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Mariano Cuadrado - One of the best experts on this subject based on the ideXlab platform.
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mate guarding and social mating system in male common chameleons chamaeleo Chamaeleon
Journal of Zoology, 2006Co-Authors: Mariano CuadradoAbstract:Male common chameleons Chamaeleo Chamaeleon actively followed the female closely as a typical mate guarding behaviour during the mating season. Guarding behaviour and spatial organization were studied in 34 radio-tagged males in a population in southern Spain during three summers. Timing and extent of guarding were highly variable among males. Overall, guarding started on 16 August (range 28 July‐ 5 September, n = 34) and ended on 4 September (range 21 August‐15 September, n = 24) lasting 13.4 days (range 0‐46 days, n = 30). Males showed a polygynous serial-type mating system where males sequentially guarded (and mated) several females during the breeding season but only one at a time. The number of guarded females (mean 2.8, range 0‐8, n = 34) and number of mates per male (mean 0.7, range 0‐3, n = 34) were also highly variable among males. In general, guarding males abandoned the females soon after mating in association with clear signs that females were no longer receptive. Males showed a remarkably complex spatial organization in close association with the home range of guarded females. Guarding behaviour resulted in territorial behaviour, and ‘stable’ as well as ‘mobile’ territories were recorded. In ‘stable’ territories, males defended non-overlapping areas where the home range of one female or more was included. Although monogamy was the predominant mating system recorded in this population, social polygyny occurred in all study years. Polygynous groups were only feasible because females aggregated in small-sized areas without apparent symptoms of intrasexual competition. Breeding asynchrony of females seems to influence this complex mating system as more competitive (large) males mated with large (early reproducing) females and small (late reproducing) ones (cf. Cuadrado, 1999). Most aggressive interactions were male‐male chasing of a solitary intruder by a guarding male. A removal experiment of guarding males revealed that newcomers were small-sized males, suggesting that an important fraction of males were acting as floaters searching for mating opportunities. Male characteristics (especially size and body weight) were the main factors influencing the spatial organization and the reproductive success of males in this population.
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comparison between tail and jugular venipuncture techniques for blood sample collection in common chameleons chamaeleo Chamaeleon
Veterinary Journal, 2003Co-Authors: Mariano Cuadrado, Isabel Molinaprescott, Luis FloresAbstract:Abstract The most common technique used for collecting blood samples from chameleons, ventral tail caudal venipuncture (Reptile care. An Atlas of Diseases and Treatments, Vol. II, T.F.H. Publication, New Jersey, 1991) sometimes presents undesired effects. Here we compared tail versus jugular vein venipuncture techniques in the common chameleon. In the first experiment, we collected 0.25% of the chameleon’s body mass in blood from either tail or jugular sites in size-matched pairs of animals to check for secondary effects. In a second experiment, we measured white blood cells (WBC), red blood cells (RBC), total plasma protein and uric acid in blood samples collected from both sites in the same individual. We found few secondary effects following the use of either venipuncture site although skin darkening was observed in few specimens when using the ventral tail vein. Blood profiles were similar between samples. The repeatability of measurements was similar in RBC and WBC counts and remarkably low (
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reproduction of chamaeleo Chamaeleon under contrasting environmental conditions
Herpetological Journal, 2002Co-Authors: Carmen Diazpaniagua, Mariano Cuadrado, M C Blazquez, Jose Antonio MateoAbstract:Reproductive characteristics of ChamaeleoChamaeleon are described and compared between a dry and a wet year. Nesting occurred in September and October, beginning later in the dry year when females also excavated their nests in longer (but not deeper) tunnels. Females were significantly smaller, with lower body mass, lower clutch mass and lower clutch size in the dry year. Relative clutch mass and body condition did not differ between the two years. Females laid a single clutch of 4-40 eggs, with a mean relative clutch mass of 60-70%. Clutch size was correlated with maternal size, being larger in the wet year, whereas egg variables were independent of maternal characteristics. Higher mortality rate was recorded in the dry than in the wet year. The observed variation in reproductive output maybe explained as a consequence oflower availability of food resources in the dry year, resulting in lower fecundity and survival of females.
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Camouflage and escape decisions in the common chameleon Chamaeleo Chamaeleon
Biological Journal of the Linnean Society, 2001Co-Authors: Mariano Cuadrado, José Martín, Pilar LópezAbstract:In species with reduced locomotory abilities, camouflage seems to be far more important than other behavioural tactics (e.g. running) to elude predatory attacks. In this study, we examined the effects of camouflage on escape decisions in the common chameleon Chamaeleo Chamaeleon. The effectiveness of camouflage was assessed by the ability of humans to detect different sized chameleons placed on different backgrounds (vegetation of high and low density, defined here as open and dense bushes), both in the field and in photographs. Escape behaviour was analysed by simulating a predator attack (in our case, approach by a human). As expected, the probability of detection by a potential predator was size- and background dependent. In the field, detection time (but not distance) was significantly higher for chameleons of a given size perched on dense (Myoporum) than open (Retama) bushes. When using photographs, the probability of detection was higher for large (adult) chameleons perched on open (Retama or Nerium) bushes and lower for hatchlings perched on dense (Myoporum or Cupressus) bushes. Conspicuousness greatly influenced the escape tactics of individuals. Chameleons perched on more protected Myoporum allowed closest approach distances than those perched on less protectedRetama . In general, antipredatory responses (defined here as «first movement», «fleeing», «mouth opening» or «free falling») occurred significantly earlier in the trial sequence in chameleons perched on clear Retama than those perched in Myoporum. Two antipredatory responses were size-dependent: juveniles and adults exhibited «mouth opening» more frequently than hatchlings whereas «free falling» was more frequently recorded for hatchlings. Our results suggest that size and vegetation greatly influence the risk of detection by predators and this variation influences an individual's decision about when and how to escape.
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The influence of female size on the extent and intensity of mate guarding by males in Chamaeleo Chamaeleon
Journal of Zoology, 1998Co-Authors: Mariano CuadradoAbstract:In ectotherms, the size of the female correlates with fecundity and thus, males prefer large more fecund females as potential mates in some species. The idea that the extent and intensity of mate guarding are also size-related was tested in the common chameleon Chamaeleo Chamaeleon. Mate guarding was studied in 43 radio-tagged females during 3 years in a population in southern Spain. The extent and intensity of male guarding of their mates varied greatly. On average, the guarding started on 20 August and ended on 2 September (mean duration = 12.6 days, range 2‐44 days, n = 35; six females were not guarded). Guarding continued for some days after mating (range = 0-13 days, n = 16). Guarding intensity (mean = 65.8% of net observation time with a guarding mate, range = 23‐90, n = 27) and number of guarding males (mean = 1.8, range = 1‐7) also varied greatly. The extent and intensity of mate guarding was strongly influenced by female size and the guarding period after mating: large females were guarded early in the season, for longer periods, and more intensively than small ones. Large females were also guarded for longer periods after mating. The overall variation in the guarding period was due to the duration of guarding before mating which was longer for large females. To my knowledge, this is the first time that prolonged mate guarding of larger females has been reported.
Paul A. Trainor - One of the best experts on this subject based on the ideXlab platform.
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The transcriptome of the veiled chameleon (Chamaeleo calyptratus): A resource for studying the evolution and development of vertebrates
Developmental dynamics : an official publication of the American Association of Anatomists, 2019Co-Authors: Brendan J. Pinto, Raul E. Diaz, Paul A. Trainor, Daren C. Card, Todd A. Castoe, Stuart V. Nielsen, Tony GambleAbstract:Purpose The veiled chameleon (Chamaeleo calyptratus) is an emerging model system for studying functional morphology and evolutionary developmental biology (evo-devo). Chameleons possess body plans that are highly adapted to an arboreal life style, featuring laterally compressed bodies, split hands/ft for grasping, a projectile tongue, turreted independently moving eyes, and a prehensile tail. Despite being one of the most phenotypically divergent clades of tetrapods, genomic resources for chameleons are severely lacking. Methods To address this lack of resources, we used RNAseq to generate 288 million raw Illumina sequence reads from four adult tissues (male and female eyes and gonads) and whole embryos at three distinct developmental stages. We used these data to assemble a largely complete de novo transcriptome consisting of only 82 952 transcripts. In addition, a majority of assembled transcripts (67%) were successfully annotated. Results We then demonstrated the utility of these data in the context of studying visual system evolution by examining the content of veiled chameleon opsin genes to show that chameleons possess all five ancestral tetrapod opsins. Conclusion We present this de novo, annotated, multi-tissue transcriptome assembly for the Veiled Chameleon, Chamaeleo calyptratus, as a resource to address a range of evolutionary and developmental questions. The associated raw reads and final annotated transcriptome assembly are freely available for use on NCBI and Figshare, respectively.
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Dynamic sex chromosomes in Old World chameleons (Squamata: Chamaeleonidae).
Journal of evolutionary biology, 2018Co-Authors: Stuart V. Nielsen, Raul E. Diaz, Paul A. Trainor, J. L. Banks, Tony GambleAbstract:Much of our current state of knowledge concerning sex chromosome evolution is based on a handful of ‘exceptional’ taxa with heteromorphic sex chromosomes. However, classifying the sex chromosome systems of additional species lacking easily identifiable, heteromorphic sex chromosomes is indispensable if we wish to fully understand the genesis, degeneration and turnover of vertebrate sex chromosomes. Squamate reptiles (lizards and snakes) are a potential model clade for studying sex chromosome evolution as they exhibit a suite of sex‐determining modes yet most species lack heteromorphic sex chromosomes. Only three (of 203) chameleon species have identified sex chromosome systems (all with female heterogamety, ZZ/ZW). This study uses a recently developed method to identify sex‐specific genetic markers from restriction site‐associated DNA sequence (RADseq) data, which enables the identification of sex chromosome systems in species lacking heteromorphic sex chromosomes. We used RADseq and subsequent PCR validation to identify an XX/XY sex chromosome system in the veiled chameleon (Chamaeleo calyptratus), revealing a novel transition in sex chromosome systems within the Chamaeleonidae. The sex‐specific genetic markers identified here will be essential in research focused on sex‐specific, comparative, functional and developmental evolutionary questions, further promoting C. calyptratus’ utility as an emerging model organism.
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The Veiled Chameleon (Chamaeleo calyptratus Duméril and Duméril 1851): A Model for Studying Reptile Body Plan Development and Evolution
Cold Spring Harbor protocols, 2015Co-Authors: Raul E. Diaz, Christopher V. Anderson, Diana P. Baumann, Richard Kupronis, David Jewell, Christina Piraquive, Jill Kupronis, Kristy Winter, Paul A. TrainorAbstract:Vertebrate model organisms have facilitated the discovery and exploration of morphogenetic events and developmental pathways that underpin normal and pathological embryological events. In contrast to amniotes such as Mus musculus (Mammalia) and Gallus gallus (Aves), our understanding of early patterning and developmental events in reptiles (particularly nonavians) remains weak. Squamate reptiles (lizards, snakes, and amphisbaenians) comprise approximately one-third of all living amniotes. But studies of early squamate development have been limited because, in most members of this lineage, embryo development at the time of oviposition is very advanced (limb bud stages and older). In many cases, squamates give birth to fully developed offspring. However, in the veiled chameleon (Chamaeleo calyptratus), embryos have progressed only to a primitive pregastrula stage at the time of oviposition. Furthermore, the body plan of the veiled chameleon is highly specialized for climbing in an arboreal environment. It possesses an entire suite of skeletal and soft anatomical modifications, including cranioskeletal ornamentation, lingual anatomy and biomechanics for projection, autopodial clefting for grasping, adaptations for rapid integumental color changes, a prehensile tail with a lack of caudal autotomy, the loss of the tympanum in the middle ear, and the acquisition of turreted eyes. Thus, C. calyptratus is an important model organism for studying the role of ecological niche specialization, as well as genetic and morphological evolution within an adaptive framework. More importantly, this species is easily bred in captivity, with only a small colony (
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Captive Care, Raising, and Breeding of the Veiled Chameleon (Chamaeleo calyptratus)
Cold Spring Harbor protocols, 2015Co-Authors: Raul E. Diaz, Christopher V. Anderson, Diana P. Baumann, Richard Kupronis, David Jewell, Christina Piraquive, Jill Kupronis, Kristy Winter, Thomas J. Greek, Paul A. TrainorAbstract:Squamate reptiles comprise approximately one-third of all living amniotes. In most of these species, it is difficult to study gastrulation and neurulation because the embryos are at a late stage of development at the time of oviposition. This is not the case, however, in veiled chameleons (Chamaeleo calyptratus), which are increasingly being used as a model organism to study these and other developmental and evolutionary phenomena. Originating from the Arabian Peninsula, veiled chameleons are arboreal specialists that possess extensive morphological specializations for climbing. They naturally inhabit semitropical habitats, but they also have an almost 30-yr history of being bred in captivity. Veiled chameleons breed readily and do not require a period of cooling to induce the reproductive cycle, and females can produce ∼45-90 eggs multiple times per year. Thus, compared with other reptiles, relatively few animals are needed to maintain a productive breeding colony. Herein, we present the conditions, equipment, and techniques required for proper husbandry and breeding of veiled chameleons within a laboratory environment.
Raul E. Diaz - One of the best experts on this subject based on the ideXlab platform.
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Serpentovirus (Nidovirus) and Orthoreovirus Coinfection in Captive Veiled Chameleons ( Chamaeleo calyptratus ) with Respiratory Disease
Viruses, 2020Co-Authors: Laura L. Hoon-hanks, Raul E. Diaz, Anke C. Stöhr, Amanda J. Anderson, Dawn E. Evans, Javier G. Nevarez, Case P. Rodgers, Shaun T. Cross, Halley R. Steiner, Roy ParkerAbstract:Serpentoviruses are an emerging group of nidoviruses known to cause respiratory disease in snakes and have been associated with disease in other non-avian reptile species (lizards and turtles). This study describes multiple episodes of respiratory disease-associated mortalities in a collection of juvenile veiled chameleons (Chamaeleo calyptratus). Histopathologic lesions included rhinitis and interstitial pneumonia with epithelial proliferation and abundant mucus. Metagenomic sequencing detected coinfection with two novel serpentoviruses and a novel orthoreovirus. Veiled chameleon serpentoviruses are most closely related to serpentoviruses identified in snakes, lizards, and turtles (approximately 40–50% nucleotide and amino acid identity of ORF1b). Veiled chameleon orthoreovirus is most closely related to reptilian orthoreoviruses identified in snakes (approximately 80–90% nucleotide and amino acid identity of the RNA-dependent RNA polymerase). A high prevalence of serpentovirus infection (>80%) was found in clinically healthy subadult and adult veiled chameleons, suggesting the potential for chronic subclinical carriers. Juvenile veiled chameleons typically exhibited a more rapid progression compared to subadults and adults, indicating a possible age association with morbidity and mortality. This is the first description of a serpentovirus infection in any chameleon species. A causal relationship between serpentovirus infection and respiratory disease in chameleons is suspected. The significance of orthoreovirus coinfection remains unknown.
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The transcriptome of the veiled chameleon (Chamaeleo calyptratus): A resource for studying the evolution and development of vertebrates
Developmental dynamics : an official publication of the American Association of Anatomists, 2019Co-Authors: Brendan J. Pinto, Raul E. Diaz, Paul A. Trainor, Daren C. Card, Todd A. Castoe, Stuart V. Nielsen, Tony GambleAbstract:Purpose The veiled chameleon (Chamaeleo calyptratus) is an emerging model system for studying functional morphology and evolutionary developmental biology (evo-devo). Chameleons possess body plans that are highly adapted to an arboreal life style, featuring laterally compressed bodies, split hands/ft for grasping, a projectile tongue, turreted independently moving eyes, and a prehensile tail. Despite being one of the most phenotypically divergent clades of tetrapods, genomic resources for chameleons are severely lacking. Methods To address this lack of resources, we used RNAseq to generate 288 million raw Illumina sequence reads from four adult tissues (male and female eyes and gonads) and whole embryos at three distinct developmental stages. We used these data to assemble a largely complete de novo transcriptome consisting of only 82 952 transcripts. In addition, a majority of assembled transcripts (67%) were successfully annotated. Results We then demonstrated the utility of these data in the context of studying visual system evolution by examining the content of veiled chameleon opsin genes to show that chameleons possess all five ancestral tetrapod opsins. Conclusion We present this de novo, annotated, multi-tissue transcriptome assembly for the Veiled Chameleon, Chamaeleo calyptratus, as a resource to address a range of evolutionary and developmental questions. The associated raw reads and final annotated transcriptome assembly are freely available for use on NCBI and Figshare, respectively.
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Dynamic sex chromosomes in Old World chameleons (Squamata: Chamaeleonidae).
Journal of evolutionary biology, 2018Co-Authors: Stuart V. Nielsen, Raul E. Diaz, Paul A. Trainor, J. L. Banks, Tony GambleAbstract:Much of our current state of knowledge concerning sex chromosome evolution is based on a handful of ‘exceptional’ taxa with heteromorphic sex chromosomes. However, classifying the sex chromosome systems of additional species lacking easily identifiable, heteromorphic sex chromosomes is indispensable if we wish to fully understand the genesis, degeneration and turnover of vertebrate sex chromosomes. Squamate reptiles (lizards and snakes) are a potential model clade for studying sex chromosome evolution as they exhibit a suite of sex‐determining modes yet most species lack heteromorphic sex chromosomes. Only three (of 203) chameleon species have identified sex chromosome systems (all with female heterogamety, ZZ/ZW). This study uses a recently developed method to identify sex‐specific genetic markers from restriction site‐associated DNA sequence (RADseq) data, which enables the identification of sex chromosome systems in species lacking heteromorphic sex chromosomes. We used RADseq and subsequent PCR validation to identify an XX/XY sex chromosome system in the veiled chameleon (Chamaeleo calyptratus), revealing a novel transition in sex chromosome systems within the Chamaeleonidae. The sex‐specific genetic markers identified here will be essential in research focused on sex‐specific, comparative, functional and developmental evolutionary questions, further promoting C. calyptratus’ utility as an emerging model organism.
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comparative musculoskeletal anatomy of chameleon limbs with implications for the evolution of arboreal locomotion in lizards and for teratology
Journal of Morphology, 2017Co-Authors: Julia Molnar, Tautis Skorka, Grant Dagliyan, Raul E. Diaz, Rui DiogoAbstract:Chameleon species have recently been adopted as models for evo-devo and macroevolutionary processes. However, most anatomical and developmental studies of chameleons focus on the skeleton, and information about their soft tissues is scarce. Here, we provide a detailed morphological description based on contrast enhanced micro-CT scans and dissections of the adult phenotype of all the forelimb and hindlimb muscles of the Veiled Chameleon (Chamaeleo calyptratus) and compare these muscles with those of other chameleons and lizards. We found the appendicular muscle anatomy of chameleons to be surprisingly conservative considering the remarkable structural and functional modifications of the limb skeleton, particularly the distal limb regions. For instance, the zygodactyl autopodia of chameleons are unique among tetrapods, and the carpals and tarsals are highly modified in shape and number. However, most of the muscles usually present in the manus and pes of other lizards are present in the same configuration in chameleons. The most obvious muscular features related to the peculiar opposable autopodia of chameleons are: (1) presence of broad, V-shaped plantar and palmar aponeuroses, and absence of intermetacarpales and intermetatarsales, between the digits separated by the cleft in each autopod; (2) oblique orientation of the superficial short flexors originating from these aponeuroses, which may allow these muscles to act as powerful adductors of the “super-digits”; and (3) well-developed abductor digiti minimi muscles and abductor pollicis/hallucis brevis muscles, which may act as powerful abductors of the “super-digits.”
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The Veiled Chameleon (Chamaeleo calyptratus Duméril and Duméril 1851): A Model for Studying Reptile Body Plan Development and Evolution
Cold Spring Harbor protocols, 2015Co-Authors: Raul E. Diaz, Christopher V. Anderson, Diana P. Baumann, Richard Kupronis, David Jewell, Christina Piraquive, Jill Kupronis, Kristy Winter, Paul A. TrainorAbstract:Vertebrate model organisms have facilitated the discovery and exploration of morphogenetic events and developmental pathways that underpin normal and pathological embryological events. In contrast to amniotes such as Mus musculus (Mammalia) and Gallus gallus (Aves), our understanding of early patterning and developmental events in reptiles (particularly nonavians) remains weak. Squamate reptiles (lizards, snakes, and amphisbaenians) comprise approximately one-third of all living amniotes. But studies of early squamate development have been limited because, in most members of this lineage, embryo development at the time of oviposition is very advanced (limb bud stages and older). In many cases, squamates give birth to fully developed offspring. However, in the veiled chameleon (Chamaeleo calyptratus), embryos have progressed only to a primitive pregastrula stage at the time of oviposition. Furthermore, the body plan of the veiled chameleon is highly specialized for climbing in an arboreal environment. It possesses an entire suite of skeletal and soft anatomical modifications, including cranioskeletal ornamentation, lingual anatomy and biomechanics for projection, autopodial clefting for grasping, adaptations for rapid integumental color changes, a prehensile tail with a lack of caudal autotomy, the loss of the tympanum in the middle ear, and the acquisition of turreted eyes. Thus, C. calyptratus is an important model organism for studying the role of ecological niche specialization, as well as genetic and morphological evolution within an adaptive framework. More importantly, this species is easily bred in captivity, with only a small colony (
Amos Bouskila - One of the best experts on this subject based on the ideXlab platform.
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Mitochondrial DNA Variation, but Not Nuclear DNA, Sharply Divides Morphologically Identical Chameleons along an Ancient Geographic Barrier
2013Co-Authors: Dan Bar Yaacov, Amos Bouskila, Karmit Arbel-thau, Yael Zilka, Ofer Ovadia, Dan MishmarAbstract:The Levant is an important migration bridge, harboring border-zones between Afrotropical and palearctic species. Accordingly, Chameleo chameleon, a common species throughout the Mediterranean basin, is morphologically divided in the southern Levant (Israel) into two subspecies, Chamaeleo Chamaeleon recticrista (CCR) and C. c. musae (CCM). CCR mostly inhabits the Mediterranean climate (northern Israel), while CCM inhabits the sands of the north-western Negev Desert (southern Israel). AFLP analysis of 94 geographically well dispersed specimens indicated moderate genetic differentiation (PhiPT = 0.097), consistent with the classical division into the two subspecies, CCR and CCM. In contrast, sequence analysis of a 637 bp coding mitochondrial DNA (mtDNA) fragment revealed two distinct phylogenetic clusters which were not consistent with the morphological division: one mtDNA cluster consisted of CCR specimens collected in regions northern of the Jezreel Valley and another mtDNA cluster harboring specimens pertaining to both the CCR and CCM subspecies but collected southern of the Jezreel Valley. AMOVA indicated clear mtDNA differentiation between specimens collected northern and southern to the Jezreel Valley (PhiPT = 0.79), which was further supported by a very low coalescent-based estimate of effective migration rates. Whole chameleon mtDNA sequencing (,17,400 bp) generated from 11 well dispersed geographic locations revealed 325 mutations sharply differentiating the two mtDNA clusters, suggesting a long allopatric history further supported by BEAST. This separation correlated temporally with the existence of an at least 1 million year ol
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Mitochondrial DNA Variation, but Not Nuclear DNA, Sharply Divides Morphologically Identical Chameleons along an Ancient Geographic Barrier
2012Co-Authors: Dan Bar Yaacov, Amos Bouskila, Karmit Arbel-thau, Yael Zilka, Ofer Ovadia, Dan MishmarAbstract:The Levant is an important migration bridge, harboring border-zones between Afrotropical and palearctic species. Accordingly, Chameleo chameleon, a common species throughout the Mediterranean basin, is morphologically divided in the southern Levant (Israel) into two subspecies, Chamaeleo Chamaeleon recticrista (CCR) and C. c. musae (CCM). CCR mostly inhabits the Mediterranean climate (northern Israel), while CCM inhabits the sands of the north-western Negev Desert (southern Israel). AFLP analysis of 94 geographically well dispersed specimens indicated moderate genetic differentiation (PhiPT = 0.097), consistent with the classical division into the two subspecies, CCR and CCM. In contrast, sequence analysis of a 637 bp coding mitochondrial DNA (mtDNA) fragment revealed two distinct phylogenetic clusters which were not consistent with the morphological division: one mtDNA cluster consisted of CCR specimens collected in regions northern of the Jezreel Valley and another mtDNA cluster harboring specimens pertaining to both the CCR and CCM subspecies but collected southern of the Jezreel Valley. AMOVA indicated clear mtDNA differentiation between specimens collected northern and southern to the Jezreel Valley (PhiPT = 0.79), which was further supported by a very low coalescent-based estimate of effective migration rates. Whole chameleon mtDNA sequencing (∼17,400 bp) generated from 11 well dispersed geographic locations revealed 325 mutations sharply differentiating the two mtDNA clusters, suggesting a long allopatric history further supported by BEAST. This separation correlated temporally with the existence of an at least 1 million year old marine barrier at the Jezreel Valley exactly where the mtDNA clusters meet. We discuss possible involvement of gender-dependent life history differences in maintaining such mtDNA genetic differentiation and suggest that it reflects (ancient) local adaptation to mitochondrial-related traits.
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Ontogenetic habitat shift and risk of cannibalism in the common chameleon (Chamaeleo Chamaeleon)
Behavioral Ecology and Sociobiology, 2006Co-Authors: Tammy Keren-rotem, Amos Bouskila, Eli GeffenAbstract:Ontogenetic habitat shifts have been documented in numerous fish and amphibians and in some reptiles. Intraspecific competition together with differential predation, prey size, social interactions, size-related thermal requirements, and morphological constraints on movement are often implicated in this ontogenetic habitat separation. In the current study, we combined field observation with experiments in seminatural arenas to test various hypotheses regarding the ontogenetic habitat shift that we have documented in the common chameleon. Juveniles (mean, 1 g) occupied low grasses and the adults (mean, 35 g) were found on bushes and trees. Overlap in habitat use between these two age classes was minimal. Our field experiments showed that juveniles actively avoid the presence of adults by concealment or flight. Adults readily attacked and consumed juveniles, regardless of their own mass. These results suggest that the risk of cannibalism towards juveniles is an important selective force behind the ontogenetic habitat shift observed in the common chameleon and may be important in other species too.
Zvi Mendel - One of the best experts on this subject based on the ideXlab platform.
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biological control of the eucalyptus gall wasp ophelimus maskelli ashmead taxonomy and biology of the parasitoid species closterocerus Chamaeleon girault with information on its establishment in israel
Biological Control, 2007Co-Authors: Alex Protasov, D Blumberg, D Brand, Zvi MendelAbstract:Abstract Closterocerus Chamaeleon (Girault) (Hymenoptera; Eulophidae) was introduced into Israel for biological control of its family member, a gall-inducing pest Ophelimus maskelli (Ashmead). Closterocerus Chamaeleon appears to be a widespread species in Australia, ranging from northern Queensland to Victoria and Western Australia. It was reared from galls on Eucalyptus camaldulensis Dehnh., E. tereticornis (= umbellata Smith.), E. amplifolia Naudin, E. cloziana F.Muell. and E. rudis Endl. Closterocerus Chamaeleon is a uniparental species; at 25 °C the entire development was completed in 3 weeks. Galls containing late second or third instar larvae and pupae of O. maskelli are suitable for successful development. A total of about 12,000 C. Chamaeleon adults were liberated in Israel. Our findings suggest that C. Chamaeleon seems to be an efficient agent and has already lowered the population density of its host galler in some locations after less than a year since its release. The parasitoid is active throughout the winter when development of its host is virtually arrested. The fast spread of C. Chamaeleon was demonstrated by its occupying areas 120 km away from the release point in less than a year. Green sticky traps are a reliable and practical device for monitoring and sampling both O. maskelli and C. Chamaeleon . The taxonomy of C. Chamaeleon is discussed, as well as several aspects of its life seasonal histories, effect of food on adult survival and its role in possible successful control of O. maskelli .
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note first record of the eucalyptus gall wasp ophelimus maskelli and its parasitoid closterocerus Chamaeleon in turkey
Phytoparasitica, 2007Co-Authors: Miktat Doganlar, Zvi MendelAbstract:The Eucalyptus gall waspOphelimus maskelli (Ashmead) (Hymenoptera: Chalcidoidea: Eulophidae: Ophelimini) and its introduced parasitoidClosterocerus Chamaeleon (Hymenoptera: Chalcidoidea: Eulophidae: Entedoninae) are recorded for the first time in the Mediterranean and Aegean Regions of Turkey. Some morphological characters of adult and larva ofO. maskelli and larva ofC. Chamaeleon are described and illustrated. Distributions of the two wasps collected in Turkey are given. Results indicate that the biological control agent,C. Chamaeleon, has spread over 1,300 km in the 16 months since its initial release.