The Stream valley, also known as the Jegenye Valley in Budaliget, was not a nature reserve, even though it is home to 1,800 salamanders in frost-free weather. The majority of people in the area were opposed to building on state-owned land, the capital’s vote on Wednesday to protect it could have an impact on this. Leer más.
Los anfibios están en peligro, dada la sexta extinción masiva de vida silvestre en curso. Por lo tanto, los Programas de Cría para la Conservación (CBP, por sus siglas en inglés) están intentando criar algunas especies en condiciones de laboratorio. La incorporación de tecnologías de reproducción asistida (TRA), como la estimulación hormonal, la recolección y criopreservación de espermatozoides y la fertilización in vitro, está contribuyendo al éxito de los PFC. El objetivo de este estudio fue aplicar ART en individuos sexualmente maduros de una especie no descrita de Atelopus (spumarius complex) (rana arlequín). Leer más.
Amphibians are in peril, given the ongoing sixth mass extinction of wildlife. Thus, Conservation Breeding Programs (CBPs) are attempting to breed some species under laboratory conditions. The incorporation of assisted reproduction technologies (ARTs), such as hormonal stimulation, sperm collection and cryopreservation, and in vitro fertilization is contributing to successful CBPs. The objective of this study was to apply ARTs in sexually mature individuals of an undescribed species of Atelopus (spumarius complex) (harlequin frog). Our procedure involves hormonal induction of gametogenesis in this species. We were able to induce gamete release through administration of human chorionic gonadotropin (hCG) in males, and in females this has been achieved through the sequential administration of hCG (priming doses), and combinations of hCG with gonadotropin releasing hormone analogue, GnRHa (ovulary dose). We standardized sperm cryopreservation by performing toxicity tests of cryoprotectants, fast/slow freezing and thawing, as well as supplementation of non-penetrating cryoprotectants (sugars). Next, we performed in vitro fertilization, evaluated the fertilization capacity of the cryopreserved sperm, and describe external features of fresh and cryopreserved sperm. We found that 10 IU/g hCG induced the release of the highest sperm concentrations between 3 and 5 h post-injection, while 2.5 IU/g hCG induced the release of eggs in most treated females. Under cryopreservation conditions, the highest recovery of forward progressive motility or FPM was 26.3 ± 3.5%, which was obtained in cryosuspensions prepared with the 5% DMF and 2.5% sucrose. Cryopreserved sperm showed narrower mitochondrial vesicles after thawing, while in frozen samples without cryodiluent showed 31% of spermatozoa lost their tails. In most cases, our attempts of in vitro fertilization were successful. However, only ∼10% of embryos were viable. Overall, our study demonstrates that the development of ARTs in individuals of Atelopus sp. (spumarius complex) bred in laboratory can be successful, which result in viable offspring through in vitro fertilization. Our study provides a baseline for assisted breeding protocols applicable to other harlequin frogs of the genus Atelopus. Ir al artículo.
Los lagartos nacidos y criados en cautividad durante varias generaciones pueden no desarrollar adecuadamente algunas aptitudes de comportamiento, que les puede afectar negativamente si su destino final es la incorporación al medio natural. Claribel González-Ortega y el resto de los autores publican el trabajo “Daily running trials increase sprint speed in endangered lizards (Gallotia simonyi)” en la revista Behavioural Processes en el número de diciembre de 2021. Leer más.
Sugeak dira narrastien eta anfibioen artetik gehien erakartzen nautenak, eta hauen artean, sugegorriak gero eta interesgarriagoak iruditzen zaizkit. Kolorazio eta patroi aldetik dagoen aniztasuna ikaragarria da gainera. Urtea hasi berri gaudela, aurreko urtean zehar ikusitako sugegorri batzuk erakusteko aprobetxatuko dut. Arrazoi desberdinak medio, sugegorri dezente ikusteko aukera izan nuen 2021ean.
Entre todos los herpetos son las serpientes las que más me atraen, y entre ellas, las víboras me parecen cada vez más interesantes. Además, la diversidad de colores y patrones es enorme. Recién comenzado el año, aprovecharé para mostrar algunas víboras que he visto durante el año pasado. Por diferentes motivos, pude ver bastantes víboras en 2021. Leer más.
