Gamete Collection, Artificial Fertilization and Captive-Rearing of Eggs in a Terrestrial-Breeding Anuran with Parental Care: Alytes obstetricans

• Published in: Animals (Basel) Vol. 13; no. 17; p. 2802
• Main Authors: Arregui, Lucía, Bosch, Jaime
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 04.09.2023; MDPI
• Subjects: amphibian; Animal reproduction; egg clutch; Eggs; Embryos; Experiments; hatching; Males; midwife toad; Ovulation; Reproductive technologies; Reptiles & amphibians; sperm; spermiation; Toads; United Kingdom > UK; Portugal; Madrid Spain; Spain
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani13172802

The genus Alytes consists of six primitive terrestrial-breeding species (five of them endangered or present in restricted distributions) with unique male parental care. Alytes obstetricans was used as a model for the development of assisted reproductive technologies for gamete collection, artificial fertilization and captive-rearing of embryos. Sperm collection was achieved with human chorionic gonadotropin (hCG), but only 17 to 50% of males responded to the hormone. In addition, an effect of captivity on sperm quality was observed. A combination of gonadotropin-releasing hormone agonist (GnRHa) and hCG was tested for induction of ovulation, and 100% of females responded to the treatment. Recently collected sperm was used in artificial fertilization, and 10% of eggs showed complete embryo development. To design a method for captive-rearing of embryos, natural clutches (n = 13) were removed from males and divided into two sub-clutches. One was kept with all eggs together and in the other, the egg string was cut and eggs were split individually. All sub-clutches with eggs kept separated presented embryo survival (ranging from 27 to 61%) that hatched normally, while only one sub-clutch with embryos maintained together had some embryo survival (36%). These results may contribute to the management of this and related species.