scholarly journals Myth busting? Effects of embryo positioning and egg turning on hatching success in the water snake Natrix maura

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Fabien Aubret ◽  
Gaëlle Blanvillain ◽  
Philippe J. R. Kok
Author(s):  
Xavier Santos ◽  
Conchita Arenas ◽  
Gustavo A. Llorente ◽  
Xavier Ruiz
Keyword(s):  

2005 ◽  
Vol 26 (2) ◽  
pp. 183-191 ◽  
Author(s):  
◽  
A. de Sostoa ◽  
◽  
◽  
◽  
...  

AbstractThe viperine snake Natrix maura is a common water snake, which forages on aquatic prey such as fish and frogs in Western Mediterranean water bodies. Female viperine snakes collected from three populations at the Iberian Peninsula during the vitellogenesis period were compared. Mean clutch size and range, as well as the slope of the regression between body size and clutch size, did not show differences between populations. In contrast, mean size of enlarged follicles of females collected in May from the Ebro Delta proved significantly smaller than those of females from the Matarranya River (50 km far) and the Granada Depression (500 km far). There were no differences in climatic conditions between areas. However, seasonal variation in food availability was significantly different in the Ebro Delta. In this area, the rice fields are dry in early spring as men control the water flow, and prey are not available. This energetic constraint induced female viperine snakes to adjust reproductive timing according to seasonal availability and to delay vitellogenesis for at least one month. By contrast, other Mediterranean populations exhibited a rather high prey availability from early spring (e.g. Matarranya River), females being in good condition in this season and consequently vitellogenesis starting earlier than in the Ebro Delta. This study illustrates a new case of reproductive plasticity in snakes.


Author(s):  
Alex Surapati ◽  
Reza Satria Rinaldi ◽  
Okta Wahyudi

ABSTRACTThe design of quail egg incubators is intended to facilitate the hatching process. The heat source used in the incubator is produced from heaters that use incandescent lamps and humidifiers are used as humidity regulators. The temperature regulator uses a fan to maintain air circulation and reduce the temperature when the temperature has exceeded the setpoint. This tool is equipped with a DHT11 temperature and humidity sensor, an incubator motor is used for the egg turning process, a sound sensor is used to detect if an egg has hatched and a GSM module will send an SMS notification to the farmer. The whole system is controlled by Arduino Mega 2560. During the hatching period, the temperature needed to incubate quail eggs is 39oC and humidity is 60%. The eggs in the hatching machine are rotated once every 3 hours with a 45o rotation angle. This is so that the egg can be heated evenly. The hatching process takes 18 days, with a hatching success rate of 98% of 50 eggs. The use of power in the hatching machine is on average 62.44 watts up to 83.45 watts and for 1 hatching period for 18 days, that is 25.2392kWh.Keywords: Arduino Mega 2560, DHT11, humidifier, GSM module


2006 ◽  
Vol 56 (3) ◽  
pp. 299-309 ◽  
Author(s):  
Adolf De Sostoa ◽  
Xavier Santos ◽  
Frederic Casals ◽  
Dolors Vinyoles ◽  
Estefania Vilardebó ◽  
...  

AbstractIn complex aquatic ecosystems, intraspecific competition for food can evolve into dietary differences related to body size, gender, capture ability, and habitat use. The diet of the viperine snake, Natrix maura, an aquatic predator which forages on fish and amphibians, has been studied in parallel with food availability in a small locality of the Matarranya River (NE Spain). Fish abundance values in this Mediterranean river, which hosts one of the highest rates of fish diversity in Europe, were estimated through electrofishing. Natrix maura fed on four of the ten fish species available and captured the only amphibian detected. Three of these fishes were the most abundant species in the river. The fourth fish was the river blenny, a small and rare benthonic species of which the males protect eggs laid under stones at the bottom of the river during reproductive periods. This behaviour makes it easy prey for N. maura. However, the river blenny was caught mostly by small- and medium-sized snakes, while larger individuals, particularly females, fed on larger and more mobile prey that were more abundant and energetically more profitable. Similar diet differences according to size and gender have been described in other water snakes. We discuss whether this coincidence may be related to the great tropic availability in aquatic environments for fish-eating snakes.


1981 ◽  
Vol 46 (04) ◽  
pp. 747-748
Author(s):  
V M Srivastava ◽  
B Dube ◽  
R K Dube ◽  
G P Agarwal

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.


2020 ◽  
Vol 27 (5) ◽  
pp. 245-256
Author(s):  
Cemil Aymak ◽  
Aşkın Hasan Uçar ◽  
Yusuf Katılmış ◽  
Eyup Başkale ◽  
Serap Ergene

In this study invertebrate infestation in green turtle (Chelonia mydas) nests were recorded for the first time for Kazanlı beach, Mersin, Turkey. For this aim, in 2006 nesting season, 294 natural intact green turtle nests were sampled to examine their contents and invertebrate infestation was found in 76 (25.85% of the total sampling green turtle nests). These infested nests were examined in terms of the invertebrate faunal composition. The specimens found in the green sea turtle nests were identified to order, family or genus levels and they were represented in 5 orders. These invertebrate groups are Elater sp. larvae (Elateridae; Coleoptera), Pimelia sp. larvae (Tenebrionidae; Coleoptera), Enchytraeidae (Oligochaeta), Cyrptostigmata (Acari), Oniscidae (Isopoda), Formicidae (Hymenoptera). Elater sp. was the most common invertebrate group in the green turtle nests. According to student t test, we found statistically significant differences between 7 independent variables and invertebrate species presence. Furthermore, logistic regression analysis explained that there is a negative relationship between hatching success rate and invertebrate species presence.


2008 ◽  
Vol 2 (1) ◽  
pp. 63-75
Author(s):  
Augusto Fachín Terán ◽  
Eduardo Matheus Von Mülhen

In this study the nesting biology of Podocnem is unifilis was investigated from July to November 1998 at the Mamirauá Sustainable Development Reserve, located in the Solimões river, near Tefé, Amazonas, Brazil. Podocnemis unifilis nested in August and September, with the hatching event occurring in October and November. Nests were excavated in clay soils (67.5%), sand (25%), and leaf litter (7.5%). Hatching success was highest in the sand beach nests and lowest in the clay banks nests. Humans and the tegu lizard (Tupinambis) were the main egg predators. This turtle population can recover only by the protection of nesting beaches, educational programs for the in habitants of the Reserve, participation of the community in the conservation and management program , and permanent guarding of the nesting beaches by Instituto Brasileiro do Meio Ambiente e Dos Recursos Naturais Renováveis-IBAMA authorities.


Sign in / Sign up

Export Citation Format

Share Document