Hemipenial Morphology Research Articles

The rare Andean pitviper Rhinocerophis jonathani (Serpentes: Viperidae: Crotalinae): redescription with comments on its systematics and biogeography

Rhinocerophis jonathani is one of the few species of the Neotropical pitvipers that inhabit xeric areas at elevations above 2000 m in the Andes. We redescribe the species based on new specimens found in southern Bolivia and northwestern Argentina and provide new data on lepidosis, coloration, hemipenial morphology and the first description of cranial osteology. Rhinocerophis jonathani exhibits a suite of unusual features that are of systematic value within bothropoid genera. We compare the species with the phenotypically similar R. alternatus and the probably sympatric R. ammodytoides to address phylogenetic affinities. The new localities for Rhinocerophis jonathani extend the known range of the species southwards, provide data on its habitat and are the first records of its presence in Argentina. This pitviper occurs in a tropical-subtropical transition area in the Southern Andes and is likely to be derived from the Chacoan fauna.

Behavioural correlates with hemipenis morphology in New World natricine snakes

Copulatory organs (hemipenes) of male snakes vary markedly among species in shape and ornamentation. We suggest that sexual conflict over copulation duration may have shaped the evolution of hemipenis morphology, favouring more elaborate organs in species in which a long duration of copulation is especially beneficial to males, despite the associated costs to females. To test this proposition, we compare mating behaviour between two species of gartersnakes differing in hemipenis morphology. In addition, we review data on copulation duration and hemipenis morphology and relate hemipenis morphology to phylogeny among of New World natricines. As predicted, copulation duration was significantly shorter in the common gartersnake (Thamnophis sirtalis), a species with simple subcylindrical hemipenes, than in the plains gartersnake (Thamnophis radix), a species with more complex, bilobed organs. Furthermore, female T. radix frequently exhibited vigorous body rolls during copulation, a behaviour associated with copulation termination, whereas female T. sirtalis never exhibited this behaviour. Copulations were of shorter duration when female T. radix (but not T. sirtalis) more greatly exceeded males in body size, suggesting that females can more easily disengage from small males. Our review of New World natricines provides only weak evidence for an association between copulation duration and hemipenis morphology. Our mapping of hemipenis morphology onto the New World natricine phylogeny suggests that hemipenis morphology is evolutionarily plastic; both simple and bilobed hemipenes occur in all three major natricine clades, as well as in two of three gartersnake subclades and several sister-species pairs.

Review of the systematics, morphology and distribution of Malagasy dwarf geckos, genera Lygodactylus and Microscalabotes (Squamata: Gekkonidae)

The Malagasy species of the dwarf gecko genera Lygodactylus Gray and Microscalabotes Boulenger have been largely neglected in recent studies on the herpetofauna of Madagascar. Since the historically earliest taxonomic description of Lygodactylus tolampyae in 1872, studies have mainly dealt with the systematics of these lizards, yet many taxonomic issues and the validity of several species is unclear. Some species have been described on the basis of immature specimens, or based on a low specimen number from single sites, and there are no assessments of geographic variation. In this paper we provide a review of Malagasy Lygodactylus and Microscalabotes based on preserved material from a number of major natural history museums, including types of most species, and on own collections. For each species we provide morphological diagnoses, standardized descriptions of up to 24 morphological characters, a list of localities, and discussions of geographical variation if it was apparent from the specimens examined. All except three Malagasy Lygodactylus species are assigned to a total of four phenetic species groups of which at least some may also represent monophyletic units. Hemipenial morphology is described for 11 species and provides a valuable source of characters to distinguish species groups, especially the L. madagascariensis group that differs from other Malagasy species by their lack of hemipenial serrated ridges with pointed papillae, short pedicel and poorly defined lobes. Lygodactylus praecox Pasteur, 1995 is considered as a junior synonym of Lygodactylus klemmeri Pasteur, 1964. One new species, Lygodactylus roavolana, is described based on a unique combination of morphological characters.

Zur systematischen Stellung der Amphisbanen (Reptilia: Squamata), mit besonderer Beriicksichtigung der Morphologie des Hemipenis

On the systematic position of the amphisbaenians The hemipenis of amphisbaenians has scincomorph characteristics, e. g. plicae and microscopic spiny epithelium. In plesiomorph forms (Bipes, Blanus) the apex is simple, in apomorph forms (Trogonophis) it is forked. The genus Amphisbaena has a variable hemipenis morphology. The species from the Antilles are clearly differentiated from those of the continent, the latter resemble Leposternon more than their Caribbean congeners. The resemblance between hisbaenians and scincomorph lizards, especiall teiids, in mode of development of the orbitosplenoid (Bacbia: Bellairs and Gans 1983) and in the mode of lung reduction (Bacbia: hoc loco) is congruent with resemblance in hemipenis characters. These resemblances are considered to be synapomorphic, not convergent.

Morphological variation in Thermophis Malnate (Serpentes: Colubridae), with an expanded description of T. zhaoermii

The colubrid snake genus Thermophis is endemic to higher altitudes on the Qinghai-Xizang Plateau of China. It has been little studied and remains poorly understood. Until Guo et al.’s (2008) description of T. zhaoermii, Thermophis had been monotypic, containing only T. baileyi (Wall 1907). Here, a detailed comparison of external characters, skull and hemipenial morphology in T. baileyi and T. zhaoermii is presented. Both species are sexually dimorphic, and clearly distinct from one another in external, skull and hemipenial characters. An expanded characterization of the recently d e s c r i b e d z h a o e r m i i is provided. Key words: China, morphology, snakes, systematics, Thermophis

New Species of the Taeniophallus occipitalis Group (Serpentes, Colubridae) from Eastern Amazonia, Brazil

Abstract We describe a new species of the Taeniophallus occipitalis group from eastern Amazonia, Brazil. This species appears to be closely related to T. occipitalis from which it differs in color pattern, hemipenial morphology, and number of ventral and subcaudal scales. Characters that distinguish the new species from all other species of Taeniophallus are the following: (1) 15-15-15 or 15-15-13 rows of dorsal scales; (2) eight supralabials; (3) nine infralabials; (4) 168–192 ventral scales; (5) 64–86 subcaudal scales; and (6) distinctive hemipenial morphology (e.g., presence of a large spine in medium-basal region on the asulcate side of the organ). Taeniophallus occipitalis exhibits a wide variety of geographically restricted color patterns, as well as variation in scale counts, making the study of this snake confusing, warranting more study.

REDESCRIPTION OF PHALOTRIS NIGRILATUS FERRAREZZI, 1993 (SERPENTES: COLUBRIDAE: XENODONTINAE)

Phalotris nigrilatus Ferrarezzi, 1993 is a poorly known species described from a single specimen from Paraguay. Two new specimens make possible a more detailed description of the species, including a description of the hemipenis, and support the validity of the species. Hemipenial morphology provides another character that further supports the inclusion of the species in the nasutus group. We describe variation within the species, probable sexual dimorphism, and the known distribution. It will be necessary to do further work in Paraguay to establish the conservation status of this apparently rare and endemic species.

FOUR NEW SPECIES OF ANOLES (GENUS ANOLIS) FROM THE SERRANÍA DE TABASARÁ, WEST-CENTRAL PANAMA (SQUAMATA: POLYCHROTIDAE)

We describe four new species of anoles (genus Anolis) from the Serranía de Tabasará, west-central Panama. Two of the new species are most similar in external morphology to a cluster of Central American species that are short-legged (fourth toe of adpressed hindlimb reaches only to tympanum), have a single elongated prenasal scale, smooth ventral scales, and slender habitus, often delicate. They differ from the other species in this cluster by hemipenial morphology and scalation characteristics. One of the new species appears to be most similar to A. pachypus and A. tropidolepis from which it differs by male dewlap coloration and its very small dorsal head scales. The fourth new species appears to be most similar to A. laeviventris from which it differs by its multicarinate head scales, lack of heterogeneous flank scalation, and an overall green coloration.

Hemipenial morphology of five Asian pitvipers, with a discussion on their taxonomy

AbstractThe hemipenial morphology of five Asian pitvipers, Protobothrops mucrosquamatus, Protobothrops jerdonii, Ovophis zayuensis, Ovophis monticola and Viridovipera yunnanensis, are described and illustrated. Of them, the hemipenes of the first three species have been briefly reported in Chinese Journal of Zoology in Chinese. The results reveal that five species are different in hemipenial structures. The differences between Ovophis zayuensis and Ovophis monticola, and between Viridovipera yunnanensis and Viridovipera stejnegeri, further confirm the validation of Ovophis zayuensis and Viridovipera yunnanensis respectively.

Redescription of Leptotyphlops koppesi Amaral, 1954, and description of a new species of the Leptotyphlops dulcis group from Central Brazil (Serpentes: Leptotyphlopidae)

AbstractA new species of Leptotyphlops dulcis group is described from the central Brazilian Cerrado, which is diagnosed by rostral shape, general colour pattern, and number of middorsal and subcaudal scales. This taxon has been commonly misidentified as L. koppesi in some Brazilian collections and by some authors. Leptotyphlops koppesi was described from the municipality of Terenos, State of Mato Grosso do Sul, Brazil, based on a single specimen. Since its original description, only three subsequent records appear in the literature reporting additional specimens of L. koppesi. We redescrib the holotype of Leptotyphlops koppesi, defining its geographic range and diagnose this from all species of L. dulcis group. Data on morphometric and meristic variation are reported for the new species and L. koppesi as well. Comparisons are made between the new species and all other South American species of the L. dulcis group. The hemipenis of the new species has a narrow basal portion and a series of lateral flounces. This general hemipenial morphology is unique among Neotropical leptotyphlopids, otherwise known only from Atlantic Rainforest species L. salgueiroi.

A survey of the southernmost representatives of the tricolor species group, genus Phalotris (Serpentes, Colubridae)

A survey of the southernmost representatives of the tricolor species group, genus Phalotris (Serpentes, Colubridae). Colubrid snakes of the South American genus Phalotris are difficult to detect because of their secretive habits, and thus they are poorly represented in collections. The species Phalotris cuyanus and P. tricolor, the southernmost representatives of the tricolor species group, were studied to determine the limits of intraspecific variation of P. cuyanus and to consolidate the taxonomic relationship between both species, the phenetically and geographically closest members in the group. The distribution of selected external characters (cephalic, ventral and subcaudal scales), coloration pattern, width of white and black collars, and hemipenis morphology were analyzed. Comparative data on the other members of the group, P. mertensi and P. matogrossensis, are briefly discussed. Males of P. cuyanus have a higher number of ventral scales than males of P. tricolor (mean of 220.3 vs. 204.6). Cephalic melanism varies among individuals and does not have discriminant or geographic value for this species group. The white nuchal collar may partially cover the parietal scales in the four species. The black collar is moderately narrow in P. cuyanus, but it can be up to 12 scales wide in P. tricolor. Vertebral dotting is neither constant nor exclusive of any species. The four species of the group are well characterized by combinations of character states for each one. We suggest considering to P. cuyanus as an evolutionary species typical of the Monte biogeographic province.

A New Species of Krait (Squamata: Elapidae) from the Red River System of Northern Vietnam

Abstract We describe a new species of krait (Elapidae: Bungarus) from the Red River drainage in northern Vietnam. The new species differs from all congeners except its sister species Bungarus bungaroides by the combination of divided subcaudals, dorsal scales arranged in 15 rows, black and white rings on body and tail, and in color pattern of the head as well as hemipenis morphology. The new species differs from B. bungaroides, a distantly allopatric species ranging from eastern Nepal to northern Myanmar, in molecular characters and color pattern. We propose a vicariance hypothesis in which speciation coincided with the uplift of intervening mountain ranges in southwestern Yunnan (China) and/or Late Tertiary glaciations.

REDESCRIPTION AND SYSTEMATICS OF TRIMERESURUS CORNUTUS (SERPENTES: VIPERIDAE) BASED ON MORPHOLOGY AND MOLECULAR DATA

We redescribe Trimeresurus cornutus, a species that has not been reported for more than half a century, based on a recently collected live specimen from the Annamite Mountains of Central Vietnam. Besides new data on the distribution and habitat, we compare coloration and morphological data of the first known male of the species with the type specimen and a third known specimen from North Vietnam. We describe male genital morphology and analyze the systematic relationships of the species using external morphology, hemipenial morphology and molecular data. A phylogenetic hypothesis, based on four mito- chondrial genes, suggests that the species is most closely related to Protobothrops jerdonii. The external morphology and hemipenial morphology are consistent with this placement. Based on the few specimens available, Protobothrops cornutus comb. nov. exhibits a very patchy distribution, with an altitudinal range reaching from 150-2000 m.

Relict snakes of North America and their relationships within Caenophidia, using likelihood-based Bayesian methods on mitochondrial sequences

This paper focuses on the phylogenetic relationships of eight North American caenophidian snake species ( Carphophis amoena, Contia tenuis, Diadophis punctatus, Farancia abacura, Farancia erytrogramma, Heterodon nasicus, Heterodon platyrhinos, and Heterodon simus) whose phylogenetic relationships remain controversial. Past studies have referred to these “relict” North American snakes either as colubrid, or as Neotropical dipsadids and/or xenodontids. Based on mitochondrial DNA ribosomal gene sequences and a likelihood-based Bayesian analysis, our study suggests that these North American snakes are not monophyletic and are nested within a group (Dipsadoidea) that contains the Dipsadidae, Xenodontidae, and Natricidae. In addition, we use the relationships proposed here to highlight putative examples of parallel evolution of hemipenial morphology among snake clades.

The Hemipenes of Some Snakes of the Semifossorial Genus Atractus, with Comments on Variation in the Genus

The hemipenes of seven species of Atractus (Atractus emigdioi, Atractus major, Atractus mariselae, Atractus poeppigi, Atractus torquatus, Atractus univittatus, and Atractus ventrimaculatus) are described. Hemipenial morphology in this poorly known genus of snakes is found to be particularly variable among the species studied. Additionally, the primitive unicapitate hemipenal condition is more widespread among Atractus than was previously thought. Given the drastic variation in hemipenal morphology observed in Atractus, it is likely that characters derived from studying this organ may prove especially useful for future work on intrageneric relationships among members of this genus.

Chamaeleo (Trioceros) narraiocan. sp. (Reptilia Chamaeleonidae), a new chameleon species from a relict montane forest of Mount Kulal, northern Kenya

A new species of chameleon — Chamaeleo (Trioceros) narraioca — is described from Kenya, East Africa. The new taxon inhabits humid montane evergreen forest on Mt Kulal in the Northern Frontier Division of Kenya, from which no representatives of this genus have been previously recorded. The new species is a further member of the Chamaeleo (Trioceros) bitaeniatus complex, but clearly distinct from its congeners by a combination of external and hemipenial morphology, coloration, biology and geographical isolation. KEY WORDS: Reptilia, Chamaeleonidae, Chamaeleo (Trioceros) narraioca, new species, taxonomy.

Evolutionary implications of hemipenial morphology in the terrestrial Australian elapid snakes

Venomous proteroglyphous or ‘elapid’ snakes are distributed across much of the tropical and subtropical world but are most diverse in Australia. Due to diVering opinions of character weight and problems associated with high levels of homoplasy in traditionally used snake character systems, there is no well accepted hypothesis of phylogenetic relationships for the Australian elapids. Moreover, few or no synapomorphies have been identified to define many of the 20 currently recognized genera. As part of a re-evaluation of previous work, I have undertaken a survey of hemipenial morphology in this diverse radiation in a search for supraspecific synapomorphies. Up to 14 aspects of hemipenial morphology were scored on 756 museum specimens and provide the basis for hemipenial descriptions of 64 species of Australian elapid. Morphology is highly conservative at generic levels and supportive of a number of previously suggested phyletic groups, but divergent between putative monophyletic lineages. Hemipenial morphology provides synapomorphies that define seven, and possibly eight, monophyletic groups at subgeneric, generic, and suprageneric levels: (1) Demansia, Oxyuranus, Pseudonaja, and Pseudechis each display unique hemipenial morphologies but share a number of character states. The following groups each share unique hemipenial types: (2) Simoselaps calonotus and the Simoselaps semifasciatus species group, (3) Vermicella and the Simoselaps bertholdi species group, (4) Cacophis and Furina, (5) Austrelaps, Echiopsis, Hoplocephalus, Notechis, and Tropidechis, (6) Drysdalia and Hemiaspis, (7) Rhinoplocephalus and Suta, and (8) Acanthophis and Denisonia. Higher level associations also are identified. The organs of Cacophis‐Furina and Vermicella‐Simoselaps bertholdi clades are very similar in shape and diVer in only a single character. The Drysdalia‐Hemiaspis and Rhinoplocephalus‐Suta clades share a hemipenial shape and also diVer in only a single character. Where sample sizes were suYcient for comparison, hemipenes displayed little or no intraspecific variation.

Evolutionary implications of hemipenial morphology in the terrestrial Australian elapid snakes

Venomous proteroglyphous or «elapid» snakes are distributed across much of the tropical and subtropical world but are most diverse in Australia. Due to differing opinions of character weight and problems associated with high levels of homoplasy in traditionally used snake character systems, there is no well accepted hypothesis of phylogenetic relationships for the Australian elapids. Moreover, few or no synapomorphies have been identified to define many of the 20 currently recognized genera. As part of a re-evaluation of previous work, I have undertaken a survey of hemipenial morphology in this diverse radiation in a search for supraspecific synapomorphies. Up to 14 aspects of hemipenial morphology were scored on 756 museum specimens and provide the basis for hemipenial descriptions of 64 species of Australian elapid. Morphology is highly conservative at generic levels and supportive of a number of previously suggested phyletic groups, but divergent between putative monophyletic lineages. Hemipenial morphology provides synapomorphies that define seven, and possibly eight, monophyletic groups at subgeneric, generic, and suprageneric levels: (1)Demansia,Oxyuranus,Pseudonaja, andPseudechiseach display unique hemipenial morphologies but share a number of character states. The following groups each share unique hemipenial types: (2)Simoselaps calonotusand theSimoselaps semifasciatusspecies group, (3)Vermicellaand theSimoselaps bertholdispecies group, (4)CacophisandFurina, (5)Austrelaps,Echiopsis,Hoplocephalus,Notechis, andTropidechis, (6)DrysdaliaandHemiaspis, (7)RhinoplocephalusandSuta, and (8)AcanthophisandDenisonia. Higher level associations also are identified. The organs ofCacophis–FurinaandVermicella–Simoselaps bertholdiclades are very similar in shape and differ in only a single character. TheDrysdalia–HemiaspisandRhinoplocephalus–Sutaclades share a hemipenial shape and also differ in only a single character. Where sample sizes were sufficient for comparison, hemipenes displayed little or no intraspecific variation.

Specific distinctness and biogeography of the dwarf chameleons Brookesia minima, B. peyrierasi and B. tuberculata (Reptilia: Chamaeleonidae): evidence from hemipenial and external morphology

Specific distinctness and biogeography of the dwarf chameleons Brookesia minima, B. peyrierasi and B. tuberculata (Reptilia: Chamaeleonidae): evidence from hemipenial and external morphology

Specific distinctness and biogeography of the dwarf chameleons Brookesia minima , B. peyrierasi and B. tuberculata (Reptilia: Chamaeleonidae): evidence from hemipenial and external morphology

In a recent paper Raxworthy & Nussbaum (1995) included the Madagascan dwarf chameleons Brookesia peyrierasi and B. tuberculata in the synonymy of B. minima, regarding known hemipenial differences between B. tuberculata and B. peyrierasi as artefacts. Our studies demonstrate that the hemipenis description of B. tuberculata by Brygoo & Domergue (1975) was largely correct and referred to unusual but real structures. The enormous differences in the hemipenis morphology of B. tuberculata (hemipenes of six specimens examined) and B. peyrierasi (hemipenes of five specimens examined) strongly suggest that they are not conspecific. Furthermore, morphological differences in the arrangement of head crests and expression of supraocular spines were noted between these two taxa and B. minima. The differentiation of the three taxa is furthermore corroborated by both univariate and multivariate analyses of morphometric data. We therefore propose to consider Brookesia minima, B. peyrierasi, and B. tuberculata as distinct species. This conclusion corroborates the validity of biogeographic regions as suggested from the analysis of distribution patterns of other Brookesia species.