ETIOLOGY AND DEVELOPMENT OF HYPERPLASIA INDUCED BY STREBLONEMA SP. (PHAEOPHYTA) ON MEMBERS OF THE LAMINARIALES (PHAEOPHYTA)1

Filaments of Streblonema sp. isolated from hyperplasia (galls) on Nereocystis luetkeana (Mert.) Post. et Rupr. induced similar gall growths when inoculated on young sporophytes of Nereocystis luetkeana, Macrocystis integrifolia Bory, and Laminaria japonica Aresch. Filaments were irregularly branched and uniseriate with cells 5–8 μm in diameter and 10–30 μm long. Growth under varied cultured conditions produced unilocular sporangia. Zoospores released from the sporangia germinated into identical filaments which also formed unilocular sporangia. Gall tissue originated from the innermost cells of the epidermal meristematic zone. When infected these cells divided in an irregular and unorganized manner. The resulting structure was a pronounced departure from normal morphology.     

Emerging new crown symptoms on Castanea sativa (Mill.): Attempting to model interactions among pests and fungal pathogens

In the 2015–2016 growing seasons, two novel symptoms were assessed on the crown of trees in orchards and coppices of chestnut groves in Central Italy. The first symptom was flagging of annual shoots with green leaves undergoing sudden wilt and turning brown later in the season. The second symptom consisted of leaves on annual shoots turning yellow before wilting in absence of flagging represented the second symptom. Samples were collected along transects in early summer, late summer and winter, and processed in the laboratory. The flagging symptom was associated in early summer with the presence of C. parasitica in cryptic dried buds on stems from the previous year's growth. The pathogen was also found in dormant buds in winter, suggesting that the infection could take place in summer during the Chinese gall wasp oviposition period. Cryphonectria parasitica was also isolated from abandoned galls in winter supporting the hypothesis that galls are a potential source of inoculum for crown infections. Aetiology of yellowing was not clarified and no fungal taxa were specifically associated with this symptom. Gnomoniopsis castanea, C. parasitica and, in early summer, Colletotrichum acutatum were the most abundant fungal taxa isolated from chestnut shoots and buds.     

Autecology and morphology of selected <Emphasis Type="Italic">Vaucheria</Emphasis> species (Xanthophyceae)

In this study, the yellow-green alga Vaucheria was collected from 86 sites with different environmental characteristics. A principal component analysis of the sites revealed a model with four principal components explaining 64.7% of the total variance in the data set. The principal components were interpreted as nutrient enrichment, ions, current, and buffer capacity. In total, seven Vaucheria species were found: V. taylorii, V. debaryana, V. sessilis, V. geminata, V. terrestris, V. walzii, and V. woroniniana. V. taylorii was noted only three times, V. terrestris occured exclusively at terrestrial sites, the remaining taxa were frequent. Vaucheria seems to have its optimal growth at lower temperatures; in the cold season thick covers were observed, which exceeded the abundance in summer. A discriminant analysis revealed that growth types are highly explained by current; high flow velocity favors the development of pads. Species occurrence along artificial gradients consisting of the obtained principal components were analyzed simultaneously by means of a canonical correspondence analysis. V. sessilis occurred widely with no preferences, but three species showed a distinct pattern within the gradient analysis: V. woroniniana mainly occurred at elevated pH and total alkalinity, V. walzii was favored by increased ion contents and slow current, and V. geminata clearly preferred unpolluted sites with decreased pH and alkalinity values. This species may be used as an indicator species for unpolluted locations, however some taxonomic uncertainties remain to be first resolved.     

SEA ICE DIATOMS (BACILLARIOPHYCEAE) OF THE CANADIAN ARCTIC. I. THE GENUS STENONEIS1

Ice diatom assemblages in the Canadian Arctic are dominated by the Naviculaceae, a family which includes the genus Stenoneis Cleve. A taxonomic history of S. inconspicua var. baculus (Cleve) Cleve (including type material of Navicula baculus Cleve) is presented with morphological data including the first SEM views of the genus. Stenoneis inconspicua var. baculus was compared with S. obtuserostrata (Hustedt) comb. nov. (basionym: Navicula obtuserostrata Hustedt). In the SEM, external, short, flattened siliceous ridges were revealed beside the proximal parts of the raphe branches and central pores. This may be a significant taxonomic feature of the genus. Valves of S. inconspicua var. baculus ranged from 40–103 μm in length, 7–11 μm in width and had 17–20 striae in 10 μm, whereas valves of S. obtuserostrata were shorter (27–53 μm), narrower (6–7.5 μm) and more finely striated (24–30 in 10 μm). Both taxa have a circumpolar Arctic distribution.     

Host-Parasite Relationships of Meloidogyne trifoliophila Isolates from New Zealand

Root-infecting nematodes are commonly found on white clover in New Zealand pasture where they reduce yield, nitrogen fixation, and persistence. The dominant root-knot nematode on white clover in New Zealand is confirmed in this study as Meloidogyne trifoliophila by isozyme phenotype comparison with the type population from Tennessee. Results from a host differential test differed in the host ranges of M. trifoliophila and M. hapla from New Zealand locations, with M. trifoliophila failing to reproduce on the standard host plants of the test. The size and character of white clover root galls differ between species as M. trifoliophila galls are large, elongate, and smooth compared to the M. hapla galls, which are small, round, inconspicuous, and generally have adventitious, lateral roots. Culture and identification of root-knot nematode populations from sites in the North Island of New Zealand showed that M. trifoliophila is more widespread and abundant than M. hapla. Similar differential resistant and susceptible galling responses among half-sib families of white clover from a breeding program indicated that all M. trifoliophila populations tested were of the same pathotype. This resistant material was not effective in reducing reproduction of M. hapla. Meloidogyne trifoliophila did not develop to maturity on six grasses tested, but galls were formed on some species.     

Novel Myxobolus and Ellipsomyxa species (Cnidaria: Myxozoa) parasiting Brachyplatystoma rousseauxii (Siluriformes: Pimelodidae) in the Amazon basin,Brazil

We describe two novel myxosporean parasites from Brachyplatystoma rousseauxii, an economically important freshwater catfish from the Amazon basin, Brazil. Myxobolus tapajosi n. sp., was found in the gill filaments of 23.5% of 17 fish, with myxospores round to oval in frontal view and biconvex in lateral view: length 15 (13.5–17) μm and width 10.7 (9.6–11.4) μm; polar capsules equal, length 5.8 (4.6–7.1) μm and width 3 (2.3–3.8) μm containing polar tubules with 6–7 turns. Ellipsomyxa amazonensis n. sp. myxospores were found floating freely or inside plasmodia in the gall bladder of 23.5% of fish. The myxospores were ellipsoidal with rounded extremities: length 12.8 (12.3–13.6) μm and width 7.6 (6.7–8.7) μm; with two equal, slightly pyriform polar capsules, length 3.8 (3.8–4.0) μm and width 3.1 (2.5–3.4) μm, containing polar tubules with 2–3 turns. We combined spore morphometry, small-subunit ribosomal DNA data, specific host, and phylogenetic analyses, to identify both of these parasites as new myxozoan species. Maximum likelihood and Bayesian analyses showed that Myxobolus tapajosi n. sp. clustered in a basal branch in a subclade of parasites from exclusively South American pimelodid fishes. Ellipsomyxa amazonensis n. sp. clustered within the marine Ellipsomyxa lineage, but we suspect that although the parasite was collected in freshwater, its hosts perform a large migration throughout the Amazon basin and may have become infected from a brackish/marine polychaete host during the estuary phase of its life.     

Comparative pollen morphology of Glechoma and Marmoritis (Nepetinae,Lamiaceae)

Abstract The pollen morphology of 13 taxa (34 specimens) of the genera Glechoma L., and Marmoritis Benth. was investigated in detail using light, scanning electron, and transmission electron microscopy. Pollen grains of all studied taxa are small to large in size (P= 32.5–60.4 μm, E= 20.2–50.5 μm), prolate‐spheroidal to prolate in shape and mostly hexacolpate (the amb more or less circular or rarely ellipsoid) with granular membranes. The sexine ornamentation of Glechoma is bireticulate; the muri of the primary reticulum are irregularly circled, and lumen size is short. In contrast, the sexine surfaces of the Marmoritis pollen tend to more elongate or wider at the muri of the primary reticulum than those of the Glechoma. The pollen wall stratification of selected taxa (three from Glechoma and one from Marmoritis) is characterized by unbranched columellae, and continuous or distinctly discontinuous endexine based on transmission electron microscopy observation. The results of Glechoma and Marmoritis reveal rather similar pollen morphological features, however, fine details of sexine ornamentation are characteristic to differentiate the pollen taxa. Although these differences may be useful in establishing the taxonomic boundary between two genera, they are too weak to segregate diagnostic characters.     

Effects of N and P supply on phytoplankton in Bizerte Lagoon (western Mediterranean)

Enriched bottle experiments were conducted in situ during winter (January and February) and summer (July and August) 2001 to examine the effects of nutrient enrichments (+ N, + P and + NP) on phytoplankton in Bizerte Lagoon, Tunisia. Chlorophyll a (Chl a), ranging from 3.05 μg L⁻¹ in winter to 4.52 μg L⁻¹ in summer, was dominated by the small size-faction (<5 μm) during both seasons. However, the contribution of the large size-fraction (5-200 μm) to Chl a increased from winter (26%) to summer (37%). Similarly, the carbon biomass of the 5-200 μm algae increased during the July/August period that was characterised by the high proliferation of several diatom taxa. In winter, N was the limiting element for phytoplankton growth. Its addition alone (+ N) or with P (+ NP) increased both the <5 μm and 5-200 μm Chl a concentrations. There was no change in the phytoplankton size structure, with the small cells dominating the final algal biomass in all treatments after 5 days. In summer, N and P limited the phytoplankton, but small and large algae exhibited diverse responses to different nutrient enrichments: addition of P increased the Chl a only in the 5-200 μm fraction, the + N treatment enhanced both size classes, and the NP fertilisation mostly stimulated the biomass of large cells. Consequently, the N and P addition in summer was followed by a significant change in the phytoplankton size structure, since both size-fractions contributed equally to the final Chl a biomass. Within the 5-200 μm algal community, various taxa had diverse responses to the nutrient supply during both seasons, leading to a change in the final community composition. The autotrophic flagellates appeared to grow well under N-deficient conditions. In contrast, diatom growth and biomass were mostly stimulated by the N enrichment while dinoflagellates exhibited the highest increase in their growth and biomass with P fertilisation. Our results suggest that the increasing anthropogenic supply of nutrients in the lagoon may influence algal dynamics as well as productivity in different ways depending on the nutrient composition.     

A new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from the dusky rice rat Melanomys caliginosus (Tomes) (Mammalia: Rodentia) in Costa Rica

We collected faecal samples from 24 dusky rice rats, Melanomys caliginosus (Tomes) (Rodentia: Cricetidae: Sigmodontinae), in a Biological Reserve in Costa Rica, and found three (12.5%) to be infected with a species of Eimeria Schneider, 1875, which we describe here as new. Sporulated oöcysts of Eimeria caliginosa n. sp. are almost spheroidal and measure 16–21 × 17–20 (mean 19.6 × 18.2) μm; micropyle, oöcyst residuum and polar granule are absent. Sporocysts are ovoidal, 9–13 × 6–8 (mean 11.2 × 6.7) μm, with small Stieda and sub-Stieda bodies present, but a para-Stieda body is absent; the sporocyst residuum is a compact mass of c.11–15 granules, c.5 μm wide. Sporozoites are crescent-shaped, 5–8 × 2–3 (mean 6.8 × 2.4) μm. This is the third species of Eimeria described from the genus Melanomys Thomas.     

ZYGOTE APPENDAGES (CIRRI), A NEW STRUCTURAL FEATURE IN THE SPHAEROPLEACEAE(CHLOROPHYCEAE)1

Cirri are curled appendages borne on the surface of mature zygotes in some members of the green algal family Sphaeropleaceae. Structures equivalent to cirri have not been reported previously in any green algae. We found cirri in four taxa: Sphaeroplea fragilis Buchheim et Hoffman, Atractomorpha porcata Hoffman, and two new undescribed species of Atractomorpha from Africa. Zygotes of seven other sphaeropleacean taxa were examined, but they did not produce cirri. Cirri may be either simple or compound. Simple cirri are less than 0.5 μm in diameter and show no evidence of longitudinal striations or subunits. Compound cirri are more massive (commonly 2.0–3.5 μm, and up to 4 μm diameter in S. fragilis) and possess longitudinal striations suggesting that each is formed of longitudinally arranged subunits ca. 0.5 μm in diameter. Simple and compound cirri are formed by zygotes of all four taxa that produce cirri. Both types may occur on the same zygote. Nonetheless, the patterns of variation in length, shape, and distribution of the two types of cirri are sufficiently distinct to characterize each taxon. Energy dispersive X-ray microanalysis (EDX) shows that cirri lack appreciable mineralization and are thus primarily organic in nature. The potential value of cirri as a taxonomic character in the Sphaeropleaceae is discussed.     

The endogenous development of two new species of Isospora Schneider, 1881 (Apicomplexa: Eimeriidae) from Thai geckoes

Two new species of Isospora are described from Thai geckoes. I. platyurusi n. sp. in Cosymbotus platyurus from Chiang Mai and Khon Kaen and I. uptoni n. sp. in Hemidactylus frenatus from Chiang Mai. Oöcysts of I. platyurusi are spherical to subspherical, 19–22.5 × 16.5–21.5 μm and have two ovoid sporocysts of 11.5–14 × 7.5–9 μm. Oöcysts of I. uptoni are spherical to subspherical, 24–31.5 × 20–27.5 μm and have two ovoid sporocysts of 12.5–15 × 9–11.5 μm. Both species have sporocysts with Stieda bodies and undergo endogenous development in the nucleus of the host gut epithelial cells. On the completion of merogony and gamogony, the host nucleus is reduced to a thin envelope.     

Genetic structure of Eurasian and North American Leymus (Triticeae) wildryes assessed by chloroplast DNA sequences and AFLP profiles

Leymus is a genomically defined allopolyploid of genus Triticeae with two distinct subgenomes. Chloroplast DNA sequences of Eurasian and North American species are distinct and polyphyletic. However, phylogenies derived from chloroplast and nuclear DNA sequences are confounded by polyploidy and lack of polymorphism among many taxa. The AFLP technique can resolve phylogenetic relationships between closely related species, with a curvilinear relationship expected between the proportion of shared bands and nucleotide substitution rate (D), up to about 0.100 D. The objective of this study was to compare D and phylogenetic relationships among 16 Leymus taxa, based on chloroplast DNA sequences and multi-locus AFLP genotypes. Estimates of chloroplast D between taxa were 0.002 and 0.013 within and among continental regions, respectively. Estimates of AFLP D between taxa were 0.076 and 0.093 compared within and between continental regions, respectively, versus 0.024 within taxa. Bayesian and neighbor-joining cluster analyses effectively separated all AFLP genotypes by species, but showed that North American L. ambiguus is a hybrid species with nearly equal contributions from sympatric L. cinereus and L. salinus taxa. Two hierarchical AFLP clades, containing six North American taxa and four Eurasian taxa, had more than 98% bootstrap confidence with 0.071 and 0.055 D among taxa. Three other Eurasian taxa clustered with 79% and 89% confidence, with up to 0.79 D between taxa. These estimates provide benchmarks for phylogenetic comparisons of AFLP profiles, but three taxa could not be reliably grouped, which may reflect concurrent radiation of multiple lineages or lack of homologous AFLP characters caused by a high D.     

Effect of vegetation data collection strategies on estimates of relevant source area of pollen (RSAP) and relative pollen productivity estimates (relative PPE) for non-arboreal taxa

Thirteen surface moss samples were collected for pollen analysis from an area of heathland in western Norway. Vegetation composition at different distances around the sampling locations was measured using three different survey methods; rooted frequency within a sub-divided 1 m × 1 m quadrat, visual estimates of cover within a 1 m × 1 m quadrat and a modified form of the ‘circle-walking method’. Extended R-value analysis was used to explore the pollen–vegetation relationships for five main taxa, Calluna vulgaris, Vaccinium-type, Cyperaceae, Poaceae and Potentilla-type. The estimates of relevant source area of pollen obtained were similar regardless of the vegetation survey method. Values obtained were always under 4 m. However, estimates of relative pollen productivity and the background pollen component (proportion of pollen coming from vegetation growing beyond the relevant source area of pollen) differ markedly depending on the method of vegetation survey chosen. This has important implications for the quantitative reconstruction of past vegetation cover.     

A size analysis of planktic foraminifera from the Arabian Sea

Planktic foraminiferal faunas from different environments in the Arabian Sea were size fractionated using 14 sieves with meshes between 100 and 710 μm, to assess the effect of the sieve mesh size cut off level on the faunal composition and to determine the size frequency distribution of individual species. Nine samples from a plankton pump and a towed net, a sediment trap, a box-core and a piston core were selected, to cover living and settling flux faunas as well as fossil faunas from the sediment. In living faunas, most species show an exponential size frequency distribution, with highest numbers in the finest interval of the size spectrum. In sediment trap and core samples, individual species size frequency distributions may consist of: (1) an exponential distribution of relatively small pre-adult specimens; (2) a Gaussian-shaped distribution of larger specimens, which may be classified as adult or terminal; or (3) a combination of both. The distributions are separated using a best fit technique. The composition of the total planktic foraminiferal fauna strongly changes along the size spectrum. Dominant taxa in >355 μm fractions are Orbulina universa, Globorotalia menardii, Globorotalia tumida, Globigerinella siphonifera and Globigerinoides sacculifer, in 125–355 μm fractions Globigerina bulloides, Globigerinoides ruber, Neogloboquadrina dutertrei and Globigerinita glutinata, and in <125 μm fractions Dentigloborotalia anfracta, Tenuitella compressa, Tenuitella iota, Turborotalita quinqueloba and the immature specimens of larger species. Consequently, the choice of the sieve mesh size strongly determines the percent composition of the assemblage and in turn the paleoceanographic interpretations based on these counts. Species richness and the Shannon diversity increase with decreasing sieve mesh size, while equitability generally decreases with decreasing size. In the water column approximately 60% of the fauna (>100 μm) is present in the 100–125 μm fraction and 1–6% is larger than 250 μm. In samples representing a settling flux (sediment trap and sediment samples) 29–57% of the fauna is present in the 100–125 μm fraction, while 6–23% is larger than 250 μm. Size frequency distributions of the dextral Neogloboquadrina complex (= Neogloboquadrina dutertrei and Neogloboquadrina pachyderma + P–D intergrades) show a bimodal pattern; a smaller peak reflecting dextral Neogloboquadrina pachyderma, and a larger peak of adult Neogloboquadrina dutertrei. By applying a best fit technique to the data, the two species may be separated from each other. In size fractions larger than 150 μm most species have reached the adult stage of ontogeny and we recommend this mesh size for standard faunal analysis. In addition, sieve mesh sizes of 125 and 250 μm have to be used to obtain a reliable estimate of the abundance of small and large species, respectively.     

Silene patula (Siphonomorpha,Caryophyllaceae) in North Africa: A test of colonisation routes using chloroplast markers

Based on morphological characters, the North African Silene patula has been divided into two subspecies, ssp. patula found North of Kabylies and Atlas Mountains, and ssp. amurensis found south of these regions. In order to test the hypothesis that S. patula could have derived from S. italica through the Sicilian Channel during the Messinian, we sequenced three chloroplast loci, trnH–psbA, trnS–trnG and rpl12–rps20. Fifteen haplotypes were found on 211 herbarium specimens, associated with a huge differentiation within species. The hypothesis that S. patula had independently evolved as two different subspecies North and South of the mountains is refuted and a morphological adaptation to different pollinators is suggested to explain the differences between the two taxa. The Kabylies–Numidie–Kroumirie gathers a large proportion of haplotypes, which points to this region as a probable refugium or place of origin from which spatial expansions have subsequently occurred towards Morocco and the Aurès Mountains.     

Late Cretaceous (Cenomanian–Maastrichtian) calcareous nannofossils from Goban Spur (DSDP Sites 549, 551): Implications for the palaeoceanography of the proto North Atlantic

The early late Cretaceous (Cenomanian–early Turonian) is thought to have been one of the warmest periods of the Phanerozoic. This period was characterised by tropical sea surface temperatures of up to 36 °C and a pole-to-equator-gradient of less than 10 °C. The subsequent Turonian–Maastrichtian was characterised by a continuous climatic cooling, peaking in the Maastrichtian. This climatic cooling and the resulting palaeoceanographic changes had an impact on planktic primary producer communities including calcareous nannofossils. In order to gain a better understanding of these Cenomanian–Maastrichtian palaeoceanographic changes, calcareous nannofossils have been studied from the proto North Atlantic (Goban Spur, DSDP Sites 549, 551). In order to see potential differences between open oceanic and shelf dwelling nannofossils, the data from Goban Spur have been compared to findings from the European shelf (northern Germany).A total of 77 samples from Goban Spur were studied for calcareous nannofossils revealing abundant (mean 6.2 billion specimens/g sediment) and highly diverse (mean 63 species/sample) nannofossil assemblages. The dominant taxa are Watznaueria spp. (mean 30.7%), Prediscosphaera spp. (mean 18.3%), Zeugrhabdotus spp. (mean 8.3%), Retecapsa spp. (mean 7.2%) and Biscutum spp. (mean 6.6%). The Cenomanian assemblages of both Goban Spur (open ocean) and Wunstorf (shelf) are characterised by elevated abundances of high fertility taxa like Biscutum spp., Zeugrhabdotus spp. and Tranolithus orionatus. Early Turonian to Maastrichtian calcareous nannofossil assemblages of Goban Spur are, however, quite different to those described from European sections. Oceanic taxa like Watznaueria spp., Retecapsa spp. and Cribrosphearella ehrenbergii dominate in Goban Spur whereas the fertility indicators Biscutum spp. and T. orionatus are more abundant in the European shelf assemblages. This shift from a homogeneous distribution of calcareous nannofossils in the Cenomanian towards a heterogeneous one in the Turonian–Maastrichtian implies a change of the ocean circulation. The “eddy ocean” system of the Cenomanian was replaced by an oceanic circulation similar to the modern one in the Turonian–Maastrichtian, caused by the cooling. The increased pole-to-equator-gradients resulted in an oceanic circulation similar to the modern one.     

Sperm characteristics in plains (Bison bison bison) versus wood (Bison bison athabascae) bison

The objective was to compare sperm characteristics between the two subspecies of North American bison, plains bison (Bison bison bison) and wood bison (Bison bison athabascae). Frozen-thawed ejaculated sperm from age-matched plains (n = 3) and wood (n = 2) bison were evaluated for morphometry, motility, viability, protein profile, and in vitro fertilization characteristics. Sperm morphometry and motility were assessed with computer-based systems, viability was assessed with SYBR-14 and propidium iodide, and fertilizing ability was determined using a heterologous in vitro fertilization system (using bovine oocytes). For plains versus wood bison, there were significant differences for head width (4.76 ± 0.22 vs 4.71 ± 0.19 μm; mean ± SD), head area (35.64 ± 1.91 vs 34.72 ± 2.64 μm²), head perimeter (23.61 ± 0.68 vs 23.31 ± 0.98 μm), midpiece length (14.58 ± 0.4 vs 14.36 ± 0.51 μm), midpiece width (0.81 ± 0.06 vs 0.79 ± 0.07 μm), and tail length (46.61 ± 2.15 vs 45.98 ± 2.08 μm). However, there was no significant difference in head length (overall, 9.04 ± 0.37 μm), progressive motility (41.16 ± 8.39%), or viability (41.58 ± 5.58%). Based on two-dimensional gel electrophoresis, 93 out of 113 protein spots were similar in their expression patterns. Furthermore, we inferred that differences in sperm biometry between these subspecies did not affect in vitro fertilization percentage (overall, 82.62 ± 12.13%). Based on these findings, we concluded that plains bison were an appropriate research model for developing reproductive technologies for wood bison.     

Morphological and molecular characterization of Isospora amphiboluri (Apicomplexa: Eimeriidae), a coccidian parasite,in a central netted dragon (Ctenophorus nuchalis) (De Vis, 1884) in Australia

An Isospora species, Isospora amphiboluri, originally described by Canon in 1967 and later by McAllister et al. (1995), was isolated from a central netted dragon (Ctenophorus nuchalis) housed at a wildlife rehabilitation centre in Perth, Western Australia. Sporulated oocysts of Isospora amphiboluri (n = 30) are spherical, 24.2 (26.5–23.0) μm in length and 23.9 (22.4–25.9) μm in width, with a shape index of 1.01. The bilayered oocyst wall is smooth and light-yellow in color. Polar granule, oocyst residuum and micropyle are absent. The sporocysts are lemon-shaped, 15.7 (15.2–18.0) × 10.2 (8.9–11.2) μm, with a shape index (length/width) of 1.53. Stieda and substieda bodies are present, the Stieda body being small and hemidome-shaped and the substieda half-moon-shaped. Each sporocyst contains four vermiform sporozoites arranged head to tail. The sporozoites are 11.7 (9.9–16.2) × 3.0 (2.4–3.5) μm, with a shape index (length/width) of 3.87. A sporocyst residuum is present. Sporozoites contain a central nucleus with a finely distributed granular residuum. Comparison of oocyst measurements and their features with other valid Isospora species from hosts in the Agamid family confirmed that this Isospora species is Isospora amphiboluri. Molecular characterization of I. amphiboluri at the 18S rRNA and MTCOI loci showed the highest similarity with I. amphiboluri from the central bearded dragon, 99.8% and 99.7% respectively. This is the first report of I. amphiboluri from a central netted dragon in Australia.