The Gastropod Thais haemastoma in Georgia: T. h. floridana or T. h. canaliculata?

In the southeastern United States, the snail Thais haemastoma has traditionally been subdivided into two subspecies according to the snail‘s locale, size of shell, number and size of spines, and depth of suture. Only Thais haemastoma floridana is supposed to occur in Georgia; since Thais haemastoma canaliculata is supposedly restricted to the Gulf of Mexico region. In Georgia, specimens fitting the description of both subspecies are common. The author concurs with the conclusions of Butler (1953) and Gunter (1979) in that the subspecies nomenclature is invalid and that they are merely ecological variants

Growth and Production of the Dwarf Surf Clam Mulinia lateralis (Say 1822) in a Georgia Estuary

The bivalve Mulinia lateralis is a dominant member of estuarine benthos, but its presence and abundance in Georgia estuarine waters is sporadic over time. Recruitment and production was monitored from 1977 through 1981 at three inner and one outer more saline ( \u3e 18 ppt) areas of Wassaw Sound. Until the winter of 1981, Mulinia lateralis was absent or at very low densities. Significant settlement occurred in January 1981 when densities in the outer sound reached as high as 63,000 individuals • m-2). The clam was more abundant in sandy mud (x̄ = 10,161 • m-2) than mud (x̄=277 • m-2) or sand (x̄=263 • m-2).Cohort production varied from 0.3 g dry wt • m-2 • 4 months-1 in the inner sound to 325 g dry wt • m-2 • 7 months-1 in the outer Sound, with the mean biomass ranging from 0.6 to 513 g dry wt • m-2, respectively. When present, Mulinia lateralis contributes significantly to benthic production available to commercially valuable fish and crabs. That this food resource is annually and seasonally episodic could contribute to year-to-year fluctuations in production of species preying on benthos

Preliminary Observations on Oyster Pearl Net Cultivation in Coastal Georgia

This work reports on survivorship and growth rates attained by a transplanted northern stock of Crassostrea virginica (x̄ = 15 mm) tested at various densities in pearl nets in sheltered and exposed sites in coastal Georgia (October 1985 - August 1986). Monthly growth increments ranged from 4.5 to 5.1 mm (shell height). One hundred oysters per net was the optimum stocking density. One hundred percent mortality was suffered at both sites during June - August (probably due to Perkinsus marinus). Current growth rates indicate a growth to market size time of 18 months or less for 15 mm seed grown in pearl nets. However, pearl net cultivation is shown to have serious drawbacks as an oyster grow-out system for coastal Georgia and alternative systems are discussed

The Effects of Cage Mesh Size and Tidal Level Placement on the Growth and Survival of Clams, Mercenaria mercenaria (L.) and Spisula solidissima (Dillwyn), in the Coastal Waters of Georgia

This work reports on the effects of cage mesh size and tidal level placement upon the growth and survival of the hard clam, Mercenarla mercenaria (L.), and the surf clam, Spisula solidissima (Dillwyn), In the coastal waters of Georgia. Surf clams (N = 50 per cage) and hard clams (N = 100 per cage) were each planted in replicated (N = 2) cages constructed of 3 mm, 6 mm, 13 mm and 19 mm mesh vexar plastic at various tidal levels. Cages were deployed by partial burial at the mean and the spring low water marks. At termination of the surf clam trial (6 months), there were no significant differences in survival determined for clams planted in different mesh cages at either tidal level or for clams grown in equivalent mesh size cages between tidal levels. There were significant differences In clam size with surf clams at the spring low water growing significantly larger than those at the mean low water mark. There were also significant differences In surf clam growth between different mesh size cages. Surf clams from 6 mm cages were smaller than those from other cages, while the largest clams reared were in the 13 mm and 19 mm mesh cages. Hard clam trials (15 month duration) illustrated that cage mesh size induced significant differences in survlval of hard clams. Significantly fewer clams survived In 19 mm mesh cages than in cages of smaller mesh at both tidal levels. No significant differences in hard clam survival were detected among other mesh sizes nor between tidal levels; neither were significant differences between tidal levels determined for equivalent mesh sizes. Significant differences in hard clam growth were determined for clams grown in different mesh size cages and between tidal levels. Clam growth was greater at the spring low water mark. Clams grew larger in 3 mm mesh cages, least In 13 mm mesh cages with no significant differences In growth in the 6 and 19 mm mesh cages. Statistical analyses (t-tests) Illustrated differences in clam growth among replicates at the spring low water mark. Growth may have been reduced in one set of cages as a result of cage excavation by currents. In Georgia, hard and surf clam growth was found to be dependent upon cage mesh size. Clam survival was Independent of cage mesh size as long as the initial size of the seed animals was greater than the mesh size of the cage

Lethal Parasites in Oysters from Coastal Georgia with Discussion of Disease and Management Implications

Extensive mortalities of oysters, Crassostrea virginica, occurred from 1985 through 1987 in coastal waters of Georgia. Fluid thioglycolate cultures of oysters collected from 16 of 17 locations revealed infections by the apicomplexan parasite Perkinsus marinus. An ascetosporan parasite, Haplosporidium nelsoni, was also observed in histopathological examination of oysters from 4 of the locations. While the range of H. nelsoni currently is recognized as the east coast of the United States from Maine to Florida, this is the first report of the parasite in Georgia waters. This paper documents the occurrence of these two lethal parasites in oysters from coastal waters of Georgia, along with potential disease and management implications. Results of an earlier independent and previously unpublished survey are also discussed which document the presence of P. marinus in Georgia as early as 1966

Gametogenic Cycle in the Non-Native Atlantic Surf Clam, Spisula solidissima (Dillwyn, 1817), Cultured in the Coastal Waters of Georgia

This study describes the gametogenic cycle of the Atlantic surf clam, Spisula solidissima (Dillwyn, 1817), cultured from fall to spring in the coastal waters of Georgia, where it is non-native. Early active stages of gametogenic development began in November, with the majority (83%) of the animals in the early active stage by December. Gonadal indices increased to late active stages by March, with ripe individuals present in April. Spawning commenced in May and continued into June. Sex ratio (0.48 female to 1.00 male) was significantly unequal. Results of this study indicate that clams achieved sexual maturity and spawned when cultured in the coastal waters of Georgia. An aquacultural enterprise in Georgia could obtain broodstock for the production of the following fall\u27s seed crop from the prior year\u27s growout field planted clams before their spring harvest

Gametogenic Cycle in the Non-Native Atlantic Surf Clam, Spisula solidissima (Dillwyn, 1817), Cultured in the Coastal Waters of Georgia

This study describes the gametogenic cycle of the Atlantic surf clam, Spisula solidissima (Dillwyn, 1817), cultured from fall to spring in the coastal waters of Georgia, where it is non-native. Early active stages of gametogenic development began in November, with the majority (83%) of the animals in the early active stage by December. Gonadal indices increased to late active stages by March, with ripe individuals present in April. Spawning commenced in May and continued into June. Sex ratio (0.48 female to 1.00 male) was significantly unequal. Results of this study indicate that clams achieved sexual maturity and spawned when cultured in the coastal waters of Georgia. An aquacultural enterprise in Georgia could obtain broodstock for the production of the following fall\u27s seed crop from the prior year\u27s growout field planted clams before their spring harvest

Bulk Scale Factor at Very Early Universe

In this paper we propose a higher dimensional Cosmology based on FRW model and brane-world scenario. We consider the warp factor in the brane-world scenario as a scale factor in 5-dimensional generalized FRW metric, which is called as bulk scale factor, and obtain the evolution of it with space-like and time-like extra dimensions. It is then showed that, additional space-like dimensions can produce exponentially bulk scale factor under repulsive strong gravitational force in the empty universe at a very early stage.Comment: 7 pages, October 201

Land Boundary Conditions for the Goddard Earth Observing System Model Version 5 (GEOS-5) Climate Modeling System: Recent Updates and Data File Descriptions

The Earths land surface boundary conditions in the Goddard Earth Observing System version 5 (GEOS-5) modeling system were updated using recent high spatial and temporal resolution global data products. The updates include: (i) construction of a global 10-arcsec land-ocean lakes-ice mask; (ii) incorporation of a 10-arcsec Globcover 2009 land cover dataset; (iii) implementation of Level 12 Pfafstetter hydrologic catchments; (iv) use of hybridized SRTM global topography data; (v) construction of the HWSDv1.21-STATSGO2 merged global 30 arc second soil mineral and carbon data in conjunction with a highly-refined soil classification system; (vi) production of diffuse visible and near-infrared 8-day MODIS albedo climatologies at 30-arcsec from the period 2001-2011; and (vii) production of the GEOLAND2 and MODIS merged 8-day LAI climatology at 30-arcsec for GEOS-5. The global data sets were preprocessed and used to construct global raster data files for the software (mkCatchParam) that computes parameters on catchment-tiles for various atmospheric grids. The updates also include a few bug fixes in mkCatchParam, as well as changes (improvements in algorithms, etc.) to mkCatchParam that allow it to produce tile-space parameters efficiently for high resolution AGCM grids. The update process also includes the construction of data files describing the vegetation type fractions, soil background albedo, nitrogen deposition and mean annual 2m air temperature to be used with the future Catchment CN model and the global stream channel network to be used with the future global runoff routing model. This report provides detailed descriptions of the data production process and data file format of each updated data set