Life cycle and population structure of the terrestrial isopod Hemilepistus klugii (Brandt, 1833) (Isopoda: Oniscidea) in Iran

The life cycle and population structure of Hemilepistus klugii were studied in a population in Varamin, Iran. The population was sampled monthly (or fortnightly during the breeding season) from February 2008 to June 2009 and a total of 7015 individuals, comprising 1069 males, 1079 females and 4867 juveniles, were collected. As in other Hemilepistus species, five distinct phenophases, namely pair formation, gestation, hatching, growth and stationary, were recorded during the life cycle of H. klugii. The overall sex ratio was 1 : 1 but varied over time. Ovigerous females were observed only in April, indicating a seasonal and very short breeding period. With a short lifespan after breeding, females demonstrated true semelparity. The mean cephalothorax width for ovigerous/post-ovigerous females was higher in 2008 than in 2009. These females attained the largest size in the population throughout the year. The number of eggs per female ranged from 28 to 147 (mean ± SE, 78 ± 1.8). There was a positive correlation between female size and fecundity. Recruitment occurred in late April and resulted in the highest population density in this month, whereas the lowest densities were observed during November to January. Despite a high percentage of ovigerous females carrying undeveloped eggs (72.3%), intramarsupial mortality was low (3.5%).     

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.     

Reproductive biology and strategies of nine meloid beetles from Central Europe (Coleoptera: Meloidae)

The reproductive biology of meloid species from Central Europe is investigated by means of laboratory breeding experiments. They show that the total reproductive potential of meloids, with up to 40,000 eggs, largely exceeds prior data. Furthermore, the number of laid eggs strongly relates to the way by which the triungulins find their host. Clutch size correlates significantly with the size of the beetle, while egg size is independent of this. Both clutch size and egg size decrease with each oviposition. For some species, reproductive data are used to demonstrate how they have adapted to their habitat and to point out existing trade‐offs. Based on the obtained results and on an evaluation of the relevant literature, three types of reproductive strategy can be distinguished within the meloids: (1) very high reproductive rates of open field species with phoretic larvae; (2) average reproductive rates of forest populations of species with phoretic larvae and of species the larvae of which search the nests of their hosts actively; and (3) small to average reproductive rates of those species depositing their clutches in the immediate proximity of their hosts' nests.     

Microhabitat selection in the sand recluse spider (Sicarius thomisoides): the effect of rock size and temperature

In spiders, temperature is considered an important environmental variable for microhabitat selection. In this study, we evaluated the effect of temperature and rock size on the presence of the sand recluse spider Sicarius thomisoides and the degree of selectivity in different locations. This species is a large spider that lives under rocks in desert and semi-desert climates and is particularly active during the summer. In Chile, these spiders can be found at both coastal and inland locations under different thermal conditions, where usually the temperatures are lower near the coast. If large-scale climatic conditions are important for this species, they may be expected to select lower rock temperatures on the coast than at inland locations. In addition, we would expect that the spiders would choose larger rocks in inland compared to coast locations, which reduce the effect of high temperatures. We found that the probability of finding individuals of this species increased according to rock temperature and rock size in the field. Our results suggest that S. thomisoides prefers larger and warmer rocks to shelter under during the day, this selectivity being similar at both coastal and inland locations. Thus, this species tends to select rocks with the same thermal and structural conditions, independent of the climatic conditions.     

The taxonomy and biology of the Polystomatidae (Monogenea) in Australian freshwater turtles (Chelidae,Pleurodira)

Polystomoides scottae n. sp. is described from the urinary and accessory bladders of Chelodina expansa. Four species of Neopolystoma are described from the conjunctival sacs of Australian freshwater turtles (Chelidae): Neopolystoma cribbi n. sp. from Emydura signata, E. macquarii, Elseya latisternum and Chelodina expansa; Neopolystoma spratti n. sp. from Chelodina longicollis; Neopolystoma tinsleyi n. sp. from Chelodina expansa; and Neopolystoma queenslandensis n. sp. from Emydura signata and E. macquarii. Polystomoides australiensis, Neopolystoma macleayi and N. chelodinae are redescribed from new individuals. Neopolystoma australis is made a junior synonym of N. kreffti. P. australiensis, N. macleayi and N. cribbi produced on average 5·6, 4·3 and 0·7 eggs per day, respectively. Eggs of P. australiensis take 33–57 days at 18–24°C and 30–33 days at 24–28°C to develop and hatch. Oncomiracidia of P. australiensis and N. macleayi had 64 ciliated cells; the patterns of the ciliated cells are the same for both species. Different sizes of worms in different sites in the hosts suggest strongly that the oncomiracidia of P. australiensis and N. macleayi enter the host, migrate to the ureters, possibly to the kidneys, then to the urinary bladder and finally to either the accessory bladders or cloaca. Successful cross-infection experiments between host genera (Emydura to Elseya) indicated that P. australiensis and N. macleayi have a low degree of host specificity.     

Geographic variation in body size and sexual size dimorphism in the giant spiny frog Paa spinosa (David, 1875) (Anura: Ranoidae)

We describe the spatial pattern of variation in body size and sexual size dimorphism in the giant spiny frog, Paa spinosa (David, 1875). The study also aims to identify potential factors responsible for geographic morphological variation in the frog. The results indicate that primary production, which positively correlates with precipitation and summer temperature in China, had an important effect on body size of P. spinosa, whereas Bergmann's rule was more efficient to explain the influence of average minimum temperature in January. The species was sexually dimorphic for body size and body shape: the body size, jaw length and forelimb length of males were significantly larger than those of females. Furthermore, the degree of sexual size dimorphism varied geographically, but the relationship between the geographic variation of sexual size dimorphism and the climate was complex. Specifically, absolute sexual size dimorphism was positively correlated with the increased ambient temperature and decreased precipitation.     

An overview of female reproductive traits in South American Mabuya (Squamata,Scincidae), with emphasis on brood size and its correlates

The viviparous New World Mabuya (Reptilia, Scincidae) are characterized by a peculiar suite of reproductive traits associated with an extreme degree of matrotrophy and a specialized placenta. We gathered information on female reproductive traits of South American Mabuya based on a compilation of literature data plus original information on two species (Mabuya dorsivittata and Mabuya macrorhyncha). Considering brood size, we identified one “large-brooded” group (brood sizes up to eight to ten) and one “small-brooded” group (brood sizes up to four to six). Brood size tended to be positively correlated with female body size among species, although the correlation is not as strong as it is within species. There were some general trends for the reproductive ecology of New World Mabuya, such as early sexual maturation, brood sizes of usually four to six young, and parturition occurring around the dry–wet season transition.     

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.     

Haematozoans,mites and body condition in the oceanic island lizard Gallotia atlantica (Peters and Doria, 1882) (Reptilia: Lacertidae)

We studied relationships among blood haemogregarines (Apicomplexa), ectoparasitic mites (Ophyonissus; Acari: Trombiculidae) and an endemic lizard host (Gallotia atlantica, Lacertidae) on an oceanic islet (Alegranza, Canary Islands). We asked whether blood infection, mite load and body condition were related in lizard subpopulations at two contrasting habitats. Both haemogregarine prevalence (100%) and intensity of parasitism (>1) were strikingly higher than values found for congeneric lizards from the other Canary Islands. There were few differences between habitats in infection levels, suggesting low influence of habitat on parasite performance. Both mite prevalence and intensity were very high, though only prevalence differed between habitats (higher in the richest and climatically more sheltered site). Body condition in lizards did not differ significantly between habitats. We found no association among blood parasite load, mite infection and lizard body condition. Results are discussed in the context of parasite‐host relationships on small islands as compared to larger areas such as continents.     

Breeding biology and population structure of the intertidal crab Petrolisthes laevigatus (Anomura: Porcellanidae) in central-southern Chile

The present study describes the seasonal reproductive cycle and population structure of the porcellanid crab Petrolisthes laevigatus, a typical inhabitant of the rocky intertidal. A total of 960 individuals (including 372 females) was collected in monthly samples from October 1993 to December 1994 in central-southern Chile. Ovigerous females were present between August and December, and were absent between January and July. The breeding season started during late winter (August), and females with embryos close to hatching occurred between October and end of spring (December). Considering the gonadosomatic index and the duration of the incubation period, it is concluded that P. laevigatus has a markedly seasonal breeding period with probably two successive spawnings per female per season. Our results compared with previous studies in temperate intertidal porcellanids suggest a lower structural variability of the population during the sampling period, but a pronounced seasonal variation in both sex ratio and abundance. The influence of environmental habitat conditions (i.e. temperature) is suggested to be responsible for the lower variation in the crab population size structure in ovigerous females, and the almost constant size distribution observed in males.     

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.     

Colony foundation in Plectroctena mandibularis F. Smith,and the evolution of ergatoid queens in Plectroctena (Hymenoptera: Formicidae)

Existing models of the evolution of worker-like morphology in queen ants postulate that the condition arose as a by-product of assisted colony foundation. Under laboratory conditions, two lone, ergatoid queens of Plectroctena mandibularis were able to raise broods to at least the pupal stage without the assistance of other ants. Although these results need to be confirmed under field conditions, they indicate the possibility of a different, additional evolutionary pathway to wingless, worker-like queens in this species. Several possible pathways are discussed.     

Structure of the reproductive system and hectocotylus in males of lesser flying squid Todaropsis eblanae (Cephalopoda: Ommastrephidae)

This paper introduces new data on Todaropsis eblanae morphology, morphometry and functional aspects of the male reproductive system and hectocotylus. Spermatophores differ in specimens from the Atlantic Ocean (average length, 18.28 ± 1.45 mm, 15.63 ± 0.8% of mantle length; weight, 2.0–12.0 mg) and the Indian Ocean (average length, 24.8 ± 2.85 mm, 16.9 ± 2.1% of mantle length; weight, 35.0–39.6 mg) (t?=?3.14; p < 0.01 for absolute sizes and t?=?0.711; p > 001 for relative sizes). An additional important distinctive trait is the form of connection of the cement body with the ejaculatory tube. In recent years, T. eblanae has been regularly caught in the Barents Sea, meaning its range has extended to subarctic waters. The morphology and morphometry of the spermatophoric complex of organs did not vary in investigated parts of its range. Hectocotylus patterns and some important spermatophore traits distinguish Todaropsis from other Ommastrephidae.     

The reproductive ecology of Leptodactylus fuscus (Anura,Leptodactylidae): new data from natural temporary ponds in the Brazilian Cerrado and a review throughout its distribution

Recent studies indicate that populations historically called Leptodactylus fuscus (Schneider, 1799) comprise at least three well‐differentiated lineages. Herein, we describe the reproductive ecology of a southeastern clade population of L. fuscus, and review the characters of the reproductive ecology for several populations of the northern and southeastern clades. Most reproductive activity occurred in December and January, which coincided with the highest rainfall period. Males had an aggregated spatial distribution in the central area of the ponds. Three courtship interactions were observed. A female was observed closing the entrance to a burrow with moist sand after oviposition. This behaviour is described for the first time in L. fuscus. The review of the reproductive biology of the northern and southeastern clades indicates a relatively high plasticity in L. fuscus. Furthermore, the results corroborate the suggestion, based on molecular data, that the northern and southeastern clades of L. fuscus represent distinct evolutionary units.     

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.     

Male size and territoriality in the cicada killer wasp Sphecius speciosus (Hymenoptera: Crabronidae)

Males of the eastern cicada killer wasp, Sphecius speciosus, occupy territories in which they may hover or where they may perch either in trees near one or more emergence holes or on the ground at these spots from which females may emerge. Large males are more likely to hold and defend these territories at a site in northern Virginia. When resident males were captured, held and weighed, the males that replaced them, which were also captured, held and weighed, had significantly lower body weights on average than the residents.     

Tropical cyclones and reproductive ecology of Crocodylus acutus Cuvier, 1807 (Reptilia: Crocodilia: Crocodylidae) on a Caribbean atoll in Mexico

Crocodylus acutus, a coastal species nesting in sand beaches, could be affected by increasing tropical cyclone frequency. We studied key characteristics of C. acutus reproductive ecology on Banco Chinchorro atoll from 2006 to 2009, including the impact of two tropical cyclones. Hurricanes increased canopy openness causing earlier nesting the following year. Crocodiles nested at the beginning of the wet season with hatching in mid-wet season; this could represent a compromise between risking nest flooding and increasing freshwater availability for hatchlings. Tropical cyclones dramatically reduced nesting success by cooling and flooding clutches. Nursery sites were usually hypersaline, but heavy rainfall from tropical cyclones can likely benefit hatchling survival by decreasing salinity. While tropical cyclones have negative short-term impacts on crocodile nesting, they likely have an overall beneficial effect by creating and maintaining open sandy nesting areas used by C. acutus and they may explain its widespread distribution in Caribbean coastal areas.