scholarly journals Taxonomy, allometry, sexual dimorphism, and conservation of the trans-Andean water-snake Helicops danieli Amaral 1937 (Serpentes: Dipsadidae: Hydropsini).

2021 ◽  
Author(s):  
Nathalie Kaladinsky Citeli ◽  
Julia Klaczko ◽  
Anderson Kennedy Soares De-Lima ◽  
Mariana de-Carvalho ◽  
Pedro M.S. Nunes ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Intraspecific Variation ◽  
Conservation Status ◽  
Tail Length ◽  
South American ◽  
Color Changes ◽  
Morphological Aspects ◽  
Water Snake ◽  
Morphological Diagnosis ◽  
Water Snakes

The extensive lack of knowledge on the morphological aspects of South American water-snakes, includes a poor understanding of phenotypic parameters, intraspecific variation, and conservation of the trans-Andean Helicops species, Helicops danieli Amaral, 1937. For the first time, we provide a multidisciplinary view using key features (e.g., morphology and niche modeling) to improve the taxonomic recognition of this species, as well as describing ontogenetic color changes, allometry, sexual dimorphism, and the conservation status of this poorly studied snake. First, we emended the morphological diagnosis of H. danieli with 23 characters and detected that juvenile tail length is positively related to allometric growth, and that juveniles differ from adults through the presence of the white nuchal collar. Females are larger than males for snout-vent length, whereas males showed proportionally longer tails and smaller head length growth. Suitable areas for H. danieli are restricted to the trans-Andean regions from the Magdalena drainage to the Caribbean coast, which also showed high values of anthropic impacts. Our multidisciplinary approach provided new insights into this South American water snake’s morphology, intraspecific variation, and distribution.

scholarly journals Sexual dimorphism in the South American water snake Helicops polylepis (Serpentes: Dipsadidae)

2021 ◽  
Vol 20 (1) ◽  
pp. 15-25
Author(s):  
Isla Carol Marialva Camargo ◽  
Jackeline Cristina Palma Veras ◽  
Síria Ribeiro ◽  
Ricardo A. Kawashita-Ribeiro ◽  
Rafael de Fraga ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Sexual Dimorphism ◽  
Prey Availability ◽  
Morphological Characters ◽  
Offspring Size ◽  
Female Size ◽  
South American ◽  
The South ◽  
Water Snake ◽  
Fecundity Selection

Sexual selection, fecundity selection and ecological divergence have been the main explanations proposed for the origin and maintenance of sexual dimorphism. In this study we provide evidence of sexual dimorphism in the South American aquatic snake Helicops polylepis, which is mainly determined by body and head sizes. Males have longer tails and more subcaudal scales, and females have larger body and head and more ventral scales. The sexual dimorphism observed in different morphological characters of H. polylepis occurs in other species of xenodontine snakes and is interpreted as a consequence of sexual selection pressures. Data on growth rates associated with prey availability and female size-related offspring size are necessary to refine our analyzes and test specific hypotheses about the ecological and evolutionary bases of sexual dimorphism in H. polylepis.

Sexual dimorphism, deformations, and epibionts of Phrynops tuberosus (Testudines, Chelidae)

2015 ◽  
Vol 65 (3-4) ◽  
pp. 311-320 ◽  
Author(s):  
João Fabrício Mota Rodrigues ◽  
José Roberto Feitosa Silva
Keyword(s):  
Sexual Dimorphism ◽  
Natural History ◽  
Tail Length ◽  
Condition Index ◽  
Head Width ◽  
Body Condition Index ◽  
Future Studies ◽  
History Of ◽  
One Year ◽  
Effective Conservation

Studies focusing on the natural history of species are essential for developing effective conservation measures and evaluating ecological hypotheses. To this end, we describe natural history data of the Cotinga River toadhead turtle, Phrynops tuberosus, in the Banabuiú River in Ceará, Brazil, and evaluated sexual dimorphism, epibionts, and mutilation effects. We hand-captured 134 individuals by snorkeling, over a period of one year, resulting in the capture of 94 males, 24 females, and 16 juveniles. Females had larger head width and body mass than males, while males had longer tail length. One quarter of the turtles captured had some sort of injury or deformation, most common injuries being missing claws, mutilations, and shell deformations. We found no difference in body condition index between mutilated and non-mutilated animals. Mollusks, insects, and leeches were found as epibionts on P. tuberosus and most of the captured turtles had extensive algal cover. Future studies should focus on understanding the effect of mutilations on animal fitness and reproductive success.

Rarity patterns and the conservation status of tree species in South American savannas

Flora ◽  
2021 ◽  
pp. 151942
Author(s):  
Everton A. Maciel ◽  
Fernando R. Martins
Keyword(s):  
Tree Species ◽  
Conservation Status ◽  
South American

Seriemas: A Literature Assessment and Recommendations for Future Research

2021 ◽  
Author(s):  
Diego Méndez ◽  
Zackery Szymczycha ◽  
Jeremiah Sullivan ◽  
Christopher J. W. McClure
Keyword(s):  
Keyword Search ◽  
Conservation Status ◽  
Future Research ◽  
South American ◽  
South American Species ◽  
Systematic Map ◽  
Conservation Actions ◽  
Forested Areas ◽  
Causes Of Mortality ◽  
Territorial Behaviors

ABSTRACT Red-legged Seriemas (Cariama cristata) and Black-legged Seriemas (Chunga burmeisteri) are two exclusively South American species that inhabit open and sparsely forested areas. Seriemas have been recently included with the raptors based on ecological and evolutionary evidence. Viewing seriemas as raptors is nontraditional and might be controversial. Therefore, further information regarding the evolution, taxonomy, morphology, and ecology of these birds will clarify the validity of their consideration as raptors. Here we present a review of the published information on seriemas, and discuss future research for these newly adopted raptors. To conduct our review, we developed a systematic map and searched all databases available within Clarivate Analytics' Web of Science, performed a keyword search of Google Scholar, and included the corresponding bibliographies from the Birds of the World website. We reviewed 98 studies, and found that the Red-legged Seriema was the subject of more studies than the Black-legged Seriema. Overall, Brazil and Argentina were the site of most studies. The majority of studies examined physiology (48), followed by behavior (37), threats to the survival of these species (36), and demography (27), while smaller numbers of studies examined stressors (e.g., habitat changes, causes of mortality and injury such as predation, hunting, etc.) (20), and conservation actions (10). Patterns of study categorizations were similar for both species, and the distribution of studies across months was also fairly even for both species. This is the first study to systematically review and assess the published information on seriemas. Our results show the topics and locations on which past studies have focused, and highlight potentially fruitful avenues for future research. Although threats to seriemas have been identified, these have not been thoroughly assessed; thus, their extent and effects on seriema populations were difficult to ascertain. Future research should focus on testing existing hypotheses regarding seriema feeding, vocalization, social, and territorial behaviors, while documenting natural history. Researchers should build on past investigations while establishing programs to monitor the conservation status of seriemas across their ranges.

The role of temperature in microhabitat selection by northern water snakes (Nerodia sipedon)

1992 ◽  
Vol 70 (3) ◽  
pp. 417-422 ◽  
Author(s):  
Ian C. Robertson ◽  
Patrick J. Weatherhead
Keyword(s):  
Experimental Manipulation ◽  
Time Of Day ◽  
Microhabitat Selection ◽  
Nerodia Sipedon ◽  
Leopard Frogs ◽  
Water Snake ◽  
Northern Water Snakes ◽  
Water Snakes ◽  
Circadian Patterns

Using field observations and laboratory experiments we examined the role of temperature in microhabitat selection by an eastern Ontario population of northern water snakes (Nerodia sipedon). From 1349 random transects through a marsh we found that basking activity peaked at 09:00 and then declined steadily until 14:00 before increasing again. Our ability to detect snakes depended upon the microhabitat they occupied, and to the time of day when the snakes were encountered in water. In the field, temperatures of basking snakes averaged (±SE) 26.3 ± 0.7 °C (n = 36), while captive snakes in a thermal gradient showed a narrower selectivity, averaging 27.7 ± 0.4 °C (n = 21). The temperatures of basking snakes never exceeded 33 °C, even though a model snake placed in the sun reached 48 °C, suggesting that the snakes were thermoregulating to prevent overheating. In both the field and enclosures, water snakes basked more frequently as the temperature of the air increased relative to the water. Experimental manipulation of water temperature relative to air temperature revealed that temperature influenced microhabitat selection independently of circadian patterns. Finally, when in water, snakes tended to frequent habitats where leopard frogs (Rana pipiens), a common prey species, were most abundant, suggesting that prey distribution may also be an important component of water snake habitat selection.

scholarly journals Sexual dimorphism in a top predator ( Notophthalmus viridescens ) drives aquatic prey community assembly

2018 ◽  
Vol 285 (1890) ◽  
pp. 20181717 ◽  
Author(s):  
Denon Start ◽  
Stephen De Lisle
Keyword(s):  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Intraspecific Variation ◽  
Structure And Function ◽  
Sexually Dimorphic ◽  
Ecological Communities ◽  
Top Predator ◽  
Aquatic Mesocosms ◽  
And Function ◽  
The Impact

Intraspecific variation can have important consequences for the structure and function of ecological communities, and serves to link community ecology to evolutionary processes. Differences between the sexes are an overwhelmingly common form of intraspecific variation, but its community-level consequences have never been experimentally investigated. Here, we manipulate the sex ratio of a sexually dimorphic predacious newt in aquatic mesocosms, then track their impact on prey communities. Female and male newts preferentially forage in the benthic and pelagic zones, respectively, causing corresponding reductions in prey abundances in those habitats. Sex ratio differences also explained a large proportion (33%) of differences in the composition of entire pond communities. Ultimately, we demonstrate the impact of known patterns of sexual dimorphism in a predator on its prey, uncovering overlooked links between evolutionary adaptation and the structure of contemporary communities. Given the extreme prevalence of sexual dimorphism, we argue that the independent evolution of the sexes will often have important consequences for ecological communities.

Morphological diagnosis and successful treatment of chorioptic mange in 2 South American coatis (Nasua nasua)

2021 ◽  
Author(s):  
Christoph J. Klinger ◽  
Teresa M.S.A. Boehm ◽  
Marco Roller ◽  
Tobias Knauf-Witzens
Keyword(s):  
Side Effects ◽  
Hair Loss ◽  
Complete Resolution ◽  
Clinical Signs ◽  
South American ◽  
Skin Scraping ◽  
Nasua Nasua ◽  
Superficial Skin ◽  
Morphological Diagnosis ◽  
Topical Applications

AbstractTwo female South American coatis (Nasua nasua) kept in a zoo in Southern Germany presented with pruritus and moderate hair loss at the dorsal trunk, thigh areas and alongside the tail. Otherwise the animals showed no clinical signs. While the clinical general examination as well as cytology of dermatologic samples showed no pathologic changes, Chorioptes sp. mites could be identified in a superficial skin scraping. Two consecutive topical applications of a selamectin/sarolaner spot-on formulation 4 weeks apart lead to a complete resolution. No side effects were observed.

Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae)

Phytotaxa ◽  
2021 ◽  
Vol 529 (1) ◽  
pp. 125-159
Author(s):  
ANELISE NUERNBERG-SILVA ◽  
PEDRO FIASCHI
Keyword(s):  
Conservation Status ◽  
Taxonomic Revision ◽  
Second Step ◽  
Morphological Description ◽  
South American ◽  
Southern Brazil ◽  
Distribution Map ◽  
Phylogenetic Studies ◽  
A New Species ◽  
Near Threatened

Phylogenetic studies indicate that several infrageneric taxa in Oxalis require taxonomic updates to attain monophyly. In this contribution, we update the morphological delimitation of the South American Oxalis sect. Ripariae and provide a taxonomic revision of the currently accepted species. The sectional delimitation was carried out by comparing micro- and macromorphological features of Oxalis sect. Ripariae, O. sect. Corniculatae, and O. sect. Myriophyllum. These sections share yellow flowers and aerial stems. Glandular hairs and larger seeds with the surface longitudinally crested and with projections are exclusive to Oxalis sect. Ripariae. We accept 11 species in the section, including three previously placed in Oxalis sect. Corniculatae (i.e., O. eriocarpa, O. niederleinii, and O. refracta), but excluding O. serpens and O. subvillosa, which are moved to O. sect. Corniculatae. We also describe a new species (Oxalis lourteiginana), propose a new name and status for O. bifrons subsp. littoralis (now O. pampeana), the synonymization of O. irreperta with O. riparia, six second-step lectotypifications, and one epitypification. For each accepted species we provide a morphological description, illustrations, ecological and taxonomic information, conservation status following IUCN, and a geographic distribution map. Most species occur in southern Brazil, but the section is widespread also in Argentina, Uruguay, and eastern Paraguay. Six species are categorized as threatened and further three as near threatened. Besides, we provide an identification key for the taxa of the section.

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