The myogenic automatism of the systemic heart of Octopus vulgaris (Cephalopoda: Coleoidea): evidence for localized stretch sensitivity and pacing activity

The localization of the stretch sensitivity and myogenic automatism in the systemic heart of Octopus vulgaris has been studied on an isolated preparation in which the ventricle was zoned by ligatures. Each region has been submitted to two different levels of internal hydrostatic pressure (1 and 2 kPa). Only the two atrio-ventricular regions were able to contract regularly when submitted to internal pressure, with a frequency dependent from the pressure value, while the ventricle-aortic region was insensitive to the stretching by internal pressure. This result supports the hypothesis that the automatism in this heart is localized. Electrocardiogram recordings from different areas of an isolated and perfused preparation of the systemic heart ventricle are also reported, which suggest that the electrical activity of the ventricle originates in two narrow areas near the atrio-ventricular valves.

Values of inland fisheries in the Mekong river basin

Asia has the most productive inland fisheries in the world. The fishery sector contributes significantly to the national economies of the region. Inland fisheries also improve food security by providing a source of protein and a livelihood for millions of people in this part of the world, especially the rural poor. The purpose of this report is to provide information on the biological, economic, social and cultural values of river fisheries in the Lower Mekong Basin, and to identify the main impacts of environmental changes on these values. A review of fisheries-related literature, including project reports and gray literature, was undertaken. More than 800 documents were reviewed, and original information was extracted from 270 of them. The analysis identified a large number of localized studies leading to generic conclusions. The report addresses the basin wide issues and studies. It is then organized by nation, namely, the Chinese province of Yunnan, then Laos, Thailand, Cambodia and Vietnam. It first gives an overview of each country’s economic, fisheries and social situation, then details the values documented for river fisheries in each country.

Vegetative Spread of Dioecious Hydrilla Colonies in Experimental Ponds

Stolon formation and fragmentation are two vegetative mechanisms by which hydrilla colonies expand. These two mechanisms of spread were studied in ponds located in Lewisville, TX over a two-year period. Stolons were determined to be the predominant mechanism for localized expansion in undisturbed areas. While some fragments were produced, they accounted for only 0.1% of the establishment of rooted plants in new quadrats. Peak production of fragments occurred in October and November, with fragment densities of 0.15 N m-2 d-1. Expansion by stolons occurred between June and November of each year, with higher rates of spread (up to 4.0 cm d-1 radial growth) observed in the second season.

Report on Marine Mammal Unusual Mortality Event UMESE0501Sp: Multispecies Mass Stranding of Pilot Whales (Globicephala macrorhynchus), Minke Whale (Balaenoptera acutorostrata), and Dwarf Sperm Whales (Kogia sima) in North Carolina on 15-16 January 2005

On 15-16 January 2005, three offshore species of cetaceans (33 short-finned pilot whales, Globicephala macrorhynchus, one minke whale, Balaenoptera acutorostrata, and two dwarf sperm whales, Kogia sima) stranded alive on the beaches of North Carolina. The pilot whales stranded near Oregon Inlet, the minke whale in northern North Carolina, and the dwarf sperm whales near Cape Hatteras. Live strandings of three species in one weekend was unique in North Carolina and qualified as an Unusual Mortality Event. Gross necropsies were conducted on 16-17 January 2005 on 27 pilot whales, two dwarf sperm whales, and the minke whale. Samples were collected for clinical pathology, parasitology, gross pathology, histopathology, microbiology and serology. There was variation in the number of animals sampled for each collection type, however, due to carcasses washing off the beach or degradation in carcass condition during the course of the response. Comprehensive histologic examination was conducted on 16 pilot whales, both dwarf sperm whales, and the minke whale. Limited organ or only head tissue suites were obtained from nine pilot whales. Histologic examination of tissues began in February 2005 and concluded in December 2005 when final sampling was concluded. Neither the pilot whales nor dwarf sperm whales were emaciated although none had recently ingested prey in their stomachs. The minke whale was emaciated; it was likely a dependent calf that became separated from the female. Most serum biochemistry abnormalities appear to have resulted from the stranding and indicated deteriorating condition from being on land for an extended period. Three pilot whales had clinical evidence of pre-existing systemic inflammation, which was supported by histopathologic findings. Although gross and histologic lesions involving all organ systems were noted, consistent lesions were not observed across species. Verminous pterygoid sinusitis and healed fishery interactions were seen in pilot whales but neither of these changes were causes of debilitation or death. In three pilot whales and one dwarf sperm whale there was evidence of clinically significant disease in postcranial tissues which led to chronic debilitation. Cardiovascular disease was present in one pilot whale and one dwarf sperm whale; musculoskeletal disease and intra-abdominal granulomas were present in two pilot whales. These lesions were possible, but not definitive, causal factors in the stranding. Remaining lesions were incidental or post-stranding. The minke whale and three of five tested pilot whales had positive morbillivirus titers (≥1:8 with one at >1:256), but there was no histologic evidence of active viral infection. Parasites (nematodes, cestodes, and trematodes) were collected from 26 pilot whales and two dwarf sperm whales. Sites of collection included stomach, nasal/pterygoid, peribullar sinuses, blubber, and abdominal cavity. Parasite species, locations and loads were within normal limits for free-ranging cetaceans and were not considered causative for the stranding event. Gas emboli lesions which were considered consistent with or diagnostic of sonarassociated strandings of beaked whales or small cetaceans were not found in the whales stranded as part of UMESE0501Sp. Twenty-five heads were examined with nine specific anatomic locations of interest: extramandibular fat, intramandibular fat, auditory meatus, peribullar acoustic fat, peribullar soft tissue, peribullar sinus, pterygoid sinus, melon, and brain. The common finding in all examined heads was verminous pterygoid sinusitis. Intramandibular adipose tissue reddening, typically adjacent to the vascular plexus, was observed in some individuals and could represent localized hemorrhage resulting from vascular rete rupture, hypostatic congestion, or erythrocyte rupture during the freeze/thaw cycle. One cetacean had peracute to acute subdural hemorrhage that likely occurred from thrashing on the beach post-stranding, although its occurrence prior to stranding cannot be excluded. Information provided to NMFS by the U.S. Navy indicated routine tactical mid-frequency sonar operations from individual surface vessels over relatively short durations and small spatial scales within the area and time period investigated. No marine mammals were detected by marine mammal observers on operational vessels; standard operating procedure for surface naval vessels operating mid-frequency sonar is the use of trained visual lookouts using high-powered binoculars. Sound propagation modeling using information provided to NMFS indicated that acoustic conditions in the vicinity likely depended heavily on position of the receivers (e.g., range, bearing, depth) relative to that of the sources. Absent explicit information on the location of animals meant that it was not possible to estimate received acoustic exposures from active sonar transmissions. Nonetheless, the event was associated in time and space with naval activity using mid-frequency active sonar. It also had a number of features in common (e.g., the “atypical” distribution of strandings involving multiple offshore species, all stranding alive, and without evidence of common infectious or other disease process) with other sonar-related cetacean mass stranding events. Given that this event was the only stranding of offshore species to occur within a 2-3 day period in the region on record (i.e., a very rare event), and given the occurrence of the event simultaneously in time and space with a naval exercise using active sonar, the association between the naval sonar activity and the location and timing of the event could be a causal rather than a coincidental relationship. However, evidence supporting a definitive association is lacking, and, in particular, there are differences in operational/environmental characteristics between this event and previous events where sonar has apparently played a role in marine mammal strandings. This does not preclude behavorial avoidance of noise exposure. No harmful algal blooms were present along the Atlantic coast south of the Chesapeake Bay during the months prior to the event. Environmental conditions, including strong winds, changes in upwelling- to downwelling-favorable conditions, and gently sloping bathymetry, were consistent with conditions which have been correlated with other mass strandings. In summary, we did not find commonality in gross and histologic lesions that would indicate a single cause for this stranding event. Three pilot whales and one dwarf sperm whale had debilitating conditions identified that could have contributed to stranding, one pilot whale had a debilitating condition (subdural hemorrhage) that could have been present prior to or resulting from stranding. While the pilot and dwarf sperm whale strandings may have had a common cause, the minke whale stranding was probably just coincidental. On the basis of examination of physical evidence in the affected whales, however, we cannot definitively conclude that there was or was not a causal link between anthropogenic sonar activity or environmental conditions (or a combination of these factors) and the strandings. Overall, the cause of UMESE0501Sp in North Carolina is not and likely will not be definitively known. (PDF contains 240 pages)

Nassau grouper (Epinephelus striatus) spawning aggregations: hydroacoustic surveys and geostatistical analysis

With the near extinction of many spawning aggregations of large grouper and snapper throughout the Caribbean, Gulf of Mexico, and tropical Atlantic, we need to provide baselines for their conservation. Thus, there is a critical need to develop techniques for rapidly assessing the remaining known (and unknown) aggregations. To this end we used mobile hydroacoustic surveys to estimate the density, spatial extent, and total abundance of a Nassau grouper spawning aggregation at Little Cayman Island, Cayman Islands, BWI. Hydroacoustic estimates of abundance, density, and spatial extent were similar on two sampling occasions. The location and approximate spatial extent of the Nassau grouper spawning aggregation near the shelf-break was corroborated by diver visual observations. Hydroacoustic density estimates were, overall, three-times higher than the average density observed by divers; however, we note that in some instances diver-estimated densities in localized areas were similar to hydroacoustic density estimates. The resolution of the hydroacoustic transects and geostatistical interpolation may have resulted in over-estimates in fish abundance, but still provided reasonable estimates of total spatial extent of the aggregation. Limitations in bottom time for scuba and visibility resulted in poor coverage of the entire Nassau grouper aggregation and low estimates of abundance when compared to hydroacoustic estimates. Although the majority of fish in the aggregation were well off bottom, fish that were sometimes in close proximity to the seafloor were not detected by the hydroacoustic survey. We conclude that diver observations of fish spawning aggregations are critical to interpretations of hydroacoustic surveys, and that hydroacoustic surveys provide a more accurate estimate of overall fish abundance and spatial extent than diver observations. Thus, hydroacoustics is an emerging technology that, when coupled with diver observations, provides a comprehensive survey method for monitoring spawning aggregations of fish.

Use of non-natal estuaries by migratory striped bass (Morone saxatilis) in summer

For most migratory fish, little is known about the location and size of foraging areas or how long individuals remain in foraging areas, even though these attributes may affect their growth, survival, and impact on local prey. We tested whether striped bass (Morone saxatilis Walbaum), found in Massachusetts in summer, were migratory, how long they stayed in non-natal estuaries, whether observed spatial patterns differed from random model predictions, whether fish returned to the same area across multiple years, and whether fishing effort could explain recapture patterns. Anchor tags were attached to striped bass that were caught and released in Massachusetts in 1999 and 2000, and recaptured between 1999 and 2007. In fall, tagged striped bass were caught south of where they were released in summer, confirming that fish were coastal migrants. In the first summer, 77% and 100% of the recaptured fish in the Great Marsh and along the Massachusetts coast, respectively, were caught in the same place where they were released. About two thirds of all fish recaptured near where they were released were caught 2–7 years after tagging. Our study shows that smaller (400–500 mm total length) striped bass migrate hundreds of kilometers along the Atlantic Ocean coast, cease their mobile lifestyle in summer when they use a relatively localized area for foraging (<20 km2), and return to these same foraging areas in subsequent ye

Effects of commercial fishing on local abundance of Pacific cod (Gadus macrocephalus) in the Bering Sea

Groundfish fisheries in the southeast Bering Sea in Alaska have been constrained in recent years by management measures to protect the endangered Steller sea lion (Eumetopias jubatus). There is concern that the present commercial harvest may produce a localized depletion of groundfish that would affect the foraging success of Steller sea lions or other predators. A three-year field experiment was conducted to determine whether an intensive trawl fishery in the southeast Bering Sea created a localized depletion in the abundance of Pacific cod (Gadus macrocephalus). This experiment produced strongly negative results; no difference was found in the rate of seasonal change in Pacific cod abundance between stations within a regulatory no-trawl zone and stations in an immediately adjacent trawled area. Corollary studies showed that Pacific cod in the study area were highly mobile and indicated that the geographic scale of Pacific cod movement was larger than the spatial scale used as the basis for current no-trawl zones. The idea of localized depletion is strongly dependent on assumed spatial and temporal scales and contains an implicit assumption that there is a closed local population. The scale of movement of target organisms is critical in determining regional effects of fishery removals.

Ecosystem-based Management for Protected Species in the North Pacific Fisheries

In the North Pacific Ocean, an ecosystem-based fishery management approach has been adopted. A significant objective of this approach is to reduce interactions between fishery-related activities and protected species. We review management measures developed by the North Pacific Fishery Management Council and the National Marine Fisheries Service to reduce effects of the groundfish fisheries off Alaska on marine mammals and seabirds, while continuing to provide economic opportunities for fishery participants. Direct measures have been taken to mitigate known fishery impacts, and precautionary measures have been taken for species with potential (but no documented) interactions with the groundfish fisheries. Area closures limit disturbance to marine mammals at rookeries and haulouts, protect sensitive benthic habitat, and reduce potential competition for prey resources. Temporal and spatial dispersion of catches reduce the localized impact of fishery removals. Seabird avoidance measures have been implemented through collaboration with fishery participants and have been highly successful in reducing seabird bycatch. Finally, a comprehensive observer monitoring program provides data on the location and extent of bycatch of marine mammals and seabirds. These measures provide managers with the flexibility to adapt to changes in the status of protected species and evolving conditions in the fisheries. This review should be useful to fishery managers as an example of an ecosystem-based approach to protected species management that is adaptive and accounts for multiple objectives.

Humpback and Fin Whaling in the Gulf of Maine from 1800 to 1918

The history of whaling in the Gulf of Maine was reviewed primarily to estimate removals of humpback whales, Megaptera novaeangliae, especially during the 19th century. In the decades from 1800 to 1860, whaling effort consisted of a few localized, small-scale, shore-based enterprises on the coast of Maine and Cape Cod, Mass. Provincetown and Nantucket schooners occasionally conducted short cruises for humpback whales in New England waters. With the development of bomb-lance technology at mid century, the ease of killing humpback whales and fin whales, Balaenoptera physalus, increased. As a result, by the 1870’s there was considerable local interest in hunting rorquals (baleen whales in the family Balaenopteridae, which include the humpback and fin whales) in the Gulf of Maine. A few schooners were specially outfitted to take rorquals in the late 1870’s and 1880’s although their combined annual take was probably no more than a few tens of whales. Also in about 1880, fishing steamers began to be used to hunt whales in the Gulf of Maine. This steamer fishery grew to include about five vessels regularly engaged in whaling by the mid 1880’s but dwindled to only one vessel by the end of the decade. Fin whales constituted at least half of the catch, which exceeded 100 animals in some years. In the late 1880’s and thereafter, few whales were taken by whaling vessels in the Gulf of Maine.

Trends and Potential Interactions Between Pinnipeds and Fisheries of New England and the U.S. West Coast

Long-term trends in the abundance and distribution of several pinniped species and commercially important fisheries of New England and the contiguous U.S. west coast are reviewed, and their actual and potential interactions discussed. Emphasis is on biological interactions or competition. The pinnipeds include the western North Atlantic stock of harbor seals, Phoca vitulina concolor; western North Atlantic gray seals, Halochoerus grypus; the U.S. stock of California sea lions, Zalophus californianus californianus; the eastern stock of Steller sea lions, Eumetopias jubatus; and Pacific harbor seals, Phoca vitulina richardii. Fisheries included are those for Atlantic cod, Gadus morhua; silver hake, Merluccius bilinearis; Atlantic herring, Clupea harengus; the coastal stock of Pacific whiting, Merluccius productus; market squid, Loligo opalescens; northern anchovy, Engraulis mordax; Pacific her-ring, Clupea pallasi; and Pacific sardine, Sardinops sagax. Most of these pinniped populations have grown exponentially since passage of the U.S. Marine Mammal Protection Act in 1972. They exploit a broad prey assemblage that includes several commercially valuable species. Direct competition with fisheries is therefore possible, as is competition for the prey of commercially valuable fish. The expanding pinniped populations, fluctuations in commercial fish biomass, and level of exploitation by the fisheries may affect this potential for competition. Concerns over pinnipeds impacting fisheries (especially those with localized spawning stocks or at low biomass levels) are more prevalent than concerns over fisheries’ impacts on pinnipeds. This review provides a framework to further evaluate potential biological interactions between these pinniped populations and the commercial fisheries with which they occur.

Species Trends in Sport Fisheries, Monterey Bay, Calif., 1959-86

Three surveys spanning 28 years were examined for changes in species caught by recreational fishermen from small boats (skiffs) and commercial passenger fishing vessels (CPFV's) in California's Monterey Bay region. As fishing effort increased, the catch of certain nearshore species of rockfish, Sebastes spp., declined. CPFV fishing was conducted farther from port and in deeper water to compensate for declining abundance while most skiffs remained in traditional areas close to port. The trend toward deeper water CPFV fishing has been interrupted only temporarily by increased availability of nearshore species. Life history characteristics of rockfish including residential behavior, variable recruitment, and natural longevity contribute to a vulnerability to localized overfishing for several species.

Patterns of orographic uplift in the Sierra Nevada and their relationship to upper-level atmospheric circulation

We examine monthly and seasonal patterns of precipitation across various elevations of the eastern Central Valley of California and the Sierra Nevada. A measure of the strength of the orographic effect called the “precipitation ratio” is calculated, and we separate months into four groups based on being wet or dry and having low or high precipitation ratios. Using monthly maps of mean 700-mb height anomalies, we describe the northern hemisphere mid-tropospheric circulation patterns associated with each of the four groups. Wet months are associated with negative height anomalies over the eastern Pacific, as expected. However, the orientation of the trough is different for years with high and low precipitation ratios. Wet months with high ratios typically have circulation patterns factoring a west-southwest to east-northeast storm track from around the Hawaiian Islands to the Pacific Northwest of the United States. Wet months with low precipitation ratios are associated with a trough centered near the Aleutians and a northwest to southeast storm track. Dry months are marked by anticyclones in the Pacific, but this feature is more localized to the eastern Pacific for months with low precipitation ratios than for those with high ratios. Using precipitation gauge and snow course data from the American River and Truckee-Tahoe basins, we determined that the strength of the orographic effect on a seasonal basis is spatially coherent at low and high elevations and on opposite sides of the Sierra Nevada crestline.

Ecological and economic consequences of hypoxia: Topic 2 Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico

In this report we have attempted to evaluate the ecological and economic consequences of hypoxia in the northern Gulf of Mexico. Although our initial approach was to rely on published accounts, we quickly realized that the body of published literature deahng with hypoxia was limited, and we would have to conduct our own exploratory analysis of existing Gulf data, or rely on published accounts from other systems to infer possible or potential effects of hypoxia. For the economic analysis, we developed a conceptual model of how hypoxia-related impacts could affect fisheries. Our model included both supply and demand components. The supply model had two components: (1) a physical production function for fish or shrimp, and (2) the cost of fishing. If hypoxia causes the cost of a unit of fishing effort to change, then this will result in a shift in supply. The demand model considered how hypoxia might affect the quality of landed fish or shrimp. In particular, the market value per pound is lower for small shrimp than for large shrimp. Given the limitations of the ecological assessment, the shallow continental shelf area affected by hypoxia does show signs of hypoxia-related stress. While current ecological conditions are a response to a variety of stressors, the effects of hypoxia are most obvious in the benthos that experience mortality, elimination of larger long-lived species, and a shifting of productivity to nonhypoxic periods (energy pulsing). What is not known is whether hypoxia leads to higher productivity during productive periods, or simply to a reduction of productivity during oxygen-stressed periods. The economic assessment based on fisheries data, however, failed to detect effects attributable to hypoxia. Overall, fisheries landings statistics for at least the last few decades have been relatively constant. The failure to identify clear hypoxic effects in the fisheries statistics does not necessarily mean that they are absent. There are several possibilities: (1) hypoxic effects are small relative to the overall variability in the data sets evaluated; (2) the data and the power of the analyses are not adequate; and (3) currently there are no hypoxic effects on fisheries. Lack of identified hypoxic effects in available fisheries data does not imply that effects would not occur should conditions worsen. Experience with other hypoxic zones around the globe shows that both ecological and fisheries effects become progressively more severe as hypoxia increases. Several large systems around the globe have suffered serious ecological and economic consequences from seasonal summertime hypoxia; most notable are the Kattegat and Black Sea. The consequences range from localized loss of catch and recruitment failure to complete system-wide loss of fishery species. If experiences in other systems are applicable to the Gulf of Mexico, then in the face of worsening hypoxic conditions, at some point fisheries and other species will decline, perhaps precipitously.

Cloning and expression of zebra fish ferroportin and investigating its influence on anemia

Iron is required for many microbes and pathogens for their survival and proliferation including Leishmania which cause leishmaniasis. Leishmaniasis is an increasingly serious infectious disease with a wide spectrum of clinical manifestations. These range from localized cutaneous leishmaniasis (CL) lesions to a lethal visceral form. Certain strains such as BALB/c mice fail to control L. major infection and develop progressive lesions and systemic disease. These mice are thought to be a model of non-healing forms of the human disease such as kala-azar or diffuse cutaneous leishmaniasis. Progression of disease in BALB/c mice has been associated with the anemia, in last days of their survival, the progressive anemia is considered to be one of the reasons of their death. Ferroportin (Fpn), a key regulator of iron homeostasis is a conserved membrane protein that exports iron across the duodenal enterocytes as well as macrophages and hepatocytes into the blood circulation. Fpn has also critical influence on survival and proliferation of many microorganisms whose growth is dependent upon iron, thus preparation of Fpn is needed to study the role of iron in immune responses and pathogenesis of micoorganisms. To prepare and characterize a recombinant ferroportin, total RNA was extracted from Indian zebrafish duodenum, and used to synthesize cDNA by RT-PCR. PCR product was first cloned in Topo TA vector and then subcloned into the GFP expression vector pEGFP–N1. The final resulted plasmid (pEGFP-ZFpn) was used for expression of FPN-EGFP protein in Hek 293T cells. The expression was confirmed by fluorescence microscopy and flow cytometery. Recombinant Fpn was further characterized by submission of its predicted amino acid sequences to the TMHMM V2.0 prediction server (hidden Markov model), NetOGlyc 3.1 server and NetNGlyc 3.1 server. Data emphasised that obtained Fpn from indian zebrafish contained eight transmembrane domains with N- and C-termini inside the cytoplasm and harboured 78 mucin-type glycosylated amino acid. The results indicate that the prepared and characterized recombinant Fpn protein has no membrane topology difference compared to other Fpn described by other researcher. Our next aim was to deliver recombinant plasmid (pEGFP-ZFpn) to entrocyte cells. However, naked therapeutic genes are rapidly degraded by nucleases, showing poor cellular uptake, nonspecificity to the target cells, and low transfection efficiency. The development of safe and efficient gene carriers is one of the prerequisites for the success of gene therapy. Chitosan and alginate 139 polymers were used for oral gene carrier because of their biodegradability, biocompatibility and their mucoadhesive and permeability-enhancing properties in the gut. Nanoparticles comprising Alginate/Chitosan polymers were prepared by pregel preparation method. The resulting nanoparticles had a loading efficiency of 95% and average size of 188 nm as confirmed by PCS method and SEM images had showed spherical particles. BALB/c mice were divided to three groups. The first and second group were fed with chitosan/alginate nanoparticles containing the pEGFP-ZFpn and pEGFP plasmid, respectively (30 μgr/mice) and the third group (control) didn’t get any nanoparticles. The result showed BALB/c mice infected by L.major, resulted in higher hematocryte and iron level in pEGFP-ZFpn fed mice than that in other groups. Consentration of cytokines determined by ELISA showed lower levels of IL-4 and IL-10 and higher levels of IFN-γ/IL-4 and IFN-γ/IL-10 ratios in pEGFP-ZFpn fed mice than that in other groups. Morover more limited increase of footpad thickness and significant reduction of viable parasites in lymph node was seen in pEGFP-ZFpn fed mice. The results showed the first group exhibited a highr hematocryte and iron compared to the other groups. These data strongly suggests the in vivo administration of chitosan/alginate nanoparticles containing pEGFP-ZFpn suppress Th2 response and may be used to control the leishmaniasis .