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A male tuatara (Sphenodon punctatus) stands outside his burrow. Tuatara are sexually dimorphic at maturity, with males being on average larger, having a wider jaw, more triangular head, and a crest with larger, more closely arranged spikes. https://doi.org/10.1371/journal.pone.0253628.g001
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Successful reproduction is critical to the persistence of at-risk species; however, reproductive characteristics are understudied in many wild species. New Zealand's endemic tuatara (Sphenodon punctatus), the sole surviving member of the reptile order Rhynchocephalia, is restricted to 10% of its historic range. To complement ongoing conservation ef...
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... were able to use artificial insemination to manage genetic diversity and increase fertility rates of these critically endangered birds without adversely affecting the survival of individuals [9]. Another species of conservation importance that could benefit from ARTs is the tuatara (Sphenodon punctatus) (Fig 1), a reptile endemic to New Zealand and the only surviving member of a once widespread order, the Rhynchocephalia [11]. Extreme distributional and demographic declines of tuatara populations prompted a massive conservation effort by the early1990s [12]. ...
Citations
... Once we encountered a mating, we hand captured both individuals and collected any semen present on either's vent, or just inside in the cloacal opening, using a sterile syringe (Lamar et al., 2023). When a mating was observed from the point of the male mounting the female, the pair was allowed to copulate for between 5 and 10 min before being interrupted for sperm collection (Lamar et al., 2021(Lamar et al., , 2023. When mating males did not have any existing permanent identification (crest beads, historic toe codes, or a passive integrated transponder: PIT tag), we injected a PIT tag into the subcutaneous space along the flank. ...
... Finally, of the 69 instances where a male successfully secured a mating opportunity, five appeared to be 'dry'. We define these as matings that were behaviourally typical, with courting being observed beforehand and an adequate amount of time for sperm deposition to have occurred elapsing before interruption (>5 min) (Lamar et al., 2021(Lamar et al., , 2023; however, no sperm or seminal fluid of any kind was present on the outside of or just inside either tuatara's cloacae. In all five of these instances the male shuddered shortly after mounting the female, a presumed indication of sperm ejaculation in this species. ...
... Finally, we report that 11% of observed matings appeared dry. Three of the five observed dry mating events were observed from the start of mating, when the male mounted the female; in these instances, we can be sure that the pair was not prematurely interrupted (Lamar et al., 2021(Lamar et al., , 2023. Individuals were allowed to mate for between 5 and 10 min after discovery, and in all cases no seminal fluid was found on or in the cloacal opening of the female. ...
Observations of reptile courting and mating behaviour are relatively scant in the literature. Here, using the largest sample of observed courting attempts and matings in tuatara (Sphenodon punctatus) ever published, we describe novel behaviours in this rare species: mirrored head bobbing between courting pairs, purring vocalizations by displaying males, and several potential instances of anejaculation in otherwise normal matings. These results highlight the complexity of reptile mating displays and have implications for how we manage this vulnerable species.
... Until recently, our only knowledge of Rhynchocephalian sperm came from a 1992 study looking at the ultrastructure of non-viable sperm excised from the testes of two euthanized tuatara (Healy and Jamieson, 1992). However, in 2021 a pilot study investigating methods of cryopreservation for tuatara sperm was carried out using seven sperm samples collected from males living on Takapourewa (Lamar et al., 2021). This study found that of the seven collected sperm samples, five were motile, and one sample had the fastest (at the time of publication) curvilinear velocity of any reptile sperm (Lamar et al., 2021). ...
... However, in 2021 a pilot study investigating methods of cryopreservation for tuatara sperm was carried out using seven sperm samples collected from males living on Takapourewa (Lamar et al., 2021). This study found that of the seven collected sperm samples, five were motile, and one sample had the fastest (at the time of publication) curvilinear velocity of any reptile sperm (Lamar et al., 2021). Additionally, sperm samples had the potential for very high viability (Lamar et al., 2021). ...
... This study found that of the seven collected sperm samples, five were motile, and one sample had the fastest (at the time of publication) curvilinear velocity of any reptile sperm (Lamar et al., 2021). Additionally, sperm samples had the potential for very high viability (Lamar et al., 2021). However, this study had a small sample size and focused largely on the effects of different buffers and cryopreservatives on tuatara sperm. ...
Managing a species of conservation concern can be best achieved when there is information on the reproductive physiology of both sexes available; however, many species lack this critical, baseline information. One such species, the tuatara (Sphenodon punctatus), is the last surviving member of one of the four reptile orders (Rhynchocephalia) and is the only reptile known to lack a male intromittent organ. Culturally and evolutionarily significant, the conservation of this species is a global priority for the maintenance of biodiversity. In light of this, we characterized the morphology, viability and swim speed of mature tuatara sperm for the first time. We found that tuatara sperm are filiform and bear the remarkably conserved three-part sperm structure seen across the animal kingdom. Tuatara sperm are long (mean total length 166 μm), with an approximate head:midpiece:tail ratio of 15:1:17. While tuatara sperm are capable of high levels of within-mating viability (94.53%), the mean viability across all samples was 58.80%. Finally, tuatara sperm had a mean curvilinear velocity swim speed (μ × s − 1) of 82.28. At the population level, there were no differences in viability or mean swim speed between sperm collected from a male’s first mating of a season and repeat matings; however, the maximum sperm swim speed increased in observed repeated matings relative to first matings. Interestingly, faster sperm samples had shorter midpieces, but had greater viability and longer head and tail sections. This work expands our understanding of male reproductive characteristics and their variation to a new order, provides wild references for the assessment of captive individuals, lays the groundwork for potential assisted reproductive techniques and highlights variation in male reproductive potential as an important factor for consideration in future conservation programs for this unique species.
... The brain of S. punctatus is relatively well known (Abbie, 1934;Christensen, 1927;Dendy, 1909Dendy, , 1911Durward, 1930;Hindenach, 1931;Platel., 1989;Reiner & Northcutt, 2000;Starck, 1979), but its endocast remains undescribed, as does the spatial correspondence between its brain and endocast. S. punctatus is a medium-sized species endemic to New Zealand with high life expectancy, late sexual maturity (beyond 14 years long), cold physiology, and very slow reproduction, with egg-laying occurring once every 2-5 years (Castanet et al., 1988;Cree, 2014;Cree et al., 1991Cree et al., , 1992Lamar et al., 2021;Scharf et al., 2015;Thompson & Daugherty, 1998). Historically, the tuatara was believed to be practically unchanged since the Mesozoic (Abbie, 1934;Edinger, 1951;Herrera-Flores et al., 2017;Hindenach, 1931;Reiner & Northcutt, 2000;Robb, 1977;Schwab & O'Connor, 2005), and regarded as a model for the ancestral amniote or reptile (e.g., Abbie, 1934;Edinger, 1951;Hindenach, 1931;Reiner & Northcutt, 2000;Robb, 1977). ...
Understanding the origins of the vertebrate brain is fundamental for uncovering evolutionary patterns in neuroanatomy. Regarding extinct species, the anatomy of the brain and other soft tissues housed in endocranial spaces can be approximated by casts of these cavities (endocasts). The neuroanatomical knowledge of Rhynchocephalia, a reptilian clade exceptionally diverse in the early Mesozoic, is restricted to the brain of its only living relative, Sphenodon punctatus, and unknown for fossil species. Here, we describe the endocast and the reptilian encephalization quotient (REQ) of the Triassic rhynchocephalian Clevosaurus brasiliensis and compare it with an ontogenetic series of S. punctatus. To better understand the informative potential of endocasts in Rhynchocephalia, we also examine the brain-endocast relationship in S. punctatus. We found that the brain occupies 30% of its cavity, but the latter recovers the general shape and length of the brain. The REQ of C. brasiliensis (0.27) is much lower than S. punctatus (0.84-1.16), with the tuatara being close to the mean for non-avian reptiles. The endocast of S. punctatus is dorsoventrally flexed and becomes more elongated throughout ontogeny. The endocast of C. brasiliensis is mostly unflexed and tubular, possibly representing a more plesiomorphic anatomy in relation to S. punctatus. Given the small size of C. brasiliensis, the main differences may result from allometric and heterochronic phenomena, consistent with suggestions that S. punctatus shows peramorphic anatomy compared to Mesozoic rhynchocephalians. Our results highlight a previously undocumented anatomical diversity among rhynchocephalians and provide a framework for future neuroanatomical comparisons among lepidosaurs.
... The reptilian clade Rhynchocephalia is the sister taxon to Squamata (lizards, snakes and amphisbaenians) within Lepidosauria (Evans 1984(Evans , 2003Gauthier et al. 1988;Zardoya & Meyer 1998;Jones et al. 2013;Chambi-Trowell et al. 2021; see clade definitions below). Whereas Squamata is represented by more than 11,000 globally distributed species today (Uetz et al. 2022), Rhynchocephalia includes only a single extant species restricted to New Zealand (Hay et al. 2010;Cree 2014;Gemmell et al. 2020;Lamar et al. 2021). However, this pattern was strikingly different for the first 100 million years of lepidosaur evolution, after the two clades diverged sometime prior to the Middle Triassic (Jones et al. 2013;Simões et al. 2018;Burbrink et al. 2020). ...
We describe a new, small-bodied rhynchocephalian reptile, Opisthiamimus gregori gen. et sp. nov., from the Upper Jurassic Morrison Formation of Wyoming, USA. Whereas many fossil rhynchocephalians are based on isolated incomplete jaws, the holotype of O. gregori includes most of the skull and postcranium and therefore represents one of the most complete specimens of Rhynchocephalia known from North America. We used micro-computed tomography to examine its skeletal anatomy in detail and to develop a three-dimensional reconstruction of the skull. The skull of O. gregori is similar to that of several non-neosphenodontian rhynchocephalians such as Planocephalosaurus (e.g. large orbits) and Clevosaurus (e.g. parietal parasagittal crests) yet exhibits a suite of other features related to the proal shearing mechanism that becomes increasingly elaborated among more phylogenetically nested taxa such as Sphenodon (e.g. lateral palatine tooth row parallels maxillary tooth row along its entire length, pyramidal dentary teeth with mesial shearing crests). The postcranial skeleton of O. gregori exhibits characteristics typical of a terrestrial rhynchocephalian. Our phylogenetic analyses use a substantially updated data set of 118 characters and 46 taxa, and both maximum parsimony and Bayesian frameworks. Results place O. gregori inside Eusphenodontia but outside Neosphenodontia, and therefore in a key position for contributing to character polarity for more deeply nested clades such as Clevosauridae, Sphenodontidae and Pleurosauridae. We also erect Leptorhynchia taxon nov., composed primarily of aquatically adapted taxa (e.g. Pleurosaurus, Sapheosaurus), which is supported by both cranial and postcranial characters. Because O. gregori is not particularly closely related to the other named Morrison rhynchocephalians (e.g. Opisthias rarus), it increases both the alpha and beta taxonomic diversities within the formation. Similarly, major differences in body size and inferred diet of the Morrison taxa imply considerable concomitant palaeoecological diversity just prior to a major global decline in rhynchocephalian diversity around the close of the Jurassic.
http://zoobank.org/urn:lsid:zoobank.org:pub:888E055B-8AC1-4BD0-A37C-8CB192F79673
... Encouragingly, while the majority of ARTs studies to date have been focussed on squamates and the saltwater crocodile, a recent study reported the first collection, characterisation, and storage of tuatara (Sphenodon punctatus) sperm (Lamar et al. 2021). Although preliminary, the authors reported low levels of live sperm recovery post-thaw using the commercial cryoprotectant Synth-a-Freeze™ (containing 10% DMSO buffered with HEPES), making it the first ART study for the ancient reptile order Rhynchocephalia (Lamar et al. 2021). ...
... Encouragingly, while the majority of ARTs studies to date have been focussed on squamates and the saltwater crocodile, a recent study reported the first collection, characterisation, and storage of tuatara (Sphenodon punctatus) sperm (Lamar et al. 2021). Although preliminary, the authors reported low levels of live sperm recovery post-thaw using the commercial cryoprotectant Synth-a-Freeze™ (containing 10% DMSO buffered with HEPES), making it the first ART study for the ancient reptile order Rhynchocephalia (Lamar et al. 2021). That means there has now been at least one published study on ARTs in all four of the extant reptile orders, a small but important step forward in reptile conservation. ...
... We note many sperm cryopreservation protocols developed to date have used sperm collected postmortem, due to the large quantities and quality of sperm obtained and the ease of protocol development this confers (Young et al. 2017(Young et al. , 2021(Young et al. , 2022Campbell et al. 2021aCampbell et al. , 2021bSandfoss et al. 2021). However, encouragingly, two recent studies have looked at sperm collected non-lethally, including the first study on tuatara (Lamar et al. 2021;Hobbs et al. 2022). We also believe that further studies on fundamental reptile reproductive ecology and physiology, along with testing fundamental hypotheses around cryopreserving reptile reproductive cells and tissues iv www.publish.csiro.au/rd ...
Amphibians and reptiles are highly threatened vertebrate taxa with large numbers of species threatened with extinction. With so many species at risk, conservation requires the efficient and cost-effective application of all the tools available so that as many species as possible are assisted. Biobanking of genetic material in genetic resource banks (GRBs) in combination with assisted reproductive technologies (ARTs) to retrieve live animals from stored materials are two powerful, complementary tools in the conservation toolbox for arresting and reversing biodiversity decline for both amphibians and reptiles. However, the degree of development of the ARTs and cryopreservation technologies differ markedly between these two groups. These differences are explained in part by different perceptions of the taxa, but also to differing reproductive anatomy and biology between the amphibians and reptiles. Artificial fertilisation with cryopreserved sperm is becoming a more widely developed and utilised technology for amphibians. However, in contrast, artificial insemination with production of live progeny has been reported in few reptiles, and while sperm have been successfully cryopreserved, there are still no reports of the production of live offspring generated from cryopreserved sperm. In both amphibians and reptiles, a focus on sperm cryopreservation and artificial fertilisation or artificial insemination has been at the expense of the development and application of more advanced technologies such as cryopreservation of the female germline and embryonic genome, or the use of sophisticated stem cell/primordial germ cell cryopreservation and transplantation approaches. This review accompanies the publication of ten papers on amphibians and twelve papers on reptiles reporting advances in ARTs and biobanking for the herpetological taxa.
The theoretical trade-off between immune and endocrine investment in mating animals has received mixed empirical support, particularly in reptiles. We investigated the relationship between male sexual characteristics, diet, and immune response to stress in an island population of tuatara (Sphenodon punctatus) across two mating seasons. Tuatara are promiscuous, with a highly skewed mating system where males face significant competition for access to mates and postcopulatory competition for fertilization success. We found that tuatara sperm viability and swim speed were negatively associated with male body condition and the ratio of heterophils to lymphocytes. Additionally, sperm swim speed was negatively associated with spine area, mite load, and the total number of circulating white blood cells, but was positively associated with tick number. This is likely a function of social dynamics in this system where larger male size predicts greater spatial overlap with potential rivals and increased tick load. Because the production of sexual characteristics may be costly, we also investigated the effect of diet on sperm quality. We did not identify an association between diet and sperm viability. However, sperm swim speed was negatively associated with carbon-13 and positively associated with nitrogen-15. We suspect that these results reflect the influence of seabird-based nutrients in this island ecosystem, particularly polyunsaturated fatty acid, and antioxidant damage on tuatara sperm. In total, these results provide evidence of a trade-off between pre- and post-copulatory sexual characteristics and the immune and endocrine systems in male tuatara.
In recent years, the interest in media representations of migrants and the media as a space for participation has increased within the
field of migration studies. Yet, most scholars’ attention is focused on immigrants and the media in destination countries, while less attention
is paid to origin countries and emigrants’ representation. Taking advantage of the increased attention paid to migrants and migration during
the first phase of the COVID-19 pandemic, we investigated the media representations of Romanian migrants in agriculture who work in other
European countries and interpreted how their voices could be heard through media accounts. Through content analysis, we investigated a
sample of 297 articles published between 1st April and 31st May 2020 on the websites of the six most visible Romanian media outlets.
This study contributes to the existing knowledge on media representations of Romanian migrants by documenting a series of tendencies,
including an event-oriented approach, oversimplified representations of migration, massification and schematisation of migrant representations, and the high sensitivity to reports from destination countries’ media on Romanian migrants.
Our analysis reveals that the approach taken to reporting on migration during the COVID-19 pandemic, at least during its first phase, highly
depended on the existing, institutionalised modes of media reporting on migration.
Biodiversity loss is the greatest environmental problem threatening ecosystem, animal, and human health. Anthropogenic induced changes to climate, habitat, disease, species distributions, poaching, and unsustainable trade have accelerated extinction rates in all vertebrates, including reptiles. Preventing reptile extinctions will require humans to acknowledge these losses and develop ex situ and in situ plans to preserve them. Assisted reproductive technologies (ART) are management tools used to protect numerous vertebrate taxa; however, progress in developing ART for reptiles has lagged. Creating functional and sustainable reptile ART will strengthen our conservation capacity by capturing genetic material from select individuals to overcome natural or manmade boundaries. Utilising short-term gamete storage and genome resource banking, in conjunction with timed artificial insemination (AI) or ex ovo incubation, could lead to profound advances in reptile conservation, mitigating the loss of reptile biodiversity. In this article, we review ART reptile research completed since the 1970s. Topics include AI, hormonal control of reproduction, gamete collection, gamete storage, and genome resource banking. Additionally, we review the potential application of advanced reproductive methodologies, including in vitro/ex ovo fertilisation, intracytoplasmic sperm injection, cloning (somatic cell nuclear transfer), and genetic editing.
