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Morphological variation of 508 hatchling alligators from three lakes in north central Florida (Lakes Woodruff, Apopka, and Orange) was analyzed using multivariate statistics. Morphological variation was found among clutches as well as among lakes. Principal components analysis was used to determine the proportion of the variation attributable to shape as opposed to size. Shape accounted for 42% and 36% of the variation among individuals and clutches, respectively. Linear discriminant analysis with cross-vali- dation was performed to determine whether the clutch from which an individual came or the lake from which a clutch came from could be predicted. Success of predicting clutch membership varied from 67% for Lake Apopka to 74% for Orange Lake. The lake from which a clutch was obtained could be predicted with a success rate of 49%. The optimal subset of measurement variables, obtained from stepwise discrim- inant analysis, was used to illustrate the morphological variation among clutches and lakes in a scatterplot of the first two canonical variables. Assuming factors such as genetics, nutrition, age, size, and stress affect hatchling morphology, one would suspect hatchlings from the same clutch to be more similar than hatch- lings from different clutches. Likewise, we suggest that a lake effect could be the result of intrapopulational similarity of environmental factors, such as food and resource availability, nutrient levels, contaminant levels, and parental lineage (genetics). We hypothesize that demographic and environmental influence on the ma- ternal contribution to the embryonic environment, rather than genetic influence, is responsible for the ob- served pattern of morphological variation.

Evidence increasingly suggests that some environmental pollutants are able to permanently affect development of the endocrine system in wildlife. Embryonic and neonatal exposure to these "endo- crine-disrupting contaminants" can cause structural and functional abnormalities of the reproductive system. It has recently been hypothesized that demasculinization of a population of male juvenile American alli- gators (Alligator mississippiensis) from Lake Apopka, Florida, could result from exposure to antiandrogenic contaminants. The persistent pesticide contaminant p.p'-DDE interacts with the mammalian androgen recep- tor and antagonizes androgen action in vivo. Wildlife from Lake Apopka, which has been contaminated through agriculture and an industrial accident, exhibit elevated levels of p.p.'-DDE, among other pesticide residues. This study provides further evidence of reproductive dysfunction in Lake Apopka juvenile alli- gators by comparison with a "reference" population from a relatively uncontaminated lake nearby, Lake Woodruff National Wildlife Refuge. Phallus size correlated strongly with plasma dihydrotestosterone (DHT) concentrations or body size in juvenile males from Lake Woodruff In contrast, males from Lake Apopka had significantly smaller phalli (adjusted for body size) than those from Lake Woodruff, and correlations with body size or plasma DHT concentrations were weak or absent. Plasma DHT concentrations did not differ significantly between juvenile males from the two lakes. In contrast, plasma DHT concentrations were significantly higher in females from Lake Apopka compared to those from Lake Woodruff This is the first report of masculinized female juvenile alligators from Lake Apopka and suggests that juveniles of both sexes exhibit altered endocrine and reproductive parameters.

Environmental contaminants can act as stressors, inducing elevated circulating concentrations of stress hormones such as corticosterone and corticod sol. Development in contaminated eggs has been reported to modify circulating sex steroid hormone concentrations in alligators (Alligator mississippiensis). We ex- amined plasma concentrations of testosterone (T), estradiol-17p (E2), and corticosterone (B) immediately upon and two hours after capture in male and female juvenile alligators living in either contaminated or relatively pristine lake systems. We observed that plasma T concentration was significantly depressed in males from the contaminated lake, whereas plasma E2 showed significant variation between sexes but not between lakes. Initial plasma B concentrations were similar between alligators from both lakes or either sex. Two hours of capture and restraint did not effect plasma T or E2 concentrations but was associated with a dramatic rise in plasma B concentrations. These data suggest that juvenile alligators exposed to contaminants in ovo are apparently unaffected in their rapid glucocorticoid response to acute stress.

Hoplodactylus maculatus is a small, nocturnal and viviparous gecko that is widespread throughout New Zealand and represents a complex of several undescribed species. Common geckos in the Macraes-Middlemarch region of Central Otago in southern New Zealand have a biennial ovarian cycle with virtually continuous ovarian activity. Females begin vitellogenesis in autumn and ovulate the fol- lowing spring. Pregnant females carry full-term, viable embryos by the end of autumn about 7 mo after ovulation, but remain pregnant during the subsequent winter. Parturition occurs the following late spring or summer, about 14 mo after ovulation. In populations of this species complex in three other regions of New Zealand, annual ovarian cycles with a 3-5 mo pregnancy have been reported. Biennial reproduction in the Macraes-Middlemarch region is associated with colder temperatures during spring-autumn than in regions with annual reproduction. Common geckos from the Macraes-Middlemarch region also have larger body sizes and a smaller mean litter size than in two populations with annual reproductive cycles. Small litter size and biennial reproduction in the Macraes-Middlemarch region result in an annual reproductive output of about 0.85 young, comparable with the lowest value reported for any other lizard. These findings imply a long life-span in common geckos from this region.

The ubiquitous distribution of many contaminants and the nonlethal, multigenerational effects of such contaminants on reproductive, endocrine, and immune systems have led to concerns that wildlife worldwide are affected. Although the causal agents and effects are known for some species, the underlying physiological mechanisms associated with contaminant-induced reproductive modifications are still poorly understood and require extensive research. We describe a study examining the steroidogenic activity of gonads removed from juvenile alligators (Alligator mississippiensis) obtained from contaminated or control lakes in central Florida. Synthesis of estradiol-17 beta (E2) was significantly different when ovaries from the contaminated and control lakes were compared in vitro. Additionally, testes from males obtained from the contaminated lake. Lake Apopka, synthesized significantly higher concentrations of E2 when compared to testes obtained from control males. In contrast, testosterone (T) synthesis from all testes examined in this study displayed a normal pattern and produced concentrations greater than that observed from ovaries obtained from either lake. Interestingly, the pattern of gonadal steroidogenesis differs from previously reported plasma concentrations of these hormones obtained from the same individuals. We suggest that the differences between the in vivo and in vitro patterns are due to modifications in the hepatic degradation of plasma sex steroid hormones.

Many of the remaining members of the endangered Florida panther (Felis concolor coryi) population suffer from one or more of a variety of physiological, reproductive, endocrine, and immune system defects including congenital heart defects, abnormal sperm, low sperm density, cryptorchidism, thyroid dysfunction, and possible immunosuppression. Mercury contamination, determined to be the cause of death of a female panther in 1989, was presented as the likely cause of thyroid dysfunction. As genetic diversity in the species was less than expected, all of the other abnormalities have been attributed to inbreeding. However, exposure to a variety of chemical compounds, especially those that have been identified as environmental endocrine disrupters (including mercury, p,p'-DDE, and polychlorinated biphenyls), has elicited all of the listed abnormalities in other species. A number of these contaminants are present in South Florida. An exposure pathway has been identified, and evidence presented in this paper, including the fact that there appears to be no significant difference between serum estradiol levels in males and females, suggests that many male panthers may have been demasculinized and feminized as a result of either prenatal or postnatal exposure. Thus, regardless of the effects of inbreeding, current evidence seems to indicate that environmental contaminants may be a major factor contributing to reproductive impairment in the Florida panther population.

The phenomenon of follicular atresia, defined as the death of ovarian follicles prior to ovulation, has seldom been noted in the ecological literature as a major factor in the proximate control of clutch size, but it has been demonstrated that it influences clutch size in many lizard species. Follicular atresia was examined by analysing the difference between the number of vitellogenic follicles recruited at the onset of reproductive activity and the number of in utero embryos in females of the viviparous lizard Sceloporus mucronatus; with female body size factored out, the number of vitellogenic follicles recruited from the germinal beds was not different between populations whereas clutch size was significantly different between the populations

The reproductive cycle of the lizard Sceloporus torquatus was determined using data obtained from field caught and museum specimens. Males exhibit testicular recrudescence during late summer and maximal testicular volumes occur during September and October. Similarly, females begin vitellogenesis in late summer, culminating in ovulation during November or December. Females are pregnant throughout the winter months with birth in April or early May. Average clutch size is 9.7 young. Neonates of both sexes are born early in summer, achieve adult size within five months and are thus capable of reproductive activity the first fall after birth. This study adds to the data that indicate that fall reproductive activity is the common reproductive strategy among viviparous lizards of the genus Sceloporus

Germinal bed (GB) number in ovaries of 26 lizard species is described. This infor- mation, along with previous data on 14 other lizards, allowed us to form the following hypotheses concerning the relationships of GB number and (1) the numbers of growing and atretic follicles in the preovulatory ovary, (2) instantaneous fecundity, (3) geographic distribution, and (4) taxonomic relationship. Germinal bed number can vary within a family, but may be consistent within other families and also within genera. The 11 species with one GB per ovary are tropical or subtropical, or are derived from a primarily tropical genus, and exhibit a relatively low instantaneous fecundity (usually 1 egg). In contrast, all but one of the 21 temperate species examined have two GBs per ovary, but some tropical or subtropical species also exhibit this ovarian condition. Presence of two GBs per ovary is related to a wide range of instantaneous fecundities. In these species, rates of follicular atresia in preovulatory ovaries are inversely proportional to instantaneous fecundity. Species with one GB per ovary have not readily evolved new forms with higher instantaneous fecundities in the past. In contrast, the condition of two (or several) GBs per ovary has been asso- ciated with greater phylogenetic flexibility of instantaneous fecundity. In the latter species, evo- lutionary changes in pituitary FSH secretion, which affect both the number of ovarian follicles and rates of follicular atresia, may have mediated changes in instantaneous fecundity. Testing of these hypotheses must await more data on the number of GBs and growing and atretic follicles in pre- ovulatory ovaries of more lizard species.

1980b. Female mate choice in a neotropical frog. Science 209:523-525. SACHS, M. B. 1964. Responses to acoustic stimuli from single units in the eighth nerve of the green frog. J. Acoust. Soc. Amer. 36:1956-1958. SIEGEL, S. 1956. Nonparametric statistics for the behavioral sciences. McGraw-Hill, New York. WELLS, K. D. 1977a. The courtship of frogs, p. 233262. In: The reproductive biology of amphibians. D. H. Taylor and S. I. Guttman (eds.). Plenum Press, New York. 1977b. The social behaviour of anuran am

A single, intraperitoneal injection of 0.02 ig arginine vasotocin (AVT) caused oviposition and associated behaviors in the lizards Sceloporus aeneus aeneus, Hemidactylus frenatus, and Lepidodactylus lugubris. In addition, AVT induced parturition in Sceloporus aeneus bicanthalis, a viviparous lizard. These results, along with previous reports that oviposition or parturition are correlated with regression or surgical removal of corpora lutea, suggest that luteal regression induces AVT secretion. Neither 0.02 ig nor 2.0 ig AVT stimulated oviposition in Anolis carolinensis, whether the animals were kept in a dry or moist substrate. Since previous work showed that the oviducts of these animals contract in response to AVT in vitro, it is hypothesized that there is a stress-induced neural inhibition of AVT-induced oviduct contraction in vivo. The neurohypophysis of lizards secretes two octapeptide hormones, arginine vasotocin (AVT) and mesotocin (Sawyer, 1977). Although AVT has been shown to induce rhythmic oviductal (uterine) contractions in vitro in several lizard species (LaPointe, 1969, 1977; Guillette and Jones, 1980), an in vivo effect of AVT on oviductal contractions has been reported in only one species, the viviparous lizard Sceloporus jarrovi (Guillette, 1979). To date, there are no studies concerning the effects of AVT on gravid, oviparous lizards. We report here that administration of a single injection of a low dosage of AVT induces oviposition in gravid lizards: Hemidactylus frenatus, Lepidodactylus lugubris, and Sceloporus aeneus aeneus, as well as parturition in the viviparous lizard Sceloporus aeneus bicanthalis. We also discuss the curious finding that AVT failed to induce oviposition in the oviparous lizard, Anolis carolinensis. MATERIALS AND METHODS Sceloporus aeneus.-Female S. aeneus of both subspecies (S. a. aeneus and S. a. Present address: Department of Biological Sciences, Wichita State University, Wichita, Kansas 67208, USA. bicanthalis) were collected from two locations in Mexico. Gravid S. a. bicanthalis were obtained from the Parque Nacional de Zoquiapan, Mexico, Mexico, whereas gravid S. a. aeneus were obt ined near El Capulin, Volcan Ajusco, Distrito Federal, Mexico. Specimens were obtained during May 1979. Both collecting sites were at 3200 meters. It should be noted that S. aeneus is reproductively bimodal; that is, the taxon S. a. aeneus is oviparous, whereas the subspecies S. a. bicanthalis is viviparous (Guillette, 1981a). Ten gravid, female S. a. aeneus and six pregnant S. a. bicanthalis were randomly partitioned into equal treatment groups. The control subjects (N = 5 S. a. aeneus and 3 S. a. bicanthalis) received a single intraperitoneal injection (0.05 ml) of 0.75% physiological saline, whereas the experimental animals (N = 5 S. a. aeneus and 3 S. a. bicanthalis) received 0.02 fig AVT/0.05 ml saline. Arginine vasotocin was obtained from Sigma Chemical Company (Lot #28C-0359). Subsequent to injection, all animals were placed in a soil-filled, 95-liter glass aquarium. The ambient temperature within the test aquarium during the experiment existed in a gradient from 25?C to 35?C. Water was available ad libitum during This content downloaded from 157.55.39.231 on Wed, 05 Oct 2016 04:22:55 UTC All use subject to http://about.jstor.org/terms INDUCED OVIPOSITION IN LIZARDS the test period. Several dependent measures of parturition or oviposition were obtained, including (1) initial contraction latency, measured as the duration from injection to first total body contraction, (2) birth latency, or the time lapse between injection and first birth (oviposition), and (3) interbirth duration, representing the period of time between individual births (ovipositions). Maximal experimental duration was 360 minutes subsequent to injection. Thus, females that did not deliver young or eggs were assessed birth latency scores of 360 minutes. Student's t-tests, for non-paired samples were used to determine significance between the control and experimental groups. In addition, a two-way ANOVA was performed on the data obtained from the two subspecies of S. aeneus to determine any differences in response to AVT between these two closely related organisms. Hemidactylus frenatus.-Gravid house geckoes were collected from the island of Oahu, Hawaii on 20-28 December 1980. The animals were transported to Boulder, Colorado, housed in an aquarium in a greenhouse, and exposed to a 12L:12D photoperiod with a temperature of 33-25?C during the photophase and 18-25?C during the scotophase. Lizards were fed mealworms and provided water ad libitum. On 6 January 1981, six gravid females were given a single intraperitoneal injection of 0.02 tg AVT in 0.05 ml saline. Five additional gravid females received an injection of 0.05 ml saline alone. It should be noted that this test began after the onset of the scotophase, due to the fact that these animals are nocturnal (it is not known if oviposition occurs at night). The geckoes then were observed for six hours. Data collected were similar to those obtained for S. aeneus and were analyzed in a similar fashion. Lepidodactylus lugubris.-Collection, housing and testing of the parthenogenetic mourning gecko were as for H. frenatus. Anolis carolinensis.-This is an oviparous lizard that alternates ovulation of one egg from each ovary approximately every 14 days (Hamlett, 1952). An egg remains in one of the two oviducts for 18 or 19 days, after which it is oviposited. T ere is, as a result, a 4 or 5 day period when an old, shelled egg is in one oviduct (the egg that soon will be laid) while a new, unshelled egg is in the contralateral oviduct. We tested the effect of AVT in female Anolis with either one or two eggs in the oviducts. In the first experiment with Anolis (Exp. 1), reproductively active females purchased from a supplier were used (arrived on 23 May 1980). Animals were exposed to an environment of 14L(32?C):10D(20?C) and high humidity, and were fed mealworms and watered ad libitum, before the experiment. Animals were partitioned into six experimental groups (N = 10 for each group) on 27 May 1980. These were: (1) females with one oviductal egg that received a single, intraperitoneal injection of 2.0 Ag AVT in 0.05 ml saline; (2) one-egg females, 0.02 ,g AVT; (3) oneegg females, 0.05 ml saline alone; (4) fem les with two eggs in the oviducts that received 2.0 jig AVT in 0.05 ml salin ; (5) two-egg females, 0.02 ,g AVT; and (6) two-egg females, 0.05 ml saline alone. Intraperitoneal injections were made during the second hour of the photophase (mean body temperature of experimental subjects was approximately 32?C). After injections, animals were housed in a clear plastic box at 32?C and observed for 24 hours. In the second experiment with Anolis (Exp. 2), gravid females (received on 14 August 1980) were housed as in the first experiment. Only "two-egg animals" were used in this experiment. These females were given a single, intraperitoneal injection of either 2.0 ,g AVT in 0.05 ml saline (N = 10) or 0.05 ml saline alone (N = 10). In addition, half of each treatment group (N = 5) were kept in dry, plastic cages at 32?C after injection, whereas the other half (N = 5) were 141 This content downloaded from 157.55.39.231 on Wed, 05 Oct 2016 04:22:55 UTC All use subject to http://about.jstor.org/terms L. J. GUILLETTE, JR. AND R. E. JONES TABLE 1. Events related to oviposition or parturition in salineor AVT-treated female lizards.'

iguanid lizard Sceloporus grammicus. I. Chromosome polymorphisms. Evolution 37:38-53. THOMPSON, P., AND J. W. SITES, JR. 1986. Two aberrant karyotypes in the sagebrush lizard (Sceloporus graciosus): Triploidy and a "supernumerary" oddity. Great Basin Natur. 46. In press. WITTEN, G. J. 1978. A triploid male individual Amphibolurus nobbi nobbi (Witten (Lacertilia: Agamidae). Australian Zool. 19:305-308.

External character data from members of the Barisia imbricata complex support the validity of Tihen's (1949b) arrangement, with two species (B. levicollis, B. imbricata) and three subspecies of B. imbricata (B. i. imbricata, B. i. ciliaris, B. i. planifrons). In addition, B. i. jonesi subsp. nov. from the isolated Sierra de Coalcoman, Michoacan, is described. A key is provided for the entire complex. The genus Barisia Gray (1838), originally proposed for Gerrhonotus imbricatus Wiegmann, G. rudicolis Wiegmann, and G. lichenigerus Wagler, was redefined by Tihen (1949b) to include all these taxa (with lichenigerus an invalid junior synonym of imbricatus) and seven other species (G. moreleti Bocourt, G. monticolus Cope, G. viridiflavus Bocourt, G. gadovi Boulenger, Pterogasterus modestus Cope, Barissia antauges Cope and B. levicollis Stejneger), with G. imbricatus the type by subsequent designation by Stejneger (1890). The validity of Tihen's grouping has never been questioned, but its proper rank has been a source of considerable disagreement beginning with Stebbins (1958), who proposed subgeneric rank. Meszoely (1970) adopted Stebbins' arrangement, but Bogert and Porter (1967) retained Barisia at the generic level. Criley (1968) could find no osteological distinction for the group. Yet Waddick and Smith (1975) maintained that generic rank is justified on grounds of scale characters, and we follow that conclusion here. The genus retains the same composition today as understood by Tihen, with the exception of the addition of Gerrhonotus lugoi McCoy (1970) to it * Present Address: Department of Biological Sciences, Wichita State University, Wichita

Eumeces copei is a viviparous, high elevation Mexican lizard. Specimens examined were obtained from several locations within the Parque Nacional de Zoquiapan, Mexico, Mixico and from museum collections. This species mates in the fall. Males exhibit maximum testicular volume and activity during the fall. Likewise, females exhibit the onset of vitellogenesis in Sep- tember, ovulation during late fall and embryonic development throughout the remaining winter months with parturition occurring in late spring. This reproductive activity pattern appears com- mon in high elevation, viviparous reptiles and its adaptive significance is discussed. The genus Eumeces is a relatively large group of skinks primarily inhabiting the temperate regions of the Northern Hemi

The oviduct of the lizard, Ctenosaura pectinata was examined prior to ovulation and during the period of oviductal transport and shelling of eggs. The oviduct was divided into four regions: infundibulum, tube, uterus and vagina. The differences noted in the four regions included: a) columnar ciliated cells were more abundant in the infundibulum and vagina; b) epithelial cells were taller in the uterus and vagina; c) glands were more abundant in the uterus; and d) smooth muscle layers were thicker in the vagina. These features were similar throughout the reproductive cycle, including during gravidity. The histological characteristics of the oviducts during gravidity included: a) a wider lumen and highly folded mucosa; b) an oviductal wall that became thicker due to an increase in myometrial thickness (primarily in the uterus and vagina); c) cilia of the epithelial cells that were longer (mainly in the infundibulum); d) secretory epithelial cells that increased in number and were more active; e) oviductal mast cells that decreased in number and degranulate; and f) connective tissue that was more lax and abundant throughout the oviduct.

Although prostaglandin synthesis in reptilian tissues has not been previously documented, studies have demonstrated that this class of hormones influences several aspects of reptilian reproductive biology. Gas chromatographic analysis for prostaglandin (PG) precursors in oviductal and hepatic tissues of the viviparous lizard Sceloporus jarrovi revealed that eicosatrienoic acid (monoenoic series precursor) and arachidonic acid (dienoic series precursor) were present. No eicosapentaenoic acid (trienoic series precusor) was detected in either tissue. Ovary, oviduct, liver, testis, and epididymis synthesized in vitro compounds which migrate with authentic series 2 (dienoic) PG standards on TLC. Furthermore, in vitro incubation of hepatic tissue produced significant amounts of PGF2 and PGE2 in the culture media. These data indicate that reptiles synthesize PG's as do other vertebrates. Prostaglandins (PG's) are potent local hormones or parahormones synthesized from polyunsaturated fatty acid precursors by tissues from mammals, birds, amphib- ians, fishes, and a number of invertebrate

Females of the hylid genus Gastrotheca carry developing eggs in a completely covered brood pouch on their backs. In our laboratory the birth of 76 tadpoles from a single, brooding G. riobambae female was observed. Development of the tadpoles, onset of metamor- phosis (94% had by 30 days), formation of the brood pouch (underdeveloped after 150 days), and initiation of calling (after 180 days) were all followed and recorded in our lab-born clutch. Froglets first displayed two distinct color morphs, which became similar with age. Coloration of the tadpoles was not influenced by changes in background color. Treatment with thyroxine (10-7M) of 6 animals immediately after birth stimulated metamorphosis within 4 days, whereas 6 untreated animals failed to transform. Finally, this account examines many aspects of the successful care of young anurans in captivity.

Examen histologique de la structure et de la maturite de l'oviducte de la salamandre femelle A. mexicanum

Male and female Sceloporus grammicus disparilis from lowland populations exhibit a fall reproductive cycle. Gonadogenesis, courtship, mating and fertilization occur during the late summer and autumn months. Pregnancy occurs throughout the winter and parturition is in spring. Fat bodies increase significantly in mass just prior to the period of reproductive activity. These data are similar to those obtained from the high elevation subspecies S. g. microlepidotus and are consistent with the hypothesis that this type of reproductive cycle may be adaptive for many environments. Reproductive cycles are indicative of the reproductive strategy of a species. Until recently, it was thought that most, if not all, temperate lizards displayed reproductive activity during the spring and summer months (Fitch, 1970). That is, gonadogenesis, courtship, mating, ovulation and fertilization would occur during spring, with either oviposition or parturition occurring during summer or early fall. However, Goldberg (1971) observed that Sceloporus jarrovi, a viviparous lizard, displays a fall reproductive activity cycle in which gonadal development, courtship and mating are exhibited during the fall and early winter months. The female retains the fertilized eggs in utero throughout the winter until spring when parturition occurs. Furthermore, the rate of embryonic development slows during the winter months but increases rapidly after exposure to warm spring temperatures (Goldberg, 1971; Ballinger, 1973; Ruby, 1977; Guillette et al., 1981). Several additional reports concerning fall breeding in viviparous and oviparous temperate lizards are available (for review, see Guillette and Casas-Andreu, 1980). Just as the timing of the reproductive cycle reflects some aspects of reproductive strategy, the fat body cycle may be related to the pattern of 'Present address: Dr. Louis J. Guillette, Jr., Department of Zoology, University of Florida, Gainesville, Florida 32611. This content downloaded from 157.55.39.145 on Sat, 02 Jul 2016 04:19:29 UTC All use subject to http://about.jstor.org/terms 32 TRANSACTIONS OF THE KANSAS ACADEMY OF SCIENCE reproductive effort of a species (Derickson, 1976a, 1976b). In females, the fat bodies are believed to be used for vitellogenesis and winter nutrition (Hahn and Tinkle, 1965; Goldberg, 1972; Guillette and Casas-Andreu, 1981) whereas in males they have been suggested to have a major function in supporting testicular recrudesence, courtship behaviors and winter nutrition (Goldberg, 1971; Ruby, 1977; Guillette and Casas-Andreu, 1981). Several taxonomic studies indicate that at least four taxa, currently accepted as subspecies of Sceloporus grammicus, are recognizable in Mexico and southern Texas: Sceloporus g. microlepidotus, Sceloporus g. disparilis, Sceloporus g. grammicus and Sceloporus g. tamaulipensis (Smith and Laufe, 1945; Hall, 1973; Sites and Dixon, 1981). In the latter work, S. g. disparilis was rejected as a valid subspecies, and was placed as a junior synonym of S. g. microlepidotus, primarily because variation in the complex over much of the Mexican plateau was not taxonomically understood. Yet that same reservation applies equally well to S. g. microlepidotus itself. Since the name disparilis was applied to the northernmost populations of the complex, in Texas, and those are regarded as reasonably consistent, hence probably monomorphic taxonomically, we here adopt that name for convenience. The reproductive biology of two of these subspecific populations have been studied (S. g. microlepidotus from Parque Nacional de Zoguiapan, Mexico; Guillette and Casas-Andreu, 1980, 1981: S. g. gammicus from the Michilia Biosphere Reserve, Durango, Mexico (Ortega and Barbault, 1984). The study by Guillette and Casas-Andreu (1980) demonstrated that male S. g. microlepidotus display maximal testicular activity during the spring whereas females of this subspecies exhibit autumn vitellogenesis and ovulation. Fertilization is thought to occur by sperm stored in the oviduct of the female until ovulation occurs. The fat body cycle of S. g. microlepidotus is seasonal and correlated with the reproductive cycle (Guillette and Casas-Andreu, 198 1). In contrast, Ortega and Barbault (1984) observed that both male and female S. g. gammicus exhibit fall reproductive activity. Males exhibit a slight increase in testicular weight during the summer. However, during August and September, the testis grows rapidly, reaching its greatest size in October. Females do not begin vitellogenesis until September, with ovulation occurring during January. These data indicate that differences do occur in the reproductive cycle of different populations of this species. The reproductive biology of northern populations (Texas, USA; Tamaulipas, Mexico) has not been studied to date. This study was performed to determine the reproductive and fat body cycle of Sceloporus g. disparilis so that these data may be compared to those reported for S. g. microlepidotus. Sceloporus g. microlepidotus inhabits high elevation, evergreen forests which have a relatively short growing season and low temperatures. In contrast, the S. g. disparilis we studied occur at low elevations in a semixeric enviThis content downloaded from 157.55.39.145 on Sat, 02 Jul 2016 04:19:29 UTC All use subject to http://about.jstor.org/terms VOLUME 89, NUMBERS 1-2 33 ronment. The following questions directed this study: (1) Does fall reproductive activity occur in other environments, besides at high elevation? (2) How conservative is a reproductive cycle after a population disperses to a new environment? Little information has been reported on the reproductive cycle of S. g. disparilis, although several pertinent observations are available. Mulaik (1936) determined that S. g. disparilis is viviparous, and observed courtship behavior in October. Additionally, Axtell and Axtell (1970) reported birth during the months of February and March (after transportation to the laboratory and exposure to laboratory temperatures), in specimens obtained from southern Texas. These data are suggestive of a fall reproductive activity cycle. MATERIALS AND METHODS Specimens examined were collected in southern Texas and the adjacent northern lowlands of Tamaulipas, Mexico. These specimens were obtained on loan from the Natural History Museum, University of Kansas; National Museum of Natural History, Smithsonian Institution; and the Cooperative Wildlife Collection, Texas A&M University, through the courtesy of the respective curators of herpetology. Each fixed specimen was weighed (dial-a-gram balance to the nearest 0.05 g) and snout-vent length (SVL) measured (dial micrometer to nearest 0.05 mm). The animal then was dissected and the right fat body removed and weighed using a balance (0.0001 g). The longest and shortest axes of the testes were measured in males and a testicular volume determined using the formula for the volume of an ellipsoid: V = 4/37ra2b, where "a" is 1/2 the shortest diameter and "b" is 1/2 the longest diameter. This measure was used as a parameter of male reproductive activity. The diameter of the largest ovarian follicle and corpus luteum as well as the longest and shortest axes of one oviductal egg in each oviduct were measured (if present) and used to determine female reproductive activity. Additionally, clutch size was obtained for all pregnant females and embryonic development was staged using the embryonic sequence defined by Defaure and Hubert (1961) for the viviparous lizard Lacerta vivipara. Lastly, date of capture was noted for each individual. All similar data for a given month then were averaged and a standard error calculated, to obtain monthly means and errors. An analysis of variance (ANOVA) was performed to determine significant changes throughout the year in reproductive activity (Sokal and Rohlf, 1969). In addition, a Pearson's correlation coefficient was calculated by regressing clutch size against SVL (Sokal and Rohlf, 1969). This content downloaded from 157.55.39.145 on Sat, 02 Jul 2016 04:19:29 UTC All use subject to http://about.jstor.org/terms 34 TRANSACTIONS OF THE KANSAS ACADEMY OF SCIENCE