Natural history of the lizard Enyalius perditus (Squamata: Leiosauridae) from an Atlantic forest remnant in southeastern Brazil

The natural history of the lizard Enyalius perditus was studied from August 2005 to July 2006, at Parque Estadual Nova Baden, in the municipality of Lambari, State of Minas Gerais, south-eastern Brazil. We found that E. perditus may be considered a semi-arboreal species, like other species in the genus, sleeping on vegetation (slim branches or large leaves) at night, possibly to minimize predation. Females with enlarged follicles or oviducal eggs were found from November to January and juveniles recruited at the end of the dry season and beginning of the rainy season, in October. The diet of this lizard is composed mainly of Lepidoptera larvae, Araneae and Formicidae. Females were larger than males, and juvenile coloration is similar to that of adult females.     

Aspects of the natural history of Leptodactylus knudseni Heyer, 1972 (Anura: Leptodactylidae) in a pristine forest in Central Amazonia,Brazil, with comments on ontogenetic variation of its tadpoles

The Leptodactylus pentadactylus species group is comprised of medium to large species of Neotropical frogs. Leptodactylus knudseni, a member of this species group, has a wide distribution throughout the Amazon Basin. Herein we describe aspects of the reproductive biology of L. knudseni and provide notes about the ontogenetic variation of its tadpoles based on a population in a non-flooded forest near Manaus, Amazonian Brazil. Amplectant pairs of L. knudseni lay foam nests in excavated basins on the edge of temporary ponds located on clay soil and at least 50 m from a stream. The tadpole development happens initially in the foam nests with access to the pond after the rain flooding the basins. Studied clutches lacked trophic eggs and tadpoles did not produce foam. Ontogenetic variations in L. knudseni tadpoles are related to size, teeth formulae and body colour. The use of excavated basins for the deposition of foam nests has been reported in several species of the L. pentadactylus group. The absence of trophic eggs and production of foam by the tadpoles differ from other species of the L. pentadactylus group. The tadpole morphology is similar to that described for other species of the group.     

Breeding biology of Phyllomedusa azurea Cope, 1862 and P. sauvagii Boulenger, 1882 (Anura) from the Cerrado,Central Brazil

Phyllomedusa azurea and P. sauvagii are treefrogs from seasonal dry environments of Central Brazil. We report on reproductive and other natural history features of these species. The study was carried out in Serra da Bodoquena, Mato Grosso do Sul, Brazil. The reproductive period was determined by the presence of vocalizing males, amplectant pair or presence of tadpoles. The reproductive effort was measured as the ratio of gonad mass in relation to body mass (BM). The reproduction of both species was correlated with the rainy season. Female P. sauvagii produced more eggs and their eggs were larger than those of P. azurea. Both species showed sexual dimorphism in relation to the snout–vent length (SVL) and BM. The mating behaviour of both species was similar. Males in both species showed similar reproductive efforts, but females of P. azurea invested more in gonads compared to the males of P. sauvagii. Phyllomedusa azurea showed a significant relation between SVL versus number of the mature eggs (NME), and P. sauvagii between SVL versus NME and BM versus ovarian mass.     

Natural history of Phyllomedusa megacephala (Miranda-Ribeiro, 1926) (Anura: Hylidae) in southeastern Brazil,with descriptions of its breeding biology and male territorial behaviour

The breeding biology and male territorial behaviour of the large-headed leaf-frog (Phyllomedusa megacephala) were studied in three temporary altitudinal streams located in the Cerrado biome of southeastern Brazil, during three consecutive years (2007–2009). Phyllomedusa megacephala showed significant sexual dimorphism, with females being bigger and heavier than males. Acoustic and physical interactions between males defending or not defending territories including amplectant and non-amplectant males, patrolling behaviour by males without established territories, and triple amplexus were observed. Neither males nor females were observed using visual cues when searching for mates. We found that males that were present at breeding sites in previous years bred more successfully and maintained territory better.     

Spatial niche variation in two sympatric species of Bokermannohyla (Anura: Hylidae) in southeastern Brazil

We studied patterns of microhabitat use by adults of two sympatric Bokermannohyla species at the Reserva Particular do Patrimônio Natural Santuário do Caraça, southeastern Brazil. We selected three streams, one where both species occurred in syntopy and the other two where each one occurred alone. We sampled 150-m transects in each stream throughout 1 year, recording microhabitat features for each frog located (substrate type, height and distance from water). Microhabitat availability varied between dry and wet seasons in all streams, and overall microhabitat diversity changed in two streams. Bokermannohyla nanuzae seemed to have a niche contraction in the presence of Bokermannohyla martinsi, but this only happened during the dry season. Microhabitat requirements during the wet season may be closely linked to similar reproductive needs that probably represent a strong selective pressure, forcing niche overlap.     

Natural prey of the crab spider Thomisus onustus (Araneae: Thomisidae), an extremely powerful predator of insects

The natural prey of the crab spider Thomisus onustus inhabiting Eryngium plants was studied in the Absheron Peninsula, Azerbaijan. The total percentage of specimens of T. onustus found while feeding was low (9.1%). However, solitary late instar and adult females exhibited a very high feeding percentage (29.9%). Other sex–age groups of T. onustus, including small juveniles, adult males, and females guarding egg sacs, were found feeding significantly less frequently. Investigation has shown that T. onustus is a polyphagous predator, with representatives of four arthropod orders found in its diet. The primary food of T. onustus was Diptera and Hymenoptera, which collectively accounted for 94.2% of total prey. Worker ants constituted about one‐fifth of the prey, suggesting that T. onustus is a myrmecophagic spider. The length of prey killed by T. onustus ranged between 1.25 and 16.00 mm (mean 6.21 mm) and constituted from 34.4 to 587.9% (mean 194.9%) of length of their captors. The most frequently captured were large arthropods, exceeding the size of the spiders (83.1%). Small and medium‐sized juveniles captured considerably larger prey (in terms of prey–predator length ratio) than late instar and adult females. Over half of their prey constituted arthropods more than two‐fold larger than the spiders.     

Reproductive patterns of Trachycephalus venulosus (Laurenti, 1768) and Scinax fuscovarius (Lutz, 1925) from the Cerrado,Central Brazil

Animal mating systems are moulded by ecological factors, mainly the temporal patterns of reproduction. We report the reproductive period, use of microhabitats, clutch and egg sizes, reproductive efforts, occurrence of sexual size dimorphism, and the relation between body size and fecundity in the gravid females of Trachycephalus venulosus and Scinax fuscovarius at Serra da Bodoquena, Central Brazil. The reproduction of both species was correlated with the rainy season. Females of T. venulosus produced more eggs and their eggs were larger than those of S. fuscovarius. The females of both species were larger and heavier than males. The reproductive effort was measured as the ratio of gonad mass in relation to body mass. Females of both species presented similar reproductive efforts, but males of S. fuscovarius invested more in gonads compared to males of T. venulosus. Trachycephalus venulosus presented significant correlation between snout–vent length versus number of mature eggs and body mass versus number of mature eggs and ovarian mass. Scinax fuscovarius showed significant correlation between body mass versus ovarian mass. Trachycephalus venulosus is an explosive breeder, whereas S. fuscovarius has prolonged reproduction. These species are able to adapt to several types of habitat, due to behavioural and physiological plasticity.     

Age,body size and growth pattern of Argenteohyla siemersi pederseni (Anura: Hylidae) in northeastern Argentina

In this study we analysed the body size, age structure, age at maturity, longevity and growth pattern of Argenteohyla siemersi pederseni in north-eastern Argentina using skeletochronological methods. Body size was sexually dimorphic; females were significantly larger and heavier than males, regardless of age. As A. s. pederseni is an explosive breeder with only one reproductive episode per year, we assumed that each Line of Arrested Growth (LAG) observed was equivalent to one period of decreasing growth, LAGs reflecting a direct estimation of individual age. The minimum number of LAGs counted was two for males and three for females, but there was no sexual difference in longevity. The von Bertalanffy's growth coefficients (K) were higher in males than in females for both size and body mass. Females had a lower growth rate than males, took longer to reach the minimum maturation size, and were older and larger at reproduction.     

Aspects of natural history in a sand boa,Eryx muelleri (Erycidae) from arid savannahs in Burkina Faso,Togo, and Nigeria (West Africa)

The ecology of West African arid savannah snakes is still poorly known, especially in regard to the fossorial species. Here, field data on distribution, morphometrics, habitat use and diet are reported for the sand boa Eryx muelleri (Erycidae) from three different countries, i.e. Burkina Faso, Togo and Nigeria. This snake was observed in 21 distinct localities, and a total of 39 individuals was recorded. The species is likely fairly common and locally abundant. Mean body length of snakes was similar among countries and between sexes, but males had proportionately longer tails than females. Body length was significantly positively correlated with both tail length and head length. Adult sex ratio was close to parity. Most of the specimens were found in well-vegetated spots with low percentage of bare soil. There were apparently both ontogenetic and intersexual dietary variations: (1) a single analysed juvenile fed upon a small-sized lizard, whereas adults fed considerably upon young rodents; and (2) females fed exclusively upon young rodents and males upon both lizards and young rodents. In conservation terms, the species is actively exported from Togo for the pet trade, and additional individuals may also be illegally collected in other countries.     

Natural history of the marsupial Thylamys macrurus (Mammalia,Didelphidae) in fragments of savannah in southwestern Brazil

The objective of this study was to furnish information on the natural history of the Neotropical marsupial Thylamys macrurus in the southern Cerrado of Brazil. A range expansion of the species was observed to the northeast of the Mato Grosso do Sul state, Brazil. Specimens were surveyed in fragments of savannah (40–600 ha) during dry and wet seasons in 2003 and 2004 with live‐trap grids and pitfall lines. With an effort of 9767 trap nights and 2200 pitfall nights, we obtained 102 captures and 49 recaptures of T. macrurus. The data analyzed (57 males and 40 females) showed that males are more abundant in the dry season and females in the wet season. Young were recorded mostly during the wet season. Thylamys macrurus was scansorial, using the floor and the understorey. Sexual dimorphism was recorded, with males being larger than females. Information on ectoparasites is supplied.     

Spatial and temporal organization in three syntopic species of the Scinax ruber group (Anura: Hylidae) in the Atlantic rainforest,southeastern Brazil

Coexistence of anuran species might lead to acoustic interference among communications, especially where species are closely related. This problem might be minimized through resource partitioning. To test this idea, we analysed calling with respect to temporal and physical space usage in three syntopic, closely related species (Scinax cuspidatus, Scinax aff. hayii and Scinax aff. x-signatus) in a temporary pond in the Atlantic rainforest. The chorus attendance of each species resulted from a different combination of factors in the rainy season. Although there was some temporal overlap of daily activity among species, peak activity time differed, particularly between the two species whose calls were most similar. Although all three species tend to aggregate in open microhabitats, their coexistence is apparently facilitated by differential use of vertical strata and organization of calling sites near the sites of conspecifics. Together, these factors apparently reduce acoustic interference among heterospecific calls.     

Reproductive aspects of Leptodactytus hylaedactylus (Anura: Leptodactylidae), a member of the Leptodactylus marmoratus species group,with a description of tadpoles and calls

In this paper we describe some aspects of the reproductive biology of Leptodactylus hylaedactylus from open areas of Central Amazonia, Brazil. We describe the calling site, reproductive season, daily pattern of calling activity, chamber structure, vocalizations and tadpole morphology. Males of Leptodactylus hylaedactylus called amidst grasses and bushes in open and urban areas, throughout the year, and a greater number of males were heard in the period from 16:00 to 20:00 h. The eggs are deposited in underground chambers, which are spherical or elliptical. Larval development occurs inside the chambers. Two types of vocalizations were detected, the advertisement and the territorial call. The advertisement call of the species studied herein differs from other calls described for L. hylaedactylus from other localities of Brazil, but is very similar to that described from Peru. Tadpole morphology is similar to that described from individuals in French Guiana.     

Breeding biology of Ameerega braccata (Steindachner, 1864) (Anura: Dendrobatidae) in the Cerrado of Brazil

Reproductive aspects of Ameerega braccata, a Cerrado endemic species of Dendrobatidae, were studied in the surroundings of the type locality of the species, Chapada dos Guimarães, mid-southern Mato Grosso State, Brazil. We found that males call mainly early in the morning and in the late afternoon. During courtship, the female approaches a calling male and tactile and visual communication occurs. Males call continuously while guiding females to the oviposition site, which may be situated as far as 24 m (in a straight line) from the initial encounter site. Spawn are deposited over fallen leaves on the soil surface or in burrows. Female snout–vent length and body mass did not explain the variation in ovary mass, or the variation in the number and size of post-vitellogenic oocytes. The results reported here for A. braccata might help to understand trends in the evolution of dendrobatids in open Cerrado environments.     

Reproductive site selection in the leaf-frog Phyllomedusa azurea Cope, 1862 (Anura: Hylidae) in altered areas of the Brazilian Cerrado

The selection of reproductive sites by anurans may be associated with each species’ behavioural restrictions, reproductive modes, morphology and physiology. We investigated the use of reproductive sites by Phyllomedusa azurea in an area of Cerrado, Central-Western Brazil, which has been modified by agricultural and cattle ranching. Reproductive activity was studied during the peak of the rainy season in two consecutive years. No correlation was found between male body size and position of the calling site, and calling sites did not vary among ponds. Conversely, the height and distance from the water margin where clutches were found varied among ponds. Phyllomedusa azurea used mainly Brachiaria sp. and Brachiaria humidicola grasses as calling sites and the grass Brachiaria sp. and the shrub Melochia villosa (Malvaceae) as oviposition sites. Calling males used the vegetation according to its availability; however, individuals seemed to exhibit significant preferences regarding the type of vegetation used for oviposition.     

Breeding biology of the rapids frog Limnomedusa macroglossa (Anura: Cycloramphidae) in southern Brazil

Limnomedusa is a monotypic genus that occurs in association with rocky outcrops and stream beds. Based on observational and mark–recapture fieldwork from 2005 to 2008, we report the breeding biology of Limnomedusa macroglossa in southern Brazil. The reproductive season lasted from late August to early February. Tadpoles were recorded from early September to late February. A clear pattern of emergence/recruitment was observed in juveniles. The occurrence of reproductive activities was clearly related to the longest photoperiods, when the highest temperatures occur. Males called from rocky or concrete substrates, mostly under rocks. Amplexus was axillary and the operational sex ratio was nearly even. Spawn occurred in lentic water bodies but tadpoles also completed their development in slow‐flowing water. Although using similar habitats for reproduction, L. macroglossa reached lower levels of specialization toward terrestriality than did the cycloramphids Cycloramphus and Thoropa. We classify L. macroglossa as a breeding habitat specialist that would be threatened by river damming.     

Natural history of the Lined Seedeater Sporophila lineola (Aves: Thraupidae) in southeastern Brazil

The Lined Seedeater (Sporophila lineola) is a migratory species that inhabits a variety of open habitats in South America. We studied the breeding biology and territorial behaviour of a colour-banded population of the species in the Universidade Federal de Viçosa, Campus Florestal (1–19,8808ºS, –44,4136ºW), during two breeding seasons (2014/2015 and 2015/2016), which spans from December to April. We monitored 74 nests of this species. The nest is a low cup supported between a fork. Nests are mainly built with grass stems and rootlets, with spider-web used to hold the material together and to bind the nest to its supporting plant. Females are solely responsible for nest building and incubation, which is synchronic, and also for feeding nestlings to a large extent. Males are responsible for defending the territory, which corresponds to a small portion of the home range restricted to the nest environs, and also feed the nestlings. Mean clutch size is two eggs (78% of nests monitored), with clutches of three (20.3%) and four (1.7%) eggs also observed. Eggs are whitish, covered with dark brown blotches and spots to a variable extent. Mean incubation period, considered as the period between the onset of incubation and hatching of the first egg, is 11 days. Nestling period, considered as the period between hatching of the first egg and fledging of the last young, is 10 days. During the first breeding season, the simple percentage of successful nests was 34.1%, while the Mayfield success was 29.8%, with slightly higher values observed during the second breeding season, with 39.4% and 35.7%, respectively. We recorded, for the first time, three cases of polygamy in the species. We also recorded breeding site fidelity for the first time in the species, with males returning to the same territory owned in a previous breeding season.     

Mating behaviour,nympho-imaginal development and description of a new Mesabolivar species (Araneae: Pholcidae) from the Brazilian dry forest

A new species of Mesabolivar is described from Brazilian forests: Mesabolivar delclaroi. The mating behaviour, postembryonic development, number of egg sacs and eggs, birth rate, number of instars, developmental time until adulthood, sex ratio and size of cephalothorax (per instar) were recorded. The sexual behaviour was described and categorized into four steps: courtship, pre-copulation, copulation and post-copulation. After hatching, individuals presented five instars until maturity. The mean number of eggs (42 ± 16.6) and live births (31.5 ± 3.4) of the first egg sac were significantly greater than that of a second one (23.8 ± 3.8, and 19.25 ± 3.9, respectively). The developmental time from birth to adulthood (130.8 ± 9.6 days) did not differ significantly between egg sacs produced (128.61 ± 11.1). The size of the cephalothorax did not differ among adults or between sexes. The sex ratio revealed a shift in favour of females (4: 3).     

Feeding ecology of the common sun skink,Eutropis multifasciata (Reptilia: Squamata: Scincidae), in the plains of central Vietnam

We studied the feeding ecology of Eutropis multifasciata in the tropical plains of central Vietnam to understand better the foraging mode, spatiotemporal and sexual variation in dietary composition, and rarefaction curves of prey-taxon richness for males and females. Stomach contents (n = 161) were collected from October 2013 to May 2014 using a nonlethal stomach-flushing technique. A total of 680 food items (624 animal items and 56 plant items) was found in 161 stomachs of skinks, representing 19 unique animal categories. We found that the diet of E. multifasciata is composed mainly of small, sedentary and clumped prey and that this skink specialises on spiders, insect larvae, snails, grasshoppers and crickets (with a combined importance index of 60%). Dietary composition, prey size and total prey volume in E. multifasciata changed between dry and rainy seasons and among regions. The total volume of food items consumed by males was larger than that of females, and the diversity and evenness index of prey categories were larger in males than in females. However, using rarefaction curves revealed that females have the higher prey-taxon richness after points between 130 and 140 prey items for frequency, and between 160 and 170 prey items for number of items, and the differences were not statistically significant. The foraging behaviour of E. multifasciata best fits a ‘widely foraging’ model.     

A new genus and species of Sarcoglanidinae (Siluriformes: Trichomycteridae) from southeastern Brazil,with a re-examination of subfamilial phylogeny

Microcambeva barbata, n. gen. et sp., is described from rio São João, Estado do Rio de Janeiro. It is proposed as the sister group of Malacoglanis and Sarcoglanis, on the basis of three characters: pectoral fin longer than the head, pectoral fin rays projecting well beyond the fin membrane, and a forked caudal fin. Monophyly of the Sarcoglanidinae is confirmed by the unique possession of a long lateral process on the premaxilla and a separate anterior ossification on the palatine. A sister group relationship between the Sarcoglanidinae and the Glanapteryginae is supported by four synapomorphies: a posteriorly directed dorsal process on the quadrate, a large dorsal anteriorly directed process on the hyomandibula, vomer reduced and generalized miniaturization. A more inclusive group composed of Sarcoglanidinae, Glanapteryginae, Tridentinae, Vandeliinae and Stegophilinae is considered monophyletic, since they all exhibit a reduced interopercular patch of odontodes, a reduced or absent metapterygoid, reduction in the number of pleural ribs, and lack an elongate process on the parasphenoid.     

A study of triphorid larvae and post-larvae at the Campos Basin deep-sea floor,southeastern Brazil (Gastropoda: Triphoroidea)

Triphoridae is a family of marine microgastropods, with hundreds of species described especially from shallow waters, comprising planktotrophic and non-planktotrophic development modes. The present study focusses on an interesting finding of the deep-sea Oceanprof Expedition, conducted in Campos Basin (southeastern Brazil), in which triphorid larvae and a few post-larvae were profusely sampled at the slope, leading us to three main questions: (1) What species of Triphoridae do these larvae belong to? (2) Why were so many triphorid larvae found at the site? and (3) What does the presence of post-larvae mean? We show that all the larvae belong to genera or species present in the Campos Basin continental shelf. Some speculations are made about the great abundance of larvae in the slope, especially to vertical migrations of larvae, and about mesh size, in addition to possible differences of larval ecology between triphorids and the closely related Cerithiopsidae. Two possible explanations are indicated for the presence of post-larvae: mass effect (formation of pseudopopulations) or mid-water metamorphosis (spontaneous metamorphosis at the water column), with the latter being the more likely scenario. Despite being essentially theoretical, the present study aims to develop new insights into the larval ecology of these small gastropods, and to furnish a base for future tests.