| 1. |
- Kuchta, Shawn
(författare)
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Contact zones and species limits: Hybridization between lineages of the California Newt, Taricha torosa, in the southern Sierra Nevada
- 2007
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Ingår i: Herpetologica. - 0018-0831. ; 63:3, s. 332-350
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Tidskriftsartikel (refereegranskat)abstract
- Recent phylogeographic work on Taricha torosa has revealed that the subspecific lineages, T. t. torosa and T. t. sierrae, are distinct evolutionary lineages that form a secondary contact zone in the southern Sierra Nevada of California. I examined the dynamics of this contact zone using two allozyme markers, mitochondrial DNA, morphometrics (head shape), and head color pattern. The subspecific lineages interbreed where they meet, and form a hybrid zone centered along the Kaweah River in Tulare County. Clines among genetic markers bad similar shapes and centers, and ranged from 7-10 km wide. There is evidence of selection against hybrid genotypes in the center of the hybrid zone. Analyses of head shape and color pattern show that the two subspecies are phenotypically differentiated, and that patterns of differentiation in these characters are congruent with the genetic clines. The two subspecies constitute distinct evolutionary lineages and merit recognition as separate species: T. torosa (California newt) and T. sierrae (Sierra newt).
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| 2. |
- Castroviejo-Fisher, Santiago, et al.
(författare)
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Resurrection of Hyalinobatrachium orocostale and notes on the Hyalinobatrachium orientale species complex (Anura: Centrolenidae)
- 2008
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Ingår i: Herpetologica. - 0018-0831 .- 1938-5099. ; 64:4, s. 472-484
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Tidskriftsartikel (refereegranskat)abstract
- Hyalinobatrachium orientale has a complex taxonomic history suggesting that more than one species could be under this name. In this review, we try to clarify the current taxonomic status of this species by means of morphological, bioacoustic, and mitochondrial DNA sequence comparisons of specimens from Tobago Island and the Venezuelan Cordillera de la Costa (Oriental Sector, Cordillera del Litoral and Cordillera del Interior). Our data support the resurrection of Hyalinobatrachium orocostale, restricted to the Cordillera del Interior. Additionally, specimens from Cordillera del Litoral and Oriental Sector do not form a monophyletic group; hence, we define as Hyalinobatrachium sp. the populations from Cordillera del Litoral and H. orientale sensu stricto the populations from the Oriental Sector. Preliminary bioacoustic and morphological analyses indicate that the populations from Tobago are conspecific with Hyalinobatrachium orientale sensu stricto.
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| 3. |
- Ceron, K., et al.
(författare)
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Ecological Niche Explains the Sympatric Occurrence of Lined Ground Snakes of the Genus Lygophis (Serpentes, Dipsadidae) in the South American Dry Diagonal
- 2021
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Ingår i: Herpetologica. - 0018-0831. ; 77:3, s. 239-248
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Tidskriftsartikel (refereegranskat)abstract
- The geographic distribution of a species is limited by many factors, including its ecological and evolutional) , history. Species distribution modeling has been used to evaluate the effects of climate and other variables on geographic distribution and to measure the degree of niche similarity among co-occurring species. Our goal in this study was to compare the geographic distributions and ecological niches of four closely related species of lined ground snakes, Lygophis dilepis, L. flavifrenatus, L. meridionalis, and L. paucidens. These species are distributed along the South American Dry Diagonal. We found that the four species of Lygophis overlap somewhat along their distributions with a low degree of niche overlap. Lygophis dilepis shows a disjunct distribution with two isolated populations. The break in the distribution of L dilepis in Central Brazil is filled by L. meridionalis, which is found mostly in the highlands of the Central Plateau. Because of the disjunct distribution of L. dilepts, we performed species distribution modeling on both populations separately. The environmental niches of the two populations of L. dilepis were indistinguishable according to the niche equivalence tests, but the distribution of one of these populations did not predict the distribution of the second one, and vice versa. Our study shows that niche partitioning may allow for the coexistence of Lygophis species.
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| 4. |
- Hansson, Alexander, et al.
(författare)
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The influence of incubation temperature on phenotype of Australian Painted Dragons (Ctenophorus pictus)
- 2018
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Ingår i: Herpetologica. - 0018-0831. ; 74:2, s. 146-151
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Tidskriftsartikel (refereegranskat)abstract
- Incubation temperature is one of the most studied factors driving phenotypic plasticity in oviparous reptiles and has been shown to affect a wide variety of traits including body size, shape, and performance. Thermal regimes during embryogenesis might therefore have direct consequences on fitness, potentially even shaping population trajectories. These effects are likely strongest in short-lived species where even temporary temperature-induced differences in body size or shape might have adaptive significance. We investigated the effects of incubation temperature on the body size and shape of hatchling Australian Painted Dragons (Ctenophorus pictus). Eggs incubated at low temperature required a longer incubation period, but produced hatchlings of greater body mass. However, no effect of temperature was found on the structural dimensions of hatchlings. These results might be explained by an increased absorption of water by the developing embryo during the prolonged incubation period. A greater water content might increase early-life desiccation tolerance in this short-lived lizard inhabiting arid and semiarid environments. Egg mass, however, had the strongest effect on hatchling phenotype, with larger eggs producing larger hatchlings. Furthermore, there was a seasonal effect on yolk allocation, with eggs laid earlier being larger than those laid later. Our results indicate that yolk allocation is the most important factor affecting hatchling phenotype in this species, while temperature mainly affects embryo developmental rate and likely has an indirect effect on hatchling water content. © 2018 by The Herpetologists' League, Inc.
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| 5. |
- Kahrl, Ariel F., et al.
(författare)
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Ecomorphological Variation in Three Species of Cybotoid Anoles
- 2018
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Ingår i: Herpetologica. - 0018-0831 .- 1938-5099. ; 74:1, s. 29-37
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Tidskriftsartikel (refereegranskat)abstract
- Caribbean Anolis lizards exhibit a complex suite of ecological, morphological, and behavioral traits that allow their specialization to particular microhabitats. These microhabitat specialists, called ecomorphs, have independently evolved on the four islands of the Greater Antilles, and diversification among anole ecomorphs has been the focus of many studies. Yet, habitat specialization has also occurred among species within the same ecomorph group. Here, we examined ecological, morphological, and behavioral divergence in three Hispaniolan trunk-ground species, the cybotoid anoles: Anolis cybotes, A. marcanoi, and A. longitibialis. We found differences in limb morphology, locomotor behavior, and perch use among the three cybotoid species that mirror differences across the ecomorphs. Among these species of cybotoids, those that have longer limbs tend to move less frequently, occupy broader perches, and have smaller fourth toes with fewer lamellae. We also observed that the species with greater male-biased size dimorphism had larger heads, smaller dewlaps, and smaller testes. These results are consistent with the predictions of sexual selection theory, in that species with large male body size may have larger heads because of increased male-male combat, and smaller testes potentially attributable to a trade-off between pre- and postcopulatory selection. Overall, our study suggests that a combination of local adaptation to different structural habitats and sexual selection might produce ecomorphological diversification within cybotoid anoles of the same ecomorph group.
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| 6. |
- Kelehear, Crystal, et al.
(författare)
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Interactions between infective helminth larvae and their anuran host
- 2011
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Ingår i: Herpetologica. - 0018-0831 .- 1938-5099. ; 67:4, s. 378-385
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Tidskriftsartikel (refereegranskat)abstract
- Detailed observations on interactions between parasites and prospective hosts during the infection process can clarify (1) the routes by which parasites enter the host and (2) the ability of prospective hosts to detect, avoid, or resist potential parasites. Such information can clarify determinants of host vulnerability. Infective larvae of the nematode Rhabdias pseudosphaerocephala entered the bodies of their anuran host the Cane Toad (Rhinella marina, formerly Bufo marinus) primarily through the orbit (i.e., by crawling over the surface of the toad's eye) rather than by burrowing through the skin (believed to be the usual route of infection for rhabditid parasites). In our experimental infections, metamorph Cane Toads detected infective R. pseudosphaerocephala larvae but did not avoid them, nor did they manage to restrict rates of infective larvae penetration by using behavioral means (the toads kicked at infective larvae but failed to dislodge them). Rhabdias pseudosphaerocephala cause damage to their toad host during the process of host entry and throughout the ensuing infection. Despite the high cost of infection and the low cost of avoidance, metamorph Cane Toads seem to lack effective parasite avoidance strategies.
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| 7. |
- Kuriyama, Takeo, et al.
(författare)
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Iridophore- and Xanthophore-Deficient Melanistic Color Variant of the Lizard Plestiodon latiscutatus
- 2016
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Ingår i: Herpetologica. - 0018-0831. ; 72:3, s. 189-195
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Tidskriftsartikel (refereegranskat)abstract
- Elucidating the ultimate and proximate mechanisms of melanistic color pattern formation has become an important focus of evolutionary biology. There are relatively few studies, however, examining the composition and architecture of pigment cells in melanistic reptiles. The typical color pattern of the skink Plestiodon latiscutatus, which inhabits the Izu Islands and Izu Peninsula of Japan, consists of brown dorsal coloration, five vivid yellowish white stripes, and a blue tail (in juveniles). We have observed melanistic morphs at a low frequency (<0.05%). Based on a histological examination of pigment cells, we determined that the melanistic morph of P. latiscutatus collected from Shikine in the Izu Islands possesses only dermal melanophores and lacks the xanthophores and iridophores seen in the normal coloration. This arrangement of pigment cells differs from the only other studied melanistic lizard, Sceloporus undulatus, in which the dark skin of the melanistic morph results from a simple increase in the density of melanophores relative to xanthophores and iridophores. Our findings indicate that associations between color pattern phenotypes and the expression of candidate color genes, such as Mc1r, are more complex than previously assumed; coloration in reptiles is controlled not only by cellular processes related to single pigment production but also by the differentiation of multiple pigment cells.
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| 8. |
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| 9. |
- Olsson, M, et al.
(författare)
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Does mate guarding prevent rival mating in snow skinks? A test using AFLP
- 2005
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Ingår i: Herpetologica. - 0018-0831. ; 61:4, s. 389-394
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Tidskriftsartikel (refereegranskat)abstract
- We report on likely mixed paternity in a natural population of snow skinks (Niveoscincus mirolepidoms) from alpine Tasmania, Australia. This species is nonterritorial and males guard females after copulation, Suggesting that guarding behavior has evolved to prevent rival mating of still-receptive females. To what degree does this mate-guarding prevent rival copulations? We sampled gravid females at random in the wild and looked for within-clutch mixed paternity among their offspring using amplified fragment length polymorphism (AFLP). Incorpating all visualized fragments, offspring band-sharing based on maternal bands was 0.94 (+/- 0.05, SD), whereas for paternal fragments it was 0.54 (+/- 0.46, SD). We then tested paternal band-sharing scores for all young of pairs against the mean score of the maternally inherited fragments to assess whether paternal genetic variation was larger than for a known single parent, hence, suggesting multiple sires. To reduce the risk of unequal sampling of polymorphic maternal and paternal fragments, We based Our statistical tests on heterozygous bands only. Offspring band sharing based on maternal heterozygous fragments was on average 0.68 ( +/- 0.22, SD), versus 0.35 (+/- 0.33, SD) based on paternally inherited fragments. in six of eight clutches (75%), at least one pair of voting in a clutch had paternal scores outside of the confidence interval for a single parent (i.e., the mother). Thus, mixed paternity seems to be widespread in this Population, despite prolonged postcopulatory mate-guarding by males.
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| 10. |
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