Hemipenial Morphology Research Articles

Cryptic species inIphisa elegansGray, 1851 (Squamata: Gymnophthalmidae) revealed by hemipenial morphology and molecular data

Iphisa elegans Gray, 1851 is a ground-dwelling lizard widespread over Amazonia that displays a broadly conserved external morphology over its range. This wide geographical distribution and conservation of body form contrasts with the expected poor dispersal ability of the species, the tumultuous past of Amazonia, and the previously documented prevalence of cryptic species in widespread terrestrial organisms in this region. Here we investigate this homogeneity by examining hemipenial morphology and conducting phylogenetic analyses of mitochondrial (CYTB) and nuclear (C-MOS) DNA sequence data from 49 individuals sampled across Amazonia. We detected remarkable variation in hemipenial morphology within this species, with multiple cases of sympatric occurrence of distinct hemipenial morphotypes. Phylogenetic analyses revealed highly divergent lineages corroborating the patterns suggested by the hemipenial morphotypes, including co-occurrence of different lineages. The degrees of genetic and morphological distinctness, as well as instances of sympatry among mtDNA lineages/morphotypes without nuDNA allele sharing, suggest that I. elegans is a complex of cryptic species. An extensive and integrative taxonomic revision of the I. elegans complex throughout its wide geographical range is needed. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166, 361–376.

A New and Threatened Insular Species of Lancehead from Southeastern Brazil

We describe a new species of Bothrops from Vitória Island, off the coast of São Paulo, southeastern Brazil. The new species differs from the mainland coastal populations of B. jararaca mostly in its smaller and stouter body, number and form of scales, and hemipenial morphology. From B. insularis and B. alcatraz, both related species endemic to islands in southeastern Brazil, B. otavioi sp. nov. differs mainly in its body form and number of scales. The new species has the most common mitochondrial haplotype for mainland populations of B. jararaca, which is also found in B. alcatraz. A mitochondrial genealogy (gene tree) shows the new species nested within the northern clade of B. jararaca. This genealogical pattern can be explained by a recent speciation event for B. otavioi sp. nov. The isolation of insular species of Bothrops from continental ancestor populations are probably related to the same vicariant process, the oscillations of sea level during the Pleistocene. The new species feeds on small hylid frogs, and attains sexual maturity at 388 mm snout–vent length (SVL; males) and 692 mm SVL (females). Bothrops otavioi sp. nov. is endemic to Vitória Island, and should be listed as critically endangered because it is known from only a single area (an island), its geographic range covers less than 100 km2, and there is a projected continuing decline in the quality of its habitat because of increasing human settlement.

Ontogenetic Effects on Snake Hemipenial Morphology

Abstract In this study we investigate hemipenial variation through ontogeny by preparing specimens of known-aged individuals from captive-bred Plains Gartersnakes, Thamnophis radix, descended from a wild population in northern Illinois, USA. We examined males at two different ages (215–254 days, N = 9) and (829–867 days, N = 12) to compare both juvenile and adult morphologies. Hemipenis length increased isometrically with tail length, and there were no significant differences detected between right and left hemipenis length or width. In addition, this study is the first to explore variation in hemipenial morphology within and among litters. We found significant litter effects on hemipenis length, on the elevation (but not the slope) of the relationship between hemipenis length and tail length, and on number of basal hooks, suggesting a possible genetic basis to these characteristics. These results highlight the importance of examining multiple males through ontogeny, as well as reporting body-size measure...

Evidence for the recognition of two species of Anolis formerly referred to as A. tropidogaster (Squamata: Dactyloidae)

Based on differences in hemipenial morphology, male dewlap coloration, pholidosis, and 16S mtDNA, we recognize twospecies of anoles related to what was formerly referred to as Anolis tropidogaster: Anolis tropidogaster Hallowell 1856and A. gaigei Ruthven 1916. The hemipenis in A. tropidogaster is large, bulbous, and bilobed whereas it is small, thin,and unilobed in A. gaigei; the male dewlap is almost uniform purplish red, sometimes with a paler orange central area inA. tropidogaster versus orange yellow with a darker orange central area in A. gaigei; and—aside from more subtle differ-ences in several pholidotic characteristics—in male A. gaigei there is a pair of greatly enlarged postcloacal scales whichis absent in A. tropidogaster. In the western part of its geographic range, A. gaigei has been confused with another anolespecies, A. polylepis Peters 1873, from which it can be readily distinguished by its strongly keeled ventral scales (smooth in A. polylepis).

Cryptic Species Within the Dendrophidion vinitor Complex In Middle America (Serpentes: Colubridae)

Snakes previously referred to Dendrophidion vinitor from southern Mexico to eastern Panama comprise three sibling species primarily distinguishable by substantial differences in hemipenial morphology and some subtle aspects of color pattern. Dendrophidion vinitor Smith is here restricted to populations from southern Mexico to Belize. Dendrophidion apharocybe new species is distributed from Honduras to Panama, primarily on the Atlantic versant. Dendrophidion crybelum new species is known from middle elevations of the Río Coto Brus valley in southwestern Costa Rica (Pacific versant). Hemipenes of D. vinitor and D. apharocybe are similar in overall shape (short, bulbous) but the former has a highly ornate apex with membranous ridges and an unusual apical boss, whereas D. apharocybe has a largely nude apex strongly inclined toward the sulcate side. Dendrophidion crybelum has an elongate cylindrical hemipenis with a large number of spines. In general, these species are not distinguishable by standard scutellation characters. Hemipenial and other characters suggest that these species are a monophyletic group within Dendrophidion and have the following relationships: (vinitor (apharocybe, crybelum)). Some aspects of the systematics and biogeography of Dendrophidion are discussed. Divergence among the three species is associated with two geological features important to speciation in Middle America, the northern Motagua–Polochíc fault zone (Guatemala–Belize) and the southern Cordillera Talamanca (Costa Rica–Panama).

Discovery of a rare snail-eater snake in Venezuela (Dipsadinae, Dipsas pratti), with additions to its natural history and morphology

The snail-eating snakes that inhabit the Sierra de Perijá, of both Colombia and Venezuela, have received little attention in part because of the difficult accessibility of this area, due to the roughness of the terrain and the geopolitical boarder instability in this region. One of the rarest and least known snail-eaters, Dipsas pratti (type species of its group, sensu Peters 1960), is known from 13 specimens (including the holotype). Since its original description in 1897, all known specimens of D. pratti have been collected from the Cordillera Central and Oriental of Colombia. In this study, we greatly improve our knowledge of the biology of D. pratti based primarily on nine newly collected specimens. Seven of these specimens are the first recorded from Venezuela, expanding the known range of this species by approximately 300 km to the northeast. These specimens provide additional information on external, reproductive, and hemipenial morphology, habitat, and defensive behaviors of the species. Additionally, we provide the first in-life photographs of D. pratti. This study sheds light on the biodiversity in a unique and underexplored region as well as bridging a critical knowledge gap in our understanding of an understudied group of Neotropical snakes. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Taxonomy, Hemipenial Morphology, and Natural History of Two Poorly Known Species of Anadia (Gymnophthalmidae) from Northern South America

Anadia pariaensis Rivas, La Marca, and Oliveros, 1999, and Anadia steyeri Nieden, 1914, are two particularly rare and poorly known lizards described from single specimens. In the case of A. pariaensis, it remains known from the holotype, whereas A. steyeri is known from three additional specimens reported in the literature after the original description of the species. A single new specimen of A. pariaensis and five of A. steyeri, including the first adult males recorded for both species, make possible a more representative description of both species, including descriptions of the hemipenes. Despite both species presenting some similar morphological characteristics, the examination of the hemipenial morphology revealed very different organs. The hemipenis of A. steyeri presents some characteristics that resemble the organs of two species from the Santa Marta Mountain Range in the “bitaeniata-group” (Anadia pulchella and Anadia altaserrania). On the other hand, the hemipenes of A. pariaensis are unique morphologically and cannot be associated with the hemipenes known from other species in the genus. We describe variation within both species, and we comment on possible sexual dimorphism (number and arrangement of the femoral pores), natural history, and the known geographic distribution of the species. We also comment on Anadia bumanguesa Rueda-Almonacid and Caicedo 2004 based on a new specimen, the second known. This species may be a synonym of A. steyeri.Anadia pariaensis Rivas, La Marca, and Oliveros, 1999 y Anadia steyeri Nieden, 1914, son dos especies raras, escasamente conocidas y descritas con ejemplares únicos. En el caso de A. pariaensis, esta permanece conocida solo por el holotipo; mientras A. steyeri se conoce por cuatro ejemplares señalados en la literatura desde su descripción. En este trabajo, un nuevo ejemplar de A. pariaensis y cinco de A. steyeri, incluyendo los primeros machos adultos registrados para ambas especies hacen posible una descripción detallada, incluyendo la descripción de los hemipenes. A pesar que estas especies presentan algunas características morfológicas similares, el examen de la morfología hemipenial reveló órganos muy diferentes. El hemipene de A. steyeri, presenta algunas características que lo asemejan a los órganos de dos especies del grupo bitaeniata de la sierra de Santa Marta (Anadia pulchella y Anadia altaserrania). Por otra parte, el hemipene de A. pariaensis es único morfológicamente, y no puede ser actualmente asociado con los hemipenes conocidos para otras especies en el género. Se describe la variación intraespecífica, posible dimorfismo sexual (número y disposición de los poros femorales), historia natural y distribución geográfica conocida para ambas especies. Por último, se analiza el estado taxonómico de Anadia bumanguesa Rueda-Almonacid y Caicedo 2004 basado en un nuevo ejemplar disponible (el segundo conocido) y esta nueva información sugiere que la especie podría ser un sinónimo o al menos estar relacionada con A. steyeri.

Morphology, phylogeny and taxonomy of South American bothropoid pitvipers (Serpentes, Viperidae)

Carrasco, P.A., Mattoni, C.I., Leynaud, G.C. & Scrocchi, G.J. (2012). Morphology, phylogeny and taxonomy of South American bothropoid pitvipers (Serpentes, Viperidae). —Zoologica Scripta, 41, 109–124.South American bothropoids comprise a monophyletic and greatly diverse group of pitvipers that were initially included in the genus Bothrops and later assigned to five genera. Until recently, most phylogenetic analyses of bothropoids used exclusively mitochondrial DNA sequences, whereas few of them have included morphological traits. Moreover, the systematic affinities of some species remain unclear. In this study, we performed a parsimony analysis of morphological data obtained from the examination of 111 characters related to lepidosis, colour pattern, osteology, and hemipenial morphology of 35 of the 48 species that compose the bothropoid group. The morphological data analysed contain novel information about several species, including the incertae sedis. Morphology was analysed separately and combined with 2393 molecular characters obtained from published sequences of four mitochondrial genes. Five characters of the ecology were also included. A sensitivity analysis was performed using different weighting criteria for the characters. The congruence among different sources of evidence was evaluated through partitioned and total evidence analyses, the analyses of reduced datasets and the use of incongruence length difference test. With few exceptions, results showed groups of species similar to those obtained in previous studies; however, incongruences between morphological and molecular characters, and within the molecular partition, were revealed. This conflict affects the relationship between particular groups of species, leading to alternative phylogenetic hypotheses for bothropoids: hierarchical radiation or two major lineages within the group. The results also showed that Bothrops sensu stricto is paraphyletic. We discuss previous taxonomic approaches and, considering both phylogenetic hypotheses, we propose an arrangement that rectifies the paraphyly of Bothrops: maintaining Bothrocophias, assigning Bothrops andianus to this genus; and recognising the sister clade as Bothrops, synonymising Bothriopsis, Bothropoides and Rhinocerophis.

Hemipenial morphology in the North American snake genus Phyllorhynchus (Serpentes: Colubridae), with a review of and comparisons with natricid hemipenes

Hemipenes of species in the North American colubrid genus Phyllorhynchus are described. Contrary to previous reports of a divided sulcus spermaticus, both species have an unusual morphology in which the lips of the sulcus diverge near the apex so that the sulcus groove opens into an extensive apical nude region. Two distinctive hemipenial morphologies were discovered within P. browni, which may signal unresolved systematic issues. Phyllorhynchus hemipenes are additionally unusual for colubrids in having calyces reduced (P. decurtatus) or absent (P. browni). These features resemble some natricid hemipenes, which are reviewed in order to make detailed comparisons. That review led to a reassessment of some hemipenial characters of natricids and the recognition of several novelties, including calyces in Rhabdophis and a peculiar lobular pocket in Xenochrophis cerasogaster. I conclude that the resemblance of the sulcus configurations in Phyllorhynchus and natricids is only superficial and therefore convergent. Other evidence supports the phylogenetic placement of Phyllorhynchus with Colubridae, for which the sulcus configuration, highly reduced calyces, and extensive apical nude areas are unusual. Relationships of Phyllorhynchus within Colubridae are unclear, but the genus shares with Salvadora an unusual morphology of the rostral scale and nude hemipenial apices. However, in other respects Salvadora and Phyllorhynchus differ greatly in morphology and ecology.

Redescription of Apostolepis longicaudata (Serpentes: Xenodontinae) with Comments on Its Hemipenial Morphology and Natural History

We redescribe the rare elapomorphine snake Apostolepis longicaudata Gomes in Amaral on the basis of a detailed examination of the holotype and comparisons with new specimens from the Cerrado of Central Brazil. The new data include information on coloration in life, hemipenial morphology, and natural history. Two specimens identified as A. quinquelineata by previous authors are now attributed to A. nelsonjorgei, which seems to be the only species in the genus with subcaudal counts overlapping those of A. longicaudata.Apresentamos a redescrição da rara espécie de serpente Apostolepis longicaudata Gomes in Amaral com base no exame do holótipo e em comparações com três novos exemplares do Cerrado do Brasil Central. O trabalho inclui dados inéditos sobre a coloração em vida, morfologia hemipeniana e história natural. Dois espécimes lineados previamente identificados como A. quinquelineata por outros autores são redeterminados aqui como A. nelsonjorgei, que parece ser a única espécie do gênero cujas contagens de subcaudais se sobrepõem às de A. longicaudata.

On the Generic Identity of Siagonodon brasiliensis, with the Description of a New Leptotyphlopid from Central Brazil (Serpentes: Leptotyphlopidae)

The geographic variation and hemipenial morphology of Siagonodon brasiliensis are described based on a comprehensive sample, allowing the reappraisal of its generic identity, and the proposal of a new nomenclatural combination. We suggest that the presence of two supralabials, as mentioned in the original description of S. brasiliensis, is not a common feature for this species, occurring at low frequencies throughout its geographic distribution. Based on a diagnosis presented in a recently published paper, as well as on additional external traits and on hemipenial characters, we recognize Siagonodon brasiliensis as a species of the genus Tricheilostoma. In addition, a new species of worm snake of the genus Siagonodon is described from the savannas of the state of Tocantins, Brazil. The new species differs from other congeners by having a slightly acuminate snout in lateral and ventral views, subcircular rostral in dorsal view, and 12 scale rows around middle of tail. The diagnosis of the genus Siagonodon ...

Systematics, natural history, and hemipenial morphology of Dendrophidion brunneum (Günther) (Serpentes: Colubridae), a poorly known snake from the Andes of Ecuador and Peru

Systematics, natural history, and hemipenial morphology of Dendrophidion brunneum (Günther) (Serpentes: Colubridae), a poorly known snake from the Andes of Ecuador and Peru

Cryptic species and hybridization in the Anolis polylepis complex, with the description of a new species from the Osa Peninsula, Costa Rica (Squamata: Polychrotidae)

Based on differences in hemipenial morphology we recognize two species of anoles related to Anolis polylepis: Anolis polylepis (Pacific versant of central and southern Costa Rica and western Panama, excluding the Osa Peninsula) and a species described herein which is restricted to the Osa Peninsula. The two species differ in hemipenial morphology (hemipenis bilobed in A. polylepis versus unilobed in the species from the Osa Peninsula) but show no discernable differences in external morphology (i.e., morphometrics, scalation, coloration, male dewlap). We therefore consider them to be cryptic species. At the neck of the Osa Peninsula where the ranges of the two species meet we detected a narrow (about 1 km wide) hybridization zone in which only individuals with an intermediate hemipenial morphology occur.

Redescripción de Anolisproboscis Peters & Orcés (Reptilia: Polychrotidae), con el descubrimiento de las hembras de la especie y comentarios sobre su distribución y taxonomía

Redescribimos a la enigmática lagartija Anolis proboscis basados en nuevo material colectado en el Distrito Metropolitano de Quito, provincia de Pichincha, Ecuador. Describimos las primeras hembras conocidas de la especie, ampliando así la diagnosis con datos sobre dimorfismo sexual; y presentamos nueva información sobre caracteres antes no descritos, como el casco craneal y la morfología de los hemipenes. Proponemos que el apéndice nasal no es un carácter homólogo apomórfico entre A. proboscis y A. phyllorhinus, por lo que el grupo-de-especies A. laevis no es un clado válido. De hecho, sugerimos que A. proboscis está cercanamente relacionado con especies previamente clasificadas como Phenacosaurus; mientras que A. phyllorhinus es parte del grupo-de-especies A. punctatus. Aportamos nueva información sobre la distribución e historia natural de A. proboscis y sugerimos que sea clasificado bajo la categoría y criterios de riesgo de extinción de la lUCN de “En Peligro EN B1ab (i,ii,ii) +2ab (i,ii,iii)”. Proponemos que A. proboscis sea considerado una especie de reptil emblemática del Distrito Metropolitano de Quito, en especial para la conservación de la zonas de Las Tolas y Lloa-Mindo.

New Endemic Species of Riama (Squamata: Gymnophthalmidae) from Northern Colombia

A new endemic species of gymnophthalmid lizard of the genus Riama is described from the Cordillera Occidental of northern Colombia. The new species differs from all known Riama by pholidosis, hemipenial morphology, and color pattern. The four known endemic Colombian species, Riama columbiana, Riama laevis, Riama stellae, and Riama striata, occur in different montane forests and are not known to be sympatric with the new species. The new species most resembles R. laevis from the Cordillera Occidental of the Colombian Andes, but it differs in having 15 longitudinal scale rows, 21–23 transverse scale rows in males and 22 in females, and limbs that do not overlap or just touch when adpressed against the body.

Taxonomic Status of Chironius multiventris and Chironius cochranae (Serpentes)

Recently four subspecies of Chironius multiventris were recognized as valid distinct species: C. m. foveatus, C. m. multiventris, C. m. cochranae, and C. m. septentrionalis. Although C. foveatus and C. septentrionalis clearly deserve specific status, a re-evaluation of the characters pointed in the literature as diagnostic of C. multiventris and C. cochranae does not support their recognition as valid distinct taxa. Additionally, our analysis of the scutellation pattern, continuous characters, and hemipenial morphology of 34 specimens, and of the available data in literature, shows that there are no significant differences between them. We therefore suggest that C. cochranae should be synonymized with C. multiventris.

Systematics, natural history, and hemipenial morphology of Dendrophidion brunneum (Günther) (Serpentes: Colubridae), a poorly known snake from the Andes of Ecuador and Peru

Systematic characters, distribution, natural history, and hemipenial morphology are described for Dendrophidion brunneum (Günther), a poorly known snake from Ecuador and Peru. It has 17 midbody scale rows; 145–165 ventrals; 135–158 subcaudals; a tail 38–44% of total length; a relatively uniform green to brown dorsum; and a maximum length of 1370 mm (700–800 mm SVL). The species occurs from northern Ecuador to 8° S latitude in Peru, primarily on the Pacific slopes of the Andes but with a few documented lowland localities in Peru. Dendrophidion brunneum is diurnal, terrestrial, heliophilic, and oviparous. It occurs in humid montane forests or mixed puna grassland/highland forest. Recorded prey are small terrestrial frogs but a large individual possibly consumed a lizard. Defensive mechanisms include a pseudautotomic tail and behaviors such as striking, biting, and neck inflation. The hemipenis has a short, narrow base, a greatly expanded distal region, and a simple, centrolineal sulcus spermaticus. The expanded region is ornamented with spines, distal to which two flounces completely encircle the organ and another extends partially around one side. The flounces are unusual in being thin, membranous structures and in having mineralized rods (reduced spinules) completely embedded within the membranes. The apex is nude except for a few vestigial calyces. Unusual hemipenial characters are discussed.

The identity of Apostolepis pymi and placement of A. quinquelineata in the synonymy of A. nigrolineata (Serpentes, Xenodontinae)

The correct application of the names Apostolepis nigrolineata, A. quinquelineata, and A. pymi has been subject of considerable controversy. Based upon review of the literature and the characteristics used to distinguish these species from each other, we conclude that A. pymi is a valid species and that A. quinquelineata is a junior synonym of A. nigrolineata. They differ from each other in hemipenial morphology and coloration. The background color of A. nigrolineata is reddish brown (vs. brown in A. pymi). In addition, only the dorsal region of end of tail is covered by a black band in A. nigrolineata (vs. end of tail completely surrounded by a black band in A. pymi). Both species are sympatrically distributed along the lowlands of Amazonia but A. nigrolineata occurs in both western and eastern regions whereas A. pymi is restricted to eastern regions with additional records from the States of Amazonas, Rondônia, Mato Grosso and an endemic population in the state of Ceará, northeastern Brazil.

Taxonomic revision of the Brazilian Atlantic Forest Atractus (Reptilia: Serpentes: Dipsadidae)

Dipsadine snakes of the genus Atractus are endemic to the Neotropical region, occurring from Panama to Argentina. Currently, the taxonomic status of most species of the genus is unclear and previous attempts of taxonomic revisions have been local in scale. In this paper we evaluate the taxonomic status of the Brazilian Atlantic Forest species of Atractus based on meristic, morphometric, maxillary dentition, and hemipenis characters. Quantitative and qualitative analyses suggest the recognition of one new species (A. caete sp. nov.) from the state of Alagoas, another (A. francoi sp. nov.) from the mountainous regions of the states of Rio de Janeiro and São Paulo, and the synonymy of A. kangueryensis with A. thalesdelemai. Specimens previously assigned to A. taeniatus in Argentina and Brazil are here considered A. paraguayensis. A key to the Atlantic Forest Atractus is provided and three new species groups are proposed for some cisAndean Atractus, mainly on the basis of hemipenial morphology: the A. emmeli, A. maculatus, and A. pantostictus species groups.

Redescription of the southernmost snake species, Bothrops ammodytoides (Serpentes: Viperidae: Crotalinae)

AbstractBothrops ammodytoides is a pitviper species endemic to Argentina that inhabits arid and semiarid areas from sea level to more than 3000 m, reaching the southernmost latitude for snakes. According to previous studies, the species is placed in the Bothrops alternatus group. We redescribe Bothrops ammodytoides based on examination of 101 specimens and provide new data on lepidosis, hemipenial morphology, cranial osteology, variation in coloration, and distribution. We compare Bothrops ammodytoides with representative species of the genus and related genera. Morphological comparisons reveal considerable affinities between Bothrops ammodytoides, Bothrops pictus, Bothrops andianus, and Bothrocophias microphthalmus, suggesting that the current taxonomy for Bothrops ammodytoides requires to be reassessed.