Ctenosaura Similis Research Articles

The use of a hand-held smartphone device for non-invasive thermal observations of the Black Spiny-tailed Iguana (Ctenosaura similis) in Panama

The use of a hand-held smartphone device for non-invasive thermal observations of the Black Spiny-tailed Iguana (Ctenosaura similis) in Panama

Helmintos de la República de Costa Rica XVI. Parallopharynx gonzalezi n. sp. (Trematoda: Plagiorchidae)

A new species, Parllopharynx is described. This species formely found in Basiliscus sp., is reported for Ctenosaura similis similis here considered as a new host for the genus.

Sex‐specific antipredator response to auditory cues in the black spiny‐tailed iguana

AbstractThe selective pressures exerted by predation can have considerable influence on the behavior of prey species across a wide range of taxa. Within a species, this force may differ between the sexes, leading to sex‐specific behavioral responses to predators. We tested whether the black spiny‐tailed iguana Ctenosaura similis is able to use auditory cues to detect an avian predator and whether antipredator responses differ in a sex‐dependent fashion. We conducted behavioral assays in which a food item was used as bait while iguanas were subjected to a recording of a Harris's hawk or white noise as a control. We found that a significantly greater percentage of individuals of either sex responded to the hawk call than to the white noise. We also found that a significantly greater percentage of females than males responded to either sound. These results suggest that not only do black spiny‐tailed iguanas incorporate auditory cues into predator detection, but that antipredator behavioral responses differ between the sexes as well. Such sex‐specific behaviors can be attributed to morphological and endocrine differences between male and female iguanas. These findings may also lend insight into how behavior can influence the evolution of sexual dimorphism within a species.

Successful Establishment of a Non-Native Species after an Apparent Single Introduction Event: Investigating ND4 Variability in Introduced Black Spiny-Tailed Iguanas (Ctenosaura similis) in Southwestern Florida

Recent studies on invasive species have led to the development of an apparent paradox when trying to explain how populations succeed after experiencing genetic bottlenecks in their new environments. Many introduced populations retain genetic diversity from multiple introduction events, but others that resulted from a single introduction event are expected to have low genetic diversity and low evolutionary potential. Introduced Black Spiny-Tailed Iguanas (Ctenosaura similis) on a barrier island (Keewaydin Island (KI)) in subtropical Florida are thought to be the result of a single introduction of a small founder group, although this population has expanded significantly since its founding in 1995. We investigated the presence of this genetic paradox by determining the genetic variation of this introduced population. We extracted DNA from muscle tissue samples (N = 21) and sequenced a region of the ND4 gene to allow for comparison with previously described native Ctenosaura populations. We documented a single haplotype from KI, which means this iguana population likely descended from a single introduction event and one geographic source population (Honduras). If this single haplotype represents an overall reduction in genetic diversity, then this population demonstrates that genetic variability is not always necessary for a species to become established in a new ecological range. This interpretation may have strong implications for invasive species management. The anthropogenic spread of animal and plant species continues to disturb native ecosystems and impact global biodiversity. Although such translocations are increasingly

Lizards (Reptilia: Squamata) of the Corn Islands, Caribbean Nicaragua

The Corn Islands are two small Caribbean islands with the richest collection of endemic herpetofaunal taxa in Nicaragua. Despite increasing human population and associated habitat alteration, both islands lack protected areas. The lizard fauna of Great Corn Island consists of 14 species corresponding to nine families, and includes three endemic taxa. We collected three lizard species (Corytophanes cristatus, Gonatodes albogularis, and Hemidactylus frenatus) that were not previously recorded from that island. On Little Corn Island, where there were no previous records of lizards, we found seven species (Ctenosaura similis, Gonatodes albogularis, Hemidactylus frenatus, Holcosus undulatus, Iguana iguana, Lepidodactylus lugubris, and Norops unilobatus), all of which are also present on Great Corn Island.

ORAL FIBROSARCOMA IN A BLACK IGUANA (CTENOSAURA PECTINATA)

A case of oral fibrosarcoma in a 13-yr-old male black iguana (Ctenosaura pectinata) is reported here. The iguana exhibited new tissue formation involving a large part of the maxilla and hard palate, which histologically and ultrastructurally corresponded to a primary fibrosarcoma of the oral cavity. Although there are reports of fibrosarcomas in other reptiles, such as snakes and crocodiles, no reports of this neoplasm in the oral cavity of an iguana were reported, which suggests that it is either infrequent or infrequently sampled for histological diagnosis. As an isolated case in an adult iguana living at a conservation center, it is likely that this diagnosis is associated with advanced age. The prognosis is considered unfavorable.

Identification of a Novel Splicing Form of Amelogenin Gene in a Reptile, Ctenosaura similis

Amelogenin, the major enamel matrix protein in tooth development, has been demonstrated to play a significant role in tooth enamel formation. Previous studies have identified the alternative splicing of amelogenin in many mammalian vertebrates as one mechanism for amelogenin heterogeneous expression in teeth. While amelogenin and its splicing forms in mammalian vertebrates have been cloned and sequenced, the amelogenin gene, especially its splicing forms in non-mammalian species, remains largely unknown. To better understand the mechanism underlying amelogenin evolution, we previously cloned and characterized an amelogenin gene sequence from a squamate, the green iguana. In this study, we employed RT-PCR to amplify the amelogenin gene from the black spiny-tailed iguana Ctenosaura similis teeth, and discovered a novel splicing form of the amelogenin gene. The transcript of the newly identified iguana amelogenin gene (named C. Similis-T2L) is 873 nucleotides long encoding an expected polypeptide of 206 amino acids. The C. Similis-T2L contains a unique exon denominated exon X, which is located between exon 5 and exon 6. The C. Similis-T2L contains 7 exons including exon 1, 2, 3, 5, X, 6, and 7. Analysis of the secondary and tertiary structures of T2L amelogenin protein demonstrated that exon X has a dramatic effect on the amelogenin structures. This is the first report to provide definitive evidence for the amelogenin alternative splicing in non-mammalian vertebrates, revealing a unique exon X and the splicing form of the amelogenin gene transcript in Ctenosaura similis.

Effect of Lysine Addition on Growth of Black Iguana (Ctenosaura pectinata)

The effects of the addition of lysine to commercial feed given to captive black iguana (Ctenosaura pectinata) were evaluated in terms of growth and feed digestibility. Twenty-eight-day-old black iguana with an initial weight of 5.5 ± 0.3 g were housed individually in cages measuring 45 × 45 × 45 cm. The experiment lasted 150 days. The ambient temperature ranged from 28 to 35°C with a relative humidity of 60 to 95%. Treatments consisted of the addition of different percentages of lysine to the feed (0.0, 0.1, 0.2, and 0.3%, dry matter [DM] base). There was a linear response (P < 0.01) in daily gain (68, 112, 118, and 151 mg/d) and daily intake (251, 289, 297, and 337 mg/d) for levels from 0 to 0.3%, respectively, as well in the growth in head size, snout-vent length, and total length. The digestibility of DM, neutral detergent fiber, and acid detergent fiber were reduced linearly (P < 0.01) as lysine levels increased. Intake and digestibility were negatively correlated (r = -0.74; P < 0.001). It is concluded that the addition of lysine to the black iguana diet in the first months of life is important to stimulate growth and intake.

Acetaminophen and zinc phosphide for lethal management of invasive lizards Ctenosaura similis

Abstract Reducing populations of invasive lizards through trapping and shooting is feasible in many cases but effective integrated management relies on a variety of tools, including toxicants. In Florida, using wild-caught non-native black spiny-tailed iguanas Ctenosaura similis, we screened acetaminophen and zinc phosphide to determine their suitability for effective population management of this prolific invasive species. Of the animals that received acetaminophen, none died except at the highest test dose, 240 mg per lizard, which is not practical for field use. Zinc phosphide produced 100% mortality at dose levels as little as 25 mg per lizard, equivalent to about 0.5% in bait which is lower than currently used in commercial baits for commensal rodent control. We conclude that zinc phosphide has potential as a useful tool for reducing populations of invasive lizards such as the black spiny-tailed iguana provided target-selective delivery methods are developed.

Effect of feed type and sex on digestibility and feed efficiency utilization in black spiny‐tailed iguana (Ctenosaura pectinata)

Digestibility, feed efficiency, and the effect of sex were evaluated in black iguanas (Ctenosaura pectinata) using two commercial pellets (rabbit and chicken). The experiment was performed in 80 iguanas in a completely randomized design with a factorial arrangement 2×2 over 105 days. No differences were detected by food type in weight gain (chicken vs. rabbit: 121 vs. 154 mg/d) and daily intake (chicken vs. rabbit: 524 vs. 551 mg/d), but differences were detected (P<0.05) in feed conversion (chicken vs. rabbit: 6.45 vs. 4.47). Rabbit pellets showed higher digestibility than chicken food (P<0.01) in dry matter (59.8 vs. 41.4%) and NDF (55.4 vs. 43.6%), respectively. Sex had no effect in any of the variable responses. Black iguanas can be raised since 6 months old in captivity with commercial food designed for rabbit or broiler. No special physiological adaptations occur in black iguanas correlated with change in feeding habits during ontogeny.

Discordant patterns of geographic variation between mitochondrial and microsatellite markers in the Mexican black iguana (Ctenosaura pectinata) in a contact zone

To delimit the distribution of matrilines of the black iguana (Ctenosaura pectinata), detect potential contact zones between them, and test the hypothesis of geographic concordance in the structuring of matrilines with respect to genetic structuring across the nuclear genome. Pacific coast of Mexico in the states of Nayarit, Jalisco, Colima, Michoacan in the lowlands adjacent to the western end of the Mexican Volcanic Belt. Tissue samples were obtained every 10–20 km along a transect across the range of three previously described mitochondrial DNA (mtDNA) clades of C. pectinata. Iguanas were genotyped with 11 nuclear microsatellites and maternal lineages were inferred based on mtDNA sequences. Geographic structure and geographic concordance between biparentally and maternally inherited markers were analysed with clustering methods, FST and NST indexes as well as haplotype networks. Geographic structure was evident for both markers and the existence of contact zones confirmed. Nevertheless, the distribution of nuclear and mtDNA genetic variation is not geographically concordant. Four matrilines exist in the area, whereas only two nuclear clusters occur. A contact zone between nuclear clusters extends along a distance of c. 60 km, and introgression is evident in individuals from several localities. High levels of genetic diversity were detected on the western coast of Mexico. Historical and contemporaneous processes seem to shape the distribution of genetic variation in C. pectinata. There are no evident geographic, environmental or ecological barriers that coincide with genetic subdivisions, and the observed mtDNA structure is likely to be the result of past climatic changes. The less structured distribution of nuclear genetic variation is consistent with the homogenizing effect of male-biased dispersal. Our findings have implications for the taxonomy and conservation strategies for this threatened species, and highlight the fact that geographic analyses of both cytoplasmic and nuclear genetic variation are important for the meaningful inference of evolutionary and demographic histories.

Predominance of single paternity in the black spiny-tailed iguana: conservation genetic concerns for female-biased hunting

Because of female-biased illegal harvesting, knowledge about the genetic mating system of the black spiny-tailed iguana Ctenosaura pectinata is of primary interest for the conservation of this threatened species. Based on the high levels of multiple paternity found in clutches of many other reptiles, particularly in lizards, it is hypothesised that multiple paternity may also be common in black iguanas. This was investigated by using microsatellite DNA to estimate the number of males siring nine litters (9 mothers, 121 offspring genotyped at ten polymorphic loci) of black iguanas. Contrary to expectations, only 11% of sampled black iguana females produced litters consistent with being sired by multiple males. These data are the first evidence for the predominance of single paternity within an iguanid lizard, and suggest that black iguana may be more susceptible to loss of genetic variation in the face of gender-biased over-hunting pressure than previously thought.

The role of urban greenspaces in fauna conservation: the case of the iguana Ctenosaura similis in the ‘patios’ of León city, Nicaragua

Private urban greenspaces, called ‘patios’ in Latin America, can act as important refuges for wildlife in scattered growing cities of the tropics. We studied the presence and abundance of the black spiny-tailed iguana (Ctenosaura similis) in patios of Leon city (Nicaragua). Forty patios were structurally characterized and abundances of iguanas were determined through surveys of inhabitants supported by observations of specimens and burrows. Patio area and maximum tree height were variables positively related with presence and abundance of iguanas and presence of burrows. The permeability of fences for iguana movements and the presence of preferred trees for food were also related to presence and abundance of iguanas. Stepwise selection model for abundance of iguanas included number of preferred trees, maximum tree height and permeability of fences. The presence of iguanas was only explained by maximum tree height. Our results show that the indigenous-root types of patios offer the most adequate conditions for the establishment and maintenance of iguana populations among the studied cases. In the light of these results, management practices to preserve the Ctenosaura similis populations in urban patios are suggested.

Isolation and characterization of polymorphic microsatellite markers in the black spiny tailed iguana (Ctenosaura pectinata) and their cross‐utility in other Ctenosaura

We isolated and characterized 10 polymorphic microsatellite loci from the Mexican black iguana (Ctenosaura pectinata) and assessed levels of polymorphism in sampling sites located in the northern areas of the species' distribution range. Two to 19 alleles per locus and observed heterozygosity ranging from 0.15 to 0.96 were detected. These markers will be useful to describe population genetic structure, the extent of gene flow in contact zones, to study the mating system of the species and to address conservation genetics issues. Additionally, we evaluated the potential utility of these markers for studies of other species within the genus Ctenosaura (i.e. C. hemilopha, C. similis and C. oaxacana).

A NEW SPECIES OF OOCHORISTICA (EUCESTODA: CYCLOPHYLLIDEA) PARASITE OF CTENOSAURA OAXACANA (REPTILIA: IGUANIDAE) FROM MEXICO

Oochoristica whitfieldi n. sp., parasitizing the intestine of the Oaxacan black iguana Ctenosaura oaxacana (Kohler and Hasbun, 2001), in Ruinas de Guiengola, Oaxaca state, Mexico, is described. The new species can be distinguished from all 4 congenera infecting Iguanidae in the neotropical realm in possessing a lower mean number of testes (122 in O. acapulcoensis Brooks, Pérez-Ponce de León, and García-Prieto, 1999; 62 in O. guanacastensis Brooks, Pérez-Ponce de León, and García-Prieto, 1999, and 95 in O. leonregagnonae Arizmendi-Espinosa, García-Prieto, and Guillén-Hernández, 2005, vs. 35 in O. whitfieldi), and a wider scolex (0.450-0.600, 0.475-0.537, 0.5-0.8, vs. 0.25-0.26, respectively). Oochoristica iguanae Bursey and Goldberg, 1996 differs from the new Mexican species in having a longer strobila (60-110 mm vs. 14.4-33.7 mm, respectively), fewer ovarian sublobes (6 vs. 11-17), and a cirrus pouch that hardly reaches excretory canals (whereas in O. whitfieldi the cirrus pouch widely overpasses these canals).

Heterogeneous Growth of Marginal Teeth in the Black Iguana Ctenosaura Similis (Squamata: Iguania)

Abstract Marginal teeth of iguanine lizards have been studied to some extent, but some aspects of tooth growth remain poorly known. Growth of marginal teeth in Ctenosaura similis is described based on examination of 22 dry skulls. The number of premaxillary teeth remains constant; the number of maxillary and mandibular teeth increases allometrically; and there is no correlation between number of pterygoid teeth and size. Ontogenetic changes in tooth morphology probably are related to ontogenetic shifts in diet. Larger individuals have large fanglike anterior marginal teeth, which might represent an adaptation for consumption of fleshy plant material and occasional carnivory. Other genera of iguanine lizards are primarily herbivorous throughout life; thus, carnivory and the related ontogenetic changes in tooth morphology are derived features within the iguanine clade.

An Apparent Mutualistic Association Between Invasive Exotics: Brazilian Pepper (Schinus terebinthifolius) and Black Spiny-tailed Iguanas (Ctenosaura similis)

Abstract Black spiny-tailed iguanas (Ctenosaura similis), invasive, exotic lizards native to Mexico and Central America, were studied on Gasparilla Island, Lee and Charlotte Counties, Florida, and found, during midwinter, to make extensive use of the fruit of Brazilian pepper (Schinus terebinthifolius), an exotic, invasive plant native to northern South America. The iguanas also find shelter and excavate burrows in thickets of Brazilian pepper. Seeds of the Brazilian pepper pass through the iguana's digestive tract intact and are likely deposited with a bit of fertilizer in areas conducive to the growth of the plant. This apparent mutualistic association is most significant to the iguanas in that the fruit of Brazilian pepper is available when the iguanas are under stress due to cold weather and short days and when other foods are limited. Control of Brazilian pepper may help control iguana populations.

Does corticosterone mediate bidirectional interactions between social behaviour and blood parasites in the juvenile black iguana, Ctenosaura similis ?

Complex bidirectional interactions between host social behaviour and infectious organisms (parasites) can be mediated by alterations in host glucocorticoid ‘stress’ hormones. As a result, an animal's social behaviour may affect its susceptibility to parasitism, and its infection status may influence its social behaviour. Our field study of behaviour, hormones and parasites in free-living juvenile male black iguanas revealed a pattern of significantly lower levels of the primary reptilian glucocorticoid, corticosterone (B), in lizards infected with either ticks or blood parasites than in uninfected lizards. To clarify both the mechanisms underpinning this association and the interaction of social behaviour with B and parasites, we conducted an experimental study in which lizards were stocked singly in field enclosures in one of the following four treatments: (1) unmanipulated; (2) implanted with B; (3) implanted with saline; and (4) exposed to a conspecific intruder. We sampled B and blood parasite levels periodically over the course of 4 weeks for each treatment. Lizards that were infected with blood parasites on the day of capture showed a significant increase in B after captivity in the enclosures, whereas uninfected lizards showed no such response. Lizards that were exposed to conspecific intruders showed a significant increase in B relative to controls, and residents that engaged in low levels of aggression showed significantly higher levels of B than residents that engaged in high levels of aggression. However, none of the experimental treatments affected the likelihood of acquiring a new blood parasite infection.

Chemical Recognition of Familiar vs. Unfamiliar Conspecifics by Juvenile Iguanid Lizards, Ctenosaura similis

The ability of juvenile black iguanas, Ctenosaura similis, to discriminate between the chemical cue of an unfamiliar and a familiar conspecific was tested. Lizards directed significantly more tongue extrusions toward the chemical cue of a size‐matched conspecific with whom they had never interacted than the chemical cue of a size‐matched conspecific with whom they had interacted for 3 d. We consider the possibility that the social relationship between familiar associates may explain variation in the direction and degree of response to unfamiliar vs. familiar chemical cues.

Blood Parasites of the Iguanid Lizard, Ctenosaura similis from Costa Rica, with a Description of Hepatozoon gamezi N. Sp.

ABSTRACT. Five species of four genera of hematozoa were observed in the blood of 15 Ctenosaura similis from the Guanacaste Conservation Area in northwestern Costa Rica. The most prevalent parasite, which occurred in all the lizards, was designated a new species, Hepatozoon gamezi, on the basis of light and electron microscopic data on its gamonts and hepatic meronts. In addition, a second species of Hepatozoon, one of Schellackia and one of Trypanosoma are described and illustrated, but not named. Microfilariae which conform with the description of Oswaldofilaria brevicaudata were recorded in 40% of the lizards. Problems in distinguishing and naming new species of certain hemoparasites solely on the basis of peripheral blood films are discussed.