A Petrographic and Mineralogical Study of Volcanic Rocks from the Mayaxueshan Area, North Qilian Fold Belt, NW China

The Ordovician volcanic rocks in the Mayaxueshan area have been pervasivelyaltered or metamorphosed and contain abundant secondary minerals such as albite, chlorite, epidote,prehnite, pumpellyite, actinolite, titanite, quartz, and/or calcite. They were denoted as spilitesor spilitic rocks in terms of their petrographic features and mineral assemblages. The metamorphicgrades of the volcanic rocks are equivalent to that of the intercalated metaclastic rocks. Thisindicates that both the spilitic volcanic rocks and metaclastic rocks in the Mayaxueshan area haveformed as a result of Caledonian regional metamorphism. We suggest that the previously denotedspilitic rocks or altered volcanic rocks should be re-denoted as metabasalts or metabasaltic rocks.The metamorphic grade of the volcanic rocks increases with their age: prehnite-pumpellyite faciesfor the upper part of the Middle Ordovician volcanic rocks, prehnite-pumpellyite to lowergreenschist facies for the lower part of the Middle Ordovician volcanic rocks, and lower greenschistfacies for the Lower Ordovician volcanic rocks. The P-T conditions are estimated as T = 240 - 290deg C and P = 1.5-4.5 kbar for the lower part of the Middle Ordovician rocks, and T = approx 300 degC for the Lower Ordovician rocks. The variations of mineral assemblages occurring at differentdomains of the volcanic rocks were controlled by the variations of the effective bulk composition inthose domains during metamorphism. The geochemical characteristics of Mg-Al chromite in theMayaxueshan volcanic rocks are consistent with an origin of island arc environment.

Reproductive biology of female sawcheek scorpionfish,Brachypterois serrulata(Richardson,1846)(Teleostei;Scorpaenidae)from Visakhapatnam Coast,India

We examined the reproductive biology of sawcheek scorpionfish,Brachypterois serrulata,collected from Visakhapatnam fish landing center(fishing area covered 16.98°-20.20°N,82.19°-86.53°E).We studied the annual reproductive cycle,fecundity,size at first maturity,mode of spawning with periodical changes and histological preparations.Size distribution and size at sexual maturity were calculated as 108 mm TL for females.The mean gonado somatic index values of female increased rapidly from January to December,and reached its peak during January and February.The fecundity of the fish species is determined by the size and weight of the individuals.The fecundity varied from 1896 to 20,488,with an average of 5721.90 ova.

Fisheries monitoring: Perspectives from the United States

Fisheries monitoring in the United States exists in many forms and serves many functions due to geographically varying objectives,practices,technology,institutional structures,and funding.In the U.S and abroad,diverse catch methods commonly exist for the same stock,thus monitoring and reporting strategies need to be tailored to unique operational needs.Common management challenges include funding limitation,survey design,coverage,and implementation.We describe three innovative examples of fisheries monitoring in the United States.These stories of success and failure can inform the design and implementation of new monitoring pilots and aid crafting both regional and national policies.We explore the innovative vessel monitoring and electronic logbook practices across multiple sectors for Gulf of Mexico red snapper(Lutjanus campechanus).Then,we examine a unique monitoring program that produces critical,near real-time genetic and population surveys for sockeye salmon(Oncorhynchus nerka)in Bristol Bay,Alaska.Our final case study describes the many fishery-dependent and-independent data streams for American lobster(Homarus americanus)in New England.Across all monitoring cases exists an explicit focus on the most critical aspects of organism life history.We find strong cross-institutional working relationships and adept agency coordination are imperatives in instances of stocks occupying multiple state or federal boundaries.Our results suggest the most effective approaches address the unique data needs of a fishery,and for this,thorough understanding of both biological and socioeconomic aspects of the fishery is a prerequisite.Ultimately,the monitoring program should jointly incentivize compliance while promoting continued and evolving interaction between resources users,scientists,and management.

Daily activity rhythms, chronotypes, and risk-taking behavior in the signal crayfish

Consistent inter-individual differences in daily activity rhythms(i.e.,chronotypes)can have ecological consequences in determining access to food resources and avoidance of predators.The most common measure to characterize chronotypes in animals as well as humans is the onset of activity(i.e.,early or late chronotypes).However,daily activity rhythms may also differ in the relative amount of activity displayed at particular time periods.Moreover,chronotypes may also be linked to other consistent inter-individual differences in behavior(i.e.,personality),such as the propensity to take risks.Here,we used the signal crayfish Pacifastacus leniusculusto test the presence of chronotypes and risk-taking personality traits and a potential behavioral syndrome between these traits.We first exposed crayfish to 5 days of light-darkness to measure daily activity rhythms and then we applied a visual predator-simulating stimulus in 2 different contexts(neutral and food).Our results showed consistent(i.e.,across 5 days)inter-individual differences in the relative nocturnal activity displayed in the early and middle,but not in the late part of darkness hours.Moreover,while crayfish displayed inter-individual differences in risk-taking behavior,these were not found to be consistent across 2 contexts.Therefore,we were not able to formally test a behavioral syndrome between these 2 traits.In conclusion,our study provides the first evidence of chronotypes in the relative amount of activity displayed at particular time periods.This could be a valuable information for applied ecological aspects related to the signal crayfish,which is a major invasive species of freshwater ecosystems.