The morphology and biology of Pterodunga mirabile Daccordi,an unusual subsocial Chrysomeline (Coleoptera: Chrysomelidae)

New information is provided on the morphology and biology of the Australian leaf‐beetle Pterodunga mirabile Daccordi. This species is unusual in the Chrysomelinae for the following features: adult with deeply grooved prothoracic hypopleuron, laterally pointed elytral margins, concealed mesoventrite and fused abdominal ventrites; female ovoviviparous and without spermatheca; first‐instar larva with lappet‐like sclerites; maternal care; host plant in the Proteaceae. The systematic position and conservation status of Pterodunga are discussed. Maternal care in the Chrysomelinae and Proteaceae‐feeding in the Chrysomelidae are reviewed. The first record of maternal care in Chrysomelinae, for Labidomera suturella Guérin‐Méneville, is shown to be a misidentification of Platyphora selvae Daccordi.     

Mating behaviour and maternal care in the tropical savanna funnel-web spider Aglaoctenus lagotis Holmberg (Araneae: Lycosidae)

Despite their abundance and diversity, Neotropical spiders have been the subject of relatively few studies of behavioural ecology. The sexual behaviour and maternal care of the spider Aglaoctenus lagotis (Lycosidae) is described here. We performed experimental manipulations to test the hypothesis that males are attracted by female cues in the web. Two predictions were tested: (a) webs used by a virgin female will attract more males than webs used by an inseminated female; (b) the main cue in the web is chemical, so webs recently used by virgin females will attract more males than those that are not recently used. Additionally, we tested the hypothesis that maternal care increases offspring survivorship. Results showed that males are attracted by recently used webs (z = 0.0015; p = 0.037; z-test) and webs of virgin females (z = 0.041; p = 0.036, z-test). Male sexual behaviour presented three different categories: court, pre-mate and mate. After the mating, the females built a cocoon that was transported adhered to the spinnerets and held by the last pair of legs. After the hatching of the eggs, the young migrated to the dorsal region of the mother's body for 5 days. During maternal care the mother eliminates a yellowish drop from its oral cavity, which is collected by the young. During the development of the young until adulthood, the offspring that have their mother present in the first stages of life have greater survival compared with those without maternal care. Our results make it possible to perform comparative analyses between a South American Lycosidae species and other species distributed worldwide.     

Origins and diversification of subsociality in leaf beetles (Coleoptera: Chrysomelidae: Cassidinae: Chrysomelinae)

Leaf beetles (Chrysomelidae; ~40,000 species) are commonly solitary animals but subsociality, maternal care of broods, is known in Cassidinae and Chrysomelinae. We report 11 novel records from Brazil and Peru, bringing the number of subsocial chrysomelids to 35 species in 10 genera. Two evolutionary models of chrysomelid subsociality have been proposed. One proposed three independent origins within Chrysomelinae, based on the potential phylogenetic positions of subsocial genera. The other hypothesised that an evolutionary arms race between chrysomelid prey and their predators, parasites, and parasitoids has led to an escalation of defences. Using our phylogenies, we propose that subsociality originated independently in Cassidinae and Chrysomelinae, and several times within each subfamily. Subsociality was preceded by particular behaviours. In Cassidinae, exophagous larvae with chemically offensive faecal weaponry preceded aggregated living, group defences (e.g. cycloalexy), and maternal guarding. In Chrysomelinae, offensive glandular compounds preceded ovi- and viviparity before subsociality.     

Offspring discrimination by female parents of the matriphagous spider Cheiracanthium japonicum (Araneae: Eutichuridae)

The ability of females of the matriphagous spider Cheiracanthium japonicum to discern their own offspring was examined based on a comparison of her maternal care for her own eggs and spiderlings with other conspecific females as well as those of other congeneric species. Cheiracanthium japonicum females did not discern their own nest from those of conspecific and congeneric individuals. In addition, the female did not distinguish her own egg sac from those of other conspecific or congeneric individuals. On the other hand, the female clearly discriminated between her own spiderlings and those of other congeneric species only if the congeneric spiderlings were introduced into the breeding nest. Consequently, the female will allow conspecific spiderlings to predate her (i.e. cannibalism). However, it is hardly expected that spiderlings of a certain female would eat another female in the field, as the reproductive period is quite short and synchronised in a population. Considering that the female can only recognise spiderlings of other species, the recognition ability of C. japonicum females will be evolved only to work as a protection against intruders of other species into the breeding nest.     

Cleavage pattern in Oscarella species (Porifera,Demospongiae, Homoscleromorpha): transmission of maternal cells and symbiotic bacteria

The cleavage and the first stages of development of larvae in five Oscarella species, from the north-west Mediterranean, O. lobularis, O. tuberculata, O. imperialis, O. microlobata and Oscarella sp., are investigated. Eggs are isolecithal, and rich in yolk inclusions. The cleavage is holoblastic, equal and asynchronous. During cleavage, there is no central cavity (blastocoel). The result of cleavage is the formation of a solid morula constituted by equal blastomeres. The polarity of the blastomeres is not expressed prior to the beginning of larva differentiation, i.e. approximately up to 64-cell stage. The superficial membrane of the blastomeres shows numerous filopodia which form blastomere contact. Symbiotic bacteria and cells with inclusions of the maternal mesohyl are present in the intercellular spaces of the embryo from the beginning of cleavage. Whereas maternal symbiotic bacteria are present in the embryo of the five species studied, maternal cells with inclusions are absent from two species (O. tuberculata and O. microlobata). The most original feature of early development in the genus Oscarella is the formation of a coeloblastula larva from a morula due to the progressive migration of the internal cells to the periphery.     

Maternal defensive behavior of mountain goats against predation by golden eagles

Maternal defensive behavior against predators may appear risky but is common in many species. Herein we describe maternal defensive behavior of mountain goats ( Oreamnos americanus ) against Golden Eagle ( Aquila chrysaetos ) predatory attempts. We found that Golden Eagles attacked goats in 1.9% of sightings ( n = 311 sightings of active Golden Eagles over 12 years) but were never successful. Mothers always defended their young against Golden Eagle attacks. Predation by Golden Eagles on young-of-the-year appears low for most ungulate species, including mountain goats. The benefits of defending offspring against eagles are likely high in ungulates, and we would therefore expect selection to favor maternal defensive behavior.     

Antipredatory defense of neonatal pronghorn ( Antilocapra americana ) by yearling male pronghorn in southwestern South Dakota

Antipredatory defense of pronghorn ( Antilocapra americana ) neonates (≤1 month old) by adult females (>18 months old) is well documented throughout the geographic range of this species. However, reports of male pronghorn defending neonates against predators are limited to a single study in northwestern Wyoming where occurrences were documented of adult males assisting female pronghorn in defending neonates against coyotes ( Canis latrans ). To our knowledge, defense of neonatal pronghorn by yearling males (12–18 months old) has not been reported previously for this species. We report occurrences of antipredatory defense of neonatal pronghorn by yearling males in southwestern South Dakota. La defensa antidepredadora de los neonatos (≤30 días de edad) del berrendo ( Antilocapra americana ) por hembras adultas (>18 meses de edad) está bien documentada en toda la distribución geográfica de esta especie. Sin embargo, no se había reportado la defensa de neonatos contra depredadores por parte de berrendos machos con excepción de un solo estudio en el noroeste de Wyoming, donde documentaron algunos casos en los que machos adultos ayudaron a los berrendos hembras a defender los neonatos contra coyotes ( Canis latrans ). Hasta donde sabemos, la defensa de berrendos neonatales por machos de alrededor de un año de edad (de 12–18 meses de edad) no se había reportado previamente. Reportamos casos de defensa antidepredadora de berrendos neonatales por parte de machos de un año de edad en el suroeste de Dakota del Sur.     

The reproductive strategies of clausiliid land snails from Northern Vietnam (Gastropoda: Stylommatophora)

Under laboratory conditions we scrutinized the reproduction and development of two clausiliid land snail species from northern Vietnam: Phaedusa paviei (Morlet, 1892) and Oospira vanbuensis (Bavay and Dautzenberg, 1899). These species, very similar in shell size and shape, feature different reproductive modes. The former is viviparous, giving birth to one or two neonates on a single occasion, with the number of developing embryos retained in the reproductive tract ranging from 1 to 11. The embryonic shells are 1.8–4.7 mm in height. The latter species is oviparous and produces eggs in clutches (four to six per clutch). Hatching occurs 18–21 days after egg-laying. Both species exhibit a similar growth pattern: the ultimate shell size is attained after 6.5–8.5 months and reproduction starts 5–7 months later. The distribution of viviparous reproduction among the Phaedusinae and its taxonomic importance are discussed.     

Qualitative relations of egg size,egg production and colony size in some ponerine ants (Hymenoptera: Formicidae)

The sizes of eggs and reproductives of 13 species of ponerine ant were measured, and information about the mature colony sizes, ovarial anatomy and individual fecundities of a selection of ponerine species was assembled. Inter-specific variation in the size of colonies was found to be poorly related to aspects of individual fecundity, and although the few cases of polygyny were associated with larger colony sizes, monogynous species often attained even larger sizes. Within the subfamily individual fecundity may be increased primarily by a decrease in the maternal investment in individual eggs, and perhaps to a lesser extent by an increase in the number of ovarioles in each ovary or an increase in the length of each ovariole. The diet of a species and the longevity of adult worker ants relative to the duration of their larval development are suggested as factors besides reproductive characteristics that might also contribute to differences in colony size.     

Female life‐history characteristics of the Mosor rock lizard,Dinarolacerta mosorensis (Kolombatović, 1886) from Montenegro (Squamata: Lacertidae)

Analysis of the female life history of the poorly studied endemic Balkan lizard species Dinarolacerta mosorensis was conducted on three population samples from Montenegro. One clutch is produced annually. Females mature at body sizes of 56–57 mm snout–vent length (SVL), attained at age 3–4 years. SVL increases with age. The average clutch size ranged from 4.3 to 5.2 eggs, and was significantly positively correlated with maternal SVL in two population samples. There were no trade‐offs between egg size/offspring size and clutch size, nor between variation in egg size/offspring size and maternal SVL. The incubation period averaged 26.5 days, while hatching success in captivity was 72%. Significant positive correlations were found between the hatchling mass and egg mass and size, and also between the hatchling total length and egg width and volume. There was a significant negative relationship between the hatchling mass and incubation duration.     

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.     

Reproductive biology of Limnoria chilensis: another boring peracarid species with extended parental care

Several boring peracarid species engage in extended parental care with parents tolerating small juveniles in their burrows, but only anecdotal observations have been reported from boring isopods of the genus Limnoria. The isopod Limnoria chilensis Menzies is frequently found in holdfasts of the macroalgae Macrocystis pyrifera (L.) C. Agardh and Durvillea antarctica (Chamisso) Hariot. In the present study, holdfasts of D. antarctica that harboured L. chilensis were carefully dissected in order to examine the association pattern of reproductive females and small juveniles. In most infested holdfasts, L. chilensis reached very high densities of 43.7 ± 3.9 (mean ± SE) individuals cm^?2 (range: 0–90 individuals cm^?2). The overall sex ratio (females:males) was close to unity (1.2). Male size varied between 1.5 and 2.6 mm body length (BL) and female size between 1.5 and 3.6mm BL. The percentage of reproductive females was low (19.7% of all females), and only the largest females (>2.6 mm BL) were reproductive. Embryo numbers ranged between six and 19 per female and a significant correlation between female BL and the number of embryos was found. Several females were found with small juveniles (0.8–1.2 mm BL) in the terminal end of their burrows. On several occasions, aggregations of similar-sized juveniles (1.0–1.5 mm BL) in their own burrows were found near a female burrow, indicating that these juveniles initiated their first individual burrows from within the maternal burrows. Some females with small juveniles in the terminal end of their burrows were either accompanied by males or they were ovigerous, indicating that they may have been in the process of producing a second brood. The fact that juveniles build their first burrows in the protection of female burrows suggests that such small juveniles have not yet developed full boring capacity. Extended parental care in this (and other boring) peracarid species represents a mechanism facilitating high juvenile survival rates. Given the highly local recruitment, it is suggested that the reproductive biology of this isopod has strong implications for Its population biology.     

Extended parental care in two endobenthic amphipods

Extended parental care is described for two endobenthic amphipods which inhabit the estuarine soft-bottoms along the Gulf of Maine. The juveniles of both amphipod species, Leptocheirus pinguis and Casco bigelowi, remain in the burrow of their mother after they hatch from the brood pouch. Several consecutive clutches of L. pinguis can inhabit the female's burrow simultaneously, but in C. bigelowi there is always only one clutch of juveniles in the burrow of the female. Larger juveniles of L. pinguis start building their own small tubes at the bottom of the female's burrow. Casco bigelowi females increase the size of their burrows during the time when the juveniles grow. The juveniles of both species leave the female's burrow at about half adult size. The major tasks of female L. pinguis and C. bigelowi during the time of extended parental care is to irrigate and maintain the deep burrow. It is hypothesized that extended parental care in L. pinguis, C. bigelowi and other tube/burrow-living peracarids is a mechanism to protect small offspring from epibenthic predation.     

Behavioural and morphological dimorphism of the sexes: an account of two primitively eusocial wasps

In social Hymenoptera, foraging, nest building, brood care and all other colony maintenance functions are carried out by the females while males function solely as reproductives. This asymmetry in social roles of the two sexes has led social insect researchers to focus almost exclusively on the females whereas males have remained relatively neglected. We studied two sympatric, primitively eusocial wasps, Ropalidia marginata and Ropalidia cyathiformis, and compared the morphological and behavioural profiles of males and females. Males of both species are smaller in size and weigh less compared to females. Males of the two species live in the nest for different durations. Borrowing from the ecological literature we use novel methods to compute and compare behavioural diversity and behavioural richness and show that females of both species are behaviourally richer and more diverse than the males.     

Locomotory activity and orientation of Mesobuthus gibbosus (Scorpiones: Buthidae) in central Aegean Archipelago

This study explores the locomotory activity of Mesobuthus gibbosus on Koufonisi Island (central Aegean). We measured orientation of movement, shelter selection and abiotic factors that influence locomotive activity throughout the circadian and lunar cycles. Our results show M. gibbosus is a highly active and negatively phototactic species with sexually dimorphic patterns of movements that are related to maternal protective behaviour. Male scorpions disperse more widely, apparently as a function of mate search, and exhibit much more opportunistic locomotive behaviour. The locomotory activity of the population was influenced by moon phase (negative phototropic) and air temperature, did not differ intersexually, and was directed towards a dry stone-wall where shelter was readily available.     

Reproduction,development and parental care in two direct‐developing flatworms (Platyhelminthes: Polycladida: Acotylea)

Variations in reproductive modes, egg production, and the effects of parental care on hatching success are compared between Pleioplana atomata and Imogine zebra. Pleioplana atomata transfers sperm via true copulation, whereas I. zebra dermally impregnates spermatophores onto the dorsal surface of partners. Pleioplana atomata lays up to 750 large eggs over a 6‐week period, and I. zebra individuals lay up to 1346 small eggs in 12 days. Female fecundity is positively correlated with body size in both species. Developmental time lines are temperature‐dependent, and juvenile worms hatch after 3 and 6 weeks for I. zebra and P. atomata, respectively. Covering of egg masses by the adult is observed for both species and although this parental care is not necessary for egg development or hatching, it plays a significant role in the hatching success of P. atomata. In I. zebra, parental covering of egg masses may play a role in eggshell development.     

Reproductive features of three maternal-caring species of Leptodactylus (Anura: Leptodactylidae) with a report on alloparental care in frogs

We describe aspects of the reproduction of three shoaling/maternal-caring Leptodactylus species (Leptodactylus aff. latrans, Leptodactylus podicipinus and Leptodactylus aff. leptodactyloides), pointing to the relevance of the female to tadpoles and describe a case of alloparental care in frogs. Females of the three species connected water bodies by digging channels to their tadpoles. Leptodactylus aff. latrans females often expelled predatory snakes and conspecific males that approached shoals to prey upon tadpoles. In water bodies containing predatory teleosts, tadpoles of L. aff. latrans only reached metamorphosis in the presence of guardian females. Channel digging can provide tadpoles with access to new feeding grounds and prevent predation and desiccation. We found brood mixing and alloparental care between L. aff. latrans and L. podicipinus which, as in some Teleostei, may be regarded as the result of identification mistakes.     

Comparison of Gila topminnow and western mosquitofish as biological control agents of mosquitoes

I compared acute tolerance of Gila topminnow, Poeciliopsis occidentalis , and western mosquitofish, Gambusia affinis , to ammonia and high water temperature and also compared diet, food selectivity, and impact on invertebrate populations to evaluate the potential for each species to effectively control mosquitoes (Culicidae) in wetland habitats. Critical thermal maxima differed among species, sexes, and lifestages, but these differences were likely not biologically significant due to their small magnitude and the ability of wild populations of both species to adapt to high temperatures. In 24-hour tests, G. affinis displayed about twice the ammonia tolerance as did P. occidentalis . However, longterm survival in habitats with high ammonia concentrations is questionable, thus reducing the perceived benefit of using G. affinis for mosquito abatement in these habitats. Diet overlap was significant between sexes within species but was not significant between species. However, both species exhibited significant dietary selection for mosquito larvae and pupae under experimental conditions. Shared dietary preference for mosquito larvae and pupae, in addition to similarity in temperature tolerance between species, suggests that P. occidentalis , a native and historically widespread species, can be used in place of nonnative G. affinis for mosquito control. There is no evidence to suggest that nonnative G. affinis is better suited for mosquito abatement, and since G. affinis is replacing P. occidentalis throughout the native species' former range, it should no longer be introduced into the Gila River basin for mosquito control. However, managers who would use P. occidentalis for mosquito abatement must take care not to interfere with conservation efforts by disrupting the genetic structure of natural populations of P. occidentalis .     

Long-term increases in clutch size in common snapping turtles (Chelydra serpentina) and diamondback terrapins (Malaclemys terrapin)

Clutch size (CS) is a well-studied life history characteristic, and optimal egg size theory predicts that CS should correlate positively with reproductive investment. Turtles are good subjects for studies of reproductive strategies because few turtle species exhibit parental care; therefore quantifying their short-term reproductive investment is mostly limited to measuring egg size and number. Clutch size is usually reported as an average value for each turtle population, and where CS variation is noted, it is usually attributable to variation in adult body size. In two long-term studies of ecologically dissimilar species we detected a dramatic increase in CS in a common snapping turtle (Chelydra serpentina) population and in a diamondback terrapin (Malaclemys terrapin) population. It is unknown whether these changes are due to either variation in adult body size or resource availability; but the temporal patterns we observed have apparently never been reported previously. These trends remain unexplained and should be explored further.     

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.