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Full-Text Articles in Life Sciences
Genetic Variation In The Timing Of Gonadal Maturation And Spawning Of The Eastern Oyster, Crassostrea Virginica (Gmelin), Bruce J. Barber, Susan E. Ford, Robert N. Wargo
Genetic Variation In The Timing Of Gonadal Maturation And Spawning Of The Eastern Oyster, Crassostrea Virginica (Gmelin), Bruce J. Barber, Susan E. Ford, Robert N. Wargo
VIMS Articles
The gonadal cycles of four groups of eastern oysters, Crassostrea virginica (Gmelin), including native stocks collected that year and inbred strains (reared in Delaware Bay for 5-6 generations) from both Long Island Sound and Delaware Bay, were compared in Delaware Bay in 1987. Inbred strains resembled their respective native stocks; both Long Island groups initiated gonadal development and spawning about one month earlier and spawned over a shorter duration than both Delaware Bay groups. Analysis of covariance revealed that the effect of time on gonadal development was statistically different (P I 0.05) for all between-location group comparisons, but not for …
Reproduction, Age And Growth, And Movements Of The Gulf Butterfish Peprilus-Burti, Michael D. Murphy, Mark E. Chittenden
Reproduction, Age And Growth, And Movements Of The Gulf Butterfish Peprilus-Burti, Michael D. Murphy, Mark E. Chittenden
VIMS Articles
Collections were made for gulf butterfish Peprilus burti along a cross-shelf transect at depths of 5-100 m in the Gulf of Mexico off Texas from October 1977 to July 1980. Butterfish mature at 100-160 mm fork length as they approach age I. Spawning occurs primarily from September through May, but length frequencies indicate it concentrates, or is most successful, in distinct "Winter" (late January-mid-May) and "Fall" (early September-late October) periods that coincide with downcoast, alongshore currents (toward Mexico). Gonad data and persistence of small fish indicate spawning in winter, but at a low level. Spawning probably occurs offshore and upcoast …
Effect Of Neutral Red Stain On Settlement Ability Of Oyster Pediveligers, Crassostrea Virginica, Patrick Baker
Effect Of Neutral Red Stain On Settlement Ability Of Oyster Pediveligers, Crassostrea Virginica, Patrick Baker
VIMS Articles
The effect of neutral red stain on the settlement of oyster Crassostrea virginica (Gmelin) pediveligers was examined. Larvae were offered two types of substrate: oyster shell and acetate sheets. Settlement was measured as the proportion of pediveligers settled after 24 hours and analyzed with two-factor ANOV A. Staining did not significantly affect settlement, although settlement onto acetate was much lower than onto oyster shell.
Swimming Rate And Responses Of Larvae Of Three Mactrid Bivalves To Salinity Discontinuities, R Mann, Bm Campos, Mw Luckenbach
Swimming Rate And Responses Of Larvae Of Three Mactrid Bivalves To Salinity Discontinuities, R Mann, Bm Campos, Mw Luckenbach
VIMS Articles
Straight-hinge, umbo and pediveliger larvae of the mactrid bivalves Spisula solidissima, Mulinia lateralis and Rangia cuneata were exposed to intense salinity discontinuities of 0, 5, 10 and 15 parts per thousand in vertically oriented swimming chambers. Larvae concentrated in the region of highest gradient, i.e. at the salinity discontinuity, regardless of species, stage of development or larval brood. S. solidisima larvae, initially swimming at 30 parts per thousand salinity, crossed discontinuities of both 5 and 10 parts per thousand but not of 15 parts per thousand. M. lateralis larvae, initially swimming at 25 parts per thousand salinity, also crossed a …
A Larva Of The Poorly Known Serranid Fish Jeboehlkia-Gladifer (Teleostei, Serranidae, Epinephelinae), Carol C. Baldwin, G. David Johnson
A Larva Of The Poorly Known Serranid Fish Jeboehlkia-Gladifer (Teleostei, Serranidae, Epinephelinae), Carol C. Baldwin, G. David Johnson
VIMS Articles
No abstract provided.
Gametogenic Cycle Of Sea Scallops (Placopecten Magellanicus (Gmelin, 1791)) In The Mid-Atlantic Bight, A. C. Schmitzer, W. D. Dupaul, J. E. Kirkley
Gametogenic Cycle Of Sea Scallops (Placopecten Magellanicus (Gmelin, 1791)) In The Mid-Atlantic Bight, A. C. Schmitzer, W. D. Dupaul, J. E. Kirkley
VIMS Articles
Gametogenesis of the sea scallop, Placopecten magellanicus , from 3 areas within the mid-Atlantic Bight was examined from January to December 1988. Histological and morphometric quantification of gonadal tissue concluded that a semiannual gametogenic cycle was characteristic of sea scallops from the mid-Atlantic Bight. The majority of spawning occurred in May and November. Gonadal development in spring comprised a longer period of time and resulted in greater fecundity than in fall. Differences were found in the timing and magnitude of the semiannual gametogenic processes between sex, area, and water depth within the study area. Varying temperature patterns between the mid-Atlantic …
Potential Predation On Fish Eggs By The Lobate Ctenophore Mnemiopsis-Leidyi Within And Outside The Chesapeake Bay Plume, John J. Govoni, John E. Olney
Potential Predation On Fish Eggs By The Lobate Ctenophore Mnemiopsis-Leidyi Within And Outside The Chesapeake Bay Plume, John J. Govoni, John E. Olney
VIMS Articles
In Chesapeake Bay in June, the predatory lobate ctenophore Mnemiopsis leidyi and the eggs of the bay anchovy Anchoa mitchilli typically reach seasonal and localized abundance together. When examined at small vertical (1-3m), horizontal (10-50m), and temporal (6-hour) scales, the co-occurrence of M. leidyi and fish eggs (32.3-74.2% of which were A. mitchilli) was greatest in the northern reaches of the mouth of Chesapeake Bay, where the water column was stratified. Stratification to the south was effected by the Chesapeake Bay plume. With estimates of ctenophore clearance rate reported elsewhere and observed densities of ctenophores and fish eggs, potential predation …
Distribution Of Striped Bass Morone-Saxatilis (Walbaum) Eggs And Larvae In Major Virginia Rivers, George C. Grant, John E. Olney
Distribution Of Striped Bass Morone-Saxatilis (Walbaum) Eggs And Larvae In Major Virginia Rivers, George C. Grant, John E. Olney
VIMS Articles
Spring ichthyoplankton surveys in the tidal freshwater reaches of Virginia rivers were used to document the temporal and spatial occurrence of spawning by striped bass Morone saxatilis (Walbaum). Single river systems were intensively surveyed in 1980 (York River system), 1981 (James River system), and 1982 (Rappahannock River). In spring 1983, all three river systems were sampled at approximately weekly intervals. Some spawning occurred in all years, including those yielding poor year-classes (1980 and 1981). Spawning occurred largely within the first 40 km of tidal freshwater in major rivers, except when drought conditions displaced spawning upstream in advance of encroaching saltwater. …
Automated Enumeration By Computer Digitization Of Age-O Weakfish Cynoscion-Regalis Scale Circuli, Stephen T. Szedimayer, Margaret M. Szedimayer, Michael E. Sieracki
Automated Enumeration By Computer Digitization Of Age-O Weakfish Cynoscion-Regalis Scale Circuli, Stephen T. Szedimayer, Margaret M. Szedimayer, Michael E. Sieracki
VIMS Articles
No abstract provided.
Density-Dependent Foraging And Mutual Interference In Blue Crabs Preying Upon Infaunal Clams, Ra Mansour, Rom Lipcius
Density-Dependent Foraging And Mutual Interference In Blue Crabs Preying Upon Infaunal Clams, Ra Mansour, Rom Lipcius
VIMS Articles
Predator-prey dynamics between the blue crab Callinectes sapidus and an infaunal soft-shelled clam, Macoma balthica, were examined in laboratory experiments to assess the joint effects of varying predator and prey densities upon predator foraging rates and prey survival. A full-factorial experimental design involved 2 prey densities (4 and 16 clams m-2) and 3 predator densities (1, 2 and 4 crabs m-2) with 6 trials per treatment combination. Blue crabs exhibited density-dependent foraging under all conditions: proportionally more clams were consumed at the higher clam density. Furthermore, at the higher crab densities mutual interference was evident in the incidence of wounds …
Mass Migration Of Juvenile Queen Conch (Strombus Gigas) In The Bahamas, Romauld Lipcius, Alan Stoner, Livingston S. Marshall Jr., Ana T. Bardales
Mass Migration Of Juvenile Queen Conch (Strombus Gigas) In The Bahamas, Romauld Lipcius, Alan Stoner, Livingston S. Marshall Jr., Ana T. Bardales
VIMS Articles
We summarize the available information for a mass migration of juvenile queen conch in the Bahamas. The migration was observed from April through June, 1987 over a large seagrass meadow and adjacent sand-algal plain at 1-5 m depths. Component aggregations ranged from 40-190 m in length and 1-6 m in width, with a maximum density of 319 conch/m2. Migrants averaged 101 mm in shell length, which ranged from 67-145 mm, and were of a similar size as non-migrants in the area The migration was directional towards ebb tidal flow and moved approximately 250 m, at rates of 2.7 - 4.8 …
Larvae Of Diploprion-Bifasciatum, Belonoperca-Chabanaudi And Grammistes-Sexlineatus (Serranidae, Epinephelinae) With A Comparison Of Known Larvae Of Other Epinephelines, Cc Baldwin, Gd Johnson, Pl Colin
Larvae Of Diploprion-Bifasciatum, Belonoperca-Chabanaudi And Grammistes-Sexlineatus (Serranidae, Epinephelinae) With A Comparison Of Known Larvae Of Other Epinephelines, Cc Baldwin, Gd Johnson, Pl Colin
VIMS Articles
Morphology is described for larvae of two species of the epinepheline serranid tribe Diploprionini and one of the tribe Grammistini, and known larvae of other epinephelines are compared. Early stage eggs and development of larvae of Diploprion bifasciatum are described from 144 laboratory-reared specimens, and postflexion larvae of Belonoperca chabanaudi are described from wild-caught specimens. Fourmanoir's (1976) description of postlarval Grammistes sexlineatus is modified and expanded. The second and third dorsal-fin spines of larval D. bifasciatum are remarkably elongate, reaching lengths many times that of the body. These spines are thin and flexible, and each is encased in a sheath …
Parasite Fauna Of 3 Species Of Antarctic Whales With Reference To Their Use As Potential Stock Indicators, Murray D. Dailey, Wolfgang K. Vogelbein
Parasite Fauna Of 3 Species Of Antarctic Whales With Reference To Their Use As Potential Stock Indicators, Murray D. Dailey, Wolfgang K. Vogelbein
VIMS Articles
Seventeen species of parasites representing the Cestoda, Nematoda, Acanthocephala, and Crustacea are reported from three species of Antarctic whales. Thirty-five sei whales Balaenoptera borealis, 106 minke whales B. acutorostrata, and 35 sperm whales Physeter catodon were examined from latitudes 30-degrees to 64-degrees-S, and between longitudes 106-degrees-E to 108-degrees-W, during the months of November to March 1976-77. Collection localities and regional helminth fauna diversity are plotted on distribution maps. Antarctic host-parasite records from B. borealis, B. acutorostrata, and P. catodon are updated and tabulated by commercial whaling sectors. The use of acanthocephalan parasites of the genus Corynosoma as potential Antarctic sperm …
Chaetognatha From The Central And Southern Middle Atlantic Bight - Species Composition, Temperature-Salinity Relationships, And Interspecific Associations, George C. Grant
VIMS Articles
Eighteen species of chaetognaths were identified from shelf waters in the Middle Atlantic Bight. Species composition in the water column and the hyponeuston was nearly identical, but the percent frequencies of the more common cold-temperate species were generally lower in surface collections. Mean surface salinity, weighted for abundance of individual chaetognath species in the hyponeuston collections, varied from 32.6 and 32.8 parts per thousand for the coastal- and estuarine-inhabiting Sagitta tenuis and Parasagitta elegans, to 34.8 and 34.9 for the offshore Pterosagitta draco and Krohnitta pacifica. Weighted mean temperatures ranged from below 14-degrees-C for Mesosagitta minima, P. elegans, and Serratosagitta …
Susceptibility Of Diploid And Triploid Pacific Oysters, Crassostrea Gigas (Thunberg, 1793) And Eastern Oysters, Crassostrea Virginica (Gmelin, 1791), To Perkinsus Marinus, Judith A. Meyers, Eugene M. Burreson, Bruce J. Barber, Roger L. Mann
Susceptibility Of Diploid And Triploid Pacific Oysters, Crassostrea Gigas (Thunberg, 1793) And Eastern Oysters, Crassostrea Virginica (Gmelin, 1791), To Perkinsus Marinus, Judith A. Meyers, Eugene M. Burreson, Bruce J. Barber, Roger L. Mann
VIMS Articles
The susceptibility of Pacific oysters, Crassostrea gigas, to the oyster parasite Perkinsus marinus was compared with that of eastern oysters, Crassostrea virginica, in two separate experiments. Experiments were conducted in flow-through seawater systems with quarantined effluent. Oysters were challenged by addition of infective P. marinus. In the first experiment, which used only diploid oysters, 40% of C. gigas became infected with P. marinus after 83 days compared to 100% of C. virginica. In the second experiment, which examined susceptibility of diploid and triploid individuals of both species, prevalence was high in all groups after 60 days. In …
Temporal Variations In Spawning Behavior Of Sea Scallops, Placopecten Magellanicus (Gmelin, 1791), In The Mid-Atlantic Resource Area, James E. Kirkley, William D. Dupaul
Temporal Variations In Spawning Behavior Of Sea Scallops, Placopecten Magellanicus (Gmelin, 1791), In The Mid-Atlantic Resource Area, James E. Kirkley, William D. Dupaul
VIMS Articles
Interannual variation in spawning of Placopecten magellanicus (Gmelin) may be important to management agencies concerned with maximizing yield-per-recruit via restrictions on meat counts or temporal restrictions on catch and effort. In this study, temporal patterns in the spawning behavior of sea scallops in the Mid-Atlantic resource area for the period April 1987-April 1991 are analyzed using conventional time-series methods. Biannual spawning was found to be characteristic of sea scallops in the Mid-Atlantic resource area but was also found to be erratic in the timing, duration, and magnitude. The spring spawning event was the more predictable and dominant spawning event. The …
The Decline Of The Virginia Oyster Fishery In Chesapeake Bay Considerations For Introduction Of A Non-Endemic Species, Crassostrea Gigas (Thunberg, 1793), Roger L. Mann, Eugene M. Burreson, Patrick K. Baker
The Decline Of The Virginia Oyster Fishery In Chesapeake Bay Considerations For Introduction Of A Non-Endemic Species, Crassostrea Gigas (Thunberg, 1793), Roger L. Mann, Eugene M. Burreson, Patrick K. Baker
VIMS Articles
The Chesapeake Bay oyster fishery for Crassostrea virginica (Gmelin) is in a state of continuing decline. Two diseases, Haplosporidium nelsoni and Perkinsus marinus have effectively eliminated oysters from many sections of the Bay. Despite over 30 years of disease activity the native oysters have developed neither tolerance nor absolute resistance to these diseases, and do not exhibit any recovery in disease endemic areas in Virginia. Repletion programs have completely failed to recover to permanent production areas lost to disease. Present fishery management activities are limited to a controlled retreat away from the disease in an arena where disease distribution is …
Sterile Triploid Crassostrea Virginica (Gmelin, 1791) Grow Faster Than Diploids But Are Equally Susceptible To Perkinsus Marinus, Bruce J. Barber, Roger L. Mann
Sterile Triploid Crassostrea Virginica (Gmelin, 1791) Grow Faster Than Diploids But Are Equally Susceptible To Perkinsus Marinus, Bruce J. Barber, Roger L. Mann
VIMS Articles
Growth, tolerance of Perkinsus marinus, and gametogenesis of diploid and triploid Eastern oysters, Crassostrea virginica (Gmelin, 1791) were compared in the York River, Virginia between June 1989 and November 1990. Triploid oysters had significantly greater mean shell height (P ,a;; 0.02) and whole weight (P ,a;; 0.005) than diploid oysters throughout the study period. In November 1990, triploids had significantly greater mean dry tissue weight (P ,a;; 0.006) than diploids. On average, triploid oysters reached commercial size (63.5 mm) 5 months before diploid oysters. Diploid and triploid groups became similarly infected with P. marinus during summer 1990. Prevalences reached 96% …