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.     

Development rates,larval survivorship and wing length of Culex pipiens (Diptera: Culicidae) at constant temperatures

In this study, the effects of rearing temperature on survival and development rate of pre-imaginal stages and on wing length of adult Culex pipiens (Diptera: Culicidae) were evaluated. Larvae I were reared until adult emergence at seven constant temperatures between 7 and 33°C. The highest survival was found at 25°C. The development rate of the immature stages decreased with increasing temperature until 30°C. The threshold temperature and thermal constant were, respectively, 5.2°C and 186.5 degree-days for males, and 5.5°C and 199.5 degree-days for females. According to a non-linear model, the lower and upper thermal thresholds were, respectively, 8.4°C and 34.4°C for males, and 9.8°C and 34.2°C for females. Wing length decreased with increasing temperature. Wings of females were longer than those of males. This study showed that survival and development of immatures and adult size were affected by rearing temperature. In addition, results suggest that this effect may differ between sexes.     

A revision of Eumedonus H. Milne Edwards, 1834 and Gonatonotus White, 1847 (Crustacea: Decapoda: Brachyura: Eumedonidae), two genera of crabs symbiotic with sea urchins

The eumedonid genera Eumedonus H. Milne Edwards, 1834 and Gonatonotus White, 1847, are revised. Members of both genera are obligate symbionts with sea urchins. Eumedonus is separated from Gonatonotus mainly by the presence or absence of crests on the merus of the ambulatory legs. Eumedonus, as here defined, contains five species, viz. E. niger H. Milne Edwards, 1834 (type species), E. vicinus Rathbun, 1918, E. zebra Alcock, 1895, E. brevirhynchus n. sp., and E. intermedius n. sp. Gonatonotus, as here re-diagnosed, includes three species, viz. G. pentagonus White, 1847 (type species), G. granulosus (MacGilchrist, 1905), n. comb. and G. nasutus n. sp.     

Development of Caligus multispinosus Shen,a caligid copepod parasitic on the black sea bream (Acanthopagrus schlegeli) cultured in Taiwan

The development of Caligus multispinosus was studied using instars reared from eggs in the laboratory and specimens obtained from the gills of pond-cultured black sea bream. Nine stages were identified, namely, two nauplii, one copepodid, four chalimus stages, one preadult and the adult. The distinctive feature of the spinulose outer spines on leg 4 appeared late in development (preadult stage) and the frontal filament produced in chalimus I is kept throughout the chalimus stages.     

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%).     

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.     

Development and demography of Phasmahyla jandaia (Bokermann and Sazima, 1978) (Anura,Hylidae) tadpoles in an Atlantic Forest site,southeastern Brazil

Mortality rates are often high during the anuran tadpole stage, making demographic parameters in this phase of their life cycle important to the understanding of population demography. Nevertheless, information on mortality rates or population size is lacking for most Brazilian anurans. Herein we report on the demographic parameters of Phasmahyla jandaia (Hylidae) during the larval stage, including number of individuals through time, mortality rates and time of recruitment. Tadpole recruitment occurred year‐round, although froglet recruitment to the terrestrial habitat was restricted to the warm, rainy season. This trend seems to result in high plasticity of the tadpole developmental period. Mortality rates decreased with advancing tadpole stage, totalling 77% during the whole aquatic phase. Survivorship can be regarded as intermediate compared with other anurans for which data are available, and is in accordance with a high investment in egg size and the low number of eggs laid by P. jandaia.     

Bait,habitat preferences and the phenology of some lesser dung flies (Diptera: Sphaeroceridae) in Britain

Two thousand eight hundred and sixty Sphaeroceridae representing 45 species were caught in eight traps, baited with horse, cow or hamster dung or carrion, placed in woodland and in the open at Silwood Park, Berkshire, during 1983/4. A list of the species and the numbers of each caught in each of the traps is given. Comparisons between the catches of open and woodland habitats and between the catches of the different baits used are made. The habitat and bait preferences and the phenologies of the dominant species are discussed.     

Reproduction,planula development,and substratum selection in three species of Stylactaria (Cnidaria: Hydrozoa) from Hokkaido,Japan

Modes of reproduction, morphology and behaviour of planulae, and substratum specificity were studied and compared in three species of the hydrozoan genus Stylactaria from Hokkaido, S. conchicola, S. uchidai, and S. multigranosi. Observed differences in these attributes provide additional characters for discrimination of the three species. Stylactaria conchicola is oviparous, its planulae are sedentary, and its hydroid is substratum specific (living only on shells of the gastropod Homalopoma amussitatum). Stylactaria uchidai differs in being ovoviviparous, in having crawling planulae, and in being a substratum generalist. Stylactaria multigranosi is parthenogenetic, its planulae are sedentary, and it is substratum specific (occurring exclusively on the gastropod Nassarius multigranosus). Only female colonies of S. multigranosi are known, and gonophores of this species differ from those of S. conchicola and S. uchidai in being eumedusoid rather than styloid. Correlations were noted between attributes of the planula larva and substratum specificity in the three species. The cnidome differences between the species suggest that penetrant nematocysts are particularly important for sedentary planulae colonizing moving substrata. These characters are also considered useful in the taxonomy of species of Stylactaria. The phylogenetic significance of different gonophore types in the genus is considered.     

A review of deviant phenotypes in bees in relation to brood parasitism,and a gynandromorph of Megalopta genalis (Hymenoptera: Halictidae)

We review the occurrence of gynandromorphy in 64 species of bee, and describe the abnormal traits as deviations from the male or female wild-type. Pheno-deviants occur at approximately equal frequency among the main body regions (head, thorax, metasoma). Cross-sex expression of character states occur more often among females (i.e. deviant expression of male-like traits) than among males (i.e. deviant expression of female-like traits). Such pathologies demonstrate how developmental switch mechanisms might generate novel structural traits similar to those expressed as a syndrome of brood parasitic traits. We also describe the first known gynandromorphic bee in the tribe Augochlorini, a specimen of the nocturnal bee, Megalopta genalis.     

Larval development of Apiomithrax violaceus (A. Milne Edwards, 1868) (Decapoda: Brachyura: Majoidea: Pisidae) reared in laboratory conditions,and a review of larval characters of Pisidae

Apiomithrax violaceus (A. Milne Edwards, 1868 Milne Edwards A 1868 Observations sur la faune carcinologique des Iles du Cap-Vert Nouvelles Archives du Muséum d'Histoire Naturelle, 4, 49–68, pls 16–18  [Google Scholar]) is a pisid majoid crab occurring in tropical and subtropical coastal waters of the eastern and western South Atlantic. Larval development consists of two zoeal stages and a megalopa. Beginning with the first zoea, the duration of each larval stage at 24°C was 3–8 (5±1), 3–5 (4±0.5) and 9–15 (11±2) days, the megalopa and first crab instar appearing 9–11 (10±1) and 20–27 (23±2) days after hatching, respectively. Larval characters agree with those proposed for the Majoidea, in having nine or more setae on the scaphognathite in the first zoea and well-developed pleopods in the second zoea. However, larvae of A. violaceus do not fit larval pisid features. Zoeal stages differ from most other Pisidae in having lateral spines, a long rostral spine extending beyond the antenna, two spines per telson fork and a dorsolateral process on the third abdominal somite. The megalopa differs in having a spine dorsally on the carapace and on the basial segment of the second pereiopod. Two characters that are potentially unique to Apiomithrax include a zoeal antenna with an exopod that is much longer than the protopod, and a rostral spine that is longer than the dorsal spine. These characters should facilitate the identification of this taxon and could also be useful for phylogenetic studies. A review of larvae of 28 species among 14 genera indicated that there is no apparent single larval character that differentiates the Pisidae, with more limited phylogenetic analyses suggesting that this is a paraphyletic group. Apiomithrax, Eurynolambrus, Pisoides, Rochinia and Scyra have the most divergent morphological characters within the family. The analysis and inclusion of additional taxa is likely to shed more light on the sister-group relationships of the Pisidae. However, based on the extent of morphological interspecific variability of known larvae it is likely that the group, as presently defined by adult morphology, is not monophyletic.