuronal ubiquitination pathways in vivo. Methodology/Principal Findings Using an in vivo biotinylation strategy we have isolated and identified the ubiquitinated proteome in neurons both for the developing embryonic brain and for the adult eye of Drosophila melanogaster. Bioinformatic comparison of both datasets indicates a significant difference on the ubiquitin substrates, which logically correlates with the processes that are most active at each of the developmental stages. Detection within the isolated material of two ubiquitin E3 ligases, Parkin and Ube3a, indicates their ubiquitinating activity on the studied tissues. Further identification of the proteins that do accumulate upon interference with the proteasomal degradative pathway provides an indication of the proteins that are targeted for clearance in neurons. Last, we report the proof-of-principle validation of two lysine residues required for nSyb ubiquitination. Conclusions/Significance These data cast light on the differential and common ubiquitination pathways between the embryonic and adult neurons, and hence will contribute to the understanding of the mechanisms by which neuronal function is regulated. The in vivo biotinylation methodology described here complements other approaches for ubiquitome study and offers unique advantages, and is poised to provide further insight into disease mechanisms related to the ubiquitin proteasome system.

Overview of Mark-recovery Studies on Adult and Juvenile Atlantic Menhaden, Brevoortia tyrannus, and Gulf Menhaden, B. patronus

Extensive mark-recapture studies using internal ferromagnetic tags have been conducted on Atlantic menhaden, Brevoortia tyrannus, and Gulf menhaden, B. patronus. From 1966 through 1969, 1,066,357 adult Atlantic menhaden were tagged; subsequently, from 1970 through 1987, 428,272 juveniles of this species were tagged. Similarly, from 1969 through 1971, 75,673 adult Gulf menhaden were tagged; concurrently from 1970 through 1985, 236,936 juveniles were tagged and released. This report provides an overview of the history of the tagging program, methodologies for both release and recovery activities, a summary of release areas and number of fish tagged within each area, and a review of assumptions necessary for the analysis of this type of mark-recovery data. The resulting data sets have proven to be highly useful for a variety of analyses ranging from determination of migratory patterns and population structure to estimating mortality rates. The relatively wide range of acceptance of tagging results by laymen, industry, and analysts alike have made these data extremely useful for management-oriented analyses.

Estudo imunológico e histopatológico da infecção experimental por Schistosoma mansoni em camundongos geneticamente selecionados para tolerância oral

A esquistossomose acomete 207 milhões de pessoas, com mais de 200 mil mortes anuais. Seu principal agente etiológico é o helminto Schistosoma e o principal modelo experimental, o camundongo. Linhagens de camundongos selecionadas geneticamente para susceptibilidade (TS) e resistência (TR) a tolerância imunológica constituem bons modelos para o estudo da resposta imunológica específica e inespecífica nas infecções. O objetivo deste trabalho foi caracterizar a infecção experimental por S. mansoni nestes camundongos, evidenciando a imunopatologia por diversos parâmetros na fase aguda da infecção. TR e TS não diferiram quanto a penetração de cercárias, recuperação de vermes adultos, fecundidade/produtividade de ovos das fêmeas de S. mansoni, mas predominaram ovos mortos em TS. Quanto maior o número de casais, maior a probabilidade de troca de casais e regressão sexual da fêmea, além de pequena redução da produtividade de ovos. Análise ultraestrutural dos parasitos machos recuperados de TS apresentaram tubérculos edemaciados, espinhos encurtados e em menor densidade que os parasitos dos TR. O tegumento dos parasitos recuperados de TS apresentou-se desorganizado, intensamente vacuolizado e com tendência a se desprender da superfície e espinhos internalizados e células vitelínicas desorganizadas. TS desenvolveram granulomas hepáticos grandes, com fibras radiais e predomínio do estágio exsudativo-produtivo com características de fase produtiva (EP/P), enquanto camundongos TR desenvolveram granulomas menores, com fibras concêntricas e predomínio de granulomas exsudativo-produtivos. TS desenvolveu hepatomegalia mais acentuada na fase aguda da infecção e exacerbada esplenomegalia na fase crônica. A aspartato aminotransferase mais elevada nos TR foi coerente com a acentuada histólise nos granulomas iniciais dos TR. É possível que a histólise menor em TS tenha contribuído para sua intensa hepatomegalia na fase aguda. Leucócitos totais séricos aumentaram em TS, nas fases aguda e crônica, mas não em TR. TS apresentaram anemia durante a fase crônica da infecção, possivelmente devido ao desvio na hematopoiese medular para a produção de leucócitos ou apoptose das hemácias. A mieloperoxidase neutrofílica hepática e no íleo foi maior em TS e a peroxidase de eosinófilos foi mais elevada no íleo do TS. Ambas as linhagens produziram IFN-γ, mas os níveis funcionais de IFN-γ foram diferentes nas duas linhagens em cultura de células. É possível que a imunopatologia hepática grave na linhagem TS possa estar relacionada aos altos títulos IFN-γ. TS produziu IL-10 em maior quantidade, entretanto esta citocina não foi capaz de regular o crescimento exacerbado dos granulomas hepáticos. Altos títulos de IL-4 na linhagem TS também são coerentes com a exacerbação dos granulomas, pois, como a IL-13, a IL-4 induz síntese de colágeno e está relacionada ao desenvolvimento da fibrose no granuloma esquistossomótico. Observamos redução do percentual relativo de células T CD4+ hepáticas de animais infectados em ambas as linhagens e redução percentual nas subpopulações de linfócitos B na medula óssea (precursores, linfócitos B imaturos, maduros e plasmócitos) mais acentuada em TS que em TR, possivelmente devido a extensa mobilização de B imaturos induzida pela inflamação ou desvio da hematopoiese para síntese de granulócitos em TS. Quantitativamente, TR não alterou suas subpopulações de linfócitos B. TS e TR são bons modelos para estudo da resposta imunológica na infecção esquistossomótica experimental. Novos estudos são necessários para confirmar nossas propostas e compreender os mecanismos envolvidos na diferença da resposta imunológica dessas linhagens na relação schistosoma-hospedeiro.

Migratory and within-estuary behaviors of adult Summer Flounder (Paralichthys dentatus) in a lagoon system of the southern mid-Atlantic Bight

We monitored the movements of 45 adult Summer Flounder (Paralichthys dentatus) between June 2007 and July 2008 through the use of passive acoustic telemetry to elucidate migratory and within-estuary behaviors in a lagoon system of the southern mid-Atlantic Bight. Between 8 June and 10 October 2007, fish resided primarily in the deeper (>3 m) regions of the system and exhibited low levels of large-scale (100s of meters) activity. Mean residence time within this estuarine lagoon system was conservatively estimated to be 130 days (range: 18–223 days), which is 1.5 times longer than the residence time previously reported for Summer Flounder in a similar estuarine habitat ~250 km to the north. The majority of fish remained within the lagoon system until mid-October, although some fish dispersed earlier and some of them appeared to disperse temporarily (i.e., exited the system for at least 14 consecutive days before returning). Larger fish were more likely to disperse before mid-October than smaller fish and may have moved to other estuaries or the inner continental shelf. Fish that dispersed after mid-October were more likely to return to the lagoon system the following spring than were fish that dispersed before mid-October. In 2008, fish returned to the system between 7 February and 7 April. Dispersals and returns most closely followed seasonal changes in mean water temperature, but photoperiod and other factors also may have played a role in large-scale movements of Summer Flounder.