Growth and Development in Wild Owl Monkeys (<Emphasis Type="Italic">Aotus azarai</Emphasis>) of Argentina

Life history predicts that in sexually dimorphic species in which males are the larger sex, males should reach sexual maturity later than females (or vice versa if females are the larger sex). The corresponding prediction that in sexually monomorphic species maturational rates will differ little between the sexes has rarely been tested. We report here sex differences in growth and development to adulthood for 70 female and 69 male wild owl monkeys (Aotus azarai). In addition, using evidence from natal dispersal and first reproduction (mean: 74 mo) for 7 individuals of known age, we assigned ages to categories: infant, 0–6 mo; juvenile, 6.1–24 mo; subadult, 24.1–48 mo; adult >48 mo. We compared von Bertalanffy growth curves and growth rates derived from linear piecewise regressions for juvenile and subadult females and males. Growth rates did not differ between the sexes, although juvenile females were slightly longer than males. Females reached maximum maxillary canine height at ca. 2 yr, about a year earlier than males, and females’ maxillary canines were shorter than males’. Thus apart from canine eruption and possibly crown–rump length, the development of Azara’s owl monkeys conforms to the prediction by life history that in monomorphic species the sexes should develop at similar paces.     

Spatial Segregation of the Sexes and Nutrients affect Reproductive Success in a Dioecious Wind-pollinated Grass

In many dioecious plant species in which spatial distributions of males and females have been examined, the sexes are spatially segregated – usually along an environmental gradient. Unless pollen is uniformly distributed in a population, spatial segregation of the sexes should reduce the average mating success of individuals. In three Californian populations of Distichlis spicata – a wind-pollinated grass species that exhibits spatial segregation of the sexes – I examined patterns of pollen movement and the effects of pollen load and nutrient availability on seed set to determine whether spatial segregation of the sexes actually reduces mating success for both males and females. In two of the populations, pollen dispersal was restricted, and pollen augmentation consistently, significantly increased seed set. However, in the third population – which had the lowest seed set – I found that although there were some indications of pollen limitation, pollen dispersal was not restricted, and seed production was limited primarily by nutrient availability. These results imply that in some populations of D. spicata nutrient limitation on the production of seeds by females may be sufficiently strong that spatial segregation of the sexes causes a fairly low cost to reproductive success compared with a more random distribution of the sexes. However, in other populations, pollen does limit mating success, and the spatial segregation of males and females in these populations is reducing the fecundity of both males and females.     

Grooming interactions among adult chimpanzees at Bossou,Guinea, with special reference to social structure

Grooming and proximity interactions among chimpanzees at Bossou, Republic of Guinea, were analyzed as an index of friendly and affinitive relationships among adult males, among adult females, and between the sexes. Data from the first (1976–1977) and the third (1982–1983) study period were used. The expected value of their interactions was calculated from the number of adult males and females in the group and also from the observed frequency of combinations of adult males and females in the parties (temporary foraging groups). In the pooled data from the two periods, there was little difference between grooming and proximity (without grooming). The frequency of male-female grooming and proximity interactions was lower than expected, and that of female-female interactions was higher than expected. The frequencies of male-male grooming and proximity were intermediate but fluctuated. Male-male grooming frequency was lower than that recorded in chimpanzees of East Africa. Characteristics of same-sex affinitive interactions, especially between Bossou chimpanzee females, clearly differ from those of East African chimpanzees and are more like those recorded for female-related groups of Japanese macaques (Macaca fuscata).These differences indicate the variability and flexibility of chimpanzee social structure.     

A new righteye flounder, Poecilopsetta pectoralis (Pleuronectiformes: Poecilopsettidae), from New Caledonia

A new righteye flounder, Poecilopsetta pectoralis, is described from 4 specimens (2 males, 2 females) collected from deep waters (510–580 m) around New Caledonia. The species is easily distinguished from 13 congeners by having 99–105 lateral line scales, a narrow interorbit [male: 37.00–40.25 in head length (HL); female: 47.33–50.71], long pectoral fin on ocular side (male: 0.89–0.91 in HL; female: 1.04–1.20), no scales from snout to anterior interorbital region, and 4 spots on caudal fin. Sexual dimorphism is evident in this species, showing males bearing the ocular-side pectoral fin longer than females, and it is the first example in Poecilopsetta.     

Breeding site fidelity in penduline tit Remiz pendulinus in Southern Hungary

Birds move between breeding locations to gain a better territory, avoid competition or reduce the deleterious effect of inbreeding. We investigated breeding site fidelity in a small European passerine, the penduline tit (Remiz pendulinus). This species has an exceptionally diverse breeding system, in which both males and females may have up to 5–7 mates in a single breeding season, and the eggs are incubated by a single parent: either the male or the female. We investigated the movements of males and females within three breeding seasons in Southern Hungary (2002–2004). Males moved for shorter distances between breeding sites (116 m, 63–333 m; median, lower quartile–upper quartile) than females (942 m, 415–2,382 m). Movements of males and females were consistent between years, and they were repeatable between subsequent nests of males, but not of females. Taken together, our results suggest that adult male penduline tits are more site-faithful than adult females. We suggest that this difference has an implication on their breeding ecology since male parental behaviour (desert/care) is expected to be influenced by local mating opportunities, whilst female parental behaviour is likely to depend on the mating opportunities in a large area around their breeding site.     

Epidemiology of dermatophytoses in a rural community in Eastern Nigeria and review of literature from Africa

A total of 4,287 primary school children, comprising 1,740 males and 2,547 females in Arochukwu local government area of Abia state Nigeria were examined for clinical signs of dermatophytoses. About 873 (20.4%), consisting of 505 males and 368 females had lesions consistent with dermatophytoses. The disease was more prevalent in males (29%) than females (14.4%) in a ratio of approximately 2:1 (P < 0.05). The infection rate increased from 16.8% in the 4–6 year age group to a peak of 28.1% in the 10–12 year age bracket and dropped sharply to 5.6% in the 16–18 year group. The highest prevalence (39%) was observed among males aged 10–12 years while females 16–18 years had the lowest prevalence (2.5%). Tinea capitis was the predominant clinical type of dermatophytoses, and occurred in 13.7% of the total population studied and 67% of lesion positive cases. Trichophyton soudanense and Trichophyton tonsurans the predominant aetiological agents of dermatophytoses with a prevalence of 26.2% and 21.6%, respectively. Others include Trichophyton mentagrophytes (18.8%), Epidermophyton floccosum (8.3%), Microsporum audouinii (6.4%), Microsporum gypseum (6.0%), Trichophyton rubrum (5.5%) and Microsporum ferrugineum (7.3%), which was isolated for the first time in Nigeria.     

Reproductive biology of the bigeye thresher shark,Alopias superciliosus (Lowe, 1839) (Chondrichthyes: Alopiidae), in the northwestern Pacific

Reproductive aspects ofAlopias superciliosus in the northwestern Pacific were described in detail, on the basis of 629 specimens (429 females and 200 males) collected from January 1984 to October 1984 and from October 1992 to March 1994.Alopias superciliosus embryos are oophagous. Six developmental stages (3 encapsulative and 3 posthatching) based on embryonic morphology and source of nutrition were recognized. The species bears 2 embryos per litter, their size at birth being between 135 and 140 cm TL. The sex ratio of embryos was 1∶1. Total length of females at maturity was 332–341. 1. cm; of males 270.1–287.6 cm. The gestation period could not be determined because most adult females were pregnant throughout the year. The typical reproductive strategy ofA. superciliosus is the production of a few large embryos per litter, with no fixed mating or birthing season.     

Visibly healthy corals exhibit variable pigment concentrations and symbiont phenotypes

Understanding the natural variability of photosynthetic pigment ranges and distributions in healthy corals is central to evaluating how useful these measurements are for assessing the health and bleaching status of endosymbiotic reef-building corals. This study examined the photosynthetic pigment variability in visibly healthy Porites lobata and Porites lutea corals from Kaneohe Bay, Hawaii and explored whether pigment variability was related to the genetic identity or phenotypic characteristics of the symbionts. Concentrations of the photosynthetic pigments chlorophyll a, peridinin, chlorophyll c ₂ , diadinoxanthin, diatoxanthin, β,β-carotene and dinoxanthin were quantified using high-performance liquid chromatography (HPLC). Pigment concentrations were found to range 1.5–10 fold in colonies of each species at similar depths (0–2, 2–4, 10–15 and 19–21 m). Despite the high pigment variability, pigment ratios for each species were relatively conserved over the 0–21 m depth gradient. The genetic identity of the symbiont communities was examined for each colony using 18S nuclear ribosomal DNA (nrDNA) restriction fragment length polymorphisms. All colonies contained symbionts belonging to clade C. The density and phenotypic characteristics of the symbionts were explored using flow cytometry, and fluorescence and side scatter (cell size) properties revealed phenotypically distinct symbiont subpopulations in every colony. The symbiont subpopulations displayed pigment trends that may be driven by acclimatization to irradiance microenvironments within the host. These results highlight the biological complexity of healthy coral–symbiont associations and the need for future research on pigments and symbiont subpopulation dynamics.     

<Emphasis Type="Italic">Samariscus multiradiatus</Emphasis>, a new dextral flounder (Pleuronectiformes: Samaridae) from New Caledonia

A new dextral flounder, Samariscus multiradiatus, is described from six specimens (four males and two females) collected in deep waters (296–430 m) around New Caledonia. The species is easily distinguished from its 16 congeners in having a combination of 85–91 dorsal fin rays, 67–72 anal fin rays, 5 pectoral fin rays, and 9 abdominal and 34–35 caudal vertebrae.     

Sex differences in tooth wear ofMacaca fuscata,the Arashiyama-A troop in Texas

The incidence of tooth wear was studied in a wild troop ofM. fuscata, that had previously been transplanted from Arashiyama, Japan, to Texas. This study was undertaken to determine differences of attrition between males and females, and between maxillary and mandibular dentitions. Contrary to other findings, the rate of wear was not found to be an expression of sex difference, but seemed rather related to function. The following observations may suffice as examples: The mandibular third premolars function as a honing surface for the maxillary canines, and experience greater wear over time in males due to their proximity to smaller canines which leave their neighbors more vulnerable to wear. The degree of attrition intensity is neither the same for males and females, nor the maxillary and mandibular dentitions. Certain maxillary and mandibular teeth “pair up”; although all “pairs” are identical in males and females, they rank differently in the degree of wear experienced. Overall, females express greater attrition in the maxillary, and males in the mandibular dentitions.     

Distribution and Biology of the New Zealand Endemic Catshark, Halaelurus dawsoni

Synopsis Halaelurus dawsoni has a restricted geographic range, occurring only in south-eastern New Zealand. It is primarily a demersal inhabitant of the upper continental slope, plateaus, and ridges at 250–800 m depth. Halaelurus dawsoni is a voracious carnivore that feeds on a wide variety of crustaceans and fishes. Maximum recorded length is 418 mm total length, and males and females grow to similar maximum lengths. Length at 50% maturity is about 340–350 mm for males and 330–360 mm for females. The reproductive mode of H. dawsoni is single oviparity, with one leathery egg case being carried per uterus. It appears that most embryonic development occurs after egg cases are deposited on the seabed. The reproductive mode of species of Halaelurus in the subgenus Halaelurus is multiple oviparity, whereas for those in the subgenus Bythaelurus it is single oviparity or aplacental viviparity. It has been suggested that single oviparity is a primitive reproductive mode, and that aplacental viviparity evolved from it via the intermediate stage of multiple oviparity. However, the relationship between reproductive mode and Halaelurus subgenus suggests that aplacental viviparity may have evolved directly from single oviparity in the subgenus Bythaelurus without passing through a multiple oviparous stage.     

Ranging Behavior and Possible Correlates of Pair-Living in Southeastern Avahis (Madagascar)

Researchers have proposed several hypotheses to explain pair-living in primates. In particular, when males are not involved in direct parental care, pair-living may be related to female dispersal, infanticide prevention, or male mate/resource defense. We aimed to evaluate, through a better understanding of the ranging patterns of avahis, which hypotheses may best account for pair-living in these nocturnal lemurs. We collected focal observations over 26 nights, June–September 2004, in a littoral forest (Sainte Luce, southeastern Madagascar) on 4 adult radiocollared avahis [Avahi laniger (Tattersall, I. (1982). The Primates of Madagascar. Columbia University Press, New York.) or Avahi meridionalis (Zaramody in Primate Reports 74:9–22, 2006)]. We followed 2 males and 2 females from 2 groups: B, a male-female couple, and A, comprising the parental pair and 1-yr-old female offspring. The adult females birthed in August. We recorded resting and feeding tree points (via global positioning system) for home range calculation through minimum convex polygon and kernel methods. We provide the first quantitative information on the ranging behavior of 2 male and 2 female avahis. Home range/daily path length values (means) are higher than the ones previously reported for the same and other folivorous pair-living lemur species. On average, the 2 females spent more time feeding and traveled shorter distances than the 2 males did. Male–female cohesion (mean values), possibly enhanced by offspring presence, was higher in A and after births than in B and before births, respectively. Although male avahis may be forced into pair-living owing to energy constraints related to size, locomotion, and diet, females might accept pair-living in exchange for indirect territory defense and mate guarding.     

Effect of age and sex on copper-induced toxicity in theMacular mutant mouse

It was determined if the sensitivity inmacular mutant mouse to copper-induced toxicity was affected by sex or age. The sensitivity in 6–8-d-old or 3–4-wk-oldmacular mutant mouse to copper-induced toxicity was not affected by sex. However, 8–9-wk-old mutant females were more sensitive to copper-induced toxicity than mutant males. Furthermore, 6–8-d-old or 3–4-wk-old mutant males were more sensitive to copper-induced toxicity than 8–9-wk-old mutant males. However, age-related differences in sensitivity to copper-induced toxicity did not occur significantly in mutant females. On the other hand, in the case of normal mice, the sensitivity in 6–8-d-old or 3–4-wk-old mice to copper-induced toxicity was not also affected by sex. In contrast to mutant, however, 8–9-wk-old normal males were more sensitive to copper-induced toxicity than 8–9-wk-old normal females. Adult males were also more sensitive to copper-induced toxicity than 6–8-d-old or 3–4-wk-old males. However, age-related differences in sensitivity to copper-induced toxicity did not occur significantly in normal females. These results indicate that sex- and age-related differences in the copper-induced toxicity exist inmacular mutant mice.     

Age, Growth Rates, Sex Change and Feeding Habits of Notothenioid Fish Eleginops Maclovinus from the Central-southern Chilean Coast

The róbalo, Eleginops maclovinus, a protandrous hermaphrodite species, is an important component of the ichthyofauna in the coastal areas and estuaries of southern Chile. However, there are many aspects about its life history that are unknown. Three hundred and eighty-three specimens of E. maclovinus (19–79 cm total length, TL) were collected between November 2002 and December 2003 from central-southern Chile. Marginal increment analysis from sagittal otoliths showed a single annual minimum in March, demonstrating that a single growth ring is formed each year. The growth of E. maclovinus was described by the von Bertalanffy growth model by following parameters: L _∞ = 105.4 cm TL, K = 0.08 per year, and t ₀ = −1.03 years. E. maclovinus can live for 10 years. The length and age at which the 50% of the males in the population transformed into females was estimated at ~36 cm TL and ~5-years old. A total of 27 prey items were identified. The most important prey items were the crustaceans Hemigrapsus crenulatus and Emerita analoga associated with estuarial and marine habitats respectively. Ontogenetic changes in the diet were related to the spatial distributional pattern of males (1–4 years old, in the estuary) and females (5–8 years old, in the sea). Also, diet changes are associated with the type of available prey in each habitat occupied, indicating a generalized opportunist strategy.     

Effects of mating rates on oviposition,sex ratio and longevity in a predatory mite <Emphasis Type="Italic">Neoseiulus cucumeris</Emphasis> (Acari: Phytoseiidae)

Two aspects of mating effects on the fecundity, sex ratio and longevity of Neoseiulus cucumeris (Acari: Phytoseiidae) were examined in laboratory experiments: (1) females mated by one, two or three different males (unmated and 3 days old) at 5-day intervals, and (2) females mated by males with different age/mating status (number of females mated previously by the male). Females allowed to mate with a second or third male at 5-day intervals produced 39 eggs on average, but those mated with a single male produced 28 eggs on average. Matings with additional males 5 or 10 days after the first male increased the duration of the oviposition period of these females by 5–7 days and at the same time reduced the post-oviposition period by about 10 days. Overall, females with additional matings by one or two different males at 5-day intervals survived a few days shorter than females without additional males. Mating with a different female each day, a male of N. cucumeris could mate with 5–8 females, which produced a total of 85–116 eggs: females mated with a male during days 1 and 2 in its adulthood and with a male of the last 2 days of life (days 7 and 8) produced about half as many eggs as females mated with a male during 3–6 days of its adulthood. Females mated with males that are too young or too old had a shorter oviposition period and a longer post-oviposition period and longevity than females mated with middle-aged males. In both experiments, rates of oviposition remained similar in females with high or low fecundity. This indicates that in both cases, the increased fecundity is due to the extension of the oviposition period through additional sperm supplied by the second male and or third male (in experiment 1) or more sperm by males not too young nor too old (experiment 2).     

Mutagenicity of Ascaris chymotrypsin inhibitor in germ cells of mice

Chymotrypsin inhibitor isolated from Ascaris suum (ACHI) was tested for the induction of dominant lethal mutations in male mice. Dominant lethal effects of ACHI for the main stages of germ cell development were analyzed by mating at specific time points after dosing. Two groups of adult BALB/c males received 24 or 40 mg per kilogram body weight (BW) per day intraperitoneal (IP) injection of ACHI in sterile phosphate-buffered saline (PBS) for five consecutive days (subacute exposure). Males from a third group were administered single IP injections of ACHI—60 mg/kg BW (acute exposure). The control group received concurrent injections of PBS for five successive days. After the last dose, each male was mated with two untreated females. For fractionated examination with regard to successive germ cell stages (spermatozoa, spermatids, spermatocytes, spermatogonia), every second week, two other untreated virgin females were placed with each male for mating. The uteri of the females were inspected on the 15th day of gestation, and preimplantation loss and postimplantation loss determined from dominant lethal parameters. Exposure of mice germ cells to ACHI did not impair mating activity of males. Fertility index was reduced (P < 0.05) only for females mated at the third week with males exposed to the highest dose of ACHI. In the females bred to ACHI-treated males, significant (P < 0.05) increase in preimplantation loss was observed at postinjection weeks 1 (reflecting exposure to spermatozoa after single treatment and to spermatozoa or late spermatids after subacute dosing) and 3 (reflecting exposure to mid and early spermatids for acute dosing and to mid and early spermatids or late spermatocytes following acute treatment), regardless of dose and length of exposure to the inhibitor. At the 60-mg/kg-BW group, a significant increase of this parameter was also noted at week 5 (reflecting exposure to early spermatocytes). During mating days 15–21, a significant (P < 0.05) increase in postimplantation loss and dominant lethal effects were observed for all doses of ACHI. Acute ACHI exposure 5 weeks prior to mating resulted in dominant lethal effects in early spermatocytes. These preliminary data suggest that ACHI induces dominant lethal mutations at postmeiotic and meiotic stages of spermatogenesis, but spermatids are the most sensitive cell stage to the effect of ACHI. These results show that ACHI may be one of the factors causing disturbances in spermatogenesis leading to a reduction of host reproductive success.     

Size-assortative pairing in the lotic amphipod <Emphasis Type="Italic">Gammarus zaddachi</Emphasis>, an examination of hypotheses and the influence of current speed

Three main hypotheses have been put forward to explain size-assortative pairing in gammarid amphipods: microhabitat separation, sexual selection and loading constraint. In order to determine which hypothesis best explains this phenomenon in the estuarine species Gammarus zaddachi, I first measured the body lengths and dry weights of precopula pairs collected from two field sites with substantially different current speeds. Second, I performed three laboratory experiments in order to estimate the importance of the following processes: (1) male choice; (2) male–male competition and (3) male–female acceptability. The loading constraint hypothesis seemed best supported by the data in that field-collected male G. zaddachi size correlated well with female size in precopula pairing in both fast and slow flowing water. In the laboratory, males preferred females of their same size group (large versus small), and ‘won’ them in the male–male competition experiments. Size-assortative pairing is thus likely a consequence of the loading constraints imposed upon these males by virtue of them having to carry and manoeuvre their partners through flowing water, while attempting to maintain station in an optimal microhabitat. Males may therefore forego the largest, most fecund females, in favour of a practicable payload (small male–large female pairings were rare). However, there seems to be a lower limit to this selection, indicated by the high degree of cannibalism on small females by large males.     

Exclusive core areas and intrasexual territoriality in Eurasian red squirrels (<Emphasis Type="Italic">Sciurus vulgaris</Emphasis>) revealed by incremental cluster polygon analysis

When animal home ranges overlap extensively in species lacking overt territorial behaviours, identifying exclusive core areas within individual ranges can be difficult. By analysing the size and overlap of successively smaller core areas among individual Eurasian red squirrels (Sciurus vulgaris), we determined exclusive areas within the home ranges of resident males and females. Possible effects of habitat composition and food supplies were explored by monitoring squirrels in different conifer forests and during years with low and high tree seed production. Using outlier-exclusive cores (OEC) revealed that the total ranges consisted of large sally zones (on average, 35% of the total minimum convex polygon [MCP] range) around home ranges with multi-nucleate cores. The mean OEC home range size did not differ between the sexes but was larger with poor food availability. Home ranges (99% incremental cluster polygons [ICP]) overlapped extensively between sexes (average overlap high food–low food: males by females 21–40%, females by males 43–45%) and among males (males by males 26–44%), while intrasexual overlap among females was low (9–10%). The overlap of inner cores among females rapidly approached zero, suggesting the intrasexual territoriality of 75% core areas. This was not the case among male squirrels, for which intrasexual overlap averaged only 4% at 50% but 18% at 75% core areas. Even the smallest inner cores had some degree of intersexual overlap, indicating that complete territoriality did not occur in this species. Female home ranges were more strongly affected by annual fluctuations in food supplies than male ranges. Females reduced the size of their food-based intrasexual territories when food availability increases. Males probably benefit from using larger home ranges and core areas, which overlap with the ranges of several females, by increasing their probability of successful mating.     

Temperature-dependent development of the predatory mite <Emphasis Type="Italic">Cheyletus malaccensis</Emphasis> (Acari: Cheyletidae)

The effect of temperature on the development of immature stages of the predator Cheyletus malaccensis Oudemans, produced by either fertilized or virgin females, was studied at 17.5, 20, 25, 30, 32.5, and 35°C, 80 ± 5% relative humidity, in complete darkness, and fed Tyrophagus putrescentiae (Schrank). The population maintained at 15°C failed to reproduce. The thermal data obtained were used for the estimation of the thermal requirements (developmental thresholds, thermal constant, optimum temperature) of this predator by a linear and nonlinear model (Logan type I model). Upper and lower developmental thresholds ranged between 37.4–37.8 and 11.6–12.0°C, respectively. Optimum temperature for development was estimated at between 33.1 and 33.5°C. The thermal constant ranged between 238.1 and 312.5 degree-days. Based on the data of the total pre-imaginal period, immatures’ survival peaked at 25°C. Arrhenotokous parthenogenesis (haplodiploidy) is confirmed in the species: virgin females always produce males, whereas fertilized females give rise to offspring of both sexes. Survival of the immature stages and offspring sex ratio were not significantly influenced by temperature.     

Distribution of <Emphasis Type="Italic">Calanus</Emphasis> populations in a glaciated fjord in the Arctic (Hornsund,Spitsbergen)—the interplay between biological and physical factors

The distribution and diversity of copepods of the genus Calanus were investigated in Hornsund Fjord (on the southwest coast of Spitsbergen) in summer 2001. The Bhattacharya method was used to sort individuals by species based on their prosome length. The established prosome length boundary values for the Calanus copepodid stages coincided with those defined for the Calanus species from Kongsfjorden (on the northwest coast of Spitsbergen). The predominant species in the main and inner fjord basins was Calanus glacialis, whereas Calanus finmarchicus was the prevailing species outside Hornsund. Younger copepodid stages (CI–CIII) of both species concentrated in the surface water layers (0–50∼70 m), while older copepodids (CIV–CVI females) that were ready for wintering stayed in deep layers (50∼70 m to bottom). Calanus hyperboreus was present in low numbers, predominantly as CIV, and in Hornsund deep water layers. The distribution and diversity of Calanus species complied with the notion that the marine fauna in Hornsund is of a more Arctic character than in Kongsfjorden, a fjord 260 km to the north on the west coast of Spitsbergen.