Seasonal Variation in Reproductive Traits of the Oviparous Water Snake, Natrix maura, in the Ebro Delta of Northeastern Spain

2001 ◽  
Vol 35 (4) ◽  
pp. 653 ◽  
Author(s):  
Xavier Santos ◽  
Gustavo A. Llorente
Keyword(s):  
Seasonal Variation ◽  
Reproductive Traits ◽  
Ebro Delta ◽  
Water Snake ◽  
Natrix Maura

Food availability induces geographic variation in reproductive timing of an aquatic oviparous snake (Natrix maura)

2005 ◽  
Vol 26 (2) ◽  
pp. 183-191 ◽  
Author(s):  
◽  
A. de Sostoa ◽  
◽  
◽  
◽  
...  
Keyword(s):  
Clutch Size ◽  
Food Availability ◽  
Prey Availability ◽  
Good Condition ◽  
Early Spring ◽  
Ebro Delta ◽  
Reproductive Timing ◽  
Mediterranean Populations ◽  
Water Snake ◽  
Natrix Maura

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.

scholarly journals Seasonal variation of reproductive traits of the caramote prawn in the Gulf of Tunis

2015 ◽  
Vol 28 (2-4) ◽  
pp. 89-98 ◽  
Author(s):  
Hela Jaziri ◽  
Rosalia Ferreri ◽  
Widien Khoufi ◽  
Safouene El Fehri ◽  
Sadok Ben Meriem ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Reproductive Traits ◽  
Gulf Of Tunis

Exploring the origin of egg protein in an oviparous water snake (Natrix maura)

2007 ◽  
Vol 147 (1) ◽  
pp. 165-172 ◽  
Author(s):  
Xavier Santos ◽  
Conchita Arenas ◽  
Gustavo A. Llorente ◽  
Xavier Ruiz
Keyword(s):  
Egg Protein ◽  
Water Snake ◽  
Natrix Maura

Organochlorine levels in viperine snake Natrix maura carcasses from the ebro delta (NE Spain): Sexual and size-related differences

Chemosphere ◽  
1999 ◽  
Vol 39 (15) ◽  
pp. 2641-2650 ◽  
Author(s):  
X. Santos ◽  
D. Pastor ◽  
G.A. Llorente ◽  
J. Albaigés
Keyword(s):  
Ebro Delta ◽  
Natrix Maura ◽  
Ne Spain

Seasonal Variation of Waterbird Prey in the Ebro Delta Rice Fields

1996 ◽  
Vol 19 ◽  
pp. 135 ◽  
Author(s):  
Jacob Gonzalez-Solis ◽  
Xavier Bernadi ◽  
Xavier Ruiz
Keyword(s):  
Seasonal Variation ◽  
Rice Fields ◽  
Ebro Delta

Breeding traits of Hermann's tortoise Testudo hermanni hermanni in two western populations

2007 ◽  
Vol 28 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Marc Cheylan ◽  
Jean Pierre Nougarède ◽  
Aurelio Marín ◽  
Albert Bertolero
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Female Body ◽  
Egg Production ◽  
Reproductive Traits ◽  
Ebro Delta ◽  
Female Size ◽  
Female Body Size ◽  
Testudo Hermanni ◽  
Testudo Hermanni Hermanni

AbstractOver a period of two years we used radiology to investigate breeding traits in females of two western populations of the threatened Hermann's tortoise Testudo hermanni hermanni. The main purpose of the study was to see if reproductive traits – clutch size, clutch frequency, annual egg production and egg width – varied between populations in Corsica (France) and the Ebro Delta (Spain), and if these traits were affected by female body size and amounts of spring rainfall. All the breeding traits analysed were greater in the Corsican population than in the Ebro Delta population. These differences were also significant when we used female body size as a covariable. In both populations the amount of spring rainfall affected breeding traits but not clutch size. Nevertheless, only in the Corsican population did clutch frequency, annual egg production and egg width increase significantly in the year with a wet spring. Contrary to the predictions of Optimal Propagule Size theory, we found that egg size and clutch size increased with female size, and that both variables were independent. On the other hand, clutch frequency was not related to female body size. Thus, in the Hermann's tortoise, as clutch size did not change between years and clutch frequency was independent of female size, all females are able to increase their reproductive output in years with favourable conditions by increasing their clutch frequency. Nevertheless, other factors besides female size and rainfall may influence in a highly complex way variability in breeding traits among populations.

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