Iguanas

Female green iguanas, Iguana iguana, were caught in Belize, Central America (17"N), in December, at the onset of seasonal gonadal activity. The animals were immediately transferred to San Diego (32"N). Ovarian follicular development continued, with peak plasma hormone levels measured in January and February; 200 pg/ml for progesterone (P) and 800 pg/ml for

The iguana had a history of coelomic cavity distention and anorexia of 2 days in duration. The iguana became acutely depressed, lethargic, and dehydrated, which is an atypical occurrence associated with simple anorexia of a few days' duration. There were numerous irregularly shaped, small (0.5-1 cm) masses in the caudal coelom. A mild tachycardia (96 bpm) was present, and the respiratory rate (1 6 breathdmin) was normal. The packed cell volume (37%) and total solids (6.2 g/dl) were normal. Radiography and ultrasonography of the coelom were performed (Figs.

Cryptosporidium infection was associated with colitis and cystitis in 2 green iguanas (Iguana iguana). The disease was characterized by a chronic clinical course of cloacal prolapses and cystitis. Histological examination of the gut and urinary bladder showed numerous Cryptosporidium developmental stages on the surface of the epithelium with mixed inflammatory response in the lamina propria. Cryptosporidium oocysts were visualised in a cytological preparation of the faeces. Based on the small subunit ribosomal RNA gene the cryptosporidia were characterized as belonging to the intestinal cryptosporidial lineage, but not to Cryptosporidium saurophilum or Cryptosporidium serpentis species.

The Fijian crested iguana (Brachylophus vitiensis) is restricted to tropical dry forest habitat and has been extirpated from over 80% of its original range primarily because of habitat destruction. A large population on Yadua Taba island has been proposed as a source for iguana translocations. This study aimed to determine the dietary and habitat requirements of the herbivorous B. vitiensis on Yadua Taba to identify essential tree species. Between September 2005 and June 2006 we examined the diet of B. vitiensis using faecal analyses, while perch preferences were examined using field surveys. Faecal analyses identified 26 plant species in the diet of B. vitiensis, while field surveys recorded iguanas in 33 tree species. The most common diet species largely overlapped with the most common perch species. There were no major seasonal shifts, sex differences, or age-class variations in diet or perch preferences. These results suggest that while B. vitiensis occurs in and consumes several plant species on Yadua Taba, it is primarily dependent on only a few species. To improve translocation success, future translocations of B. vitiensis need to ensure that these important tree species are present at new sites.

INTRODUCCIÓN: La Iguana negra es una especie endémica de México, su distribución es bastante amplia, encontrándose desde Sinaloa hasta Chiapas, también en los estados de Durango, Nayarit, Jalisco, Colima, Michoacán, Morelos Guerrero, Puebla, Oaxaca y Zacatecas (1,2). Es una iguana de talla grande, larga y robusta, con párpados móviles y cola larga con púas características; la cabeza es larga y aplanada, el color del cuerpo es uniforme negro con manchas dispersas de color blanco-amarillentas, además de que la cabeza siempre es de color negra. (3) En algunas regiones de México, la iguana negra ha sido considerada una fuente de alimento desde mucho tiempo atrás (1), tan atrás que se han encontrado restos arqueológicos que muestran que la cultura maya utilizaba a la iguana negra como fuente de alimento (4). Actualmente es utilizada como fuente de proteína, principalmente en regiones rurales del país, no obstante no solo la carne es aprovechada sino que también los huevos y la piel son utilizados para su comercialización en diversas actividades (1,5); sin embargo este aprovechamiento excesivo, la utilización de su hábitat para suelos ganaderos o para la construcción de vías para uso humano, las falsas creencias en diversos poblados y también la venta y comercialización ilegal ha llevado a que las poblaciones en vida silvestre se vean en declive (5,6). En México la demanda anual es de 12,500 ejemplares, en donde los criaderos registrados son capaces de abastecer 2,500 ejemplares anualmente (6), lo que lleva a centrar miras a este ejemplar, principalmente para poder abastecer esas necesidades que el país requiere y para poder evitar que la población siga en declive, además de que desarrollar sistemas de crianza en unas

The widespread montane Mexican horned lizard Phrynosoma orbiculare (Squamata: Phrynosomatidae) represents an ideal species to investigate the relative impacts of Neogene vicariance and Quaternary climate change on lineage diversification across the Mexican highlands. We used mitochondrial DNA to examine the maternal history of P. orbiculare and estimate the timing and tempo of lineage diversification. Based on our results, we inferred 11 geographically structured, well supported mitochondrial lineages within this species, suggesting P. orbiculare represents a species complex. Six divergences between lineages likely occurred during the Late Miocene and Pliocene, and four splits probably happened during the Pleistocene. Diversification rate appeared relatively constant through time. Spatial and temporal divergences between lineages of P. orbiculare and co-distributed taxa suggest that a distinct period of uplifting of the Transvolcanic Belt around 7.5-3 million years ago broadly impacted diversification in taxa associated with this mountain range. To the north, several river drainages acting as filter barriers differentially subdivided co-distributed highland taxa through time. Diversification patterns observed in P. orbiculare provide additional insight into the mechanisms that impacted differentiation of highland taxa across the complex Mexican highlands.

Guide to Lizards is an essential directory to more than 300 lizard species, including readily available terrarium choices plus dozens of seldom seen and rare species that are of great interest to hobbyists and travelers alike. Written by an acknowledged expert on lizards, each profile contains information on size, range, habitat, natural history, care, and suitability as a pet. Profiles are color-coded and organized by native region and feature discussion of how to find lizards in their habitat, making this an excellent book for outdoor-loving hobbyists and ecotourists. Full-color photos of species, subspecies, and color variants are complimented by informative sidebars.

Carotenoids have received much attention from biologists because of their ecological and evolutionary implications in vertebrate biology. We sampled Galápagos land iguanas (Conolophus subcristatus) to investigate the types and levels of blood carotenoids and the possible factors affecting inter-population variation. Blood samples were collected from populations from three islands within the species natural range (Santa Cruz, Isabela, and Fernandina) and one translocated population (Venecia). Lutein and zeaxanthin were the predominant carotenoids found in the serum. In addition, two metabolically modified carotenoids (anhydrolutein and 3V-dehydrolutein) were also identified. Differences in the carotenoid types were not related to sex or locality. Instead, carotenoid concentration varied across the localities, it was higher in females, and it was positively correlated to an index of body condition. Our results suggest a possible sex-related physiological role of xanthophylls in land iguanas. The variation in the overall carotenoid concentration between populations seems to be related to the differences in local abundance and type of food within and between islands. D

The persistence of reptile populations in a specific location is influenced by individuals' capacity to regulate their body temperatures, among other factors. Anthropogenic climate change may pose a risk to the survival of ectothermic animals due to their dependence on external heat sources to thermoregulate. In this study, we calculated indices of thermal habitat quality, thermoregulatory precision, and thermoregulatory effectiveness for the endemic spiny-tailed iguana Ctenosaura oaxacana. We evaluated these indices and the thermoregulatory behavior of the iguanas in the four types of vegetation that provide the most favorable conditions for thermoregulation. We also performed our experiments during both the wet and dry seasons to capture the full range of thermal conditions available to C. oaxacana over the course of a year. Finally, we evaluated the potential niche for the iguana in the years 2020, 2050, and 2080. Thermoregulation depends on both seasonal and environmental factors in this species. We found that thermoregulation effectiveness in both wet and dry seasons depends not only on the thermal conditions of the immediate environment, but also on the cover vegetation and habitat structure available across the range of habitats the species uses. Thus, heterogeneous habitats with dispersed vegetation may be most suitable for this species' thermoregulatory strategy. Likewise, niche modeling results suggested that suitable habitat for our study species may continue to be available for the next few decades, despite global warming tendencies, as long as cover vegetation remains unaltered. Our results suggest that thermoregulation is a complex process that cannot be generalized for all ectothermic species inhabiting a given region. We also found that temperature changes are not the only factor one must consider when estimating the risk of species loss. To understand the necessary thermal conditions and extinction risk for any ectothermic species, it is necessary to focus studies on the species' general ecology.

While Quaternary climatic changes are considered by some to have been a major factor promoting speciation within the neotropics, others suggest that much of the neotropical species diversity originated before the Pleistocene. Using mitochondrial and nuclear sequence data, we evaluate the relative importance of Pleistocene and pre-Pleistocene events within the evolutionary history of the Mexican iguana Ctenosaura pectinata, and related species. Results support the existence of cryptic lineages with strong mitochondrial divergence (> 4%) among them. Some of these lineages form zones of secondary contact, with one of them hybridizing with C. hemilopha. Evolutionary network analyses reveal the oldest populations of C. pectinata to be those of the northern and southern Mexican coastal regions. Inland and mid-latitudinal coastal populations are younger in age as a consequence of a history of local extinction within these regions followed by re-colonization. Estimated divergence times suggest that C. pectinata originated during the Pliocene, whereas geographically distinct mitochondrial DNA lineages first started to diverge during the Pliocene, with subsequent divergence continuing through the Pleistocene. Our results highlight the influence of both Pliocene and Pleistocene events in shaping the geographical distribution of genetic variation within neotropical lowland organisms. Areas of high genetic diversity in southern Mexico were detected, this finding plus the high levels of genetic diversity within C. pectinata, have implications for the conservation of this threatened species.

Iguaninae is a monophyletic taxon of tetrapodous squamates (lizards) that can be distinguished from other iguanians by at least five synapomorphies. Skeletal variation within Iguaninae is described and forms the basis of systematic characters used to determine phylogenetic relationships among eight basic taxa, the currency recognized iguanine genera. Evolutionary character polarities are determined by comparison with four closely related taxa, basiliscines, crotaphytines, morunasaurs, and oplurines.
    The distributions of derived characters among iguanine taxa suggest that: (1) Either Brachylophus or Dipsosaurus is the sister group of the remaining iguanines (Iguanini). (2) Dipsosaurus is a monophyletic taxon diagnosed by at least six synapomorphies. (3) Brachylophus is a monophyletic taxon diagnosed by at least eight synapomorphies. (4) Iguanini, containing Amblyrhynchus, Conolophus, Ctenosaura, Cyclura, Iguana, and Sauromalus, is a new monophyletic taxon diagnosed by at least three synapomorphies. (5) Within Iguanini, the relationships among four taxa--Ctenosaura, Sauromalus, Amblyrhynchina, and Iguanina--are unresolved. (6) Ctenosaura is a monophyletic taxon diagnosed by at least three synapomorphies. (7) Enyaliosaurus is monophyletic, but it is a subgroup of Ctenosaura rather than a separate taxon. If Enyaliosaurus is separated from Ctenosaura, then Ctenosaura is not monophyletic. (8) Sauromalus is a monophyletic taxon diagnosed by at least 24 synapomorphies, many of which are convergent in  Amblyrhynchus. (9) Amblyrhynchina is a new monophyletic taxon containing the Galapagos iguanas Amblyrhynchus and Conolophus, and is diagnosed by at least 11 synapomorphies. (10) Amblyrhynchus is a monophyletic taxon diagnosed by at least 28 synapomorphies and is perhaps the most divergent iguanine from the most recent common ancestor of all of them. Many of the unique features of Amblyrhynchus appear to be related to its unique natural history. (11) Conolophus is a monophyletic taxon diagnosed by at least eight synapomorphies and cannot, therefore, be considered ancestral to Amblyrhynchus. (12) Iguanina is a new monophyletic taxon composed oi Iguana and Cyclura and is diagnosed by at least three synapomorphies. (13) Iguana is a monophyletic taxon diagnosed by at least seven synapomorphies. (14) Monophyly of Cyclura is a problem in need of further study. Although three ostensible synapomorphies support monophyly of Cyclura, other derived characters suggest that some Cyclura shared a more recent common ancestor with Iguana than with other Cyclura.
    Summaries of Iguaninae and its monophyletic subgroups down to the level of the eight basic taxa are provided; each summary includes the type of the taxon, etymology of the taxon name, a phylogenetic definition, geographic distribution, a list of diagnostic synapomorphies, the fossil record, and various comments.

Unlike extant birds and mammals, most non-avian theropods had large muscular tails, with muscle arrangements similar to those of modern reptiles. Examination of ornithomimid and tyrannosaurid tails revealed sequential diagonal scarring on the lateral faces of four or more hemal spines that consistently correlates with the zone of the tail just anterior to the disappearance of the vertebral transverse processes. This sequential scarring is interpreted as the tapering boundary between the insertions of the M. caudofemoralis and the M. ilioischiocaudalis. Digital muscle reconstructions based on measurements of fossil specimens and dissections of modern reptiles showed that the M. caudofemoralis of many non-avian theropods was exceptionally large. These high caudofemoral mass estimates are consistent with the elevation of the transverse processes of the caudal vertebra above the centrum, which creates an enlarged hypaxial region. Dorsally elevated transverse processes are characteristic of even primitive theropods and suggest that a large M. caudofemoralis is a basal characteristic of the group. In the genus Tyrannosaurus, the mass of the M. caudofemoralis was further increased by dorsoventrally lengthening the hemal arches. The expanded M. caudofemoralis of Tyrannosaurus may have evolved as compensation for the animal's immense size. Because the M. caudofemoralis is the primary hind limb retractor, large M. caudofemoralis masses and the resulting contractile force and torque estimates presented here indicate a sizable investment in locomotive muscle among theropods with a range of body sizes and give new evidence in favor of greater athleticism, in terms of overall cursoriality, balance, and turning agility.

Multiple subcutaneous masses from two sibling bearded dragons were removed. Nodules were well demarcated, restricted to the subcutis, and soft, white to yellow, resembling adipose tissue. Histologically, the masses were composed of short interlacing streams and bundles of spindle cells, with regions of vague nuclear palisading. Two of the tumors contained a subpopulation of polygonal cells with abundant periodic acid-Schiff (PAS)-positive cytoplasmic granules. Neoplastic cells were immunohistochemically positive for S100 and neuron-specific enolase (NSE) but negative for desmin and smooth muscle actin. Electron microscopy and reticulin stains demonstrated a continuous basal lamina separating intertwining cells. Histologic, ultrastructural, and immunohistochemical features were consistent with a peripheral nerve sheath origin. At 1 year postexcision, local reoccurrence of a single incompletely excised mass from the left shoulder was noted.

The Paris Natural History Museum herpetological collection (MNHN-RA) has seven historical specimens of Brachylophus spp. collected late in the 18<sup>th</sup> and early in the 19th centuries. Brachylophus fasciatus was described in 1800 by Brongniart but its type was subsequently considered as lost and never present in MNHN-RA collections. We found that 220 year old holotype among existing collections, registered without any data, and we show that it was donated to MNHN-RA from Brongniart's private collection after his death in 1847. It was registered in the catalogue of 1851 but without any data or reference to its type status. According to the coloration (uncommon midbody saddle-like dorsal banding pattern) and morphometric data given in its original description and in the subsequent examination of the type in 1802 by Daudin and in 1805 by Brongniart we found that lost holotype in the collections. Another MNHN-RA specimen has Horn Islands (Wallis and Futuna) as the...

We compared the natural ultraviolet B (UV-B) exposure, dietary vitamin D, and skin-generated vitamin D synthesis for adult males of two species of Jamaican anoles. The more shadetolerant and thermal-conforming Anolis lineotopus merope, rarely exposed to full sun, experienced less UV-B irradiation in its shady environment than the more heliophilic and thermophilic Anolis sagrei, which frequently basked in full sun during the morning hours (0800-1100 hours). Both species obtained detectable levels of vitamin D 3 in their diet, but the heliophilic A. sagrei obtained more. To compensate for less availability of UV-B and dietary vitamin D, the skin of A. lineotopus merope seems to have acquired a greater sensitivity than that of A. sagrei regarding UV-B-induced vitamin D 3 photobiosynthesis. We assessed this by observing a greater conversion of provitamin D to photoproducts in skin exposed to UV-B from a sunlamp. The reduced skin sensitivity of A. sagrei regarding vitamin D photobiosynthesis may reflect a correlated response associated with less need for vitamin D photobiosyn-* thesis and greater need for UV-B screening capacity as an adaptation to a more damaging UV-B environment. However, the possibility that adaptations for photobiosynthesis of vitamin D and for protection from skin damage could involve independent mechanisms needs investigation. Also, the ability to behaviorally regulate UV-B exposure, as shown for the panther chameleon, would benefit both species of Anolis and should be investigated.

The reptile Iguana iguana exhibits four states of vigilance: active wakefulness (AW), quiet wakefulness (QW), quiet sleep (QS) and active sleep (AS). Cerebral activity decreases in amplitude and frequency when passing from wakefulness to QS. Both parameters show a slight increase during AS. Heart rate is at a maximum during AW (43.8 ± 7.9 beats/min), decreases to a minimum in QS (25.3 ± 3.2 beats/min) and increases in AS (36.1 ± 5.7 beats/min). Tonical and phasical muscular activity is present in wakefulness, decreases or disappears in QS and reappears in AS. Single or conjugate ocular movements are observed during wakefulness, then disappear in QS and abruptly reappear in AS. Although these reptiles are polyphasic, their sleep shows a tendency to concentrate between 20:00 and 8:00 h. Quiet sleep occupies the greater percentage of the total sleep time. Active sleep episodes are of very short duration, showing an average of 21.5 ± 4.9 (mean ± SD). Compensatory increment of sleep following its total deprivation was significant only for QS. Reaction to stimuli decreased significantly when passing from wakefulness to sleep. It is suggested that the lizard I. iguana displays two sleep phases behaviorally and somatovegetatively similar to slow wave sleep and paradoxical sleep in birds and mammals. Comparative Biochemistry and Physiology, Part A 151 (2008) 305 -312 www.elsevier.com/locate/cbpa ☆ This paper is part of the 5th special issue of CBP dedicated to The Face of Latin American Comparative Biochemistry and Physiology organized by Marcelo Hermes-Lima (Brazil) and co-edited by Carlos Navas (Brazil), Rene Beleboni (Brazil), Carolina A. Freire (Brazil), Tania Zenteno-Savín (Mexico) and the editors of CBP. This issue is dedicated to the memory of Knut Schmidt-Nielsen (1915-2007), a great mind in comparative physiology, with books translated into 16 languages, including Spanish and Portuguese, and Cicero Lima , journalist, science lover and Hermes-Lima's dad.

The generally accepted framework for the evolution of a key feature of the avian respiratory system, unidirectional airflow, is that it is an adaptation for efficiency of gas exchange and expanded aerobic capacities, and therefore it has historically been viewed as important to the ability of birds to fly and to maintain an endothermic metabolism. This pattern of flow has been presumed to arise from specific features of the respiratory system, such as an enclosed intrapulmonary bronchus and parabronchi. Here we show unidirectional airflow in the green iguana, a lizard with a strikingly different natural history from that of birds and lacking these anatomical features. This discovery indicates a paradigm shift is needed. The selective drivers of the trait, its date of origin, and the fundamental aerodynamic mechanisms by which unidirectional flow arises must be reassessed to be congruent with the natural history of this lineage. Unidirectional flow may serve functions other than expa...

"Originally published in 1992, Giant Lizards is a bestselling reference held in high regard within every level of the herpetological community for its authoritative and thorough coverage of lizard biology.

Now in a completely revised and expanded volume, Giant Lizards features all newly written information by an expert on monitors and other large lizards (defined as those reaching over 3 feet in length) and it covers over 90 species. Lizard profiles range from the relatively affordable to the extremely expensive, and from those commonly kept as pets to those critically endangered and unobtainable. Species include iguanas (including green iguanas), rock iguanas, Galapagos Island iguanas, tegus, sail-fin lizards, Gila monsters, beaded lizards, water dragons, monitors (including savannah, water, and Nile monitors plus Komodo dragons), and more."

We collected ectoparasites from 27 of 51 wild-caught, free-ranging exotic reptiles examined in Florida from 2003 to 2008. Sampled animals represented eight species, Þve of which yielded ectoparasites. Reported new parasite distribution records for the United States include the following: the Þrst collection of the African tick Amblyomma latum (Koch) from a wild-caught animal [ball python, Python regius (Shaw)] in the United States; the Þrst collection of the lizard scale mite Hirstiella stamii (Jack) from any wild-caught animal [green iguana, Iguana iguana (L.)]; and the Þrst collection of the lizard scale mite Geckobia hemidactyli (Lawrence) in the continental United States from a wild-caught tropical house gecko, Hemidactylus mabouia (Moreau de Jonnè s). We also report the Þrst collections of the Neotropical ticks Amblyomma rotundatum (Koch) and Amblyomma dissimile (Koch) from wild-caught Burmese pythons, Python molurus bivittatus (Kuhl); the Þrst collections of A. dissimile from a wild-caught African savannah monitor, Varanus exanthematicus (Bosc); and from wild-caught green iguanas in the United States; and the Þrst collections of the native chiggers Eutrombicula splendens (Ewing) and Eutrombicula cinnabaris (Ewing) from wild-caught Burmese pythons. These reports may only suggest the diversity of reptile ectoparasites introduced and established in Florida and the new hostÐparasite relationships that have developed among exotic and native ectoparasites and established exotic reptiles.

The effects of the direct interaction between hybridization and speciation-two major contrasting evolutionary processes-are poorly understood. We present here the evolutionary history of the Galápagos marine iguana (Amblyrhynchus cristatus) and reveal a case of incipient within-island speciation, which is paralleled by between-island hybridization. In-depth genome-wide analyses suggest that Amblyrhynchus diverged from its sister group, the Galápagos land iguanas, around 4.5 million years ago (Ma), but divergence among extant populations is exceedingly young (less than 50 000 years). Despite Amblyrhynchus appearing as a single long-branch species phylogenetically, we find strong population structure between islands, and one case of incipient speciation of sister lineages within the same island-ostensibly initiated by volcanic events. Hybridization between both lineages is exceedingly rare, yet frequent hybridization with migrants from nearby islands is evident. The contemporary snaps...

The histological and physiological effects of the removal of superficial corneous epidermal materials have been studied in several squamate species and a caiman. The gross and microscopic anatomy of the squamate integument has characteristics which make cellophane stripping inherently variable, but in general, when corneous materials were removed, they are replaced over a period of one to two weeks, by a tissue with the histological characteristics of the normal alpha-layer. This tissue may be produced by stimulated germinal activity and/or metaplasia of the other presumptive cell populations. In caiman, the thickness of the corneous tissues of the outer scale surface is reduced by stripping and the tissue is restored to normal in approximately two weeks by stimulated germinal proliferation. Measurements of cutaneous water loss (CWL) before, immediately after, and during two weeks post-trauma revealed the following. There is a sudden rise in CWL immediately after stripping, and valu...

The persistence of reptile populations in a specific location is influenced by individuals' capacity to regulate their body temperatures, among other factors. Anthropogenic climate change may pose a risk to the survival of ectothermic animals due to their dependence on external heat sources to thermoregulate. In this study, we calculated indices of thermal habitat quality, thermoregulatory precision, and thermoregulatory effectiveness for the endemic spiny-tailed iguana Ctenosaura oaxacana. We evaluated these indices and the thermoregulatory behavior of the iguanas in the four types of vegetation that provide the most favorable conditions for thermoregulation. We also performed our experiments during both the wet and dry seasons to capture the full range of thermal conditions available to C. oaxacana over the course of a year. Finally, we evaluated the potential niche for the iguana in the years 2020, 2050, and 2080. Thermoregulation depends on both seasonal and environmental factors in this species. We found that thermoregulation effectiveness in both wet and dry seasons depends not only on the thermal conditions of the immediate environment, but also on the cover vegetation and habitat structure available across the range of habitats the species uses. Thus, heterogeneous habitats with dispersed vegetation may be most suitable for this species' thermoregulatory strategy. Likewise, niche modeling results suggested that suitable habitat for our study species may continue to be available for the next few decades, despite global warming tendencies, as long as cover vegetation remains unaltered. Our results suggest that thermoregulation is a complex process that cannot be generalized for all ectothermic species inhabiting a given region. We also found that temperature changes are not the only factor one must consider when estimating the risk of species loss. To understand the necessary thermal conditions and extinction risk for any ectothermic species, it is necessary to focus studies on the species' general ecology.

We compared the natural ultraviolet B (UV-B) exposure, dietary vitamin D, and skin-generated vitamin D synthesis for adult males of two species of Jamaican anoles. The more shadetolerant and thermal-conforming Anolis lineotopus merope, rarely exposed to full sun, experienced less UV-B irradiation in its shady environment than the more heliophilic and thermophilic Anolis sagrei, which frequently basked in full sun during the morning hours (0800-1100 hours). Both species obtained detectable levels of vitamin D 3 in their diet, but the heliophilic A. sagrei obtained more. To compensate for less availability of UV-B and dietary vitamin D, the skin of A. lineotopus merope seems to have acquired a greater sensitivity than that of A. sagrei regarding UV-B-induced vitamin D 3 photobiosynthesis. We assessed this by observing a greater conversion of provitamin D to photoproducts in skin exposed to UV-B from a sunlamp. The reduced skin sensitivity of A. sagrei regarding vitamin D photobiosynthesis may reflect a correlated response associated with less need for vitamin D photobiosyn-* thesis and greater need for UV-B screening capacity as an adaptation to a more damaging UV-B environment. However, the possibility that adaptations for photobiosynthesis of vitamin D and for protection from skin damage could involve independent mechanisms needs investigation. Also, the ability to behaviorally regulate UV-B exposure, as shown for the panther chameleon, would benefit both species of Anolis and should be investigated.

Little is known regarding the ultrastructure of the genus Fallisia (Apicomplexa: Haemosporina: Garniidae). This report describes the fine structure of some developmental stages of Fallisia audaciosa that infect neutrophils in the peripheral blood of the Amazonian lizard Plica umbra (Reptilia: Iguanidae). The parasites lie within a parasitophorous vacuole and exhibit the basic structures of members of the Apicomplexa, such as the pellicle and the cytostome. Invaginations of the inner membrane complex were seen in the gametocytes and may be concerned with nutrition. The meronts were irregularly shaped before division, a feature unusual among members of the Apicomplexa. The unusual presence of a parasitic protozoan within neutrophils, in some way interfering with or modulating the microbicidal activity of such cells, is discussed.

Background: Melioidosis caused by Burkholderia (B.) pseudomallei is an endemic zoonotic disease mainly reported from northern Australia and Southeast Asia. In Europe, cases of human melioidosis have been reported only from patients travelling to endemic regions. Besides humans, B. pseudomallei has a very broad host range in domestic and wild animals. There are some reports about importation of B. pseudomallei-infected animals from endemic areas into Europe. The present report describes the first case of B. pseudomallei infection of a pet iguana in Europe. Case presentation: In a 5-year-old pet Iguana iguana living in a private household in Prague, Czech Republic, B. pseudomallei was isolated from pus of an abscess. The isolate VB976100 was identified by Vitek®2, MALDI-TOF mass spectrometry and polymerase chain reaction as B. pseudomallei. The molecular typing resulted in multi-locus sequence type 436 hitherto, which has been found only once worldwide in a B. pseudomallei strain isolated in the USA and originating from Guatemala. The identification as internal transcribed spacer type G indicates a close relatedness to strains mainly isolated in the Western Hemisphere. These findings support the hypothesis that the iguana became infected in this region or in a breeding facility through contact to other infected animals.

A two-phase cross-over therapeutic study was performed with 19 green iguanas (Iguana iguana) maintained within a preferred optimum temperature range of 26 to 37 degrees C. During phase 1, they were fed a normal vegetarian diet and medicated orally with either allopurinol or a placebo control once a day for seven days. Uric acid concentrations, total protein, packed-cell volumes (pcv) and bodyweights were recorded from each lizard before and after treatment to determine the effects of allopurinol. In phase 2, after a 10-day washout period, the iguanas were fed a high protein diet to induce hyperuricaemia. Normo- and hyperuricaemic iguanas that received 24.2 (3.2) mg/kg allopurinol had significantly lower mean (sd) uric acid concentrations (100.3 [53.1] micromol/l) than the controls (159.3 [100.3] micromol/l). There were no detectable interactions between the doses of allopurinol or placebo, and the iguanas' diet, weight, pcv or total protein. The allopurinol was well tolerated, a...

Objective To assess the cardiovascular e¡ects (arterial blood pressure, heart rate, and metabolic acidb ase status) of three doses (MAC multiples) of iso£urane alone and combined with butorphanol in the green iguana (Iguana iguana). Study design Prospective randomized double-blind, two-period cross-over trial. Animals Six mature healthy green iguanas (Iguana iguana). Methods The iguanas received each of two treatments, saline 0.1 mL kg À1 (SAL) and butorphanol 1.0 mg kg À1 (BUT) during iso£urane anesthesia. Treatments were separated by at least 1 week. The iguanas were exposed to each of the three minimum alveolar concentration (MAC) multiples (1.0, 1.5, and 2.0) in random order. Anesthesia was induced with iso£urane and maintained using controlled ventilation. Instrumentation included use of an ECG, airway gas monitor, cloacal thermometer, esophageal pulse oximeter, and the placement of a femoral arterial catheter. Body temperature was stabilized and maintained at 32 8C. The treatment was administered, and the animals were equilibrated for 20 minutes at each MAC multiple. At each concentration, the heart rate, blood pressure (systolic, mean, diastolic), endtidal CO 2 , and SpO 2 were measured. At 1.0 and 2.0 MAC, simultaneous blood samples were drawn from the tail vein/artery complex and femoral catheter for blood gas analysis. Data were analyzed using a twoway analysis of variance for repeated measures looking for di¡erences between treatments and among MAC multiples. Results There were no signi¢cant di¡erences in any of the cardiovascular variables between the treatments. Signi¢cant di¡erences among iso£urane MAC multiples were observed for HR, mean, diastolic, and systolic blood pressures. Blood pressure and heart rate decreased with an increasing dose of anesthetic. There were no signi¢cant di¡erences between treatments or MAC multiples for any of the blood gas variables. The blood pH, PCO 2 , HCO 3 À , and hemoglobin saturation di¡ered signi¢cantly between sites. Pulse oximetry values measured from the carotid complex did not correlate with and were signi¢cantly di¡erent from the calculated hemoglobin saturation values determined using the gas analyzer. Conclusion and clinical relevance Cardiovascular depression associated with iso£urane anesthesia in the green iguana is dose dependent. The degree of cardiovascular depression was not signi¢cantly different when iso£urane was combined with butorphanol. This ¢nding suggests that the pre-emptive or intraoperative use of butorphanol is unlikely to be detrimental to cardiovascular function. Butorphanol may be a useful anesthetic adjunct to iso£urane anesthesia in the green iguana.

The El Niñ o-Southern Oscillation (ENSO) is a major source of climatic disturbance, impacting the dynamics of ecosystems worldwide. Recent models predict that human-generated rises in green-house gas levels will cause an increase in the strength and frequency of El Niñ o warming events in the next several decades, highlighting the need to understand the potential biological consequences of increased ENSO activity. Studies have focused on the ecological and demographic implications of El Niñ o in a range of organisms, but there have been few systematic attempts to measure the impact of these processes on genetic diversity in populations. Here, we evaluate whether the 1997-1998 El Niñ o altered the genetic composition of Galá pagos marine iguana populations from eleven islands, some of which experienced mortality rates of up to 90% as a result of El Niñ o warming. Specifically, we measured the temporal variation in microsatellite allele frequencies and mitochondrial DNA diversity (mtDNA) in samples collected before (1991/1993) and after the El Niñ o event. Based on microsatellite data, only one island (Marchena) showed signatures of a genetic bottleneck, where the harmonic mean of the effective population size (N e ) was estimated to be less than 50 individuals during the period between samplings. Substantial decreases in mtDNA variation between time points were observed in populations from just two islands (Marchena and Genovesa). Our results suggests that, for the majority of islands, a single, intense El Niñ o event did not reduce marine iguana populations to the point where substantial neutral genetic diversity was lost. In the case of Marchena, simultaneous changes to both nuclear and mitochondrial DNA variation may also be the result of a volcanic eruption on the island in 1991. Therefore, studies that seek to evaluate the genetic impact of El Niñ o must also consider the confounding or potentially synergistic effect of other environmental and biological forces shaping populations.