Influence of Photoperiod and Temperature on Serum Melatonin in the Diamondback Water Snake, Nerodia rhombifera

1993 ◽  
Vol 92 (3) ◽  
pp. 347-354 ◽  
Author(s):  
Andrea R. Tilden ◽  
Victor H. Hutchison
Keyword(s):  
Water Snake

Prothrombin-Activator (Thromboplastin) Generation in the Blood of Water Snake (Natrix piscator)

1981 ◽  
Vol 46 (04) ◽  
pp. 747-748
Author(s):  
V M Srivastava ◽  
B Dube ◽  
R K Dube ◽  
G P Agarwal
Keyword(s):  
Comparative Studies ◽  
One Stage ◽  
Water Snake ◽  
Generation Test ◽  
Mammalian System

SummaryThe generation of prothrombin-activator (thromboplastin) in water snake (Natrix piscator) is clearly delayed, Compared to a mammalian system, but the final activity is well comparable to that in man, when homologous sources of “phospholipid” (erythrocyte-lysate) and of substrate plasma are employed in one stage “thromboplastin generation test”. The use of heterologous source of either of the above reagents resulted in significantly longer clotting times; hence the need for homologous source of above reagents in the test is emphasized for comparative studies on animal haemostasis.

Ontogeny of Water Snake Foraging Ecology

Ecology ◽  
1982 ◽  
Vol 63 (6) ◽  
pp. 1624 ◽  
Author(s):  
Henry R. Mushinsky ◽  
James J. Hebrard ◽  
Darrell S. Vodopich
Keyword(s):  
Foraging Ecology ◽  
Water Snake

W chromosome in the Indian water snake (checkered keel back)Natrix piscator (colubridae)

1968 ◽  
Vol 24 (1) ◽  
pp. 79-80 ◽  
Author(s):  
L. Singh ◽  
T. Sharma ◽  
S. P. Ray-Chaudhuri
Keyword(s):  
W Chromosome ◽  
Indian Water ◽  
Water Snake

Diet of the large water snake Hydrodynastes gigas (Colubridae) from northeast Argentina

2004 ◽  
Vol 25 (2) ◽  
pp. 178-184 ◽  
Author(s):  
María Soledad López ◽  
Alejandro Giraudo
Keyword(s):  
Water Snake ◽  
Large Water

Effect of pinealectomy on the testicular response of the freshwater snake Natrix piscator to different environmental factors

1989 ◽  
Vol 67 (10) ◽  
pp. 2352-2357 ◽  
Author(s):  
C. Haldar ◽  
R. Pandey
Keyword(s):  
High Temperature ◽  
Pineal Gland ◽  
High Humidity ◽  
Testicular Function ◽  
Experimental Conditions ◽  
Gland Weight ◽  
Tropical Water ◽  
Water Snake ◽  
Temperature Regimes ◽  
Testicular Weight

The effects of different humidity, photoperiod, and temperature regimes on the testicular function of the tropical water snake Natrix piscator were investigated in both sham-operated and pinealectomized snakes. Moderate humidity (50 ± 5%) had no effect on the testis, but high humidity (85 ± 5%) increased the testicular weight and activity of sham-operated snakes after 3, 6, and 9 weeks. Exposures to 14L:10D or 24L:0D and high temperature (42 ± 2 °C) inhibited testicular weight and activity in sham-operated snakes, whereas exposure to 10L:14D or 0L:24D and a low temperature (20 ± 2 °C) had no effect. Pinealectomized snakes did not respond to any of these experimental conditions, but their testicular weight remained the same as that of the pinealectomized controls under natural environmental conditions. The pineal gland showed an opposite response to that of the testes. Pineal gland weight decreased under high humidity and increased under 14L:10D, 24L:0D, and high temperature. These findings suggest that the ecofactors humidity, photoperiod, and temperature play a role in the regulation of testicular function in this snake, and that the pineal gland is implicated in the mediation of these factors.

The role of temperature in microhabitat selection by northern water snakes (Nerodia sipedon)

1992 ◽  
Vol 70 (3) ◽  
pp. 417-422 ◽  
Author(s):  
Ian C. Robertson ◽  
Patrick J. Weatherhead
Keyword(s):  
Experimental Manipulation ◽  
Time Of Day ◽  
Microhabitat Selection ◽  
Nerodia Sipedon ◽  
Leopard Frogs ◽  
Water Snake ◽  
Northern Water Snakes ◽  
Water Snakes ◽  
Circadian Patterns

Using field observations and laboratory experiments we examined the role of temperature in microhabitat selection by an eastern Ontario population of northern water snakes (Nerodia sipedon). From 1349 random transects through a marsh we found that basking activity peaked at 09:00 and then declined steadily until 14:00 before increasing again. Our ability to detect snakes depended upon the microhabitat they occupied, and to the time of day when the snakes were encountered in water. In the field, temperatures of basking snakes averaged (±SE) 26.3 ± 0.7 °C (n = 36), while captive snakes in a thermal gradient showed a narrower selectivity, averaging 27.7 ± 0.4 °C (n = 21). The temperatures of basking snakes never exceeded 33 °C, even though a model snake placed in the sun reached 48 °C, suggesting that the snakes were thermoregulating to prevent overheating. In both the field and enclosures, water snakes basked more frequently as the temperature of the air increased relative to the water. Experimental manipulation of water temperature relative to air temperature revealed that temperature influenced microhabitat selection independently of circadian patterns. Finally, when in water, snakes tended to frequent habitats where leopard frogs (Rana pipiens), a common prey species, were most abundant, suggesting that prey distribution may also be an important component of water snake habitat selection.

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