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.     

‘On the rocks’: reproductive biology of the endemic toad Xanthophryne (Anura: Bufonidae) from the Western Ghats,India

Xanthophryne is a toad genus endemic to the northern Western Ghats of India, with two extant sister species – Xanthophryne koynayensis and Xanthophryne tigerina. Both species are local endemics and endangered. We studied reproductive biology of these toads and found that they are specialized to the lateritic rocky outcrops at mid-elevations in high rainfall areas. Xanthophryne toads have sporadic, multiple spawning bouts lasting 2–4 days during early monsoon. In this explosive breeding behaviour, we observed male toads to engage in ‘pelvic thrusts’, a unique and novel behaviour among anurans. Females oviposit in shallow pools in depressions of lateritic boulders where their tadpoles metamorphose. These ephemeral rocky pools have limited resources and they desiccate rapidly with a break in the rains. To mitigate the stochastic risk of desiccation and subsequent large-scale egg/tadpole mortality, females may disperse their reproductive investment spatially and temporally in multiple clutches, and tadpoles metamorphose rapidly. Here, we describe the amplexus, spawning and male advertisement call, and provide a comparative account of the life history traits of the two Xanthophryne species. These toads face numerous threats and are in need of urgent conservation action. These toads, seemingly well adapted to the isolated rocky outcrops, offer an excellent opportunity to understand endemism, mating systems, anuran ecology and behaviour.     

The strangest tadpole: the oophagous,tree-hole dwelling tadpole of Rhacophorus vampyrus (Anura: Rhacophoridae) from Vietnam

The tadpole of the vampire flying frog Rhacophorus vampyrus from Vietnam is one of the strangest tadpoles known. These tadpoles develop from non-pigmented eggs suspended in a foam nest placed on the wall of a tree hole. The elongate, depressed body resembles that of some phytotelmon-breeding frogs, but the mouthparts bear little resemblance to any other tadpole: upper labium reduced to one large papilla-like structure on each side, upper jaw sheath with a few huge, widely spaced, hook-shaped serrations that face backwards into the buccal cavity, lower jaw sheath absent, sinistral spiracle visible only ventrally, and two large, forward facing, keratinized hooks accompanied laterally by two similar sized fleshy papillae on the margin of the reduced lower labium. All evidence suggests that the tadpoles are oophagous and that the mother returns to deposit trophic eggs.     

Goliath frogs build nests for spawning – the reason for their gigantism?

ABSTRACT

In contrast to its popularity, astonishingly few facts have become known about the biology of the Goliath Frog, Conraua goliath. We herein report the so far unknown construction of nests as spawning sites by this species. On the Mpoula River, Littoral District, West Cameroon we identified 19 nests along a 400 m section. Nests could be classified into three types. Type 1 constitutes rock pools that were cleared by the frogs from detritus and leaf-litter; type 2 constitutes existing washouts at the riverbanks that were cleared from leaf-litter and/or expanded, and type 3 were depressions dug by the frogs into gravel riverbanks. The cleaning and digging activities of the frogs included removal of small to larger items, ranging from sand and leaves to larger stones. In all nest types eggs and tadpoles of C. goliath were detected. All nest types were used for egg deposition several times, and could comprise up to three distinct cohorts of tadpoles. Nests seemed to be clustered. Camera trapping revealed that nests are guarded by adult frogs at night. The breeding nests may allow the frogs to deposit their eggs away from the torrent rivers, and potential egg and tadpole predators. As nest construction, at least in some cases, requires the removal of large and heavy items, we hypothesize that this can only be achieved by decent sized frogs, possibly explaining the unique size of the species.     

Habitat,egg‐laying behaviour,eggs and tadpoles of four sympatric species of Pseudopaludicola (Anura,Leiuperidae)

In contrast to most leiuperid frogs, Pseudopaludicola falcipes does not lay eggs in foam nests; this could represent a reversion to the primitive state. We found that in four other Pseudopaludicola species, eggs were also not embedded in foam nests and had a well‐defined outermost jelly layer. The females also constantly moved or dived and males lacked vigorous “wiping/kicking” leg motions while eggs were being laid, features that make foam nesting difficult. The tadpoles of three species have two gaps in the marginal papillae along the lower labium and two posterior rows of labial teeth; the tadpoles of one species had three gaps and three rows, a pattern resembling that of some Physalaemus (Leiuperidae) species. Our data on tadpole morphology and reproductive behaviour do not allow us to rule out the paraphyletic nature of Physalaemus in relation to Pseudopaludicola but they provide some support against the “foam‐loss hypothesis” in Pseudopaludicola.     

Prolonged parental behaviour by males of Limnonectes palavanensis (Boulenger 1894), a frog with possible sex-role reversal

ABSTRACT

In sex-role-reversed systems, males carry out all parental care duties, forgoing further mating opportunities. Cases of complete sex-role reversal have not been reported in anurans. We describe the parental care behaviour of the leaf-litter frog Limnonectes palavanensis, a Bornean endemic with egg-guarding and tadpole transport, possibly the first anuran with sex-role reversal. In this study, we tested one of the predictions of the sex-role reversal hypothesis: males invest more in parental care than females do, and this prevents them from quickly acquiring additional mates. We observed egg-guarding behaviour in captivity to determine the length and intensity of parental care. Also, we describe the tadpole climbing and tadpole transport behaviour. We found that males perform all of the parental duties, remaining with the clutch until hatching. They do not call during this time, nor do they care for more than one clutch at a time. Observations of tadpole transport in the field indicate that all tadpoles in the clutch are retrieved at once. The behaviour of males during tadpole retrieval suggests that they stimulate synchronous hatching. Together, these results indicate that the male parental expenditure in this species is high, resulting in lost mating opportunities. The prolonged male-only parental care behaviour of this species satisfies an important criterion for the occurrence of sex-role reversal.     

Mixed‐species social aggregations in Madagascan tadpoles—determinants and species composition

The frequency, species composition, and determinants of mixed‐species tadpole aggregations were analysed under natural conditions in a dry forest of western Madagascar. Most aggregations (73%) were formed by more than one species, with up to four species per individual aggregation. Dyscophus insularis (Microhylidae) and Aglyptodactylus securifer (Mantellidae) were the most abundant species in these aggregations. Using a logistic regression model we analysed to what extent the presence and absence of aggregations in a pond can be predicted by its biotic and abiotic habitat variables. Aggregations are more likely in deep, clear ponds with little leaf litter cover on the bottom, while the overall density of invertebrate predators in the pond seems to play a minor role. Our observations suggest that the formation of mixed‐species aggregations in tadpoles of the Kirindy Forest in our system is primarily a reaction to vertebrate predators. Therefore, aggregation behaviour may play a key role in the ability of several anuran species to utilize these spawning waters that are unpredictable in regard to the presence of fish and other vertebrates.     

On the natural history of the South American pepper frog,Leptodactylus labyrinthicus (Spix, 1824) (Anura: Leptodactylidae)

Some species of Leptodactylus of the L. pentadactylus group lay their eggs outside water but the tadpoles need to reach water to complete the larval phase; other species complete development in terrestrial nests. Here we present details of the reproduction of L. labyrinthicus in south‐eastern Brazil. The proportion of tadpoles and trophic eggs in aged egg clutches was determined, as well as the growth of the tadpoles while in the nest. The gut contents of tadpoles that were in egg clutches of frogs were analysed. Adult males did not differ from females in size and had hypertrophied forearms and an enlarged spine on the thumb. Reproduction was initiated with the first rains of August/September and extended to mid‐January. Calling and spawning occurred at permanent or temporary water bodies. The foam nests were built in excavated basins outside of, but close to the water. The male determined the place of the basin construction; after amplexus, the female completed the excavation. The amplexus was axillary. One female spent the day after spawning in the foam. The eggs were pale grey, the yolk averaging 2.3?mm in diameter. The mean number of eggs was 2101 per egg clutch. The number of tadpoles in individual nests varied between 0.05% and 11.40% in relation to the total laid eggs. The tadpoles entered water when rains flooded the basin. The tadpoles grew to 12 times the weight of an individual egg while in the nest; no nesting tadpole was beyond stage 25. The longest time we followed tadpoles in a nest was 25 days. Tadpoles were found preying upon eggs of three other frog species and upon conspecific eggs. Males fought by grasping each other in a belly‐to‐belly position; the powerful arms and the thumb spines represent weapons. Even though males can reach maturity in the season following birth, small size would prevent them from establishing their own territory. All the species of the L. pentadactylus group may build their foam nests within excavated basins. The basins may protect the eggs and embryos from cannibalistic tadpoles and may have an anti‐desiccation effect. In order to produce trophic eggs, the female may delay laying additional unfertilized eggs until after the male has abandoned the foam nest. Anuran eggs represent an important food item for tadpoles after they leave the nest.     

Reproductive ecology and behaviour of a species of Adenomera (Anura,Leptodactylinae) with endotrophic tadpoles: Systematic implications

The species of the Leptodactylus fuscus group and those of the genus Adenomera lay their eggs in underground chambers. According to current systematic arrangement of these genera, this behaviour is convergent. Here we describe reproduction, courtship, tadpole morphology, calls, chamber structure, and populational phenology of an Adenomera species, and compare some of these features with those of other species of the genus and with species of Leptodactylus of the fuscus and pentadactylus groups. We tested the tadpoles of the Adenomera sp. and those of Leptodactylus labyrinthicus (pentadactylus group) for their foam‐making abilities. There was sexual dimorphism in size; males averaged 22.0?mm and females 24.3?mm in snout–vent length. Males called from late September to late February; calling often began about 2–3?h before sunset. Males called exclusively in open (non‐forest) areas. Egg clutches were found around male calling sites. Males excavated spherical chambers which had a direct entrance. During mating, the male led the female towards a previously excavated chamber. Territorial interactions (aggressive calls and fights) occurred when an intruder male approached a calling male. Late‐stage tadpoles and newly metamorphosed juveniles were found within underground chambers. Clutch size averaged 10.6; eggs averaged 3.7?mm in diameter and were cream coloured. Tadpoles had horny beaks, but no labial tooth; spiracle was present. All tested groups of tadpoles generated foam within 10?h. As we report for Adenomera sp., the males of Leptodactylus species of the fuscus group lead the female to a previously excavated chamber. Tadpole foam‐making behaviour was reported in Leptodactylus of the fuscus group and was previously unknown for any species of Adenomera or for Leptodactylus of the pentadactylus group. The way in which the tadpoles of Adenomera sp., Leptodactylus spp. (of the fuscus group) and L. labyrinthicus made foam was quite similar. The foam‐making behaviour of the studied tadpoles may act to avoid compaction of the tadpoles at the bottom of the basin or underground chamber, avoiding overcrowding and increasing respiratory and excretory efficiency. As presently recognized, the phylogenetic position of Adenomera suggests that reproductive major behavioural features are convergent with some Leptodactylus species. Alternatively, our data point to close phylogenetic relationships between Adenomera and Leptodactylus of the fuscus and pentadactylus groups, reinforcing the paraphyletic nature of the genus Leptodactylus.     

Are there costs to extended larval transport in the Trinidadian stream frog,Mannophryne trinitatis (Dendrobatidae)?

Previous work has shown that male Mannophryne trinitatis (Dendrobatidae) carry their larvae on their backs for up to 4 days in search of a predator‐free pool in which to deposit them. The experiments reported here investigated whether costs to the larvae or to the adults limit transport duration. We simulated transport durations of 0, 4, 8, and 12 days for larvae, but found no deterioration in terms of ability to grow to metamorphosis; indeed, 12‐day larvae grew better than all the others. After 8 days of simulated transport, larvae had used up all their yolk reserves and begun to lose dry weight. Larvae on wet substrates gained wet weight and length but on drier substrates merely maintained weight, suggesting that dehydration could be a problem on the male's back. In a trial of locomotor performance (mean jump length; number of jumps to traverse a runway), females performed best with calling males not significantly different from transporting males, despite an average larval load equivalent to 15–20% of the frog's mass. Assessment of gut contents showed that females foraged more than males, but that transporting males foraged as much as did calling males. We found no differences between the three classes of adult frogs in fat body weight.     

Life History of Western Ghats endemic and threatened Anuran – Matheran leaping frog, (Indirana leithii) with notes on its feeding preferences

The species Indirana leithii (Anura: Ranixalidae) is endemic to the northern Western Ghats of India and is distributed between latitudes 16°N and 21°N in this region. The tadpoles of this species have been previously studied for their morphology and feeding behaviour; however, their natural history is still not completely understood. In the current study, we provide information about the mating behaviour, egg laying and metamorphosis of the species. We observed that the species possesses reproductive mode number 19 as these frogs lay eggs inside the natural cavities of vertical rock surfaces near streams and waterfalls and their tadpoles are adapted for adhering to the wet rock surface, where they feed on algae (including diatoms) growing in seepage on the rocks. Interestingly, there is no audible calling or territory guarding involved during the courtship behaviour. This has been observed for the first time in any Indian anuran. We also provide data on food preferences of adults and tadpoles.     

XV.—Information respecting botanical travellers

Summary

A new species of mysid, Parvimysis pisciscibus, is described from leaf litter banks in the Igarapé Tarumazinho, a freshwater side stream of the Rio Negro, Brazil. This small species is the first freshwater mysid to be described from the Amazon basin.     

Field and laboratory observations on reproductive aspects of Pseudopaludicola ameghini (Cope, 1887) (Leptodactylidae: Leiuperinae)

ABSTRACT

The genus Pseudopaludicola includes small-sized anurans, widely distributed throughout South America. Twenty-three out of the 25 species occur in Brazil. Although described more than a century ago, from mid-southern Mato Grosso state, central Brazil, Pseudopaludicola ameghini is poorly known. Here we describe the characteristics of reproductive site, amplexus, egg-laying behaviour, eggs and tadpoles of P. ameghini based on specimens and observations performed in the vicinities of the type locality. Pairs of P. ameghini reproduce in shallow and slow groundwater established on hydromorphic terrains, in open environments amidst the Brazilian Cerrado savanna. Reproductive activity occurred between 17:00 and 21:00 h at two sites studied from December 2013 to April 2014. Amplexus is axillary. Eggs are spherical, with a mean diameter of 5.1 mm (yolk plus jelly envelope). Oviposition occurs in shallow sites at a depth of nearly 2.0 cm. Females deposit their eggs one at a time, directly onto sediment at the bottom of waterbodies or attached to submerged vegetation. The tadpole body is oval in dorsal view and globular/depressed in lateral view; eyes are large and dorsally positioned. Nares are large, round, with a small apophysis on marginal rim, dorsally positioned, near the eyes. The spiracle is short, with posterodorsal opening. The oral disc is anteroventral, emarginated laterally, with one dorsal and two ventral gaps; the tooth row formula is 2(2)/2(1), and the upper jaw sheath is ‘arc’ shaped. Pseudopaludicola ameghini has a unique behaviour of oviposition among members of the genus. The differences in reproductive pattern and larval characteristics of P. mystacalis and P. ameghini reinforce the taxonomic validity of the latter, questioned until recently.     

Reproductive biology of Scinax fuscomarginatus (Anura,Hylidae) in south‐eastern Brazil

The present study describes the reproductive biology of Scinax fuscomarginatus in a remnant of Cerrado in south‐eastern Brazil. Observations were made between September 2002 and March 2004 at Estação Ecológica de Itirapina, State of São Paulo, south‐eastern Brazil. Breeding activities occurred in lentic and temporary bodies of water during the rainy season. Scinax fuscomarginatus exhibited a prolonged breeding pattern and a lek mating system. Males were smaller than females and defended individual calling areas through acoustic and physical interactions. Resident males consistently won encounters, but did not differ in size or mass from intruder males. Satellite behaviour was observed, but no female or amplected pair interception was registered. Scinax fuscomarginatus exhibited low operational sex ratios and the general reproductive mode in which eggs are laid in the water and tadpoles are aquatic. Amplexus was axillary and the eggs were deposited at the bottom of temporary ponds. Details on oocytes, egg masses, and eggs are included.     

Breeding behaviour and mating success of Phyllomedusa rohdei (Anura,Hylidae) in south‐eastern Brazil

Observations on the courtship behaviour, mating behaviour and mating success of a leaf‐frog, Phyllomedusa rohdei, population were conducted in a temporary flooded site of the Atlantic Forest, south‐eastern Brazil. We did not find any influence of size and body weight on male mating success across three scales: seasonal, nightly chorus and local groups (males found within 1?m of a mated pair). In addition, no evidence was found that female Phyllomedusa rohdei exhibit overt mate choice. The formation of mated pairs in P. rohdei occurred because males moved toward the females, rather than reverse. The only variable that was significantly related to male mating success was the number of nights of participation in chorus activity. Besides calling tactics, males showed active searching behaviour. There was no evidence of size‐ and mass‐assortative mating, and a high percentage of fertilization at all size and mass ratios of males and females was observed. Clutches in this species are produced in the same manner found in others members of Phyllomedusa; a purse‐like nest is made over water by folding a leaf around the egg mass (embryos and fluid‐filled capsules). Finally, we supply a list of several studies that examined the relationship between size or mass ratios of males and females in amplexus and its influence on fertilization rate, and show that size‐assortative mating in anurans is inconsistent (present in some species but not in other).     

Studies on Alenophalera bronneomixia (Lepidoptera: Notodontidae)—a pest of the West African indigo plant,Lonchocarpus cyanescens (Papilionaceae)

Summary

This paper is concerned with the general biology of the notodontid moth, A. bronneomixia whose larvae are found to be serious defoliators of the West African indigo plant, Lonchocarpus cyanescens.

At temperatures fluctuating between 21°C and 29°C (mean 22·5°C) and humidities between 70 to 95 per cent eggs developed and hatched in a mean of 11·1 days from deposition, mean hatch being 93 per cent.

Under the said environmental conditions, the life cycle from egg to adult entailed six larval instars and a prepupal stage before the real pupa, all lasting 60 to 80 days. Larvae were strongly monophagous, fed communally and in nature pupated in soil/litter very close to the foot of their invaded food plant.

Adults were retiring and in the field deposited clusters of numerous eggs preferably on the abaxial surfaces of their food plants. In nature, this moth's population seemed strongly regulated by high egg and larval parasitization, larval predation and fungal attacks at the pupal stage.     

Home range behaviour in male and female poison frogs in Amazonian Peru (Dendrobatidae: Ranitomeya reticulata)

The poison frog Ranitomeya reticulata was studied for 3 months while mark–recapture surveys were performed. Ranitomeya species deposit terrestrial clutches and carry tadpoles to phytotelmata with few taxa performing biparental brood care including larval feeding. Home range size and spatial affinity to phytotelmata in the genus are linked to mating systems. In R. reticulata, individual home range size and overlap were similar in both sexes, indicating equal levels of site fidelity. Although territory defence was never observed, strong intrasexual intolerance within individuals' core areas was found. The large intersexual home range overlap for breeding pairs indicated that mate fidelity occurs. Individuals' home ranges were not overlapping, suggesting that R. reticulata lacks pair-bonding or strongly cooperative behaviour in parental duties. The number of ground bromeliads containing phytotelmata and home range size of males were positively correlated. Our findings suggest that females do not perform egg-feeding and male-only parental care is likely.     

Laboratory fattening and dietary-fat effects on Meadow voles ( Microtus pennsylvanicus )

When removed from the field and maintained under laboratory conditions, meadow voles exhibited significant change in body composition. Voles increased body mass due primarily to large gains in lipid mass combined with small losses in fat-free mass. Lipid deposition amounts increased as dietary fat was increased, and animals demonstrated a leveling of body mass instead of continuous unregulated obesity. When dietary fat content was changed, lipid deposition or utilization responded directly. Thus, meadow voles regulate overall body mass and body composition (lipid and fat-free mass) at levels that correspond to dietary quality (fat) and abundance in the laboratory, and they deposit considerably more lipid than do animals in the field. Our experiments demonstrate that food quality has a substantial effect on the body composition of wild-caught animals maintained in the laboratory.     

Notes on the occurrence of the introduced landhopper Arcitalitrus dorrieni (Hunt, 1925) on Guernsey,Channel Islands

The introduced landhopper Arcitalitrus dorrieni (Hunt, 1925) has been recorded at various locations (woodlands, private gardens and garden centres, disused quarries) throughout the island of Guernsey, Channel Is. Landhoppers were present in the leaf litter of most of the deciduous and coniferous woodlands with one exception. Although it possessed a well developed litter layer, the oak/mixed woodland at Fauxquets valley was devoid of landhoppers. Landhopper populations were less dense in confierous cf. deciduous, leaf litter. Generally the population density of landhoppers was low (21–300 individual m^-2) compared with other UK sites (due possibly to the study coinciding with the driest summer for 19 years), but was related to the depth of the litter layer. There was also a direct relationship between the total copper content of the leaf litter/soil and landhopper population density even allowing for different litter thickness. While locating an actual original introduction site is problematic, the date of introduction, for reasons discussed in the text, is likely to have been between the early 1900s and 1950.