Diet of tuatara (Sphenodon punctatus) translocated to Ōrokonui Ecosanctuary in southern New Zealand

ABSTRACT

Scats from tuatara (Sphenodon punctatus) were investigated in autumn at ōrokonui Ecosanctuary on South Island, New Zealand. Eighty-seven tuatara had been translocated there 5–7 months previously, either directly from Stephens Island/Takapourewa or via captivity. Tuatara at ōrokonui fed on diverse invertebrates, including beetles, millipedes, spiders, dipteran flies and cave wētā. Prey occurrence in large scats (presumed to come from adults) was similar in frequency to that in small scats (presumed to be from medium–large juveniles), apart from a higher incidence of spiders in those from adults. Tuatara scats contained scarabaeid and large carabid beetles more frequently, and tenebrionid beetles less frequently, than reported on Stephens Island. Unlike tuatara on Stephens Island, those at ōrokonui do not have access to seabirds or tree wētā, and showed no certain predation on passerines or reptiles. Some differences in diet composition may reflect differences in prey availability resulting from the past presence of rodents at ōrokonui.     

Endocrinology of oviposition in the tuatara (Sphenodon punctatus)—II. Plasma arginine vasotocin concentrations during natural nesting

• 1.1. Plasma concentrations of the neurohypophysial arginine vasotocin (AVT) were measured during three stages of natural nesting [nest digging (N = 16), oviposition (N = 6), nest guarding (N = 6)] in the rare New Zealand reptile, the tuatara (Sphenodon punctatus).
• 2.2. Nest digging females (X ± 1 SE: 134.9 ± 15.0 pg/ml) exhibited elevated but significantly lower concentrations of plasma AVT compared to those observed during oviposition (216.0 ± 28.1 pg/ml). Nest guarding females (54.6 ± 29.8 pg/μl) had plasma AVT concentrations significantly lower than other stages.
• 3.3. These data are similar to those reporting elevated plasma AVT concentrations during oviposition in sea turtles but tuatara exhibit significantly lower plasma AVT values (10-fold difference). Plasma AVT concentrations reported for tuatara and birds are comparable.

     

Predicting the fate of a living fossil: how will global warming affect sex determination and hatching phenology in tuatara?

How will climate change affect species'' reproduction and subsequent survival? In many egg-laying reptiles, the sex of offspring is determined by the temperature experienced during a critical period of embryonic development (temperature-dependent sex determination, TSD). Increasing air temperatures are likely to skew offspring sex ratios in the absence of evolutionary or plastic adaptation, hence we urgently require means for predicting the future distributions of species with TSD. Here we develop a mechanistic model that demonstrates how climate, soil and topography interact with physiology and nesting behaviour to determine sex ratios of tuatara, cold-climate reptiles from New Zealand with an unusual developmental biology. Under extreme regional climate change, all-male clutches would hatch at 100% of current nest sites of the rarest species, Sphenodon guntheri, by the mid-2080s. We show that tuatara could behaviourally compensate for the male-biasing effects of warmer air temperatures by nesting later in the season or selecting shaded nest sites. Later nesting is, however, an unlikely response to global warming, as many oviparous species are nesting earlier as the climate warms. Our approach allows the assessment of the thermal suitability of current reserves and future translocation sites for tuatara, and can be readily modified to predict climatic impacts on any species with TSD.     

Is Giardia a living fossil?

Despite enormous efforts, the patterns of the rise of eukaryotic life on Earth are not clearly defined. The ability of eukaryotes to produce energy using oxygen and sugars was a key factor in advancing life on Earth towards complex multicellular organisms. However, this was not the only way to produce energy and survive. Mitochondria probably appeared soon after the oxygen increase in the Earth's atmosphere but many microaerophilic protists require little or no oxygen to survive. New ultrastructural, biochemical and molecular phylogeny data about structures and processes involved in the generation of energy by currently known protists have forced the revision of understanding of the "tree of life".     

Is the bacterial ferrous iron transporter FeoB a living fossil?

The cytoplasmic membrane protein FeoB of Escherichia coli, Helicobacter pylori, Legionella pneumophila and Synechocystis sp. strain PCC 6803 is necessary for Fe(2+) uptake. The C-terminal part of FeoB is predicted to contain 8-12 membrane-spanning helices. The N-terminal domain shows much similarity to eukaryotic and prokaryotic G proteins and, indeed, GTPase activity is necessary for Fe(2+) transport. Four of the five characteristic conserved G protein motifs have been identified in FeoB proteins. Whether FeoB is involved directly, via its Me(2+) binding site, or indirectly in Fe(2+) transport, remains to be investigated.     

Symbiophagy and biomineralization in the “living fossil” Astrosclera willeyana

Representatives of all major metazoan lineages form biominerals. The molecular mechanisms that underlie this widespread and evolutionarily ancient ability are gradually being revealed for some lineages. However, until a wider range of metazoan biomineralization strategies are understood, the true diversity, and therefore the evolutionary origins of this process, will remain unknown. We have previously shown that the coralline demosponge, Astrosclera willeyana, in some way employs its endobiotic bacterial community to form its highly calcified skeleton. Here, using in situ hybridization and immunohistochemistry, we show that an ortholog of ATG8 (most likely a GABARAPL2/GATE-16 ortholog) is expressed in cells that construct the individual skeletal elements of the sponge. In TEM sections sponge cells can be observed to contain extensive populations of bacteria, and frequently possesses double-membrane structures which we interpret to be autophagosomes. In combination with our previous work, these findings support the hypothesis that the host sponge actively degrades a proportion of its bacterial community using an autophagy pathway, and uses the prokaryotic organic remains as a framework upon which calcification of the sponge skeleton is initiated.     

Symbiophagy and biomineralization in the “living fossil” Astrosclera willeyana

Representatives of all major metazoan lineages form biominerals. The molecular mechanisms that underlie this widespread and evolutionarily ancient ability are gradually being revealed for some lineages. However, until a wider range of metazoan biomineralization strategies are understood, the true diversity, and therefore the evolutionary origins of this process, will remain unknown. We have previously shown that the coralline demosponge, Astrosclera willeyana, in some way employs its endobiotic bacterial community to form its highly calcified skeleton. Here, using in situ hybridization and immunohistochemistry, we show that an ortholog of ATG8 (most likely a GABARAPL2/GATE-16 ortholog) is expressed in cells that construct the individual skeletal elements of the sponge. In TEM sections sponge cells can be observed to contain extensive populations of bacteria, and frequently possesses double-membrane structures which we interpret to be autophagosomes. In combination with our previous work, these findings support the hypothesis that the host sponge actively degrades a proportion of its bacterial community using an autophagy pathway, and uses the prokaryotic organic remains as a framework upon which calcification of the sponge skeleton is initiated.     

Palm distribution patterns in Amazonian rainforests: What is the role of topographic variation?

Question: Are soil properties and topographic variation related with palm (Arecaceae) species composition and distribution patterns? If so, are species distribution patterns consistent across sites? Location: 100–200 m a.s.l, non‐inundated Amazonian rainforest, NE Peru. Methods: One 0.65‐ha line transect divided into 5 m by 5 m subunits was inventoried for all palm individuals at each site. Soil samples were collected, and topography was measured. Results: A total of 56 palm taxa were recorded. Floristic similarity among transects clearly corresponded with similarity in soil cation content when species abundances were taken into account, but less so when only presence‐absence data were used. Taxon‐wise distribution analyses were done for the 37 most abundant palm taxa. Quite a few of these taxa proved not to be randomly distributed along the transects, but instead were clearly more abundant in some topographic positions than in others. However, the consistency of the distribution patterns across study sites proved to be rather low, and many of the palm taxa showed different distribution patterns at different sites. Conclusions: The ambiguity in distribution patterns across study sites may partly be due to the complexity of topography as a measure of ecological conditions, and the probability that it is related to the variation in different environmental variables at different sites.     

Unusual signals in a halo catheter: what is the mechanism?

In this "featured arrhythmia" article we present a set of unusual intracardiac electrode tracings that were recorded in a patient with typical clockwise flutter but a very dilated right atrium. The potential mechanism underlying this phenomenon is discussed with reference to the current literature.     

Polygynandry in a red fox population: implications for the evolution of group living in canids?

Canid social groups are typically thought to consist of extendedfamilies, that is, a dominant breeding pair and related nonbreedingsubordinates, that principally obtain indirect fitness benefitsfrom helping to raise the offspring of the dominant pair. Consequently,the monogamous pair has been viewed as the basic fundamentalunit of canid social organization. However, there have beenfew genetic studies that have tested this assumption. We analyzedthe parentage of red foxes (Vulpes vulpes) in a high-density(19.6–27.7 adult foxes/km²) population in Bristol, UK,to determine (1) whether groups typically produced a singlelitter of cubs annually and (2) whether male and female foxesexhibited monogamous mating strategies. Social monogamy (theproduction of one litter in a social group) was observed orassumed in 54% of breeding attempts (N = 13 group-years). However,polyandrous and polygynous patterns of mating were common. Multiplepaternity was confirmed in 38% of litters (N = 16) containingoffspring with resolved maternity and paternity (N = 30 cubs);when including cubs with unresolved paternity (N = 20), multiple-paternitymay have occurred in 69% of litters. Litters were sired by anaverage of 1.6 identified males (range = 1–4); when includingcubs with unresolved paternity, litters may have been siredby up to seven males. Only 20% (6/30) of cubs with resolvedmaternity and paternity were sired by males within the socialgroup. Within groups, dominant females did not breed with subordinatemales; dominant males did breed with subordinate females. Dominantand subordinate females both produced cubs with dominant andsubordinate males from other social groups. Mean adult relatednessin groups typically ranged from 0.15–0.35, indicativeof second-order rather than first-order relatives.     

Making a living in the tropical forest: Yuquí foragers in the Bolivian Amazon

Questions concerning the availability of resources in tropical rain forests have given rise to the current debate centering on whether human subsistence based solely on foraging is possible in these biomes without agricultural subsidies. This paper takes the position that changing perspectives on ecological pattern and process in tropical forests and the significant variation among tropical forests on a worldwide as well as regional scale must be taken into consideration. Human disturbance is also proposed as a cause of dependence on agriculture by modern human foragers rather than as a necessary precondition for successful exploitation of the tropical forest. These issues are discussed against the background of a case study of the Yuquí, who, until very recently, were true foragers in the Bolivian Amazon. For the Yuquí, the sustainability of their subsistence system depended on a finegrained knowledge of their environment and the freedom of movement over a large territory to access resources within it.     

Inference of evolutionary patterns of the land snail Albinaria in the Aegean archipelago: is vicariance enough?

Mitochondrial DNA sequences from 16S rRNA and ATPase8 genes were used to investigate phylogeographic patterns of the land snail Albinaria (Gastropoda: Clausiliidae) in the Aegean archipelago. Forty-two populations of Albinaria were analyzed, mainly A. turrita, A. caerulea and A. brevicollis, collected from 22 Aegean islands and certain surrounding regions. Maximum parsimony, maximum likelihood and Bayesian analyses on 16S rRNA and combined datasets produced trees that share significant similarity and reveal a phylogeny with distinct branches which are in general, but not full, agreement with current taxonomy. The Aegean taxa are not monophyletic as a whole, since A. turrita does not cluster with A. caerulea and A. brevicollis. The latter form a distinct monophyletic cluster, within which two groups are evident. These groups do not readily correspond to currently accepted morphospecies; one contains the populations that inhabit the central part of the archipelago plus some eastern islands, while the other contains populations whose geographic distribution is restricted to the southeastern part of the archipelago. The divergence between these two groups is attributed to vicariance events that primarily shape contemporary distributions. Although dispersal may also be present, certain small- and large-scale vicariance events can be traced; alternative phylogeographic hypotheses are discussed in view of the historical biogeography of the region.