Whole Snake Genomes from Eighteen Families of Snakes (Serpentes: Caenophidia) and Their Applications to Systematics.

We present genome assemblies for 18 snake species representing 18 families (Serpentes: Caenophidia): Acrochordus granulatus, Aparallactus werneri, Boaedon fuliginosus, Calamaria suluensis, Cerberus rynchops, Grayia smithii, Imantodes cenchoa, Mimophis mahfalensis, Oxyrhabdium leporinum, Pareas carinatus, Psammodynastes pulverulentus, Pseudoxenodon macrops, Pseudoxyrhopus heterurus, Sibynophis collaris, Stegonotus admiraltiensis, Toxicocalamus goodenoughensis, Trimeresurus albolabris, and Tropidonophis doriae. From these new genome assemblies, we extracted thousands of loci commonly used in systematic and phylogenomic studies on snakes, including target-capture datasets composed of UCEs and AHEs, as well as traditional Sanger loci. Phylogenies inferred from the two target-capture loci datasets were identical with each other, and strongly congruent with previously published snake phylogenies. To show additional utility of these non-model genomes for investigative evolutionary research, we mined the genome assemblies of two New Guinea island endemics in our dataset (Stegonotus admiraltiensis and Tropidonophis doriae) for the ATP1a3 gene, a thoroughly researched indicator of resistance to toad toxin ingestion by squamates. We find that both these snakes possess the genotype for toad toxin resistance despite their endemism to New Guinea, a region absent of any toads until the human-mediated introduction of Cane Toads in the 1930s. These species possess identical substitutions that suggest the same bufotoxin resistance as their Australian congenerics (Stegonotus cucullatus and Tropidonophis mairii) which forage on invasive Cane Toads. Herein, we show the utility of short-read high coverage genomes, as well as improving the deficit of available squamate genomes with associated voucher specimens.

Specimen collection is essential for modern science.

Natural history museums are vital repositories of specimens, samples and data that inform about the natural world; this Formal Comment revisits a Perspective that advocated for the adoption of compassionate collection practices, querying whether it will ever be possible to completely do away with whole animal specimen collection.

Multi-vendor evaluation of artificial intelligence as an independent reader for double reading in breast cancer screening on 275,900 mammograms.

BACKGROUND: Double reading (DR) in screening mammography increases cancer detection and lowers recall rates, but has sustainability challenges due to workforce shortages. Artificial intelligence (AI) as an independent reader (IR) in DR may provide a cost-effective solution with the potential to improve screening performance. Evidence for AI to generalise across different patient populations, screening programmes and equipment vendors, however, is still lacking. METHODS: This retrospective study simulated DR with AI as an IR, using data representative of real-world deployments (275,900 cases, 177,882 participants) from four mammography equipment vendors, seven screening sites, and two countries. Non-inferiority and superiority were assessed for relevant screening metrics. RESULTS: DR with AI, compared with human DR, showed at least non-inferior recall rate, cancer detection rate, sensitivity, specificity and positive predictive value (PPV) for each mammography vendor and site, and superior recall rate, specificity, and PPV for some. The simulation indicates that using AI would have increased arbitration rate (3.3% to 12.3%), but could have reduced human workload by 30.0% to 44.8%. CONCLUSIONS: AI has potential as an IR in the DR workflow across different screening programmes, mammography equipment and geographies, substantially reducing human reader workload while maintaining or improving standard of care. TRIAL REGISTRATION: ISRCTN18056078 (20/03/2019; retrospectively registered).

Evolution of the albumin protein family in reptiles.

The albumin family of proteins consists of vitamin-D binding protein/group-specific component (GC), serum albumin (ALB), alpha-fetoprotein (AFP), and afamin (AFM), which are responsible for transporting many ligands throughout the body. The albumin family proteins are physiologically and medically important, but our understanding of their functions and applications is hindered by the dearth of information regarding these proteins' evolutionary relationships and functions in non-mammalian lineages. In this study we investigate the evolution of the albumin family proteins in reptiles, using bioinformatic methods to survey available reptile genomes and transcriptomes for albumin family proteins and phylogenetically characterize their relationships. We reinforce the established evolutionary relationships among the albumin protein family in reptiles, however, they are variable in their number of domains, overall genetic sequence, and synteny. We find a novel absence of the physiologically important ALB in squamates and identify two distinct lineages of AFP, one in mammals and another in reptiles. Our study provides a comparative genomic framework for further studies identifying lineage-specific gene expansions that may compensate for the lack of serum albumin in squamates.

A new species of Cyrtodactylus Gray (Gekkonidae: Squamata) from Manus Island, and extended description and range extension for Cyrtodactylus sermowaiensis (De Rooij).

Systematic investigations of vertebrate faunas from the islands of Melanesia are revealing high levels of endemism, dynamic biogeographic histories, and in some cases surprisingly long evolutionary histories of insularity. The bent-toed geckos in the Cyrtodactylus sermowaiensis Group mainly occur in northern New Guinea and nearby islands, however a further isolated population occurs on Manus Island in the Admiralty Archipelago approximately 300 km to the north of New Guinea. Here we first present a review of the genetic diversity, morphological variation and distribution of Cyrtodactylus sermowaiensis from northern New Guinea. Genetic structure and distributional records within Cyrtodactylus sermowaiensis broadly overlap with underlying Terranes in northern New Guinea, suggesting divergence on former islands that have been obscured by the infill and uplift of sedimentary basins since the late Pleistocene. Based on a combination of genetic and morphological differentiation we then describe the population from Manus Island as a new species, Cyrtodactylus crustulus sp. nov. This new species emphasises the high biological endemism and conservation significance of the Admiralty Islands, and especially Manus Island.

Habitat preference modulates trans-oceanic dispersal in a terrestrial vertebrate.

The importance of long-distance dispersal (LDD) in shaping geographical distributions has been debated since the nineteenth century. In terrestrial vertebrates, LDD events across large water bodies are considered highly improbable, but organismal traits affecting dispersal capacity are generally not taken into account. Here, we focus on a recent lizard radiation and combine a summary-coalescent species tree based on 1225 exons with a probabilistic model that links dispersal capacity to an evolving trait, to investigate whether ecological specialization has influenced the probability of trans-oceanic dispersal. Cryptoblepharus species that occur in coastal habitats have on average dispersed 13 to 14 times more frequently than non-coastal species and coastal specialization has, therefore, led to an extraordinarily widespread distribution that includes multiple continents and distant island archipelagoes. Furthermore, their presence across the Pacific substantially predates the age of human colonization and we can explicitly reject the possibility that these patterns are solely shaped by human-mediated dispersal. Overall, by combining new analytical methods with a comprehensive phylogenomic dataset, we use a quantitative framework to show how coastal specialization can influence dispersal capacity and eventually shape geographical distributions at a macroevolutionary scale.

The polyphyly of Plasmodium: comprehensive phylogenetic analyses of the malaria parasites (order Haemosporida) reveal widespread taxonomic conflict.

The evolutionary relationships among the apicomplexan blood pathogens known as the malaria parasites (order Haemosporida), some of which infect nearly 200 million humans each year, has remained a vexing phylogenetic problem due to limitations in taxon sampling, character sampling and the extreme nucleotide base composition biases that are characteristic of this clade. Previous phylogenetic work on the malaria parasites has often lacked sufficient representation of the broad taxonomic diversity within the Haemosporida or the multi-locus sequence data needed to resolve deep evolutionary relationships, rendering our understanding of haemosporidian life-history evolution and the origin of the human malaria parasites incomplete. Here we present the most comprehensive phylogenetic analysis of the malaria parasites conducted to date, using samples from a broad diversity of vertebrate hosts that includes numerous enigmatic and poorly known haemosporidian lineages in addition to genome-wide multi-locus sequence data. We find that if base composition differences were corrected for during phylogenetic analysis, we recovered a well-supported topology indicating that the evolutionary history of the malaria parasites was characterized by a complex series of transitions in life-history strategies and host usage. Notably we find that Plasmodium, the malaria parasite genus that includes the species of human medical concern, is polyphyletic with the life-history traits characteristic of this genus having evolved in a dynamic manner across the phylogeny. We find support for multiple instances of gain and loss of asexual proliferation in host blood cells and production of haemozoin pigment, two traits that have been used for taxonomic classification as well as considered to be important factors for parasite virulence and used as drug targets. Lastly, our analysis illustrates the need for a widespread reassessment of malaria parasite taxonomy.

Multiple origins of green blood in New Guinea lizards.

Several species of lizards from the megadiverse island of New Guinea have evolved green blood. An unusually high concentration of the green bile pigment biliverdin in the circulatory system of these lizards makes the blood, muscles, bones, tongue, and mucosal tissues bright green in color, eclipsing the crimson color from their red blood cells. This is a remarkable physiological feature because bile pigments are toxic physiological waste products of red blood cell catabolism and, when chronically elevated, cause jaundice in humans and all other vertebrates. Although these lizards offer a promising system to examine the evolution of extraordinary physiological characteristics, little is known about the phylogenetic relationships of green-blooded lizards or the evolutionary origins of green blood. We present the first extensive phylogeny for green-blooded lizards and closely related Australasian lizards using thousands of genomic regions to examine the evolutionary history of this unusual trait. Maximum likelihood ancestral character state reconstruction supports four independent origins of green blood. Our results lay the phylogenetic foundation necessary to determine the role, if any, of natural selection in shaping this enigmatic physiological trait as well as understanding the genetic, proteomic, and biochemical basis for the lack of jaundice in those species that have independently evolved green blood.

Two new species of Crocodile Skinks (Squamata: Scincidae: Tribolonotus) from the Solomon Archipelago.

We describe two new species of the scincid lizard genus Tribolonotus from the islands of Buka and Choiseul in the Solomon Archipelago, closely related to, and previously included within, T. pseudoponceleti. One species, T. parkeri sp. nov., is endemic to Buka Island and was revealed in our previous study via taxonomically focused analyses of both next-generation sequencing data and morphology. Here, we also further support the validity of this species by more taxonomically comprehensive Bayesian species delimitation of three Sanger sequenced nuclear loci. The second species, T. choiseulensis sp. nov., is endemic to Choiseul Island and was revealed by an expanded morphological data analysis. These results suggest that numerous other species found on multiple island groups in the Solomon Archipelago may similarly represent complexes of multiple, closely related species, and that the biodiversity of the region is vastly underestimated.

The dynamic evolutionary history of genome size in North American woodland salamanders.

The genus Plethodon is the most species-rich salamander genus in North America, and nearly half of its species face an uncertain future. It is also one of the most diverse families in terms of genome sizes, which range from 1C = 18.2 to 69.3 pg, or 5-20 times larger than the human genome. Large genome size in salamanders results in part from accumulation of transposable elements and is associated with various developmental and physiological traits. However, genome sizes have been reported for only 25% of the species of Plethodon (14 of 55). We collected genome size data for Plethodon serratus to supplement an ongoing phylogeographic study, reconstructed the evolutionary history of genome size in Plethodontidae, and inferred probable genome sizes for the 41 species missing empirical data. Results revealed multiple genome size changes in Plethodon: genomes of western Plethodon increased, whereas genomes of eastern Plethodon decreased, followed by additional decreases or subsequent increases. The estimated genome size of P. serratus was 21 pg. New understanding of variation in genome size evolution, along with genome size inferences for previously unstudied taxa, provide a foundation for future studies on the biology of plethodontid salamanders.

Phylogenomics using formalin-fixed and 100+ year-old intractable natural history specimens.

Museum specimens provide a wealth of information to biologists, but obtaining genetic data from formalin-fixed and fluid-preserved specimens remains challenging. While DNA sequences have been recovered from such specimens, most approaches are time-consuming and produce low data quality and quantity. Here, we use a modified DNA extraction protocol combined with high-throughput sequencing to recover DNA from formalin-fixed and fluid-preserved snakes that were collected over a century ago and for which little or no modern genetic materials exist in public collections. We successfully extracted DNA and sequenced ultraconserved elements (x¯ = 2318 loci) from 10 fluid-preserved snakes and included them in a phylogeny with modern samples. This phylogeny demonstrates the general use of such specimens in phylogenomic studies and provides evidence for the placement of enigmatic snakes, such as the rare and never-before sequenced Indian Xylophis stenorhynchus. Our study emphasizes the relevance of museum collections in modern research and simultaneously provides a protocol that may prove useful for specimens that have been previously intractable for DNA sequencing.

Four New Species of Eimeria (Apicomplexa: Eimeriidae) from Emoia spp. Skinks (Sauria: Scincidae), from Papua New Guinea and the Insular Pacific.

Between September and November 1991, 54 adult skinks from 15 species were collected by hand or blowpipe from several localities on Rarotonga, Cook Islands, Ovalau Island, Fiji, and Papua New Guinea (PNG), and their feces were examined for coccidians. Species included 5 seaside skinks (Emoia atrocostata), 1 Pacific blue-tailed skink (Emoia caeroleocauda), 2 Fiji slender treeskinks (Emoia concolor), 15 white-bellied copper-striped skinks (Emoia cyanura), 1 Bulolo River forest skink (Emoia guttata), 6 dark-bellied copper-striped skinks (Emoia impar), 5 Papua five-striped skinks (Emoia jakati), 2 Papua slender treeskinks (Emoia kordoana), 3 Papua robust treeskinks (Emoia longicauda), 1 brown-backed forest skink (Emoia loveridgei), 3 Papua black-sided skinks (Emoia pallidiceps), 2 Papua white-spotted skinks (Emoia physicae), 2 Papua yellow-head skinks (Emoia popei), 1 Papua brown forest skink (Emoia submetallica), and 5 Fiji barred treeskinks (Emoia trossula) Species of Eimeria (Ei.) were detected from these Emoia (Em.) spp. and are described here as new. Oocysts of Eimeria iovai n. sp. from Em. pallidiceps from PNG were ellipsoidal with a bilayered wall (L × W) 26.5 × 18.1 µm, with a length/width ratio (L/W) of 1.1. Both micropyle and oocyst residuum were absent, but a fragmented polar granule was present. This eimerian also was found in Em. atrocostata from PNG. Oocysts of Eimeria kirkpatricki n. sp. from Em. atrocostata from PNG were ellipsoidal with a bilayered wall, 18.6 × 13.5 µm, L/W 1.4. A micropyle and oocyst residuum were absent, but a fragmented polar granule was present. This eimerian was also shared by Em. cyanura from the Cook Islands and Fiji, Em. impar from the Cook Islands, Em. loveridgei from PNG, Em. pallidiceps from PNG, Em. popei from PNG, and Em. submetallica from PNG. Oocysts of Eimeria stevejayuptoni n. sp. from Em. longicauda were subspheroidal to ellipsoidal with a bilayered wall, 18.7 × 16.6 µm, L/W 1.1. A micropyle and oocyst residuum were absent, but a fragmented polar granule was present. Oocysts of Eimeria emoia n. sp. from Em. longicauda from PNG were cylindroidal with a bilayered wall, 29.2 × 15.7 µm, L/W 1.9. A micropyle and oocyst residuum were absent, but a polar granule was present. These are the first eimerians reported from Emoia spp. and they add to our growing knowledge of the coccidian fauna of scincid lizards of the South Pacific.

Sequence capture and next-generation sequencing of ultraconserved elements in a large-genome salamander.

Amidst the rapid advancement in next-generation sequencing (NGS) technology over the last few years, salamanders have been left behind. Salamanders have enormous genomes-up to 40 times the size of the human genome-and this poses challenges to generating NGS data sets of quality and quantity similar to those of other vertebrates. However, optimization of laboratory protocols is time-consuming and often cost prohibitive, and continued omission of salamanders from novel phylogeographic research is detrimental to species facing decline. Here, we use a salamander endemic to the southeastern United States, Plethodon serratus, to test the utility of an established protocol for sequence capture of ultraconserved elements (UCEs) in resolving intraspecific phylogeographic relationships and delimiting cryptic species. Without modifying the standard laboratory protocol, we generated a data set consisting of over 600 million reads for 85 P. serratus samples. Species delimitation analyses support recognition of seven species within P. serratus sensu lato, and all phylogenetic relationships among the seven species are fully resolved under a coalescent model. Results also corroborate previous data suggesting nonmonophyly of the Ouachita and Louisiana regions. Our results demonstrate that established UCE protocols can successfully be used in phylogeographic studies of salamander species, providing a powerful tool for future research on evolutionary history of amphibians and other organisms with large genomes.

Thriving in the Cold: Glacial Expansion and Post-Glacial Contraction of a Temperate Terrestrial Salamander (Plethodon serratus).

The dynamic geologic history of the southeastern United States has played a major role in shaping the geographic distributions of amphibians in the region. In the phylogeographic literature, the predominant pattern of distribution shifts through time of temperate species is one of contraction during glacial maxima and persistence in refugia. However, the diverse biology and ecology of amphibian species suggest that a "one-size-fits-all" model may be inappropriate. Nearly 10% of amphibian species in the region have a current distribution comprised of multiple disjunct, restricted areas that resemble the shape of Pleistocene refugia identified for other temperate taxa in the literature. Here, we apply genetics and spatially explicit climate analyses to test the hypothesis that the disjunct regions of these species ranges are climatic refugia for species that were more broadly distributed during glacial maxima. We use the salamander Plethodon serratus as a model, as its range consists of four disjunct regions in the Southeast. Phylogenetic results show that P. serratus is comprised of multiple genetic lineages, and the four regions are not reciprocally monophyletic. The Appalachian salamanders form a clade sister to all other P. serratus. Niche and paleodistribution modeling results suggest that P. serratus expanded from the Appalachians during the cooler Last Glacial Maximum and has since been restricted to its current disjunct distribution by a warming climate. These data reject the universal applicability of the glacial contraction model to temperate taxa and reiterate the importance of considering the natural history of individual species.

Combined next-generation sequencing and morphology reveal fine-scale speciation in Crocodile Skinks (Squamata: Scincidae: Tribolonotus).

Next-generation sequencing has vast potential to revolutionize the fields of phylogenetics and population genetics through its ability to collect genomic scale data sets of thousands of orthologous loci. Despite this potential, other types of data (e.g. morphology, ecology) remain important, particularly for studies endeavouring to delimit species. Here, we integrate next-generation sequencing with morphology to examine divergence between populations of Tribolonotus pseudoponceleti on the islands of Buka and Bougainville in the Solomon Archipelago. We used the Ion Torrent PGM to collect over 648 Mbp of sequence data for 12 samples, representing 1526 loci recovered from all samples, and 3342 were recovered from at least six samples. Genetic structure analyses strongly support the distinctiveness of these two populations, and Bayes factor delimitations decisively select speciation between Buka and Bougainville. Principal components and discriminant function analyses reveal concordant morphological divergence. Finally, demographic analyses via diffusion approximation and approximate Bayesian computation prefer a complex model of mid-Pleistocene divergence with migration, and a later decrease or cessation of migration and population size shift, suggesting a scenario in which migration was enabled by Pleistocene merging of these two islands, and limited when isolated by higher sea levels. Further analysis of four Sanger sequenced loci in IMa2 had limited power to distinguish among models including and excluding migration, but resulted in similar population size and divergence time estimates, although with much broader confidence intervals. This study represents a framework for how next-generation sequencing and morphological data can be combined and leveraged towards validating putative species and testing demographic scenarios for speciation.

Four new species of coccidia (Apicomplexa: Eimeriidae) from Owen Stanley Skinks, Papuascincus stanleyanus (Sauria: Scincidae), from Papua New Guinea.

Between September and November 1991, 12 Owen Stanley skinks, Papuascincus stanleyanus (Booulenger) were collected from various localities on Papua New Guinea and examined for coccidians. Six (50%) were found to harbour four eimerians that we describe here as new. Oocysts of Eimeria burseyi sp. n. were elongate to ellipsoidal with a bilayered wall and measured (length x width, L x W) 36.0 x 24.0 microm, with a L/W ratio of 1.5. Both micropyle and oocyst residuum were absent, but a polar granule was present. Oocysts of Eimeria goldbergi sp. n. were ellipsoidal, with a bilayered wall, and measured 21.4 x 16.1 microm; L/W ratio was 1.3. Both micropyle and oocyst residuum were absent, but a single or fragmented polar granule was present. Oocysts of Eimeria boulengeri sp. n. were spheroidal to slightly subspheroidal, with a thin, single-layered wall that readily collapses, and measured 16.0 microm, L/W ratio was 1.0. Both micropyle and oocyst residuum were absent, but usually one (sometimes two) polar granule(s) were present. Oocysts of Eimeria niuginiensis sp. n. were oblong to tapered with a bilayered wall, and measured 20.0 x 13.1 microm; L/W ratio was 1.5. A micropyle, oocyst residuum and polar granule were absent. To our knowledge, these represent the only coccidians ever described from P. stanleyanus.

Two new species of Eimeria (Apicomplexa, Eimeriidae) from tree skinks, Prasinohaema spp. (Sauria: Scincidae), from Papua New Guinea.

Between September 1991 and June 1992, feces from 4 species of tree skinks, Prasinohaema spp. from Papua New Guinea, were collected and examined for coccidia. Two species, P. flavipes and P. prehensicauda were found to harbor eimerians which are described as new. Oocysts of Eimeria krausi sp. nov. from P. flavipes were ellipsoidal to subspheroidal with a smooth bilayered wall and measured (L × W) 19.2 × 16.9 µm, with a length/width (L/W) ratio of 1.1. Micropyle and oocyst residuum were absent but a fragmented polar granule was present. Sporocysts were ellipsoidal, 9.7 × 6.7 µm, L/W of 1.5. Stieda, subStieda and paraStieda bodies were absent. The sporocyst residuum was composed of many small granules in a compact mass between sporozoites. The sporozoites were sausage-shaped, 11.7 × 2.7 µm, in situ, with an ellipsoidal posterior refractile body and a spheroidal anterior refractile body. Oocysts of Eimeria greeri sp. nov. from P. prehensicauda were ellipsoidal with a smooth bilayered wall, (L × W) 23.0 × 18.3 µm, with a L/W of 1.3. Micropyle and oocyst residuum were absent but a fragmented polar granule was present. Sporocysts were ellipsoidal, 9.7 × 8.4 µm, with a L/W of 1.2. Stieda, subStieda and paraStieda bodies were absent. The sporocyst residuum was composed of many large granules in a compact mass between sporozoites. The sporozoites were sausage-shaped, with an ellipsoidal posterior refractile body and a spheroidal anterior refractile body. We document here the first report of coccidia from skinks of the genus Prasinohaema.

A new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from the Solomon ground skink, Sphenomorphus solomonis (Boulenger) (Sauria: Scincidae) from Papua New Guinea.

Between September 1990 and November 1991, 19 Sphenomorphus spp. skinks, including nine S. jobiense, three S. simus, and seven Solomon ground skinks, S. solomonis (Boulenger), were collected from Madang and Morobe Provinces, Papua New Guinea (PNG), and examined for coccidia. A single S. solomonis was found to be infected with a new species of Eimeria Schneider, 1875. Oöcysts of Eimeria perkinsae n. sp. are ellipsoidal with a smooth, colourless, bi-layered wall, measure 18.6 × 14.7 µm, and have a length/width (L/W) ratio of 1.3; both micropyle and oöcyst residuum are absent, but a fragmented polar granule is present. Sporocysts are ovoidal, 8.9 × 6.4 µm, L/W 1.4; neither Stieda, sub-Stieda or para-Stieda bodies are present; a sporocyst residuum consisted of a loose cluster of granules dispersed between sporozoites. Sporozoites are comma-shaped with spheroidal anterior and posterior refractile bodies. This represents the first report of coccidia from this skink genus.

Two new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from emerald tree skinks, Lamprolepis smaragdina (Lesson) (Sauria: Scincidae) from Papua New Guinea and the Philippines.

Two new species of Eimeria Schneider, 1875, from emerald tree skinks, Lamprolepis smaragdina (Lesson) are described from specimens collected in Papua New Guinea (PNG) and the Philippines. Oöcysts of Eimeria nuiailan n. sp. from the only L. smaragdina from PNG are ovoidal, with a smooth, colourless, bi-layered wall, measure 23.7 × 19.1 µm, and have a length/width (L/W) ratio of 1.3; both micropyle and oöcyst residuum are absent, but a fragmented polar granule is present. Sporocysts are ovoidal to ellipsoidal, 11.9 × 7.0 µm, L/W 1.7, and the wall is composed of two valves joined by a longitudinal suture; neither Stieda nor sub-Stieda bodies are present; a sporocyst residuum is present as a compact mass of granules. Sporozoites are elongate, 14.6 × 2.6 µm, and contain anterior and posterior refractile bodies with a nucleus between them. Oöcysts of Eimeria auffenbergi n. sp. from L. smaragdina collected in the Philippines are ovoidal, with a smooth, colourless, bi-layered wall, measure 19.9 × 15.8 µm, L/W 1.3; both micropyle and oöcyst residuum are absent, but one to four polar granules are present. Sporocysts are ovoidal to ellipsoidal, 10.3 × 5.8 µm, L/W 1.8, and the wall is composed of two valves joined by a longitudinal suture; neither Stieda nor sub-Stieda bodies are present; a sporocyst residuum is composed of dispersed granules.

Three new species of coccidia (Apicomplexa: Eimeriidae) from skinks, Lipinia spp. (Sauria: Scincidae), from Oceania.

Between September 1991 and March 1993, 25 moth skinks (Lipinia noctua) were collected from various localities on the Cook Islands, Fiji, Papua New Guinea (PNG), and Vanuatu and examined for coccidians. In addition, a single Roux's lipinia skink (Lipinia rouxi) was collected from PNG and examined for coccidia. Sixteen (64%) L. noctua were found to harbor 2 new eimerians, and L. rouxi harbored another new Eimeria sp. Oocysts of Eimeria lipinia n. sp. from 9 (36%) L. noctua from the Cook Islands, Fiji, and PNG were subspherical with a bilayered wall and measured (L × W) 18.6 × 16.9 µm, with a L/W ratio of 1.1. Both micropyle and oocyst residuum were absent, but a polar granule was present. Oocysts of Eimeria melanesia n. sp. from 6 (24%) L. noctua from Fiji and Vanuatu and a single L. rouxi from PNG were subspherical to ellipsoidal with a bilayered wall and measured 19.8 × 17.5 µm, and L/W was 1.1. Both micropyle and oocyst residuum were absent, but a single or fragmented polar granule was present. Oocysts of Eimeria lessoni n. sp. from 1 (4%) L. noctua from PNG were cylindroidal with a bilayered wall and measured 28.1 × 15.7 µm, and L/W was 1.8. Both micropyle and oocyst residuum were absent, but a single polar granule was present. These represent the third report of Eimeria spp. reported from any host on PNG and the only coccidians, to our knowledge, ever described from L. noctua and L. rouxi and from the Cook Islands and Vanuatu.