Alenka Dovč (Author), Mateja Stvarnik (Author), Renata Lindtner-Knific (Author), Gordana Gregurić Gračner (Author), Igor Klobučar (Author), Olga Zorman-Rojs (Author)

Abstract

The causes of embryonic mortality in Hermann’s tortoises (Testudo hermanni) during artificial incubation were determined. Total egg failure at the end of the hatching period was investigated. The hatching artefacts represented 19.2% (N = 3557) of all eggs (N = 18,520). The viability rate of incubated eggs was 80.8%. The eggs, i.e., embryos, were sorted according to the cause of unsuccessful hatching and subsequently analyzed. Some of the eggs were divided into two or more groups. Unfertilized eggs were confirmed in 61.0%, infected eggs in 52.5%, and eggs in various stages of desiccation in 19.1%. This group also included mummified embryos. Pseudomonas aeruginosa, Bacillus sp., Purpureocillium lilacinum, and Escherichia coli were frequently confirmed in infected eggs. Embryos were divided into three groups: embryos up to 1.0 cm—group 1 (2.2%), embryos from 1.0 cm to 1.5 cm—group 2 (5.4%) and embryos longer than 1.5 cm—group 3 (7.3%) of all unhatched eggs. Inability of embryos to peck the shell was found in 1.3%. These tortoises died shortly before hatching. Embryos still alive from the group 2 and group 3 were confirmed in 0.7% of cases. Dead and alive deformed embryos and twins were detected in the group 3 in 0.5% and 0.1% of cases, respectively. For successful artificial hatching, it is important to establish fumigation with disinfectants prior to incubation and elimination of eggs with different shapes, eggs with broken shells, and eggs weighted under 10 g. Eggs should be candled before and periodically during artificial incubation, and all unfertilized and dead embryos must be removed. Heartbeat monitor is recommended. Proper temperature and humidity, incubation of “clean” eggs on sterile substrate and control for the presence of mites is essential. Monitoring of the parent tortoises is also necessary.

Keywords

Testudo hermanni;eggs;artificial incubation;hatching artefacts;turtles;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UL VF - Veterinary Faculty
UDC: 636.09:796.015:612:577
COBISS: 51457795 Link will open in a new window
ISSN: 2076-2615
Views: 207
Downloads: 71
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary keywords: Eggs;Turtles;
Type (COBISS): Article
Pages: art. 478, str. 1-22
Volume: ǂVol. ǂ11
Issue: ǂno. ǂ2
Chronology: 2021
DOI: 10.3390/ani11020478
ID: 13689613