scholarly journals The Reproductive Biology of the Softshell Clam,Mya arenaria, in Ireland, and the Possible Impacts of Climate Variability

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
M. E. Cross ◽  
S. Lynch ◽  
A. Whitaker ◽  
R. M. O'Riordan ◽  
S. C. Culloty
Keyword(s):  
North America ◽  
Climate Variability ◽  
Histological Examination ◽  
Reproductive Biology ◽  
Mya Arenaria ◽  
Eastern North America ◽  
Fertilisation Success ◽  
Male Ratio ◽  
The Mean ◽  
Softshell Clam

Little is known about the biology of the softshell clam in Europe, despite it being identified as a potential species to culture for food in the future. Monthly samples of the softshell clam,Mya arenaria, were collected intertidally from Co. Wexford, Ireland, over a period of sixteen months. The mean weight of sampled individuals was74±4.9 g and mean length was8.2±0.2 cm. Histological examination revealed a female-to-male ratio of 1 : 1.15. In 2010,M. arenariaat this site matured over the summer months, with both sexes either ripe or spawning by August. A single spawning event was recorded in 2010, completed by November. Two unusually cold winters, followed by a warmer-than-average spring, appear to have affectedM. arenariagametogenesis in this area, potentially affecting the time of spawning, fertilisation success, and recruitment of this species. No hermaphrodites were observed in the samples collected, nor were any pathogens observed. Timing of development and spawning is compared with the coasts of eastern North America and with other European coasts.

Climate variability and the timing of spring raptor migration in eastern North America

2015 ◽  
Vol 47 (2) ◽  
pp. 208-218 ◽  
Author(s):  
Alexis R. Sullivan ◽  
David J. Flaspohler ◽  
Robert E. Froese ◽  
Daena Ford
Keyword(s):  
North America ◽  
Climate Variability ◽  
Eastern North America

Chemosystematic studies in the genus Pinus. IV. Leaf oil composition and geographic variation in jack pine of eastern North America

1982 ◽  
Vol 60 (12) ◽  
pp. 2762-2769 ◽  
Author(s):  
Martin S. Lapp ◽  
E. von Rudloff
Keyword(s):  
North America ◽  
Jack Pine ◽  
Bornyl Acetate ◽  
Eastern North America ◽  
Gas Liquid Chromatography ◽  
Oil Composition ◽  
Leaf Oil ◽  
Euclidean Distances ◽  
The Mean ◽  
Individual Trees

Leaf terpenes of 420 jack pines from 43 sites (Petawawa provenances) in eastern North America were analyzed by gas–liquid chromatography (GLC). In most trees the major components were α-pinene, β-pinene, myrcene, car-3-ene, limonene, β-phellandrene, and bornyl acetate. Eighteen other monoterpenes were identified and 13 sesquiterpenes were characterized by their spectral properties and GLC retention times. These data were analyzed by centroid cluster analysis of the mean-squared Euclidean distances, which showed that jack pine is a diverse species of two major terpene types with eight minor types and a few outlying individual trees. With the exception that the minor clusters and outliers tend to occur at the fringes of the jack pine range, there is no obvious geographic pattern to these clusters.

scholarly journals Multiproxy evidence of Holocene climate variability from estuarine sediments, eastern North America

2005 ◽  
Vol 20 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
T. M. Cronin ◽  
R. Thunell ◽  
G. S. Dwyer ◽  
C. Saenger ◽  
M. E. Mann ◽  
...  
Keyword(s):  
North America ◽  
Climate Variability ◽  
Estuarine Sediments ◽  
Eastern North America ◽  
Holocene Climate

Biogeography of resistance to paralytic shellfish toxins in softshell clam, Mya arenaria (L.), populations along the Atlantic coast of North America

2018 ◽  
Vol 202 ◽  
pp. 196-206 ◽  
Author(s):  
Jennifer M. Phillips ◽  
V. Monica Bricelj ◽  
Maren Mitch ◽  
Robert M. Cerrato ◽  
Scott MacQuarrie ◽  
...  
Keyword(s):  
North America ◽  
Atlantic Coast ◽  
Mya Arenaria ◽  
Shellfish Toxins ◽  
Paralytic Shellfish Toxins ◽  
Paralytic Shellfish ◽  
Softshell Clam

Reproductive biology of the large freshwater crayfish Cherax cainii in south-western Australia

2003 ◽  
Vol 54 (5) ◽  
pp. 597 ◽  
Author(s):  
Stephen J. Beatty ◽  
David L. Morgan ◽  
Howard S. Gill
Keyword(s):  
Histological Examination ◽  
Reproductive Biology ◽  
Western Australia ◽  
Ovarian Development ◽  
Reproductive Potential ◽  
Stage Iv ◽  
Gonadal Development ◽  
Freshwater Crayfish ◽  
Potential Fecundity ◽  
The Mean

The reproductive biology of Cherax cainii was studied in an impoundment dam in south-western Australia using histological examination of ovarian development (previous studies describing the reproductive biology of freshwater crayfish have relied solely on macroscopic descriptions of gonadal development). Spawning occurred between August and November and peaked in late August and September, with the percentage of berried females increasing from 50% in September to 96% in November before declining to 11% in December. Juveniles were released from berried females between late November and early December. Female gonads recovered dramatically after spawning with 81% of mature females possessing stage IV (maturing) gonads in March. The respective orbital carapace lengths at which 50 and 95% of C. cainii reached maturity were 32.1 and 37.9 mm for females, and 28.6 and 38.8 mm for males. The mean potential fecundity (i.e. number of mature ovarian oocytes prior to spawning) was 443 compared with 286 for the mean effective fecundity (i.e. number of pleopodal eggs, embryos or juveniles following spawning). The fact that the full ovarian reproductive potential of C. cainii is not attained is probably due to the limitation of egg attachment space on the pleopods.

THE WINTER MOTH, OPEROPHTERA BRUMATA (LEPIDOPTERA: GEOMETRIDAE), A NEW PEST ATTACKING APPLE ORCHARDS IN NOVA SCOTIA, AND ITS COLDHARDINESS

1967 ◽  
Vol 99 (8) ◽  
pp. 829-834 ◽  
Author(s):  
A. W. MacPhee
Keyword(s):  
Nova Scotia ◽  
North America ◽  
Freezing Point ◽  
Maximum Density ◽  
Eastern North America ◽  
Operophtera Brumata ◽  
Winter Moth ◽  
Rate Of Increase ◽  
The Mean ◽  
Selective Chemical

AbstractThe winter moth, Operophtera brumata (L.), a recent introduction to North America, is a serious pest of apple in Nova Scotia. Natural controls, mainly the parasite Cyzenis albicans (Fall.), reduce its rate of increase, and selective chemical controls are applied to maintain economic levels. Its maximum density is limited by its food supply in neglected orchards. The mean freezing point of O. brumata winter eggs is −31°F. Egg mortality increases appreciably with increase of duration of exposure to low temperatures in the −26°F to −34°F vulnerable range. It seems probable that winter moth will continue to spread slowly over much of Eastern North America.

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