Temporal Variation in Shell Growth Rate of CockleAnadara granosain Relation with its Reproductive Cycle

2017 ◽  
Vol 36 (1) ◽  
pp. 69-78
Author(s):  
M. Reza Mirzaei ◽  
Aileen Tan Shau Hwai ◽  
Munawar Khalil
Keyword(s):  
Growth Rate ◽  
Temporal Variation ◽  
Reproductive Cycle ◽  
Shell Growth ◽  
Shell Growth Rate

Variations de la croissance de la coquille, et de la structure d'âge du bivalve Macoma balthica (L.) dans une population intertidale de l'estuaire du Saint-Laurent (Québec)

1987 ◽  
Vol 65 (8) ◽  
pp. 1906-1916 ◽  
Author(s):  
Bruno Vincent ◽  
Claude Brassard ◽  
Michel Harvey
Keyword(s):  
Growth Rate ◽  
Water Level ◽  
Shell Growth ◽  
Macoma Balthica ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
Tidal Level ◽  
Lawrence Estuary ◽  
Mean Water Level ◽  
Shell Growth Rate

Greater annual shell growth rate and increased mortality are observed in Macoma balthica (L.) with an increase of immersion time in the intertidal zone of the St. Lawrence estuary. There is also a greater annual growth rate in tidal pools, and sediment temperature alone may explain spatial variations in spring and annual growth. Reciprocal transfers of specimens between upper (0.8 m above mean water level) and lower (1.2 m below mean water level) tidal level result in enhanced shell growth for individuals of the upper level transferred to the lower level. There is no corresponding change of shell growth rate for individuals of the lower level. This genotypic difference in short-term physiological responses to environmental changes may be the result of different selective pressures associated with habitat temporal heterogeneity. An opportunistic strategy is associated with the more terrestrial and unpredictable environment (upper tidal level) and a more specialized strategy accompanied by low phenotypic variability is associated with the more marine and stable environment (lower tidal level).

Isotopic partitioning between scallop shell calcite and seawater: effect of shell growth rate

2002 ◽  
Vol 66 (10) ◽  
pp. 1727-1737 ◽  
Author(s):  
Richard Owen ◽  
Hilary Kennedy ◽  
Christopher Richardson
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Scallop Shell ◽  
Shell Growth Rate

The influence of shell growth rate on striae deposition in the scallop Pecten maximus

2002 ◽  
Vol 82 (4) ◽  
pp. 621-623 ◽  
Author(s):  
Richard Owen ◽  
Christopher Richardson ◽  
Hilary Kennedy
Keyword(s):  
Growth Rate ◽  
Reliable Method ◽  
Seasonal Pattern ◽  
Shell Growth ◽  
Shell Height ◽  
Pecten Maximus ◽  
Growth Cycles ◽  
North Wales ◽  
Shell Growth Rate ◽  
The Relationship

The relationship between shell growth rate and striae deposition was investigated in a field study in which groups of juvenile scallops, Pecten maximus, (Pectinidae: Bivalvia) were deployed for monthly periods over a year in the Menai Strait (North Wales). The number of striae deposited per day, inter-striae width (the increment of shell deposited between successive striae) and striae abundance (the number of striae deposited per mm of shell height) all correlated well with measured shell growth rates. During the winter months, when seawater temperatures were minimal (6°C), inter-striae width declined, whilst striae abundance increased, whereas during the summer when seawater temperatures were maximal (18°C), shell growth was rapid with maximum inter-striae width, resulting in a seasonal pattern of narrowly grouped, then widely spaced striae. This seasonal pattern in inter-striae width variation provides an accurate and reliable method for estimating the number of growth cycles and hence the age of P. maximus.

Temporal Variation in Growth Rate and Age at Maturity of Male Painted Turtles, Chrysemys picta

1993 ◽  
Vol 130 (2) ◽  
pp. 314 ◽  
Author(s):  
Nat B. Frazer ◽  
Judith L. Greene ◽  
J. Whitfield Gibbons
Keyword(s):  
Growth Rate ◽  
Temporal Variation ◽  
Chrysemys Picta ◽  
Age At Maturity ◽  
Painted Turtles

Ecophenotypic plasticity in shell growth direction of asari clam Ruditapes philippinarum

2021 ◽  
pp. 1-6
Author(s):  
Takeshi Tomiyama
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Shell Height ◽  
Growth Direction ◽  
Ruditapes Philippinarum ◽  
Shell Morphology ◽  
Individual Growth ◽  
Shell Size ◽  
Internal Factors ◽  
Suitable Habitats

Abstract Asari clam (or Manila clam) Ruditapes philippinarum is an important bivalve for local fisheries. This species exhibits a large variation in shell morphology, and the shell roundness tends to be greater in more unsuitable habitats. To test whether the increments in shell size parameters (length, height and width) were affected solely by environmental conditions or by internal factors such as initial shell shapes or growth rate, a field caging experiment was conducted at two different sites of unsuitable and suitable habitats in Matsukawaura Lagoon, Japan, where shell shapes of wild clams were significantly different between the habitats. In the experiment, clams were released from the two sites to the same site or to the other site and were re-collected after 3, 6 and 12 months of caging. Caged clams originating from unsuitable habitats and released to suitable habitats showed a reduction in shell height relative to shell length, while clams from suitable habitats introduced to unsuitable habitats showed marked increases in both shell height and width. Generalized linear mixed models suggested that the increase in shell height was affected largely by the release habitat (environment) whereas the increase in shell width was affected largely by the individual growth rate. These results suggest that marginal growths in shell height and width respond differently to external and internal factors of clams, resulting in plasticity in their shell shapes according to the environments to which they are translocated.

The Effects of Reduced Salinity on the Shell Growth of Small Mytilus Edulis

1984 ◽  
Vol 64 (1) ◽  
pp. 171-182 ◽  
Author(s):  
Patricia C. Almada-Villela
Keyword(s):  
Growth Rate ◽  
Mytilus Edulis ◽  
High Salinity ◽  
Shell Growth ◽  
Experimental Period ◽  
Gradual Decline ◽  
Poor Growth ◽  
Term Response ◽  
Better Than

The shell growth of small coastal Mytilus edulis L. was measured at three different constant low salinities over short periods of time. Growth was significantly depressed in 6·4 and 16‰ S but not in 22·4‰ S. Fluctuating salinities between 0 and 32‰ S depressed growth whether the fluctuations were of sinusoidal or abrupt form. After 1 week of preconditioning to constant 32‰ S the growth of coastal (Bangor) mussels was better than estuarine (Conwy) mussels. However, after two weeks’ preconditioning to 32‰ S the estuarine mussels displayed the best growth. In the fluctuating regime, both coastal and estuarine mussels exhibited poor growth rates. The long-term response of the shell growth of coastal M. edulis was followed over a period of 44 days. Salinities in the range 1·8–9·6‰ S were lethal to the mussels within 10 days. In 12·8 and 16‰ S growth was initially delayed but recovered eventually. There was a gradual decline in the growth rate of the mussels exposed to the higher salinities (19·2–32‰) and an improvement in the growth of the mussels living in lower salinities (12·8 and 16‰) to levels nearly matching that of the high salinity animals by day 37. This suggests that acclimation of the shell growth of M. edulis to salinities in the 12·8–28·8‰ S range was achieved by the mussels during the experimental period.

Emission characteristics of GaInN/GaN multiple quantum shell nanowire-based LEDs with different p-GaN growth conditions

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sae Katsuro ◽  
Weifang Lu ◽  
Kazuma Ito ◽  
Nanami Nakayama ◽  
Naoki Sone ◽  
...  
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Light Output ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Current Injection ◽  
Emission Characteristics ◽  
Multiple Quantum ◽  
Plane Region

Abstract Improving current injection into r- and m-planes of nanowires (NWs) is essential to realizing efficient GaInN/GaN multiple quantum shell (MQS) NW-based light-emitting diodes (LEDs). Here, we present the effects of different p-GaN shell growth conditions on the emission characteristics of MQS NW-LEDs. Firstly, a comparison between cathodoluminescence (CL) and electroluminescence (EL) spectra indicates that the emission in NW-LEDs originates from the top region of the NWs. By growing thick p-GaN shells, the variable emission peak at around 600 nm and degradation of the light output of the NW-LEDs are elaborated, which is attributable to the localization of current in the c-plane region with various In-rich clusters and deep-level defects. Utilizing a high growth rate of p-GaN shell, an increased r-plane and a reduced c-plane region promote the deposition of indium tin oxide layer over the entire NW. Therefore, the current is effectively injected into both the r- and m-planes of the NW structures. Consequently, the light output and EL peak intensity of the NW-LEDs are enhanced by factors of 4.3 and 13.8, respectively, under an injection current of 100 mA. Furthermore, scanning transmission electron microscope images demonstrate the suppression of dislocations, triangular defects, and stacking faults at the apex of the p-GaN shell with a high growth rate. Therefore, localization of current injection in nonradiative recombination centers near the c-plane was also inhibited. Our results emphasize the possibility of realizing high efficacy in NW-LEDs via optimal p-GaN shell growth conditions, which is quite promising for application in the long-wavelength region.

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