Effect of temperature on the behaviour of the endeavour prawns Metapenaeus endeavouri (Schmitt) and Metapenaeus ensis (De Haan) (Decapoda : Penaeidae)

1999 ◽  
Vol 50 (4) ◽  
pp. 327 ◽  
Author(s):  
Y. C. Park ◽  
N. R. Loneragan

The effect of water temperature on the duration of emergence and speed of movement of adult endeavour prawns, Metapenaeus endeavouri and M. ensis, was investigated in the laboratory under controlled conditions from 20˚ to 32˚C. The behaviour of 50 prawns was recorded on videotape over 48 h at five temperatures (20˚, 23˚, 26˚, 29˚ and 32˚C). In general, both species emerged from the substratum during dusk and remained on the substratum until dawn or just before dawn when they buried again. At 32˚C, however, some M. endeavouri emerged for much less time and started to bury shortly after midnight. The mean daily duration of emergence for M. endeavouri varied with temperature and was higher at 26˚ and 29˚C (653 40 min per day) than at other temperatures. In contrast, the mean duration of emergence for M. ensis was not significantly affected by temperature (range of times 663 45 to 693 9 min). The pattern of the mean hourly speed of movement for M. endeavouri varied with temperature, whereas that for M. ensis was bimodal at most temperatures: they were more active during dusk (1700 to 1800 hours) and dawn (0400 to 0500 hours) than at other times.

2013 ◽  
Vol 45 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Weihong Dong ◽  
Gengxin Ou ◽  
Xunhong Chen ◽  
Zhaowei Wang

In this study, in situ and on-site permeameter tests were conducted in Clear Creek, Nebraska, USA to evaluate the effect of water temperature on streambed vertical hydraulic conductivity Kv. Fifty-two sediment cores were tested. Five of them were transferred to the laboratory for a series of experiments to evaluate the effect of water temperature on Kv. Compared with in situ tests, 42 out of the 52 tests have higher Kv values for on-site tests. The distribution of water temperature at the approximately 50 cm depth of streambed along the sand bar was investigated in the field. These temperatures had values in the range 14–19 °C with an average of 16 °C and had an increasing trend along the stream flow. On average, Kv values of the streambed sediments in the laboratory tests increase by 1.8% per 1 °C increase in water temperature. The coarser sandy sediments show a greater increase extent of the Kv value per 1 °C increase in water temperature. However, there is no distinct increasing trend of Kv value for sediment containing silt and clay layers.


2018 ◽  
Vol 21 (0) ◽  
Author(s):  
Melicia Cintia Galdeano ◽  
Allan Eduardo Wilhelm ◽  
Isabella Borges Goulart ◽  
Renata Valeriano Tonon ◽  
Otniel Freitas-Silva ◽  
...  

Abstract Ozone has been used for many years to disinfect water due to its oxidizing potential. Since it decomposes quickly into molecular oxygen, leaving no residue, it has important advantages for use. The decomposition of ozone is affected by the temperature and pH of the medium, low pH values and temperatures increasing its half-life, which can result in more efficient disinfection. With the objective of increasing the effectiveness of ozonation, this study investigated the effect of temperature (8 ºC and 25 °C) and pH (3.0 and 6.0) of the water on the saturation time and gas concentration, employing two initial gas concentrations (13.3 and 22.3 mg L-1). The concentration of ozone saturation increased as the temperature and pH of the medium decreased, as also with the higher initial gas concentration ( C0). The highest saturation concentrations were obtained at pH 3.0 and 8 °C (4.50 and 8.03 mg L-1 with C0 of 13.3 and 22.3 mg L-1, respectively). This higher ozone content could result in greater decontamination efficiency of the food products washed with this water.


1995 ◽  
Vol 69 (4) ◽  
pp. 337-345 ◽  
Author(s):  
J.M. Mason ◽  
W.M. Hominick

AbstractThe effect of temperature on infection, development and reproduction of five Heterorhabditis isolates was examined in Galleria mellonella larvae. Infectivity was examined at six temperatures (5,10, 15,20,25 and 30°C). The proportion of Galleria infected remained relatively constant, only dropping at extremes of the temperature range tested. However, the mean number of nematodes per host produced a different trend, with each isolate displaying optimal infectivity at 25°C. The temperature range over which the juveniles could infect differed between the isolates. This is thought to be related to the geographic origins of the species. Development and reproduction occurred over a slightly narrower temperature range than that allowing infection to occur. Differences between the isolates at which development and reproduction occurred were noted. There were also differences in the mean number of juveniles produced per cadaver following either infection in sand (10 nematodes/larva) or the injection of one juvenile per larva, suggesting that reproduction is tightly regulated by density-dependent constraints.


Author(s):  

The effect of seawater temperature on the subsidence and development of the Gonothyraea loveni (Allman) hydroid at a specific point in the water area was discussed This allows us to trace the connection of seasonal changes in sea temperature with the process of sedimentation of planules and the development of hydroid G. loveni on artificial substrates of various exposures in the Sevastopol bay. Observations were carried out over two periods: from 1979 to 1987. and from 2011 to 2015. The temperature range of 5-10 °C corresponds to the subsidence of planul on plates with a community 10 days aged in the autumn and spring periods. The peak of subsidence was detected at a water temperature of 9 °C. At this time, the greatest number of plates with settled hydroids was detected (22%). The number of hydrotecas in the temperature range of 11-19 °C reaches maximum values due to sedimentation and active growth of colonies, since the frequency of occurrence of plates with hydroids during this period is halved and remains at this level at higher temperatures (17-24 °C). With an increase in the exposure of substrates up to 30 days, the bulk of the plates with hydroid (80%) are concentrated in the temperature range of 6–11 °C. When the temperature of water in the sea is 16-24 °C, plates with hydroids are less than 5%, which is determined in addition to the effect of temperature by the massive subsidence of Botryllys schlosseri (Pallas), which replaces the hydroid. In communities of 2-12 months of age, the hydroid G. loveni develops over a wide range of temperatures, from 5 to 23 °C. Dynamic changes in communities show that the growth of colonies occurs at a temperature of 5-9 °C with a maximum intensity of 10 to 15 °C. At temperatures above 17 °C, the reduction of colonies occurs. Key words: subsidence, development of hydroid Gonothyraea loveni, the temperature of the sea water of the Sevastopol Bay, the Black sea


2020 ◽  
Vol 3 (1) ◽  
pp. ACCEPTED
Author(s):  
Rho-Jeong Rae

This study investigated the boreal digging frog, Kaloula borealis, to determine the egg hatching period and whether the hatching period is affected by incubation temperature. The results of this study showed that all the eggs hatched within 48 h after spawning, with 28.1% (±10.8, n=52) hatching within 24 h and 99.9% (±0.23, n=49) within 48 h after spawning. A significant difference was noted in the mean hatching proportion of tadpoles at different water temperatures. The mean hatching rates between 15 and 24 h after spawning was higher at a water temperature of 21.1 (±0.2) °C than at 24.1 (±0.2) °C. These results suggest that incubation temperature affected the early life stages of the boreal digging frog, since they spawn in ponds or puddles that form during the rainy season.


2020 ◽  
Vol 32 (2) ◽  
pp. 78-83
Author(s):  
Jin Choi ◽  
Gyeong Sik Han ◽  
Ki Wook Lee ◽  
Soon-Gyu Byun ◽  
Hyun Jeong Lim ◽  
...  

1984 ◽  
Vol 49 (6) ◽  
pp. 1448-1458
Author(s):  
Josef Kopešťanský

The effect of temperature and structure of the palladium surfaces on acetylene chemisorption was studied along with the interaction of the adsorbed layers with molecular and atomic hydrogen. The work function changes were measured and combined with the volumetric measurements and analysis of the products. At temperature below 100 °C, acetylene is adsorbed almost without dissociation and forms at least two different types of thermally stable adsorption complexes. Acetylene adsorbed at 200 °C is partly decomposed, especially in the low coverage region. Besides the above mentioned effects, the template effect of adsorbed acetylene was studied in the temperature range from -80° to 25 °C. It has been shown that this effect is a typical phenomenon of the palladium-acetylene system which is not due to surface impurities.


2018 ◽  
Vol 116 (1) ◽  
pp. 110
Author(s):  
Lixiong Shao ◽  
Jiang Diao ◽  
Wang Zhou ◽  
Tao Zhang ◽  
Bing Xie

The growth behaviour of spinel crystals in vanadium slag with high Cr2O3 content was investigated and clarified by statistical analyses based on the Crystal Size Distribution (CSD) theory. The results indicate that low cooling rate and Cr2O3 content benefit the growth of spinel crystals. The chromium spinel crystals firstly precipitated and then acted as the heterogeneous nuclei of vanadium and titanium spinel crystals. The growth mechanisms of the spinel crystals at the cooling rate of 5 K/min consist two regimes: firstly, nucleation control in the temperature range of 1873 to 1773 K, in which the shapes of CSD curves are asymptotic; secondly, surface and supply control within the temperature range of 1773 to 1473 K, in which the shapes of CSD curves are lognormal. The mean diameter of spinel crystals increases from 3.97 to 52.21 µm with the decrease of temperature from 1873 to 1473 K.


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