identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
038549144C56FF895E4EFC5AFD98B929.text	038549144C56FF895E4EFC5AFD98B929.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cnemidophorus exsanguis Stebbins 1985	<div><p>CNEMIDOPHORUS EXSANGUIS</p> <p>Parthenogenetic C. exsanguis is a medium­sized triploid species. Our sample of 11 representatives had a mean snout–vent length (in mm ± SE, range limits) of 74.1 ± 4.1, 58–98. The species is characterized by three pairs of pale longitudinal stripes (paravertebrals, dorsolaterals, and laterals), all with straight margins, alternating with brown or reddish­brown dark fields. Numerous pale spots are superimposed on the stripes and dark fields. Pale stripes of large individuals may become obscure, but conspicuous spots on a fundamentally brown dorsum is a per­</p> <p>common, C. tesselatus was rare, and C. tigris marmoratus was absent. The dark patch of shrubs partially cupped by the distant rocky outcrop is creosote bush (Larrea tridentata); a few individuals of C. tigris marmoratus were using this patch of habitat, and numerous C. tesselatus and hybrids were found in this area. B. A closer view of the patch of creosote bush (shown in A) surrounded by preferred microhabitat of C. tesselatus and hybrids. Other scattered patches of creosote bush were located north and east of this escarpment. Representatives of C. tigris were essentially restricted to the patches of creosote bush.</p> <p>sistent feature of the pattern. A pale vertebral line (or its fragments) is missing in older</p> <p>adults, and the pale ventral surfaces are unspotted. Hybrids did not exhibit any of the basic color pattern features of C. exsanguis.</p> </div>	https://treatment.plazi.org/id/038549144C56FF895E4EFC5AFD98B929	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	TAYLOR, HARRY L.;COLE, CHARLES J.;HARDY, LAURENCE M.;DESSAUER, HERBERT C.;TOWNSEND, CAROL R.;WALKER, JAMES M.;CORDES, JAMES E.	TAYLOR, HARRY L., COLE, CHARLES J., HARDY, LAURENCE M., DESSAUER, HERBERT C., TOWNSEND, CAROL R., WALKER, JAMES M., CORDES, JAMES E. (2001): Natural Hybridization Between the Teiid Lizards Cnemidophorus tesselatus (Parthenogenetic) and C. tigris marmoratus (Bisexual): Assessment of Evolutionary Alternatives. American Museum Novitates 3345: 1, DOI: 10.1206/0003-0082(2001)345<0001:NHBTTL>2.0.CO;2, URL: http://www.bioone.org/doi/abs/10.1206/0003-0082%282001%29345%3C0001%3ANHBTTL%3E2.0.CO%3B2
038549144C57FF895D8DFEA5FDB5BCB4.text	038549144C57FF895D8DFEA5FDB5BCB4.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cnemidophorus inornatus (Neaves 1971)	<div><p>CNEMIDOPHORUS INORNATUS</p> <p>This is the smallest of the four species at Arroyo del Macho; snout–vent length = 57.1 ±1.13, 50–65 (18). Males and females have similar body sizes (t 16 = 0.876, P = 0.39). This species is distinguished by a sharply contrasting dorsal pattern of unspotted dark fields and pale stripes with straight margins. In the Arroyo del Macho population, the number of pale stripes may be 6 (no vertebral stripe; 2 of 18 specimens, 11%), 6.5 (vertebral stripe to midbody; 1 of 18 specimens, 6%), or 7 (a complete vertebral stripe; 15 of 18 specimens, 83%). The unspotted ventral surface is embellished with blue pigmentation of variable intensity, which is usually quite striking in males.</p> <p>Cnemidophorus inornatus was a candidate for the paternal parent of the hybrids because of its abundance at Arroyo del Macho (thus opportunities for many contacts with individuals of C. tesselatus) and because of several attempted copulations in captivity between males of C. inornatus and individuals of C. tesselatus (Neaves, 1971). In addition, C. inornatus has hybridized in the past with species of both reproductive modes— C. tigris marmoratus (reviewed by Cole et al., 1988; Dessauer et al., 2000) and C. neomexicanus (reviewed by Taylor and Walker, 1996b).</p> </div>	https://treatment.plazi.org/id/038549144C57FF895D8DFEA5FDB5BCB4	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	TAYLOR, HARRY L.;COLE, CHARLES J.;HARDY, LAURENCE M.;DESSAUER, HERBERT C.;TOWNSEND, CAROL R.;WALKER, JAMES M.;CORDES, JAMES E.	TAYLOR, HARRY L., COLE, CHARLES J., HARDY, LAURENCE M., DESSAUER, HERBERT C., TOWNSEND, CAROL R., WALKER, JAMES M., CORDES, JAMES E. (2001): Natural Hybridization Between the Teiid Lizards Cnemidophorus tesselatus (Parthenogenetic) and C. tigris marmoratus (Bisexual): Assessment of Evolutionary Alternatives. American Museum Novitates 3345: 1, DOI: 10.1206/0003-0082(2001)345<0001:NHBTTL>2.0.CO;2, URL: http://www.bioone.org/doi/abs/10.1206/0003-0082%282001%29345%3C0001%3ANHBTTL%3E2.0.CO%3B2
038549144C49FF9C5FD8FFF4FE1DBBCA.text	038549144C49FF9C5FD8FFF4FE1DBBCA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cnemidophorus neomexicanus Lowe & Zweifel 1952	<div><p>parthenogen C. neomexicanus and the bisexual C. tigris have the greatest color pattern</p> <p>resemblance to their paternal parent, C. tigris, in an area where C. tigris is highly polymorphic (Dessauer et al., 2000). These hybrids, like those from Arroyo del Macho, have two sets of tigris chromosomes, with C. neomexicanus rather than C. tesselatus contributing one of the two sets.</p> <p>KARYOTYPIC ANALYSIS</p> <p>Only one clearly resolved karyotype of the allodiploid C. tesselatus has been published (Dessauer and Cole, 1989: 57). However, additional studies of karyotypes (Wright and Lowe, 1967b; Lowe et al., 1970b) and of protein electrophoresis (Neaves and Gerald, 1968, 1969; Neaves, 1969; Parker and Selan­ der, 1976; Dessauer and Cole, 1989) reveal that the diploid unisexual C. tesselatus had a hybrid origin involving C. tigris marmoratus X C. gularis septemvittatus.</p> <p>Cnemidophorus tigris marmoratus and C. gularis septemvittatus belong to the tigris and sexlineatus species groups, respectively. Each species group has a diagnostically distinctive karyotype (Lowe et al., 1970b). The C. tigris marmoratus complement (n = 23) consists of three large set I biarmed macrochromosomes + eight smaller set II biarmed intermediate­sized macrochromosomes + 12 set III microchromosomes. The second largest chromosome in set I of C. tigris has a dotlike satellite on the end of one arm, which is often difficult to see, and the third largest chromosome is the sex chromosome (Cole et al., 1969; Bull, 1978), of which the X­chromosome is recognizable in the karyotype of C. tesselatus. The complement from C. gularis septemvittatus (n = 23) consists of only one large set I metacentric macrochromosome (with a subterminal secondary constriction on one arm followed by an elongate satellite) + 12 smaller set II intermediate­sized telocentric or subtelocentric macrochromosomes + 10 set III microchromosomes. The sex chromosomes of C. gularis septemvittatus are not morphologically recognizable. The secondary constrictions on the set I chromosomes are the nucleolar organizer regions (Ward and Cole, 1986).</p> <p>As expected, three representatives of C. tesselatus from Arroyo del Macho had a diploid karyotype consisting of one normal tigris group haploid complement and one normal sexlineatus group haploid complement of chromosomes, or 2 n = 46 (fig. 9A). The other seven C. tesselatus from Arroyo del Macho that were karyotyped were all of a slightly derived karyotypic clone (2 n = 47) in which the X­chromosome of C. tigris had apparently undergone centric fission, as it was represented by two telocentric chromosomes, each being the size of one of the arms of the ancestral X. Such karyotypic variants among parthenogenetic species are known to perpetuate themselves through cloning (Cole, 1979).</p> <p>Nine suspected hybrids of C. tesselatus X C. tigris marmoratus from the Arroyo del Macho site were karyotyped. Eight of these were triploids having 3 n = 69 chromosomes,</p> <p>including the full diploid karyotype of C. tesselatus with the ancestral tigris X­chromosome unfissioned plus a second haploid complement of tigris chromosomes (fig. 9B). One individual was a modified triploid having 3 n = 70 chromosomes, with the fissioned tigris X­chromosome inherited from C. tesselatus. The four female hybrids had the tigris X­chromosome in both tigris complements, whereas the five male hybrids had the tigris Y­chromosome in the second tigris complement (fig. 9B). Clearly, these individuals all appeared to be F 1 hybrids between C. tesselatus X C. tigris marmoratus.</p> <p>RELATIONSHIP BETWEEN KARYOTYPIC CYTOTYPE AND MORPHOLOGY</p> <p>There was an unequal distribution of the two cytotypes between C. tesselatus and the hybrids. The fissioned X­chromosome was found in a majority of C. tesselatus karyotyped (7 of 10), but only one hybrid had the fissioned X­chromosome (1 of 9). This disparity might reflect different effects of the fissioned X in the two groups. Although the type of X­chromosome inherited does not affect the expression of meristic characters in C. tesselatus, the presence of a fissioned X may exaggerate the expression of certain meristic characters in hybrids—with potentially negative effects. Evidence supporting this possibility comes from both univariate and multivariate analyses. At the univariate level, the two karyotypic clones in C. tesselatus (2 n = 46 [intact X] and 2 n = 47 [fissioned X]) are similar (t ­tests; P s&gt; 0.38) in all 12 meristic characters (see Materials and Methods section for character descriptions), supporting a hypothesis that the two cytotypes confer equivalent reproductive success in C. tesselatus. Whether the 3:7 ratio reflects the true frequencies of the two cytotypes in the population of C. tesselatus is unknown; it could simply represent a deviation from a 1: 1 ratio based on sampling variation (Chisquare = 1.600, 1 df, P = 0.21). Nevertheless, the ratio of 8 hybrids with intact Xchromosomes to 1 hybrid with a fissioned Xchromosome is a significant deviation from the 3:7 ratio in C. tesselatus (Chi­square [with Yate’s correction for small samples] = 4.539, 1 df, P = 0.03).</p> <p>To summarize the morphological differences associated with the two cytotypes, we used 11 meristic characters (table 3) in a principal components analysis to compare the hybrid with a fissioned X­chromosome to hybrids with intact X­chromosomes. Principal components scores for the only hybrid with a fissioned X­chromosome lie outside the 95% confidence ellipse for the sample of the other eight hybrids (fig. 10). All significant differences between the two hybrid cytotypes were conveyed by the first principal component (t = 12.804, 1 df, P &lt;0.00005; table 4). This component provided a contrast between the three color pattern characters and number of granules around midbody (all with positive loadings) and two characters associated with the hindlimb, number of subdigital lamellae on the fourth toe and number of femoral pores (both with negative loadings; table 3).</p> <p>The disjunct position of the hybrid with a fissioned X­chromosome in the ordination of PC scores (fig. 10) was based on striking differences between the two cytotypes in univariate scores (table 4). We used one­sample t ­tests on individual meristic characters to determine if the unusual hybrid was significantly different from the sample of hybrids with intact X­chromosomes. The hybrid with a fissioned X had fewer pale segments in the vertebral field (t = 6.804, 1 df, P = 0.0003), fewer interruptions in the dorsolateral stripes (t = 6.065, 1 df, P = 0.0005), fewer interruptions in the paravertebral stripes (t = 6.174, 1 df, P = 0.0005), fewer granular scales around midbody (t = 12.477, 1 df, P &lt;0.0005), more femoral pores (t = 7.332, 1 df, P = 0.0002), more circumorbital scales (t = 4.314, 1 df, P = 0.0035), more subdigital lamellae on the fourth toe (t = 3.000, 1 df, P = 0.0199), and more scales contacting the outer perimeter of the parietal and interparietal scales (t = 7.483, 1 df, P = 0.0001) (table 4). Whether these deviations, or others undetected by us, translate into higher mortality in hybrids inheriting a fissioned Xchromosome is unknown. The low frequency of the fissioned X cytotype in our sample of hybrids compared to its higher frequency in C. tesselatus indicates that this might be the case. However, alternative hypotheses, such as a lower susceptibility of individuals of C. tesselatus with fissioned X­ chromosomes to hybridization, cannot be tested with our evidence.</p> <p>EVIDENCE FROM BIOCHEMICAL GENETICS</p> <p>Based on genotypes detected at 34 loci, we obtained evidence bearing on the following questions: (1) how many electrophoretically detected clones of C. tesselatus are present in our sample from the Roswell area; (2) were the suspected hybrids actually hybrids; (3) were the male parents of the hybrids representatives of C. tigris marmoratus; (4) was there evidence for separate fertilization events in the origin(s) of these hybrids; and (5) are the parental taxa at the hybridization</p> <p>Derived from Meristic Variation Between Two Cytotypes of Hybrids Derived from the Parthenogenetic Species Cnemidophorus tesselatus X the Bisexual Species C. tigris marmoratus</p> <p>site genetically similar to individuals representing the same taxa from other localities?</p> <p>All 11 C. tesselatus examined electrophoretically, including a laboratory­reared offspring and her mother, had identical genotypes at each of the 34 loci (table 5). Seventeen loci (50%) had alleles in the heterozygous state, attesting to the origin of this taxon from a hybridization event, and the specific alleles at each locus were consistent with the parental taxa being C. tigris marmoratus and C. gularis septemvittatus (Neaves, 1969; Parker and Selander, 1976; Dessauer and Cole, 1989). The presence of identical genotypes in the laboratory­reared specimen, its mother, and every other individual of these C. tesselatus showed that they reproduce by parthenogenetic cloning, as do other individuals of different pattern classes of this taxon (Dessauer and Cole, 1986). Only one electrophoretic clone of tesselatus was detected at the hybridization site. Because individuals examined included both of the local karyotypic clones of C. tesselatus (see above), no molecular marker was correlated with the two cytotypes. In addition, these representatives of C. tesselatus were electrophoretically identical to other speci­</p> <p>for 11 Meristic Characters and Scores of Four Principal Components for Two Cytotypes in Cnemidophorus tesselatus X C. tigris marmoratus Hybrids Scores for one hybrid with a fissioned X­chromosome are compared with scores (mean ± SE and range) from a sample of eight hybrids with intact X­chromosomes.</p> <p>mens of pattern class E from several other localities (work in progress), although more than one clone does exist among specimens examined from elsewhere (also see Parker and Selander, 1976).</p> <p>The alleles found in the four specimens of C. tigris marmoratus from the hybridization site (table 5) were also the same ones commonly found in specimens of this taxon from other localities (Dessauer et al., 2000; however, we did not cross­correlate allele designations for the uncommon alleles found in their large samples from southwestern New Mexico). Despite our small sample from the Roswell area, four loci (IDDH, PEPA [by deduction from hybrids], PEPD, and GPI) showed local polymorphism in this bisexual species that reproduces with a Mendelian pattern of inheritance.</p> <p>TABLE 5 Genotypes or Allelesa at 34 Gene Locib in Samples of Cnemidophorus from the Hybridization Site</p> <p>Of the 34 loci analyzed, 15 showed no variation among all individuals of each taxon</p> <p>and the hybrids examined (the same alleles were shared universally), but 19 loci were particularly informative for identifying hybrids and their parental species (table 5). For each locus, all 10 suspected hybrids (based on morphology and karyotypes) had electrophoretic banding patterns consistent with triploids bearing a combination of alleles that included the two alleles found in the diploid C. tesselatus plus a third allele from the local C. tigris marmoratus. This is consistent with a cloned tesselatus ovum having been fertilized by a haploid marmoratus spermatozoan (table 5).</p> <p>Although we did not examine, electrophoretically, representatives of C. inornatus from the hybridization locality, this was not necessary. Previous studies (e.g., the review by Cole et al., 1988) have shown that C. tigris marmoratus and C. inornatus are electrophoretically distinguished from each other at many loci, including the following eight in table 5: ADH, LDH1, sSOD, sAAT, mAAT, PEPE, ADA, and TF. In addition to the third haploid set of chromosomes being diagnostic of marmoratus in the hybrids reported here (see above), the alleles detected at these loci were also those specifically of marmoratus, not inornatus.</p> <p>The presence of the extra marmoratus allele in hybrids was detected at most loci based on allele dosage effects on band densities (isozyme activities) in electrophoretic phenotypes. For example, at GPI, specimens of the diploid C. tesselatus, which are heterozygotes, show a three­banded pattern. Hybrids show the same three bands, but the relative band densities differ from those of tesselatus. Phenotypes (gel patterns) predicted for the ab genotype of this dimeric enzyme by the expansion of (a + b) 2, which equals a 2 + 2ab + b 2, consist of three isozymes with a ratio of activities (band densities on gels) approximating 1:2:1, as observed for tesselatus (fig. 11). Phenotypes predicted for the abb genotype predicted by the expansion of (a + 2b) 2, which equals a 2 + 4ab + 4b 2, consist of the same three isozymes but with a ratio of activities approximating 1:4:4, as observed in triploid hybrids (fig. 11). Consequently, tesselatus and the hybrids had three­ banded patterns for GPI, but the ratio of the band densities differed between them.</p> <p>Banding patterns for IDDH and PEPA, however, involved differences in both the number of isozymes and the band densities present in C. tesselatus versus hybrids. All hybrid genotypes at IDDH included the ballele of marmoratus (fig. 12). Phenotypes predicted for the aab genotype of this tetrameric enzyme by the expansion of (2a + b) 4, which equals 16a 4 + 32a 3 b + 24a 2 b 2 + 8ab 3 + b 4, consist of five isozymes with a ratio of activities approximating 16:32:24:8:1. The least active isozyme (b 4) is not visible in the hybrids in figure 12.</p> <p>Although dosage effects were not as clear for PEPA as for IDDH, comparison of the tesselatus and hybrid patterns in figure 13 clearly shows that the banding pattern of the hybrids varies according to which allele was inherited from marmoratus. Nine of the 10 hybrids had phenotypes of five isozymes. Dosage effects for the triple heterozygote bcd of this dimeric enzyme predict a sixbanded phenotype, estimated by the expansion of (b + c + d) 2, which is b 2 + 2bc + c 2 + 2bd + 2cd + d 2, with band intensities approximating the ratio of 1:2:1:2:2:1. Five of the six isozymes were resolved in these triple heterozygotes (fig. 13). Note that the middle band of the triple heterozygotes is the most dense, suggesting that the c 2 and 2bd bands are superimposed to produce a fivebanded pattern with a ratio of 1:2:3:2:1.</p> <p>One would expect a sample of 10 hybrids from the Roswell area to include individuals with different genotypes at IDDH, PEPD, and GPI because the local population of marmoratus is polymorphic at these loci (table 5). For both IDDH and GPI, all 10 hybrids inherited the b­allele, which has a frequency of 0.75 in the local marmoratus. For PEPD, six hybrids inherited the b­allele and four inherited the c­allele, which have frequencies</p> <p>as follows in the local marmoratus: b = 0.25, c = 0.75. In addition, for PEPA, nine hybrids inherited the b­allele (bcd genotype), whereas one inherited the c­allele (ccd genotype) from marmoratus. The marmoratus in our small sample from the Roswell area expressed only the b­allele at PEPA, but the callele is present in marmoratus from other sites (frequency of about 0.08; Dessauer et al., 2000).</p> <p>Finally, the apparent sterility of the triploid female hybrids (see Histological Analysis, below) also is consistent with hypothesizing that a new triploid parthenogenetic clone has not been generated from the triploid hybrids at this site. If such a new clone were present, our sample of 10 triploids would have included a preponderance of females bearing identical genotypes, which is not the case. In fact, considering the combination of genotypes together with the presence of the Y­chromosomes observed, we have evidence for nine separate fertilization events (nine different combinations of eggs and sperm) among the 10 hybrids examined electrophoretically.</p> <p>HISTOLOGICAL ANALYSIS</p></div> 	https://treatment.plazi.org/id/038549144C49FF9C5FD8FFF4FE1DBBCA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	TAYLOR, HARRY L.;COLE, CHARLES J.;HARDY, LAURENCE M.;DESSAUER, HERBERT C.;TOWNSEND, CAROL R.;WALKER, JAMES M.;CORDES, JAMES E.	TAYLOR, HARRY L., COLE, CHARLES J., HARDY, LAURENCE M., DESSAUER, HERBERT C., TOWNSEND, CAROL R., WALKER, JAMES M., CORDES, JAMES E. (2001): Natural Hybridization Between the Teiid Lizards Cnemidophorus tesselatus (Parthenogenetic) and C. tigris marmoratus (Bisexual): Assessment of Evolutionary Alternatives. American Museum Novitates 3345: 1, DOI: 10.1206/0003-0082(2001)345<0001:NHBTTL>2.0.CO;2, URL: http://www.bioone.org/doi/abs/10.1206/0003-0082%282001%29345%3C0001%3ANHBTTL%3E2.0.CO%3B2
038549144C57FF975D81FB41FD9CBEA9.text	038549144C57FF975D81FB41FD9CBEA9.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cnemidophorus tesselatus (Neaves 1971)	<div><p>CNEMIDOPHORUS TESSELATUS</p> <p>This is the largest of the four species at Arroyo del Macho; snout–vent length = 88.6 ± 1.66, 59–109 (40). Zweifel (1965) provid­ ed the original descriptions of color pattern variation among populations presently assigned to pattern class E. This variation involved the degree to which the lateral stripes (a pair of pale stripes extending from dorsal edge of the ear opening to anterodorsal aspect of the thigh) were disrupted by vertical black bars. The lateral stripes were absent in some populations while other populations had a predominance of individuals with relatively intact lateral stripes, resembling pat­ tern class C in this respect. This variation within pattern class E (as presently con­</p> <p>ceived) has been dealt with, consistently and conveniently, by using Zweifel’s (1965) depiction of the geographic distributions of col­ or pattern classes, rather than actual color pattern characteristics, to assign certain individuals and populations to pattern class. As an example of the problem, refer to Dessauer and Cole (1989: fig. 1A, 1B). Although they referred the individual in their figure 1A to pattern class C, this specimen would be identified as a representative of pattern class E (with relatively intact lateral stripes) based on its sampling locality in the northern Rio Grande drainage (Zweifel, 1965: fig. 1). This problem is currently under study.</p> <p>The Arroyo del Macho population of C. tesselatus is distinguished from the other three sympatric species of Cnemidophorus by a sharply contrasting dorsal pattern of pale stripes and their transverse expansions on black dark fields (figs. 2A, 4). One color pattern element, evidence of lateral stripes, can be used to distinguish members of C. tesselatus from hybrids at this locality. Ontogenetic development can reduce definition of the lateral stripes in two ways. Fundamentally, dark fields subtending the lateral stripes can become subdivided into linear series of dark­field remnants through localized loss of melanin; this produces a series of transverse pale bars of the same hue as the stripes. Because pale bars and dark­field remnants can be in register above and below the stripes, there is loss of stripe definition where pale bars pass through the stripes. Similarly, stripes are disrupted by black bars where localized production of melanin in the pale stripes causes fusion of dark­field remnants above and below the stripes. However, the disruption of lateral stripes is reduced in the Arroyo del Macho population, and evidence of lateral stripes persists in all individuals of this population. Individual variation in dorsal color pattern is particularly evident in the vertebral dark field (fig. 4). A vertebral stripe is usually evident on the nape, extending posteriorly for variable distances before fragmenting into a series of pale elements. Lateral expansions of the vertebral stripe or its fragmented elements establish a sequence of contacts with the paravertebral stripes. These expansions can be highly exaggerated in the final color pattern as a longitudinal series of</p> <p>transverse pale bars connecting the paravertebral stripes to form a ladderlike pattern. The ventral surfaces are immaculate or nearly so (fig. 3A); i.e., there are no black spots in the central gular region, although there may be one or two spots laterally. A few small black spots (often confined to single scales) may be scattered on the chest.</p> <p>CNEMIDOPHORUS TIGRIS MARMORATUS There is sexual dimorphism in body size, with males being significantly larger than females in our sample (t 29 = 2.469, P = 0.02); snout–vent length of males = 80.7 ± 1.81, 63–92 (21); snout–vent length of females = 73.3 ± 2.24, 57–80 (10). Individual variation in this subspecies can be observed in the relative prominence of pale stripes or their remnants in the dorsal pattern, ranging from clearly evident stripes to a loss of stripe identity in an irregular reticulum of pale and dark sectors. All stripes may be fragmented to various degrees. The double nature of the pale vertebral stripe (or its remnants) is usually evident, thus resembling its hybrid derivatives, pattern classes Colorado D and New Mexico D of C. tesselatus, in this feature. Pale stripes, or significant segments thereof, are retained in the dorsal pattern of many adult individuals of C. tigris marmoratus in the Pecos River drainage, and these populations were described as C. marmoratus reticuloriens by Hendricks and Dixon (1986). All individuals in our samples lack lateral stripes (fig. 2C). Pastel hues embellish the ventral pigmentation, with pink shades added to the gray throat and chest, shifting to orange or tan shades on the ventrolateral areas of the abdomen. Individuals larger than 78 mm snout–vent length have black spots and blotches on the gular and chest regions (fig. 3C), with considerable variation in their size and number. Although C. tigris marmoratus was uncommon at the hybridization site, it was a strong candidate for the paternal parent of the hybrids because of two shared color pattern features (see below).</p> <p>HYBRIDS</p> <p>Males and females had similar snout–vent lengths (t 18 = 0.194, P = 0.85): males = 89.2</p> <p>± 3.15, 56–97 (12) and females = 88.4 ± 2.85, 71–97 (8). The dorsal color pattern (fig.</p> <p>2B) is most similar to C. tesselatus (fig. 2A), but the hybrid pattern tends to be coarser, with larger dark and pale sectors (compare figs. 4–6). There is no vertebral stripe, and, from the shoulder region posteriorly, the vertebral dark field is either rather open or bridged by transverse pale elements. Ventrally, hybrids are intermediate to parental species in degree of black­spotting (fig. 3B). As currently understood (Lowe et al., 1970a; Cuellar and McKinney, 1976; Taylor et al., 1989; Walker et al., 1989a, 1989b), a lizard with male reproductive structures that has a color pattern resembling a normal parthenogenetic species is either a triploid or tetraploid hybrid—cytological states that are attained only through fertilization of unreduced eggs from diploid or triploid parthenogens by haploid, Y­bearing sperm from males of bisexual species.</p> <p>COLOR PATTERN AND IDENTIFICATION OF HYBRIDS</p> <p>Although there is color pattern variation among the hybrids (figs. 5, 6), all bear a strong resemblance to their maternal parent, C. tesselatus (fig. 4). There are, however, several color pattern features that distinguish hybrids from C. tesselatus and implicate C. tigris marmoratus as their paternal parent. The most obvious difference is dichotomous—lateral stripes (or obvious remnants) are present in the Arroyo del Macho population of C. tesselatus and absent in hybrids and C. tigris marmoratus (fig. 2). In addition, some hybrids (particularly males) have subtle suffusions of pink on the throat and chest and yellowish­tan on the lateral abdominal surfaces. These are pigmentation features of C. tigris marmoratus. Certain hybrids also resemble C. tigris marmoratus in having small black spots in the central gular region and on the chest. However, the intensity of pastel hues and the size and number of black ventral spots are reduced in such hybrids compared to C. tigris marmoratus (figs. 2, 3, 5, 6).</p> <p>As a group, hybrids differ from C. tesselatus in having a greater number of interruptions of the dorsolateral stripes (IDLS; t 26.747 = 5.438, P &lt;0.0005; table 1) and paravertebral stripes (IPVS; t 58 = 5.730, P &lt;0.0005; table 1). The presence of a stripe or smaller pale segments in the vertebral dark field of C. tesselatus (fig. 4) and a more open vertebral dark field in hybrids (figs. 5, 6) will distinguish many individual hybrids from C. tesselatus. However, a quantification of this feature (PSVF, number of midsagittal pale segments in the vertebral dark field) did not</p> <p>distinguish the two groups (t 55 = 1.754, P = 0.08; table 1).</p> <p>UNIVARIATE MORPHOLOGICAL COMPARISONS</p> <p>Sexual dimorphism was lacking in meristic characters of the hybrids (all P s&gt; 0.09) and representatives of C. tigris marmoratus (all P s&gt; 0.14) from the vicinity of Arroyo del Macho, permitting us to pool the sexes into single samples for each group. For seven of the eight scalation characters, there was one significant difference among the pairwise comparisons of hybrids, C. tesselatus, and C. tigris marmoratus (table 1). Hybrids differed significantly from both parental species in number of granules around midbody and in subdigital finger lamellae. However, the pattern of nonsignificant differences (resemblance) between hybrids and parental species was also informative. All 20 hybrids from Arroyo del Macho had abruptly enlarged mesoptychial scales (those bordering the gular fold anteriorly), thereby resembling C. tesselatus rather than C. tigris marmoratus in this character. Hybrids also resembled C. tesselatus in number of subdigital toe lamellae and gular scales, but resembled C. tigris marmoratus in number of femoral pores, circumorbital scales, and lateral supraocular granules (table 1). Cnemidophorus tesselatus, itself a product of past hybridization, also exhibited a mosaic pattern, resembling its maternal progenitor (C. tigris marmoratus) in some characters and its paternal progenitor (C. gularis septemvittatus) in others (Parker, 1979b).</p> <p>MULTIVARIATE MORPHOLOGICAL ANALYSES</p> <p>Principal Components Analysis</p> <p>The first three principal components summarized 64.1% of the variation found in eight meristic characters used in the PCA of C. tesselatus, C. tigris marmoratus, and their hybrids. Significant differences in principal</p> <p>components scores (treating these variables as univariate characters) among the three groups are shown in table 1. A comparison of component loadings (table 2) to characters with nonsignificant differences between hybrids and one of the two parental groups (table 1) indicated that principal component 1 was expressing similarities of hybrids to C. tigris marmoratus in number of femoral pores, circumorbital scales, and lateral supraocular granules. Principal component 2 expressed similarities of hybrids to C. tesselatus in number of subdigital toe lamellae and gular scales.</p> <p>The pattern of variation was depicted in an ordination of principal components scores on the first two axes (fig. 7). There was considerable overlap in principal components scores of all three groups, presumably reflecting shared parentage; i.e., that C. tigris marmoratus was the maternal parental species of C. tesselatus and the paternal parental species of the hybrids from Arroyo del Macho. The third principal component reflected the distinctively low numbers of granules around midbody in hybrids compared to both parental species (table 1), and it effectively separated hybrids from parental species on this axis.</p> <p>Phylogenetically (because C. tesselatus is also a hybrid derivative of C. tigris marmoratus), the hybrids at Arroyo del Macho have approximately 67% of their genes from C. tigris marmoratus and approximately 33% of their genes from C. gularis septemvittatus. Proximately, and more important in terms of phenotypic expression, the triploid hybrids have 100% of the genes of C. tesselatus and 50% of the genes of C. tigris marmoratus; the matriclinous nature of the multivariate expression of meristic characters is revealed by the canonical variate analysis that follows.</p> <p>TABLE 1 Descriptive Statistics of Morphological Characters and Tests of Significancea Among the Parthenogenetic</p> <p>Species Cnemidophorus tesselatus, the Bisexual Species C. tigris marmoratus, and Their Hybrids</p> <p>CANONICAL VARIATE ANALYSES</p> <p>Each specimen was assigned to its correct a priori group in a quadratic canonical variate analysis of eight meristic characters, and hybrids were significantly different from both parental species in both canonical variates (table 1). The separation of the three groups on discriminant axes is depicted in figure 8. We ran a second canonical variate analysis (linear) with three characters excluded from the model (number of circumorbital scales, number of lateral supraocular granules, and number of gular scales) in order to achieve homogeneous covariance matrices (P = 0.06). This analysis provided squared Mahalanobis distances (D 2) among centroids of the three a priori groups for quantifying the degree of multivariate resemblance among</p> <p>TABLE 2 Factor Loadings for Three Principal Components</p> <p>Derived from Meristic Variation Among the Parthenogenetic Species Cnemidophorus tesselatus, the Bisexual Species C. tigris marmoratus, and Their Hybrids</p> <p>hybrids and parental species. The hybrid group resembled maternal C. tesselatus more closely than paternal C. tigris marmoratus — D 2 values were 11.0 between hybrids and C. tesselatus and 19.9 between hybrids and C. tigris marmoratus. In comparison, the D 2 value between C. tesselatus and C. tigris marmoratus was 18.9. Because C. tesselatus has one set of chromosomes from C. tigris marmoratus and the hybrids have two sets of chromosomes from C. tigris marmoratus, one might assume that the resemblance to C. tigris marmoratus would increase (i.e., D 2 values would decrease) with each additional set of chromosomes inherited from this taxon. However, the distances of 18.9 (one set of C. tigris marmoratus chromosomes in C. tesselatus) and 19.9 (two sets of C. tigris marmoratus chromosomes in the hybrids) are evidence of an absence of significant additive interactions among the tigris genomes and substantiate the matriclinous nature of phenotypic expression in the hybrids; i.e., there is a disproportionate resemblance of hybrids to the female parent (see also Parker, 1979b).</p> <p>The overall dorsal color pattern of the Arroyo del Macho hybrids most closely resembles that of the maternal parent, C. tesselatus. As an example of the unpredictability that seems to be associated with the genus Cnemidophorus, there is an example where the opposite is true. Hybrids between the diploid</p> </div>	https://treatment.plazi.org/id/038549144C57FF975D81FB41FD9CBEA9	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	TAYLOR, HARRY L.;COLE, CHARLES J.;HARDY, LAURENCE M.;DESSAUER, HERBERT C.;TOWNSEND, CAROL R.;WALKER, JAMES M.;CORDES, JAMES E.	TAYLOR, HARRY L., COLE, CHARLES J., HARDY, LAURENCE M., DESSAUER, HERBERT C., TOWNSEND, CAROL R., WALKER, JAMES M., CORDES, JAMES E. (2001): Natural Hybridization Between the Teiid Lizards Cnemidophorus tesselatus (Parthenogenetic) and C. tigris marmoratus (Bisexual): Assessment of Evolutionary Alternatives. American Museum Novitates 3345: 1, DOI: 10.1206/0003-0082(2001)345<0001:NHBTTL>2.0.CO;2, URL: http://www.bioone.org/doi/abs/10.1206/0003-0082%282001%29345%3C0001%3ANHBTTL%3E2.0.CO%3B2
038549144C42FFA55D1CFC74FD92B8A4.text	038549144C42FFA55D1CFC74FD92B8A4.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cnemidophorus tesselatus	<div><p>Cnemidophorus tesselatus</p> <p>Sexually mature and reproductive adults of C. tesselatus usually exhibit the following characteristics: oocytes are present, the ovarian follicle cell layer is complete and well organized, connective tissue is not conspicuous, vacuoles are few, and the follicle is well vascularized. The distal oviduct contains a thin mucosa with poorly developed folds. The middle oviduct is ciliated and contains well­developed alveolar glands, which are restricted to this section of the oviduct. The proximal oviduct has a thick (normal) mucosa and well­developed folds. The mesonephric tubules are 20–30 µm in diameter (figs. 15C, 18A–D).</p> <p>The ovary of a normal, reproductive C. tesselatus contains developing follicles with a well­developed tunica granulosa that includes active pyriform cells (fig. 14E, F). The zona radiata (formed by microvilli) is usually evident and probably indicates the active transport of components (such as phosvitin and lippovittelin) for the later syn­</p> <p>thesis of yolk granules (fig. 14G). The increase in the surface area that results from the presence of the microvilli facilitates transport of substances between the oocyte and the follicle cells (Balinsky, 1975; Anderson and Beams, 1960). The cytoplasm is granular but homogeneous in distribution in young oocytes and becomes layered in older oocytes (fig. 14I, K). Yolk deposition begins when the oocyte is 2.3 mm (largest nonyolked oocyte measured) to 3.1 mm (smallest yolked oocyte measured) in diameter (table 6, fig. 14G, H); as vitellogenesis progresses the theca granulosa regresses with the loss of pyriform cells but retention of the small granulosa cells (fig. 16G). Atretic oocytes have stopped development for some unknown reason. A previtellogenic oocyte that is atretic shows irregular or vacuolated cytoplasm (fig. 14A, B). The theca granulosa is often hypertrophied, and enlarged granulosa cells move through the disrupted zona radiata or zona pellucida into the oocyte cytoplasm (fig. 14C, D). As atresia progresses the basement lamina of the theca granulosa becomes a hyaline layer known as the glassy membrane (fig. 14C, D). At ovulation the follicle wall appears thicker because the thin, stretched wall of the mature follicle is now shrunken due to the collapse of the follicle; cellular debris may be present in the lumen, but neither oocyte nor yolk will be present (fig. 14J). As the corpus luteum ages the lumen becomes filled with luteal cells (fig. 14K, L). The fully developed corpus luteum is easily distinguished from an advanced atretic follicle by the absence of yolk, absence of the glassy membrane, and the presence of vacuolated luteal cells (fig. 14L). Corpora lutea regress rapidly to a distinctive, triangular collapsed structure, composed primarily of connective tissue and usually located between other follicles (fig. 14I). Perhaps this is typical of lizard corpora lutea (Miller, 1948: pl. 13d, e for Xantusia; Goldberg, 1970: fig. 12 for Sceloporus).</p> <p>Two individuals exhibited gonadal abnormalities. One of these (AMNH R­146636), a large individual (95 mm snout–vent length), had very small ovaries lacking enlarged oocytes; no sperm were seen in the reproduc­ tive tract. The second (AMNH R­146640) was the smallest C. tesselatus in the sample</p> <p>(snout–vent length = 65 mm) and contained a few abnormal follicles (many irregular spaces and an incomplete theca granulosa); no sperm were found in her reproductive tract. All other representatives of C. tesselatus contained 3–22 follicles; seven individuals were undergoing vitellogenesis in follicles 1.4–8.5 mm in diameter (table 6).</p> <p>Salient features of the reproductive systems of representative individuals of C. tesselatus, all C. tesselatus X C. tigris marmoratus hybrids, and all male C. tigris marmoratus collected at the hybridization site are described below with date of collection in parentheses. The first series are representatives of C. tesselatus.</p> <p>AMNH R­146629 (June 11, 1998): The left ovary was 3 X 7 mm. Both oviducts were swollen; the left was 16 X 3.5 mm, the right was 14 X 4 mm. The largest oocyte had not begun vitellogenesis but the cytoplasm is differentiated into at least three zones, and the granulosa and zona radiata are well developed (as in fig. 14A, I). Several oocytes show pyriform cells (fig. 16H), which indicate the onset of yolk deposition in Sceloporus (Goldberg, 1970). At least two corpora lutea were present (fig. 14I). The small size and triangular shape of the corpora lutea suggest that ovulation and oviposition occurred from at least two weeks (Miller, 1948: pl. 12 for the viviparous Xantusia) to several</p> <p>months earlier (Goldberg, 1970, for the ovoviviparous Sceloporus jarrovi); however, the sequence and timing of corpus luteum degeneration in Cnemidophorus is not well known. Two atretic follicles were present. No sperm were found.</p> <p>AMNH R­146636 (June 12, 1998): The left ovary and oviduct were smaller than those of the other C. tesselatus examined; however, this individual is 95 mm snout–vent length, clearly of adult size; the mean snout– vent length for the other 25 specimens examined is 89.6 (65–109 mm). The mesonephric kidney and adrenal were well developed and vascularized. The ovarian epithelium (cortex) was very thin and contained some oocytes and a well­developed lip (fig. 15E). The ovary consisted of a thin layer (3– 4 cells thick) over a thinner layer of smooth muscle, all of which were on the surface of the adrenal away from the mesonephros (fig. 15E). Follicles were not present, the ovary was probably just beyond the indifferent stage of development, and the oviduct was tiny. This animal, although of large size for a mature female, is equivalent to a hatchling in its reproductive anatomy. The karyotype and protein electrophoresis confirmed the identity of this specimen. No sperm were found.</p> <p>of an oocyte; note the layered cytoplasm of the adjacent oocyte (AMNH R­146629, slide 28, row 1, section 4). J. A recently ovulated follicle that will become a corpus luteum; note triangular shape and point of rupture (AMNH R­146620, slide 31, row 1, section 1). K. Corpus luteum (left) and normal follicle (right; AMNH R­146618, slide 1, row 2, section 13). L. Detail of corpus luteum (AMNH R­ 146621, slide 1, row 2, section 9). Slides stained with Mallory triple connective tissue technique are designated MT; all other slides were stained with Harris hematoxylin and eosin. Abbreviations for this and the following figures are as follows: A, adrenal gland; AC, adrenal cells; AF, atretic follicle; Al, alveolar gland; BGE, boundary of germinal epithelium; BV, blood vessel; CL, corpus luteum; CT, connective tissue; C1, outermost layer of pre­yolk cytoplasm of oocyte; C2, middle layer of pre­yolk cytoplasm of oocyte; C3, innermost layer of preyolk cytoplasm of oocyte; D, discharging pyriform cell; Dod, distal oviduct; E, epididymis; FC, follicle cell; FR, site of follicle rupture due to ovulation; GM, glassy membrane of an atretic follicle; Gr, granulosa cells of follicle; I, interrenal cells; L, lumen; LC, luteal cells; Le, Leydig cell layer; Lip, lip of germinal epithelium; LRV, left renal vein; M, mesonephros; ML, mesonephros, large tubules; Mod, middle oviduct; MS, mesonephros, small tubules; Mu, mucosa; Mus, muscularis; N, nucleus; O, ovary; Od, oviduct; OF, ovarian follicle; Og, oogonia of germinal epithelium; Oo, oocyte; P, pyriform cell in theca granulosa; S, serosa; Sp, spermatozoa; ST, seminiferous tubules; TE, theca externa of ovarian follicle; TG, theca granulosa of ovarian follicle; TI, theca interna of ovarian follicle; V, vas deferens; Y, yolk of oocyte; ZR, zona radiata. Scale bar, 0.1 mm, except E– H and L, which are 0.01 mm.</p> <p>Female C. tesselatus X C. tigris marmoratus Hybrids</p> <p>row 1, section 5). E. Germinal epithelium with lip (AMNH R­146636, slide 11, row 1, section 3). F. Germinal epithelium with developing oocytes; section did not pass through lip (AMNH R­146618, slide 1, row 1, section 15). G. One follicle containing two oocytes. The theca interna completely separates the two oocytes and a single theca externa encompasses the follicle (AMNH R­146618, slide 4, row 2, section 2). Scale bar, 0.1 mm, except B, which is 0.01 mm.</p> <p>AMNH R­146637 (June 12, 1998): The left oviduct was enlarged but lacked eggs.</p> <p>The left ovary contained 14 enlarged follicles (fig. 14F) up to 1.4 mm in diameter and one corpus luteum. Macroscopically, the ovary showed one reddish spot, possibly the corpus luteum detected later by histological examination. The germinal epithelium contained oogonia and a distinctive lip (fig. 15D). The two largest oocytes had not begun vitellogenesis. No sperm were found.</p> <p>AMNH R­146638 (June 12, 1998): The left ovary and oviduct were enlarged and the largest oocyte was yolked. No other oocytes were yolked and no recognizable corpora lutea were visible. No sperm were present in the oviduct.</p> <p>AMNH R­146639 (June 12, 1998): The left ovary and oviduct were enlarged and the ovary contained three enlarged and yolked oocytes. The largest nonyolked oocyte was 1.9 mm in diameter, almost as large as those containing yolk, and larger by 0.5 mm than a yolked oocyte in AMNH R­146637. There were at least four corpora lutea present, all flattened or triangular, and up to 1.4 mm wide. No sperm were found.</p> <p>AMNH R­145142 (May 12, 1999): Two oocytes 8.5 mm in diameter were depositing yolk when preserved. Several previtellogenic follicles exhibited secretory activity of the theca granulosa and conspicuous pyriform cells (fig. 14E) similar to those seen in Ctenosaura (del Carmen et al., 1996). Near the end of vitellogenesis, the granulosa was still evident as a distinctive cell layer (fig. 14H). The distal oviduct had a very thin mucosa and very thin folds near the infundibulum, but near the junction with the middle oviduct the mucosa was thickened (fig. 17F). The middle oviduct contained normal alveolar glands (fig. 17G, H). No sperm were found.</p> <p>AMNH R­145143 (May 14, 1999): This specimen had an early atretic follicle with disorganized cytoplasm (fig. 14A, B) and follicles that were undergoing vitellogenesis</p> <p>(fig. 14G). The oviducts were enlarged; the folds of the distal oviduct were shallow near­ er the infundibulum (fig. 17E, left) and deep­ er away from the infundibulum (fig. 17E, right). No sperm were found.</p> <p>AMNH R­146612 (June 10, 1996): This specimen contained a yolked follicle (6.4 X 6.7 mm) and a corpus lutuem (0.5 mm diam.). The mesonephric tubules were small (0.02 mm diam.). Other ovarian and oviductal structures appeared normal. No sperm were found.</p> <p>AMNH R­146613 (June 10, 1996): The ovary contained follicles of several sizes (as in fig. 16E), including yolked and atretic follicles (fig. 16F). No sperm were found.</p> <p>AMNH R­146614 (July 20, 1997): This specimen contained two small corpora lutea and very small follicles (table 6). Like all others collected in July 1997 (fig. 21, table 6), this individual was postreproductive.</p> <p>AMNH R­146618 (July 20, 1997): This specimen contained a recently ovulated follicle (fig. 14K), several normal follicles with germinal epithelium (fig. 15F), and two oocytes in one follicle (future twins that might share the same eggshell; fig. 15G). This follicle would have been available for the 1998 reproductive season. No sperm were found.</p> <p>AMNH R­146620 (July 21, 1997): A large (7.0 X 3.7 mm) yolked atretic follicle (fig. 14C) and a recent corpus luteum with visible rupture site (fig. 14J) suggest that one of the two large oocytes ovulated and the other aborted, perhaps within two weeks (Miller, 1948) prior to collection. No sperm were found.</p> <p>AMNH R­146621 (July 21, 1997): An atretic follicle (fig. 14D) and two corpora lutea (fig. 14L) were present. No sperm were found.</p> <p>follicles containing oocytes (AMNH R­146619, slide 3, row 1, section 3, MT). F. Follicle edges of a normal yolked follicle (upper right), atretic yolked follicle (lower right), and normal nonyolked follicle (left; AMNH R­146613, slide 6, row 2, section 9, MT). G. Previtellogenic follicle (right) and vitellogenic follicle (left) showing differences in cytoplasm, yolk, and theca development (AMNH R­146613, slide 6, row 2, section 6, MT). H. Theca granulosa of normal developing oocyte (AMNH R­146629, slide 19, row 1, section 3). Scale bar, 0.1 mm, except C, D, G, H, which are 0.01 mm.</p> <p>AMNH R­146640 (June 12, 1998): This specimen contained enlarged oviducts but</p> <p>tiny (unrecognizable macroscopically) ovaries. Many spaces were present around follicle cells and the theca granulosa was almost absent; however, there were no follicle cells in the cytoplasm of the oocytes, which appeared normal (fig. 18C). The adrenal and mesonephric tubules appeared normal (not enlarged) for a female (fig. 18C). No sperm were found.</p> <p>Other specimens examined did not vary conspicuously from the above descriptions. Important to the question of hybridization frequency, none of the specimens of C. tesselatus had sperm in the oviducts.</p> <p>During development the ovary is attached to the surface of the adrenal. In its earliest stages (during and soon after the indifferent stage) the ovary appears as a thickened epithelium, almost always with a distinctive lip on one edge. This ovarian lip makes the extremely young ovary more easily recognizable (see Hardy and Cole, 1981: fig. 3, top right corner, fig. 4, lower right corner, and fig. 6, lower right corner; Hardy and Cole, 1998: fig. 3B, top center, and fig. 2). In some samples the ovary is so small that only a few oocytes are present. The scarcity of oocytes (figs. 15F, 16B, E) and small size of the immature ovary make it a difficult organ to recognize. Thus, one must focus on the shape of the ovarian lip, plus the presence of oocytes, in order to recognize the small ovary (fig. 15A–E).</p> <p>Vitellogenesis in C. tesselatus begins when the follicles are between 3.1 mm (smallest yolked oocyte measured) and 2.3 mm (largest nonyolked oocyte measured) in diameter (using largest dimension of oocyte [table 6]); however, if vitellogenesis is well under way for a normal complement of eggs (2–3 per ovary), then vitellogenesis might be delayed for other oocytes even though they are within the minimum size range for initiation of vitellogenesis.</p> <p>The two oocytes in one follicle (fig. 15G) could have been independently derived from two different oogonia; a mutation in one oogonium but not in the other would result in these two oocytes being genetically different (one preserving the mutation). Alternatively, they could be the daughter cells, fol­ lowing endomitotic duplication, of a single oogonium, and mutation in the oogonium</p> <p>would be contained in both daughter oocytes.</p> <p>Rupture of the follicle during ovulation would probably result in both oocytes moving as a unit, held together by the theca interna, into the oviduct and thence becoming incorporated within a single eggshell. Development of each oocyte to hatching would produce two hatchlings from a single shell—apparent twinning. However, if the oocytes separated after ovulation but before eggshell formation so that each had its own eggshell, then the potential twinning event would never be detected.</p> <p>The number of normal yolks produced by a mature female in a season (about five, see below) is probably determined by the energy required for yolk synthesis and the available food supply. How the yolk is packaged is independent of the food supply and reflects the anatomical constraints of the lizard (is the egg too large to be laid?). Containment of both embryos in the same eggshell would probably result in a much larger egg (if both had a normal yolk reserve); this could be detrimental to the mother—the only significant evolutionary consequence of the apparent twinning.</p> <p>All except 1 of the 26 adult C. tesselatus females had developing follicles and oocytes, and 4 were nearly ready for oviposition (oocyte diameters greater than 6 mm). One female (AMNH R­146636; snout–vent length = 95 mm) was nonreproductive, evidently because of developmental failure. This specimen had a snout–vent length large enough that one would expect it to contain enlarged oocytes, but it had no follicles, only a thin ovarian epithelium (almost an indifferent stage of embryonic development; fig. 15E), no corpora lutea, no increase in collagen, no evidence of atretic follicles, and a tiny oviduct, whereas the smallest female (AMNH R­146640; snout–vent length = 65 mm) had at least 10 enlarged oocytes (maximum size = 0.3 X 0.5 mm) in follicles that appeared normal (fig. 18C). With the exception of AMNH R­146636, these specimens of C. tesselatus appeared to be typical females in all details.</p> <p>Cnemidophorus tesselatus X C. tigris mar­</p> </div>	https://treatment.plazi.org/id/038549144C42FFA55D1CFC74FD92B8A4	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	TAYLOR, HARRY L.;COLE, CHARLES J.;HARDY, LAURENCE M.;DESSAUER, HERBERT C.;TOWNSEND, CAROL R.;WALKER, JAMES M.;CORDES, JAMES E.	TAYLOR, HARRY L., COLE, CHARLES J., HARDY, LAURENCE M., DESSAUER, HERBERT C., TOWNSEND, CAROL R., WALKER, JAMES M., CORDES, JAMES E. (2001): Natural Hybridization Between the Teiid Lizards Cnemidophorus tesselatus (Parthenogenetic) and C. tigris marmoratus (Bisexual): Assessment of Evolutionary Alternatives. American Museum Novitates 3345: 1, DOI: 10.1206/0003-0082(2001)345<0001:NHBTTL>2.0.CO;2, URL: http://www.bioone.org/doi/abs/10.1206/0003-0082%282001%29345%3C0001%3ANHBTTL%3E2.0.CO%3B2
038549144C7BFFA85FD8FB39FB6EB920.text	038549144C7BFFA85FD8FB39FB6EB920.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cnemidophorus tigris subsp. marmoratus	<div><p>Cnemidophorus tigris marmoratus Males</p> <p>AMNH R­146650 (June 11, 1998): The left testis was 3.7 X 2.9 mm. The seminiferous tubules contained sperm and spermatids (fig. 19D), and meiotic divisions were visible. A thick tunica vasculosa and thinner tunica albuginea were present. The Leydig cell layer was thin.</p> <p>AMNH R­146652 (June 13, 1998): The left testis was 2.6 X 1.9 mm. The seminiferous tubules had poorly developed lumina that contained large spermatogonia­like cells with darkly stained nuclei (fig. 19E). The tubule walls also contained large vacuolated cells; spermatocytes were present but no sperm were visible (fig. 19F). The thin wall contained smooth muscle. The large lumen</p> <p>of the vas deferens contained irregular cells, almost like debris; no sperm were present. The tunica albuginea and tunica vasculosa were as described by Goldberg and Lowe (1966). The Leydig cell layer of the tunica vasculosa was thin and incomplete. The seminiferous tubules were occluded with fibrous material and some spermatids, and only a few spermatogonia and primary spermatocytes were present. Since the specimen (snout–vent length = 65 mm) was at the minimum size for sexual maturity (snout– vent length = 64 mm; Vitt and Breitenbach, 1993), it is likely that limited spermatogenesis had begun, but that sperm were not yet being moved from the seminiferous tubules to the epididymis. Sertoli cells were not obvious (fig. 19E, F). The mesonephric tubules were of normal (20–30 µm) or large (75–100 µm) size.</p> <p>AMNH R­146653 (June 13, 1998): The left testis was 5.4 X 3.3 mm. Most of the seminiferous tubules were almost empty but all contained a few sperm; however, masses of sperm were present in a few tubules in the center of the testis and also in the vas deferens and epididymis (fig. 18H). Those tubules without masses of sperm were occluded with fibrous material and a few spermatids as in AMNH R­146652. Reproductive activity was probably ending because the seminiferous tubules had a poorly defined lumen, occluded with nonreproductive material, and spermatids were less abundant. Since the epididymis contained sperm (fig. 18H), a recent copulation probably had not occurred, if empty vasa deferentia are true indicators of copulation (Goldberg and Lowe, 1966).</p> <p>Of the three male C. tigris marmoratus examined, one small individual of 65 mm snout–vent length (AMNH R­146652) appeared to be in the process of acquiring re­ productive maturity, and the other two (each 92 mm snout–vent length) were reproduc­</p> <p>tively competent.</p> <p>Cnemidophorus tesselatus X C. tigris mar­</p> </div>	https://treatment.plazi.org/id/038549144C7BFFA85FD8FB39FB6EB920	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	TAYLOR, HARRY L.;COLE, CHARLES J.;HARDY, LAURENCE M.;DESSAUER, HERBERT C.;TOWNSEND, CAROL R.;WALKER, JAMES M.;CORDES, JAMES E.	TAYLOR, HARRY L., COLE, CHARLES J., HARDY, LAURENCE M., DESSAUER, HERBERT C., TOWNSEND, CAROL R., WALKER, JAMES M., CORDES, JAMES E. (2001): Natural Hybridization Between the Teiid Lizards Cnemidophorus tesselatus (Parthenogenetic) and C. tigris marmoratus (Bisexual): Assessment of Evolutionary Alternatives. American Museum Novitates 3345: 1, DOI: 10.1206/0003-0082(2001)345<0001:NHBTTL>2.0.CO;2, URL: http://www.bioone.org/doi/abs/10.1206/0003-0082%282001%29345%3C0001%3ANHBTTL%3E2.0.CO%3B2
