Genetic evidence for multiple paternity in the critically endangered Cuban crocodile (Crocodylus rhombifer)

2016 ◽  
Vol 37 (3) ◽  
pp. 273-281 ◽  
Author(s):  
Yoamel Milián-García ◽  
Evelyn L. Jensen ◽  
Sheila Ribalta Mena ◽  
Etiam Pérez Fleitas ◽  
Gustavo Sosa Rodríguez ◽  
...  

Conservation strategies can be most effective when factors influencing the persistence of populations are well-understood, including aspects of reproductive biology such as mating system. Crocodylians have been traditionally associated with a polygynous mating system, with genetic studies revealing multiple paternity of clutches in several species. The endemic Cuban crocodile,Crocodylus rhombifer, is currently listed as Critically Endangered, and is one of the least understood crocodylian species in terms of its mating behavior. Here, we tested a hypothesis of multiple paternity in the Cuban crocodile by collecting genotypic data at nine microsatellite loci for 102 hatchlings from five nests sampled at the Zapata Swamp captive breeding facility and analyzing them in relation to data previously collected for 137 putative parents. All five nests showed evidence of multiple paternity based on the numbers of alleles per locus, with sibship analyses reconstructing all nests as having four to six full-sib family groups. Accordingly, mean pairwise relatedness values per nest ranged from 0.21 to 0.39, largely intermediate between theoretical expected values for half-siblings (0.25) and full-siblings (0.50). It is not possible to differentiate whether the multiple paternity of a nest was due to multiple matings during the same breeding season, or a result of sperm storage. Our results reveal that theC. rhombifermating system is likely best characterized as promiscuous and suggest that the standard practice of enforcing a 1:2 sex ratio at the captive breeding facility should be altered in order to better maintain a demographically and genetically healthy ex situ population.

2015 ◽  
Vol 21 (2) ◽  
pp. 122
Author(s):  
Robert Townsend ◽  
Adam Stow ◽  
Maria Asmyhr ◽  
Paolo Momigliano

The grey nurse shark (Carcharius taurus) is listed as threatened throughout much of its global distribution, and as critically endangered in eastern Australia. Captive breeding programs have thus far been largely unsuccessful and little is known of its mating system in this context. Here we carry out a paternity analysis to determine if the mating system in captivity is characterised by multiple mating, and whether poor offspring survival is associated with a particular male. Tissue samples from grey nurse sharks were collected from three potential sires, the two dams and nine pups housed at Manly SEA LIFE Sanctuary in eastern Australia. Each individual was genotyped at seven microsatellite markers and three cases of multiple paternity were inferred. No paternal link to stillborn (5), or scoliotic (2) pups was indicated. For the first time, we show the natural wild phenomenon of multiple paternity occurring in a captive environment.


2018 ◽  
Author(s):  
T. Mendonca ◽  
A. J. Cadby ◽  
N. Hemmings

AbstractFemales across many internally fertilising taxa store sperm, often in specialised storage organs in their reproductive tracts. In birds, several hundred sperm storage tubules exist in the utero-vaginal junction of the oviduct and there is growing evidence that sperm storage in these tubules is selective. The mechanisms underlying female sperm storage in birds remain unknown due to our limited ability to make three dimensional, live observations inside the large, muscular avian oviduct. Here, we describe a new application of fluorescence selective plane illumination microscopy to optically section oviduct tissue from zebra finchTaeniopygia guttatafemales label-free, by harnessing tissue autofluorescence. Our data provide the first description of the 3D structure of sperm storage organs in any vertebrate and reveal the presence of gate-like constricted openings that may play a role in sperm selection.Statement of SignificanceFemale birds can store sperm in microscopic tubular structures in their reproductive tract for up to several months, depending on species. Studying these sperm storage tubules has been a major challenge due to the muscular and opaque nature of reproductive tracts in birds. We have developed a new method for imaging live reproductive tract tissue using selective plane illumination microscopy, a fluorescence microscopy technique. From these images, we could extract three-dimensional measurements of sperm storage tubules and found these structures to have a gate-like constriction, providing evidence that females can actively select sperm at storage and ultimately influence the paternity of her offspring. Understanding these reproductive adaptations can help improve captive breeding programs and similar conservation strategies.


Hacquetia ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 307-315
Author(s):  
Ümit Subaşı ◽  
Fatoş Şekerciler ◽  
Mecit Vural

AbstractLotus sanguineus is one of the endemic taxa from Mediterranean Region of Turkey. It has hitherto been known from type locality and was assessed under VU and EN categories despite the lack of information on the population size, number of location and habitat quality. This study aims to determine the global conservation status and conservation strategies of the narrow endemic species. We collected all available data and evaluated them with the field studies. We reported the sizes of populations, altitude, coordinates, habitat types and the threats it faces for each locality. GeoCAT analyses at global levels indicate the extent of occurrence 19.965 km2 and area of occupancy 9 km2 and there could be an inferred decline due to habitat loss and fragmentation of the original population, suggesting this species might be classified as Critically Endangered, based on criterium B1ab (i, ii, iii) + 2ab (i, ii, iii) in the Red List categorization. Conservation priorities include life history and ecology studies, in-situ conservation, population monitoring and ex-situ conservation to prevent the destruction of the existing gene pool.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3447 ◽  
Author(s):  
Emilio Valbuena-Ureña ◽  
Anna Soler-Membrives ◽  
Sebastian Steinfartz ◽  
Mònica Alonso ◽  
Francesc Carbonell ◽  
...  

Ex situ management strategies play an important role in the conservation of threatened species when the wild survival of the species cannot be ensured. Molecular markers have become an outstanding tool for the evaluation and management of captive breeding programs. Two main genetic objectives should be prioritized when planning breeding programs: the maintenance of maximum neutral genetic diversity, and to obtain “self-sustaining” captive populations. In this study, we use 24 microsatellite loci to analyze and evaluate the genetic representativity of the initial phases of the captive breeding program of the Montseny brook newt, Calotriton arnoldi, an Iberian endemic listed as Critically Endangered. The results show that the initial captive stock has 74–78% of the alleles present in the wild populations, and captures roughly 93–95% of their total genetic diversity as observed in a previous study on wild newts, although it does not reach the desired 97.5%. Moreover, the percentage of unrelatedness among individuals does not exceed 95%. Therefore, we conclude that the genetic diversity of the captive stock should be improved by incorporating genetic material from unrelated wild newts. In recognition of the previously described significant genetic and morphological differentiation between eastern and western wild populations of C. arnoldi, we suggest maintaining two distinct breeding lines, and we do not recommend outbreeding between these lines. Our comparisons of genetic diversity estimates between real and distinct sample-sized simulated populations corroborated that a minimum of 20 individuals are needed for each captive population, in order to match the level of genetic diversity present in the wild populations. Thus, the current initial stock should be reinforced by adding wild specimens. The captive stock and subsequent cohorts should be monitored in order to preserve genetic variation. In order to avoid genetic adaptation to captivity, occasionally incorporating previously genotyped individuals from the wild into the captive populations is recommended.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Mohammed Kasso ◽  
Mundanthra Balakrishnan

Biodiversity encompasses variety and variability of all forms of life on earth that play a great role in human existence. Its conservation embraces maintenance, sustainable utilization, and restoration, of the lost and degraded biodiversity through two basic and complementary strategies called in situ and ex situ. Ex situ conservation is the technique of conservation of all levels of biological diversity outside their natural habitats through different techniques like zoo, captive breeding, aquarium, botanical garden, and gene bank. It plays key roles in communicating the issues, raising awareness, and gaining widespread public and political support for conservation actions and for breeding endangered species in captivity for reintroduction. Limitations of ex situ conservation include maintenance of organisms in artificial habitats, deterioration of genetic diversity, inbreeding depression, adaptations to captivity, and accumulation of deleterious alleles. It has many constraints in terms of personnel, costs, and reliance on electric power sources. Ethiopia is considered to be one of the richest centers of genetic resources in the world. Currently, a number of stakeholders/actors are actively working on biodiversity conservation through ex situ conservation strategies by establishing gene banks, botanical garden, and zoo.


2020 ◽  
Vol 11 (1) ◽  
pp. 1-8
Author(s):  
Muhammad Idnan ◽  
Arshad Javid ◽  
Muhammad Nadeem ◽  
Ali Hussain ◽  
Sajid Mansoor ◽  
...  

Background: Study of behavioral conformations play a significant role in ex-situ conservation of ungulates particularly of deer to propagate deer farming. Due to advancement in animal hunting techniques, captive breeding is the best solution to propagate animals for sports or other traditional & medicinal uses. Due to the lack of management methods, captive breeding programs have been used on trial and error basis for rearing of wild animals like Chinkara. Objectives: The present study was planned to investigate behavioral patterns in captivity to explore factors over reproductive success of the Chinkara and potential of this wild animal (Chinkara) for deer farming practices in Pakistan. Methodology: Present study was conducted on the behavior of Chinkara (Gazella bennettii) [wild-caught (WC)=20, captive-bred (CB)=10] for a period of one year from April 2013 to March 2014 at Captive breeding facilities for ungulates, Ravi campus Pattoki, University of Veterinary and Animal Sciences (UVAS), Pakistan. Results: The behavior of captive-born and wild-caught animals was observed by focal sampling pattern to frame conservation strategies for successful management practices for promotion of deer farming in Pakistan. Similar behavioral patterns were observed in both WC and CB animals but WC male Chinkara displayed a higher degree of agonistic interaction than of CB males. From these results it is predicted that there is no obvious immediate effect of captivity on behavioral configurations up to 10 generations in Chinkara. Conclusion: It is suggested that Chinkara is not suitable for domestication like Goat until further studies on ethology of Chinkara.


2021 ◽  
pp. 24-27
Author(s):  
Jay Redbond

The Nguru spiny pygmy chameleon (Rhampholeon acuminatus) is endemic to the Nguru mountains in Tanzania. It is assessed as Critically Endangered and is collected from the wild for the pet trade. An ex-situ population of this species was recently established at The Wild Planet Trust, Paignton Zoo, in the hope of learning more about the husbandry and biology of this species. We report on the captive husbandry of adults and the successful breeding, hatching and rearing of juveniles. Females carried four eggs but laid them in pairs. When eggs were incubated at 19.2-22.8 °C, hatchlings emerged roughly 180 days after laying. The hatchlings had a total length of about 30 mm and weighed 0.2-0.3 g. To our knowledge, this is the first published account of captive breeding for this species. The husbandry methods described could be used to establish populations of this and other Rhampholeon species in captivity, which in turn would reduce the demand for wild caught (Rhampholeon), as well as inform future conservation breeding programmes for this species.


Gaia Scientia ◽  
2016 ◽  
Vol 10 (2) ◽  
pp. 1-9
Author(s):  
D. Mameri ◽  
C. Sousa Santos ◽  
M. F. Magalhães ◽  
J. I. Robalo

Cyprinid fauna endemic to the Iberian Peninsula is currently facing several human-caused threats which enhance their risk of extinction. The populations of the critically endangered Achondrostoma occidentale, occurring only in three small and intermittent Portuguese river basins, have been reinforced with fish bred ex-situ in order to minimize their risk of extinction. This study aimed to describe the restocking actions conducted and to identify and characterize the summer refugia that should become targets for restoration and further restocking. The results evidence population increments and a high representativeness of younger age classes in the restocked populations. The importance of annual monitoring of fish abundance to assess how the species is coping with the stochastic and deterministic stressors that may eventually compromise its survival is highlighted.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2191
Author(s):  
Pablo García-Salinas ◽  
Victor Gallego ◽  
Juan F. Asturiano

The chondrichthyan fishes, which comprise sharks, rays, and chimaeras, are one of the most threatened groups of vertebrates on the planet. Given this situation, an additional strategy for the protection of these species could be the ex situ conservation projects developed in public aquaria and research centers. Nevertheless, to increase sustainability and to develop properly in situ reintroduction strategies, captive breeding techniques, such as sperm extraction and artificial insemination, should be developed. These techniques are commonly used in other threatened species and could be also used in chondrichthyans. However, the different reproductive morphologies found in this group can complicate both processes. Therefore, a comparison of the reproductive anatomy of eight distinct chondrichthyans, with an emphasis on those important differences when performing sperm extraction or artificial insemination, is carried out herein. Sharks and chimaeras belonging to the Scyliorhinidae, Carcharhinidae, Centrophoridae, Etmopteridae, Hexanchidae, and Chimaeridae families were obtained from commercial fisheries, public aquaria, and stranding events. In addition, the process of obtaining viable sperm samples through cannulation, abdominal massage, and oviducal gland extraction is described in detail for both living and dead animals.


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