Female SVL Research Articles

A new species of Pristimantis (Anura: Strabomantidae) from white-sand forests of central Amazonia, Brazil.

The white-sand ecosystems in the Solimões-Negro Interfluve are among the less studied in Amazonia. Recent herpetological surveys conducted west of Manaus, Brazil (central Amazonia) indicate that white-sand forests host a unique anuran fauna comprising habitat specialized and endemic species. In the present study we describe a new species of rain frog belonging to the Pristimantis unistrigatus species group from the white-sand forest locally called "campinarana" (thin-trunked forests with canopy height below 20 m). The new species is phylogenetically close to rain frogs from western Amazonian lowlands (P. delius, P. librarius, P. matidiktyo and P. ockendeni). It differs from its closest relatives mainly by its size (male SVL of 17.3-20.1 mm, n=16; female SVL of 23.2-26.5 mm, n=6), presence of tympanum, tarsal tubercles and dentigerous processes of vomers, its translucent groin without bright colored blotches or marks, and by its advertisement call (composed of 5-10 notes, call duration of 550-1,061 ms, dominant frequency of 3,295-3,919 Hz). Like other anuran species recently discovered in the white-sand forests west of Manaus, the new species seems to be restricted to this peculiar ecosystem.

Measuring Annual Variation in Reproductive Output Reveals a Key Role of Maternal Body Condition in Determining the Size of Eggs in Snakes.

Simple SummaryWe measured female reproductive traits of a colubrid snake (Lycodon rufozonatus) from Zhejiang, East China in four years (1999, 2010, 2011, and 2014). After removing the influence of female size, postpartum body mass was greater in 2010 than in 2014, clutch mass was greater in 2010 than in 2011 and 2014, and egg size was greater in 2010 than in the other three years. Egg size was positively related to postpartum body condition in each year. Females laid larger eggs in 2010 than in other three years after removing the influence of maternal size and body condition. Our study does not follow the prediction that reproductive females with different amounts of resources to invest should give priority to adjusting the number rather than size of offspring.Long-term studies are especially suited for disentangling the effects of extrinsic and intrinsic factors on both total reproductive investment and reproductive allocation in offspring number versus offspring size. Female reproductive traits of the red-banded wolf snake (Lycodon rufozonatus) from Zhejiang, East China were studied in four years between 1999 and 2014. Egg-laying dates overall extended from late June to late July, and varied among years. Postpartum body mass, clutch size, clutch mass, and egg size were positively related to female size (snout vent length, SVL) in each year. Postpartum body mass, clutch mass, and egg size differed among years after accounting for female SVL, whereas clutch size did not. Setting female SVL at the same level, postpartum body mass was greater in 2010 than in 2014, clutch mass was greater in 2010 than in 2011 and 2014, and egg size was greater in 2010 than in the other three years. Females did not trade off egg size against number. Egg size was positively related to postpartum body condition in each year. Females laid larger eggs in 2010 than in other three years after removing the influence of maternal body condition. Our study provides evidence for the traditional view that reproductive output is highly linked to maternal body size in snakes, but not following Smith and Fretwell’s (1974) classic prediction that females with different amounts of resources to invest in reproduction should give priority to adjusting the number rather than size of their offspring. Maternal body size and condition both are important sources of variation in egg size, but factors other than these two variables may also affect the size of eggs produced by female L. rufozonatus.

A New Species of Scinax Wagler (Amphibia, Anura, Hylidae) from the Atlantic Forest, Southeastern Brazil

The Scinax catharinae clade comprises the S. perpusillus and S. catharinae groups. The S. catharinae group has 38 species, mostly from Brazil's Atlantic Forest. We describe a new species of S. catharinae group based on external morphology, color pattern, and bioacoustics. The new species calls from herbaceous vegetation of slow-flowing streams from Santa Teresa, State of Espírito Santo, southeastern Brazil. The new species is distinguished from species of the S. catharinae group by the following combination of characters: male SVL 24.8–28.3 mm and female SVL 31.2–38.6 mm; males with hypertrophied forearms and inguinal glands; interocular region with a dark blotch not exceeding beyond the anterior margin of tympanic level; black blotches on a whitish-green background on the inguinal region and hidden surfaces of legs; call type A of 0.301–0.883 s, and 12–30 notes emitted at a rate of 31.4–42.0 notes/s. We also provide remarks on its natural history and conservation status.

Maternal Body Size and Condition Predict Measures of Reproductive Success and Future Reproductive Allocation in Territorial Eastern Red-Backed Salamanders

Female fitness is often influenced by trade-offs in energy allocated to reproduction or self-maintenance that is dependent upon the life history of the organism. Maternal body size and condition are factors that are often positively correlated with clutch size and offspring size. We investigated whether maternal body size (snout–vent length, SVL) and condition (residual of mass on SVL) could predict measures of reproductive success including clutch size, offspring body size (SVL), and offspring survival in the territorial Eastern Red-backed Salamander (Plethodon cinereus). Brooding females and their eggs were collected and then housed in a controlled laboratory setting. We recorded the number of eggs found with each female and separated offspring from females once hatched. At 40 d after hatching, we measured the SVL and mass of females and juveniles. Maternal SVL, but not condition, was positively related to clutch size and offspring SVL; however, there was no significant relationship between clutch size and offspring SVL, indicating no trade-off between number and body size of offspring. In the laboratory, survival of the offspring to 185 d post-hatching was positively related to maternal SVL and negatively related to maternal condition. Also, the mean SVL, measured on day 40, of the offspring that survived to 185 d was significantly greater than the SVL of the offspring that did not survive, indicating a benefit of larger offspring body size. Finally, subsequent egg production (number of new oocytes produced by females following the current reproductive bout) was positively related to maternal SVL and condition (measured 185 d after hatching their previous clutches). These results suggest that larger maternal body size and condition of Eastern Red-backed Salamanders provide increased reproductive success through the number and body size of offspring produced in current or subsequent reproductive bouts and in offspring survival. Large body size in territorial animals like P. cinereus provides benefits for holding high quality territories as well as for increased reproductive success.

The breeding biology of Fejervarya limnocharis complex, F. multistriata (Hallowell, 1861) in Mizoram, northeast India

The breeding behavior of Fejervarya multistriata was studied from the selected study sites in Mizoram for over three years between 2016 and 2019. In natural condition, breeding took place in group. The advertisement call of males consisted of a series of notes emitted at an interval of 0.1–0.4 s where the frequency spectra had a dominant band at 2670.1172 Hz and the band width ranges from 2497.8516–28422.3828 Hz. Morphometric measurements showed that females are larger than males with snout-vent length of 45.55 ± 1.54 mm vs 33.77 ± 1.03 mm, respectively. The clutch sizes ranges from 488 to 1035. We found that the calculated ‘t’ value 0.03 is less than the ‘p’ value, i.e. 1, therefore there is no correlation between SVL of females and clutch sizes.

Geographic variation in maternal investment and trade-offs between egg size and clutch size in an endemic toad of the Qinghai-Tibet Plateau

Life history theory predicts that animals often produce fewer offspring of larger size and indicate a stronger trade-off between the number and size of offspring to cope with increasing environmental stress. In order to evaluate this prediction, we tested the life history characteristics of Bufo minshanicus at eight different altitudes on the eastern Tibetan Plateau, China. Our results revealed a positive correlation between female SVL and clutch size or egg size, revealing that larger females produce more and larger eggs. However, high-altitude toads seem to favor more offspring and smaller egg sizes when removing the effect of female SVL, which is counter to theoretical predictions. In addition, there was an overall significantly negative relationship between egg size and clutch size, indicative of a trade-off between egg size and fecundity. Therefore, we suggest that higher fecundity, rather than larger egg size, is a more effective reproductive strategy for this species of anuran living at high-altitude environments.

Anomaloglossus meansi sp. n., a new Pantepui species of the Anomaloglossus beebei group (Anura, Aromobatidae).

Recent extinctions and drastic population declines have been documented in the Guiana Shield endemic frog genus Anomaloglossus, hence the importance to resolve its alpha-taxonomy. Based on molecular phylogenies, the literature has long reported the occurrence of an undescribed species in the Pakaraima Mountains of Guyana in the Pantepui region. We here describe this new taxon and demonstrate that in addition to divergence at the molecular level the new species differs from congeners by a unique combination of morphological characters, notably a small size (maximum SVL in males 18.86 mm, maximum SVL in females 21.26 mm), Finger I = Finger II when fingers adpressed, Finger III swollen in breeding males, fringes on fingers absent, toes basally webbed but lacking fringes, in life presence of a thin dorsolateral stripe from tip of snout to tip of urostyle, and a black throat in preserved males (immaculate cream in females). Virtually nothing is known about the ecology of the new species. We suggest the new species to be considered as Data Deficient according to IUCN standards.

Comparison of the body size and age structure of Lebanon lizard, Phoenicolacerta laevis (Gray, 1838) at different altitudes in Turkey

In this study, comparison of a life history traits (e.g. body size, age at maturity, longevity) of two populations of Phoenicolacerta laevis from different altitudes is being carried out (Anamur, 22 m a.s.l.; Andırın, 1.083 m a.s.l.) for the first time. We applied phalangeal skeletochronology to obtain the age of juveniles and adults. Age was determined by counting the lines of arrested growth (LAGs) in cross-sections. Males in both populations were the larger of the two sexes and a male biased sexual dimorphism was determined for both populations. Body size (SVL) was similar in both sexes and populations. Age of maturity was calculated to be 3 years of age for males and females in both populations. The average age of males and females was calculated as 6.62 ± 0.37 (Mean±SE) and 6.11 ± 0.26 years in Anamur, and 6.15 ± 0.51 and 5.26 ± 0.24 years in Andırın. There was statistically significant variation between sexes, but no significant difference in populations was found in relation to age. For both populations, a significant positive correlation was found between age and SVL in males and females.

The aggressive call of Dendropsophus cruzi (Pombal Bastos, 1998) (Anura; Hylidae) in Central Brazil.

Dendropsophus cruzi (Pombal Bastos, 1998) is a small hylid (male snout-to-vent length = 16.3-19.4 mm; female SVL = 21.3-25.0 mm) that is allocated in the D. microcephalus group (Faivovich et al. 2005). It is commonly found in Open and forested areas from Central Brazil to Provincia Velasco, Departamento de Santa Cruz, Bolivia (Frost 2017; Tessarolo et al. 2016). Pombal Bastos (1998) described the advertisement call of D. cruzi as a single pulsed note. Posteriorly, studies uncovered relationships between dominant frequency variation in the advertisement calls of D. cruzi and variation in the SVL and mass of males (Bastos et al. 2003), as well as the existence of a clinal geographic pattern in the variation of acoustic parameters of these calls (Tessarolo et al. 2016). However, the acoustic communication in anurans is usually mediated by more than one vocalization type (Toledo et al. 2015). Due the importance of call types in the social context of anurans (e.g., Reichert 2011; Forti et al. 2017), we expand the vocal repertoire of D. cruzi by describing its aggressive call.

Four new species of terrestrial-breeding frogs of the genus Phrynopus(Anura: Terrarana: Craugastoridae) from Río Abiseo National Park, Peru.

We describe four new species of terrestrial-breeding frogs belonging to the genus Phrynopus from specimens collected on the eastern slopes of the Cordillera Oriental (2800-3850 m) near and within Río Abiseo National Park, Provincia Mariscal Cáceres, Departments of San Martín and La Libertad, northeastern Peru. All four species lack a visible tympanum and inhabit the upper ridges and slopes within or adjacent to the Park. Phrynopus anancites sp. nov. and P. capitalis sp. nov. inhabit the wet montane grasslands on the upper ridges and valleys from 3600 to 3850 m. Phrynopus anancites (SVL = 25.3 mm) has coarsely aerolated skin and olive green coloration and has small vomerine teeth, while P. capitalis (female SVL = 35.6 mm) is characterized by a large head, short limbs, and distinctive dorsal pattern. Phrynopus dumicola sp. nov. (female SVL = 25.3 mm) has a short head and dark colored body with granular skin on the flanks, and is known only from forest patches along the treeline from 3225 to 3550 m, whereas P. personatus sp. nov. (female SVL = 28.2 mm) has a dark facemask and bright yellow groin spots (possibly aposematic), and inhabits a narrow band of continuous tropical montane rain forest from 2890 to 3110 m. We report infection with Batrachochytrium dendrobatidis from one specimen of P. dumicola collected in July of 1988. With the addition of these four new species, Phrynopus now includes 32 nominal species.

A new species of semiarboreal toad of the Rhinella festae group (Anura, Bufonidae) from the Cordillera Azul National Park, Peru.

A new semiarboreal species of the Rhinella festae group is described from montane forests of the Cordillera Azul National Park between 1245 and 1280 m a.s.l. in the Cordillera Oriental, San Martín region, northern Peru. The new species is morphologically and genetically compared with members of the Rhinella acrolopha group (former genus Rhamphophryne) and members of the R. festae group. The new species is characterized by its large size (female SVL 47.1–58.3 mm, n = 4), eight presacral vertebrae, fusion of the sacrum and coccyx, long protuberant snout, snout directed slightly anteroventral in lateral view, cranial crests moderately developed, absence of occipital crest, presence of tympanic membrane, dorsolateral rows of small conical tubercles extending from parotoid gland to groin, hands and feet with long digits, fingers basally webbed and toes moderately webbed. Phylogenetically it is a member of the R. festae group which is most closely related to R. chavin and R. yanachaga from Peru. Morphologically the new species shares similarities with R. tenrec and R. truebae, members of the R. acrolopha group from Colombia.

Female Reproductive Characteristics Among Populations of the Oviparous LizardSceloporus aeneus(Squamata: Phrynosomatidae) from Central Mexico

Abstract: We studied female reproductive characteristics (clutch size, clutch frequency, egg volume, egg mass, and snout–vent length [SVL] at sexual maturity) in five populations of the Mexican endemic oviparous lizard, Sceloporus aeneus, from the Transmexican Volcanic Belt. Adult females showed a range in SVL of 40–60 mm. Mean clutch size was determined by counting vitellogenic follicles or eggs of females during the reproductive season, and was 6.6 ± 1.5 eggs. There was a positive relationship between clutch size and female SVL for all populations collectively. When analyzed by population, however, only two populations showed this relationship. Females lay at least two clutches during the reproductive period (from April to September). We found differences in the mean SVL of females with eggs and vitellogenic follicles among populations, but not in size-adjusted clutch size, egg mass, or egg volume. Our results showed life-history traits (SVL at sexual maturity, reproductive period, clutch size, clutch ...

The effect of size-assortative mating on fertilization success of the common toad (Bufo bufo)

Although size-assortative mating (SAM) is a frequently studied phenomenon in anurans, its effect on fitness rarely has been evaluated. Using a controlled experiment, we assessed the presence of SAM in the common toad,Bufo bufo, and evaluated the effect on fertilization success of male-female size (snout-vent length, SVL) difference and ratio in mated pairs. Even though the toads paired non-randomly with respect to size, the difference and ratio of female and male SVL in pairs had no significant effect on fertilization success. Our findings and the majority of other studies suggest that the commonly accepted idea that SAM serves to maximize fitness may not be completely accurate. The statistical power and effect size in these studies are often poor, however, and the methods used are inconsistent. We conclude that more manipulative experiments with appropriate sample sizes are needed to fully understand this phenomenon.

Body size, reproduction and feeding ecology of Pleurodema diplolister (Amphibia: Anura: Leiuperidae) from Caatinga, Pernambuco state, Northeastern Brazil

We present data about body size, sexual dimorphism, reproductive traits and diet ecology of Pleurodoma diplolister. This species is sexually dimorphic with females larger than males, corroborating others Leiuperidae species. The number of eggs varied from 62 to 1241 and we found a positive relationship between SVL of females and number of mature ovarian eggs but there is no relationship between SVL and volume of eggs. The diet of P. diplolister was composed by 11 categories of which Formicidae, Coleoptera and Orthopterans were the most important items and showed generalist and oportunistic predator habits. Data presented here should be considered in the development of future conservation strategies of anurans from Caatinga biome and other semiarid/arid environments.

Reproductive biology of the bushmaster Lachesis muta (Serpentes: Viperidae) in the Brazilian Atlantic Forest

The Neotropical genus Lachesis Daudin, 1803 includes snakes restricted to the humid forests of Central and South America. The species L. muta is the most widely dispersed, occurring throughout the Amazon rainforest, and with an isolated population in the Atlantic Forest, from the north of the state of Ceará to the south of the state of Rio de Janeiro, Brazil. We present information about the reproductive biology of L. muta from a large series of samples gathered in southern Bahia. Mature males L. muta are larger than females. Degree of sexual size dimorphism (SSD) is 0.16. Vitellogenic follicles and eggs are not distributed equally throughout the year. Clutch size was 3–14 oviductal eggs and was positively correlated with female SVL. Testes volume and ductus deferens diameter in mature individuals did not vary significantly throughout the year. The reproductive pattern of L. muta differs from that of the phylogenetically related genera because L. muta is oviparous, and has a discontinuous cycle and reproductive synchrony between the sexes.

Body Size and Reproductive Tactics in Varanid lizards

Body size and female reproduction in the water monitor lizard (Varanus salvator) were studied. Forty-two adult females larger than 500 mm SVL and 32 adult males larger than 400 mm SVL were donated by local people in Ledong, Hainan under permit to our laboratory in Hainan in 2013 and 2014. The largest male and female measured 745 and 755 mm SVL, respectively. The mean SVL was greater in adult females than in adult males. Males had larger heads (head width) than females of the same SVL. The smallest reproductive female in our sample was 565 mm SVL. Females produced a single clutch of 17.1 (10−23) pliable-shelled eggs per breeding season stretching from mid-June and mid-September. Clutch size and clutch mass were all positively related to female SVL. However, there was no significant linear relationship between egg mass and female SVL. Larger females generally produced more eggs, and thus heavier clutches than did smaller ones. There was no significant linear relationship between relative clutch mass and female SVL. Phylogenetic generalized least squares (PGLS) analysis, accounting for phylogenetic relationships, showed that clutch size was positively correlated with mean maternal SVL in varanid lizards. PGLS analysis showed that phylogenetic relationships did not affect clutch (or/and egg) mass and the SVL although there were significant linear relationship between clutch (or/and egg) mass and mean maternal SVL. Therefore, we could draw some general conclusions about the body size and reproductive tactics in varanid lizards that larger females generally produced more eggs, larger eggs and thus heavier clutches than did smaller ones.

Characterization and Significance of Sexually Dimorphic Gape in the Rough Earth Snake,Virginia striatula

The availability of a large morphometric data set from over 2,000 specimens of Virginia presented the opportunity to examine gape dimorphism within V. striatula and its potential adaptive significance in greater detail within this specialist species. In V. striatula, females attain a larger SVL. Gape was strongly associated with increasing SVL in both males and females. Males have significantly larger gapes at all but the shortest SVLs and the dimorphism becomes significant ca 145mm SVL which correlates with sexual maturity. The observed dimorphism is hypothesized to allow males to utilize a wider range of prey (earthworm) sizes at any SVL in order to successfully compete with females for the resource. This would be of particular importance to male fitness during years in which significant drought limits availability of prey.

Variation in morphological and reproductive characteristics of females of Anolis nebulosus (Squamata: Dactyloidae) from island and mainland populations near the Pacific Coast of Mexico

AbstractWe present a comparative analysis of the morphological and reproductive characteristics of adult female Anolis nebulosus, an arboreal lizard found on both mainland and insular habitats near the Pacific Coast of Mexico. Females from San Pancho Island were larger in all measured morphological variables than females from Biological Field Station Chamela (BFSCH) on the mainland, and those also reproduced at smaller body size (snout‐vent length, SVL: range = 35–44, = 39 mm) than females on San Pancho Island (range = 40–47, = 43 mm). Egg mass and egg volume were also greater on San Pancho Island, but clutch frequency was higher on BFSCH during breeding season; in this place, one egg every 8 days over a period of 4 months (123 days) versus one egg every 10 days over a period of 4 months (130 days) on San Pancho Island. Thus, we conclude that certain characteristics related to reproduction (e.g. size at sexual maturity, egg mass and egg volume) in A. nebulosus with populations inhabiting islands and mainland, vary primarily in accordance with female SVL. These variations are most likely a response to the different pressures where A. nebulosus inhabits on environments the islands and mainland near the Pacific Coast of Mexico.

Dressed in black. A New Ansonia Stoliczka, 1870 (Lissamphibia: Anura: Bufonidae) from Gunung Murud, Sarawak, East Malaysia (Borneo).

A new species of stream toad of the genus Ansonia is described from Gunung Murud, Pulong Tau National Park, of northern Sarawak, Malaysia, Borneo. Ansonia vidua, sp. nov., is morphologically distinguished from its Bornean congeners by the following combination of characters: medium size (SVL of adult females 33.5-34.4 mm); body uniformly black-brown in life; absence of a visible pattern on dorsum or limbs; presence of two low interorbital ridges; shagreened skin on dorsum, sides and upper surfaces of the limbs with numerous homogeneously small, rounded warts; first finger shorter than second; reduced webbing between the toes and an absence of a sharp tarsal ridge. Uncorrected genetic distances between related taxa of > 4.3% in 16S rRNA gene support its status as a hitherto undescribed species.

Phyllomedusa ecuatoriana Cannatella (Amphibia: Hylidae): variación, descripción del renacuajo, vocalización y anotaciones sobre la historia natural

Information is presented on morphological variation in the frog, Phyllomedusa ecuatoriana, with a description ot the tadpole, vocalizations, and notes on its natural history and distribution, based on material recently collected in the Cordillera del Condor, Zamora Chinchipe Province, Ecuador. Phyllomedusa ecuatoriana is of medium size (male SVL length 46.1 to 55.4 mm; female SVL 72.2 mm). The tapole (Gosner stage 26) has a dentary formula of 2 (2)/3 (1); tooth row P3 is smaller than P1 and P2. The tadpoles develop in pools of various sizes in turbid water stained by the presence of tanins. The vocalizations are modulated frequencies, with the dominant frequency averaging 1.53 kHz; the calls are composed of a single note and 2-3 pulses. Adult frogs feed primarily on spiders (20%) of the family Argiopidae.