scholarly journals Sul comportamento di alcuni innesti di occhi nelle larve di Discoglossus pictus

1913 ◽  
Vol 37 (2) ◽  
pp. 222-232 ◽  
Author(s):  
Dott O. Anastasi
Keyword(s):  
Discoglossus Pictus

Mild segregation in the breeding preferences of an invasive anuran (Discoglossus pictus) and its main native competitor (Epidalea calamita) in ephemeral ponds

2019 ◽  
Vol 40 (4) ◽  
pp. 425-435 ◽  
Author(s):  
Eudald Pujol-Buxó ◽  
Gabriel M. Riaño ◽  
Gustavo A. Llorente
Keyword(s):  
Alien Species ◽  
Native Species ◽  
Evolutionary History ◽  
Reproductive Season ◽  
Breeding Sites ◽  
Ecological Segregation ◽  
Ephemeral Ponds ◽  
Interspecific Differences ◽  
Discoglossus Pictus ◽  
Epidalea Calamita

Abstract The choice of breeding sites by pond-breeding anurans has notable consequences for the fitness of larvae. Hence, beyond pond typology and phenology, adults can also discriminate according to several other features, for instance to favour allotopy with potential competitors. However, the lack of shared evolutionary history might impede proper ecological differentiation with alien species during the first stages of invasions. Here, we studied several possible sources of ecological segregation between the invasive Discoglossus pictus and the native Epidalea calamita in ephemeral ponds, where the native toad hardly had competition before the arrival of the invasive frog. During spring of 2016, we periodically surveyed 69 ephemeral ponds in three areas with different invasion histories to detect the presence/absence of eggs and tadpoles of these species. Invasive D. pictus started breeding earlier than E. calamita, but differences were not significant. Similarly, there were not clear differences among areas with different invasion histories. However, we found for both species a mutual tendency to directly avoid larval syntopy at the end of the reproductive season. We also found interspecific differences in the features that both species use for pond choice, preferring the native species shallower and less vegetated ephemeral ponds. Globally however, co-occurrence was high, pointing at other processes as key to the coexistence between both species in these habitats.

Development of the ethmoidal structures of the endocranium in Discoglossus pictus (Anura: Discoglossidae)

2010 ◽  
Vol 271 (9) ◽  
pp. 1078-1093 ◽  
Author(s):  
Karel Královec ◽  
Zbyněk Roček ◽  
Pavla Žáková ◽  
Vladimíra Mužáková
Keyword(s):  
Discoglossus Pictus

Unusual Chromosomal Distribution of a Major Satellite DNA from Discoglossus pictus (Amphibia, Anura)

2009 ◽  
Vol 127 (1) ◽  
pp. 33-42 ◽  
Author(s):  
N. Amor ◽  
G. Odierna ◽  
G. Chinali ◽  
K. Said ◽  
O. Picariello
Keyword(s):  
Satellite Dna ◽  
Chromosomal Distribution ◽  
Major Satellite ◽  
Discoglossus Pictus

Jelly plug dissolution in Discoglossus pictus eggs (Anura) involves peroxidase-like activity and oxidative opening of disulphide bonds

Zygote ◽  
1993 ◽  
Vol 1 (1) ◽  
pp. 61-69 ◽  
Author(s):  
G. Pitari ◽  
S. Dupré ◽  
C. Fusco ◽  
G. Maurizi ◽  
C. Campanella
Keyword(s):  
Hydrogen Peroxide ◽  
Peroxidase Activity ◽  
Electrophoretic Analysis ◽  
Ringer Solution ◽  
Cysteic Acid ◽  
Jelly Coat ◽  
Discoglossus Pictus ◽  
Disulphide Bonds ◽  
Sds Page

SummaryIn amphibian eggs the formation of a capsular chamber is one of the most striking events occurring either upon oviposition or after fertilisation. In the egg of the anuran Discoglossus pictus a capsular chamber forms following fertilisation or activation; the egg with its vitelline envelope rotates in this chamber according to gravity. Previous work showed that the chamber is the product of plug dissolution. The plug is a lens-shaped jelly coat, typical of Discoglossus, covering only part of the animal hemisphere. Its dissolution is caused by material released from the egg about 15 min after fertilisation through exocytosis of at least two types of vacuoles. Liquefaction of the plug correlates with the reduction of disulphide bonds present in the jelly matrix. In this study we investigated the nature of the substances released from the egg and some changes occurring in the plug during liquefaction. SDS-PAGE showed that the proteic profile of the plug changes dramatically after fertilisation, confirming proteic cleavage in the plug matrix during its dissolution. Through in vitro tests and electrophoretic analysis of the Ringer solution in which the egg exudate was collected, an increase in the activity of the solution was determined in the presence of hydrogen peroxide, and peroxidase activity was depicted in the egg exudate. The presence of free thiol groups and cysteic acid residues (or cysteine sulphinic acid) in the plugs of activated eggs was established, suggesting that during plug dissolution some disulphide bonds are oxidatively opened. This suggests that enzyme(s) with peroxidase activity are released following fertilisation. We surmise that such enzymes are contained in the intraovular vacuoles the exocytosis of which triggers the onset of plug liquefaction. The possible release of hydrogen peroxide from the egg is discussed.

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