Observations on the reproductive ecology of Thalassia testudinum (Hydrocharitaceae) II. Leaf width as a secondary sex character

Short-shoots of Thalassia testudinum Banks ex König were collected from 5 sites in Florida. A total of 284, 625-cm² quadrat samples, containing 6182 shhort-shoots was analyzed for leaf width, inflorescence number and sex (the latter if determinable). Although leaf widths and reproductive densities differed at the 5 sites, leaf width was consistently greater when reproductive structures were present, and when the number of inflorescences increased. The mean number of inflorescences per short-shoot was significantly higher for shoots bearing male inflorescences compared to female shoots. Female inflorescences were normally solitary; male short-shoots usually had 2 or 3 inflorescences. Sex ratios were male-biased for 4 of the 5 sites. Comparisons of leaf widths between the sexes indicated that leaf width constituted a secondary sex character for this species. Female short-shoots tend to have narrower leaves than male short-shoots. This relationship should also be considered when evaluating the significance of morphogeographic and stress-related variation in leaf width for this species.     

Selected aspects of Lemur variegatus reproductive biology

Results from data collected during the 1978–1979 breeding season on the reproduction of Lemur variegatus at the San Diego Zoo provide information which generally supports previously published reports on this species. Comparison of selected results from these data to a larger data base of which they are a part makes it possible to resolve some of the discrepancies between reports. Certain aspects of the reproductive biology of this species may then be generally characterized with confidence: The onset of seasonal breeding as evidenced by estrous behavior begins as early as mid-December in the northern hemisphere and may continue through March; genital changes associated with estrus in females last 9.85 ± 1.67 days (± SD); female receptivity occurs 7.0 ± 1.53 days after the onset of these genital changes and lasts 12-24 hours, during which breeding occurs; gestation averages 99.47 ± 4.19 days; the peak birth season is April–May; litters normally contain two to three offspring, with full-term neonates weighing an average of 104.63 ± 19.10 grams. In addition, L variegatus appears to be highly resistant to the impact of captivity on both its reproductive physiology and behavior, as indicated by the 100% breeding success of the diversely reared and managed groups of study animals.     

Analysis of the reproductive cycle of female wild marble trout <Emphasis Type="Italic">Salmo marmoratus</Emphasis> in a prealpine brook of the Soča River basin (Northeast Italy)

The reproductive cycle of female wild marble trout Salmo marmoratus was studied in a prealpine watercourse (Northeast Italy). Gonadosomatic index, oocyte growth and plasma levels of 17β-oestradiol and testosterone were bimonthly measured during one year to obtain a detailed dataset and to gain useful tools for the identification of the reproductive stage without impact for the species. Monitored features showed significant variations during the study period: gonadosomatic index and oocyte size increased slightly but significantly during the first part of the cycle (from February to June), while steroid levels remained quite constant; for all parameters, major increases were highlighted between August and the spawning season (which occurred from the middle of November to the middle of December). Ranges and trends observed for gonadosomatic index (from 0.87 ± 0.41% to 10.91 ± 3.37%) and oocyte diameter (from 0.692 ± 0.031 mm to 4.624 ± 0.208 mm) were generally in agreement with literature regarding salmonids, while plasma levels of 17β-oestradiol (from 0.214 ± 0.015 ng ml^?1 to 78.090 ± 23.882 ng ml^?1) and testosterone (from 0.327 ± 0.086 ng ml^?1 to 71.800 ± 29.406 ng ml^?1) showed wider ranges. A strong non-linear relationship was found between oocyte size and 17β-oestradiol plasma concentration (r ² = 0.890) and especially between oocyte size and testosterone plasma concentration (r ² = 0.947). This last relationship could likely be used to obtain information relative to the gonadal development, especially in the case of an endangered species like Salmo marmoratus, which needs non-invasive tools for management.     

Floral display influences male and female reproductive success of the deceptive orchid Phaius delavayi

The influence of floral display on male and female reproductive success is variable without consistent patterns. Few studies concentrate on the integrated influence of the different components of floral display on reproductive fitness at population level. We studied the impact of different components of floral display on reproductive success in the Chinese orchid Phaius delavayi. This deceptive orchid has flowers in which male and female success can be readily assessed in the field by observing rates of pollinarium removal and fruit initiation. The results showed that mean pollinarium removal (52.05?±?2.08%) was higher than fruit set (36.78?±?1.89%), and both male and female reproductive success decreased with increasing clump size in Phaius delavayi. Nevertheless, floral display expressed by clump size and flower position impacted both female and male reproductive success, whereas flowering initiation and duration, and inflorescence size had no effect.     

Hemispheric asymmetry of the auditory evoked N100m response in relation to the crossing point between the central sulcus and Sylvian fissure

The positions of the bilateral N100m sources of the auditory evoked magnetic fields (AEFs) were measured in relation to the central sulcus (CS) using an MRI-linked whole head magnetoencephalography system in 20 right-handed normal male subjects. The location of the N20m source of the median nerve-stimulated somatosensory evoked magnetic fields (SEFs), in the left hemisphere was 3.9±5.4 mm (mean±SD) posterior to that in the right hemisphere (P<0.005). The crossing point (CP) between the CS and Sylvian fissure in the left hemisphere was 4.3±4.8 mm posterior to that in the right hemisphere (P<0.001). The N100m sources were posterior to the CP in both hemispheres. The left hemispheric N100m source was 9.4±6.4 mm posterior to that on the right (P<0.0001) in absolute position. The relative distance between CP and the N100m source was 22.7±8.5 mm in the left hemisphere and 17.7±5.3 mm in the right hemisphere (P<0.01). Comparison of positions of the AEF sources and the CS as defined by the SEF demonstrated functional asymmetry of the human temporal lobe and possible source extension of the AEF-N100m beyond the Heschl gyrus over the planum temporale.     

Batch fecundity and spawning frequency of invasive Hemiculter leucisculus (Basilewsky, 1855) in Erhai Lake,China

Hemiculter leucisculus are multiple spawners with indeterminate fecundity, although previous fecundity estimates have assumed a determinate spawning pattern. Batch fecundity and spawning frequency of H. leucisculus were studied in Erhai Lake, China, in which the fish, as an exotic species, has become a successful colonizer. Spawning frequency was 16.05 %, as determined from the percent of females with postovulatory follicles 12 to 36 h old during the peak reproductive period (from May 27 to August 8). The average interval between spawning was 6.2 days and there were more than 16 total spawning batches during the peak reproductive period. The average batch fecundity (mean ± SD) was 11,934?±?5,921 hydrated oocytes in 40 females (standard length or SL: 9.1–14.4 cm), while relative batch fecundity was 560?±?137 eggs g^?1 wet weight. The total potential annual fecundity was approximately 190,944 oocytes over the whole spawning season and was much higher than the estimated standing stock (31,585 oocytes) of yolked oocytes (36 females, SL: 9.5–16.2 cm) at the beginning of the spawning season in April 2010. This high annual fecundity is likely to have contributed to successful invasion of Erhai Lake by H. leucisculus.     

Diversity of inflorescences in the Boutelouinae subtribe (Poaceae: Chloridoideae: Cynodonteae)

The Boutelouinae subtribe is comprised of one monophyletic genus, Bouteloua, with 57 species inhabiting the semi-arid regions of the New World. The inflorescences show significant structural variations, which provides an interesting system to examine their morphological evolution and identify characters and processes that may help to understand the group systematics. The structure of inflorescences was studied in 25 species of Bouteloua. All the species covered under this study have truncated polytelic inflorescences. Structural variations in the inflorescence unit among species may be accounted for by: (1) symmetry of the inflorescence unit, (2) total number of long primary branches, (3) total number of spikelets per branch, (4) number of perfect flowers per spikelet, (5) number of rudimentary flowers, and (6) reproductive system. Homogenization and truncation processes account for the diversity of mature inflorescences that exists in Bouteloua. In this work, we discuss the systematic and taxonomic value of the inflorescence in the Boutelouinae subtribe.     

Pattern of space use by female black bears in the White River National Wildlife Refuge,Arkansas, USA

The manner in which space is used by animals may influence several aspects of biology, including the pattern of resource use and intra-specific competition. We monitored 16 radio-collared female black bears (Ursus americanus) for 9,216 radio days during 1993–1995 in the White River National Wildlife Refuge (WRNWR), Arkansas, U.S.A. to investigate space use patterns. Annual home ranges (95% convex polygon) ranged from 2.10 to 11.34 km² with a mean (± SD) size of 4.90 (± 2.09) km² (n = 16). Largest home ranges were occupied by 2 females with yearlings during one year of study. Home ranges among neighbouring bears overlapped considerably. Although bears maintained larger home ranges during summer, the size of home range did not differ among seasons (P > 0.50). Our estimates of home range size for female black bears were smaller than those obtained in a study of the same population during 1979–1982. Because the size of the bear population at WRNWR was substantially smaller (about 130 bears) during 1979–1982 compared to the present population of ≥348 bears, these results suggested that population density and size of female black bear home ranges may be negatively correlated. Conservation implications of density-dependent space use pattern are also discussed.     

Fertility in the Afrikaner cow. 2. Ovarian recovery and conception in suckled and non-suckled cows post partum

The post-partum reproductive performance of suckled and non-suckled Afrikaner cows was compared in order to assess the importance of suckling in the resumption of post-partum ovarian function in this breed. Non-suckled cows were weaned at 3 days post partum whilst calves in the control group had continuous access to their dams. Commencement of ovarian activity was significantly (P < 0.01) earlier in non-suckled cows at 18.1 ± 5.2 (mean ± SD) days post partum than in suckled cows 53.2 ± 19.7 days. Conception rates were significantly higher (P = 0.01) in non-suckled cows (80%) than in suckled cows (50%). Mean intervals from parturition to conception were 45.8 ± 15.8 (mean ± SD) days in non-suckled cows as compared with 70.9 ± 17.9 days in suckled cows. The conception rate associated with each ovulation appears to be highest between 50 and 70 days post partum regardless of the degree of suckling stimulus. Four classes of ovarian activity were recorded from the progesterone profiles compiled. The incidence of short cycles was unaffected by the degree of suckling stimulus. Weaning may (P = 0.05) reduce the proportion of cows which exhibit regular cyclic ovarian activity without conceiving. Coitus during oestrus may (0.01 < P > 0.05) be more easily observed in non-suckled cows than in their suckled contemporaries. Suckling altered the diurnal distribution of coitus, with non-suckled cows showing the highest frequency for this component of oestrus before 09.00 h and after 15.00 h, whilst in suckled cows coitus appeared to be more evenly distributed throughout the day.     

Phenology of Sargassum spp. in Tung Ping Chau Marine Park, Hong Kong SAR, China

Eight species of the brown alga Sargassum have been recorded from Tung Ping Chau Marine Park in Hong Kong and the phenology of four of these was monitored from 1996 to 2000. All four species followed a typical growth cycle of Sargassum species reported elsewhere but with some annual variations. For S. hemiphyllum, the maximum mean (±SD) plant length, ranging from 38.5 ± 10.5 to 61.9 ± 19.9 cm, was recorded in January to March. The peak reproductive season was also mainly in February to March with up to 89% of the plants being reproductive. Some plants, however, remained reproductive until May. For. S. henslowianum, the maximum mean plant length, ranging from 45.5 ± 25.5 to 77 ± 24.8 cm, was recorded mainly in November to January. The peak reproductive season was in November to February with up to 100% of the plants being reproductive. For S. siliquastrum, the maximum mean plant length, ranging from 48.2 ± 29.9 to 63.4 ± 22.1 cm, was also recorded mainly in January. The reproductive plants were found mainly between late December and mid February with up to 98% of the plants being reproductive. For. S. patens, the maximum mean plant length ranging from 87.6 ± 62.4 to 118.7 ± 41.3 cm was recorded in January to March. Reproduction of this species was not monitored. Changes in water temperature over seasons were likely to be critical in affecting the phenological patterns of these species.     

常绿阔叶树种栲树开花物候动态及花的空间配置

 基于定株观测和随机枝取样法,对浙江天童常绿阔叶林内栲树（Castanopsis fargesii）的开花物候动态及其雌花、雄花的空间配置进行了研究。结果表明：在栲树的生殖枝上,并非所有的芽都分化、萌发生成花序,栲树花芽的分化和发育集中在一级生殖枝上。生殖枝上花芽的分化与该枝的空间位置密切相关。栲树花期明显晚于春季的展叶期,与叶片生长时间重叠。盛花期集中于5月下旬,约持续8 d左右,属于同步发生的花期。栲树雄花序的数量明显高于雌花序,雄花序约占花序总数的77.88%,雌花序仅占22.12%。大量雄花和花粉的存在是保证雌花接受花粉和完成受精的基础。花序在植冠层中的空间配置明显不同：在同一植冠内,向阳面和背阴面生殖枝上芽萌发成花序的比率存在明显差异(p<0.01),阳面生殖枝上顶芽萌发成花序的比率高于阴面生殖枝的比率,并且,阳面的每个生殖枝上平均花序数和雄花数量均高于阴面生殖枝,花序的分化和发育与枝系的生长发育状况有密切关系。     

The influence of azaperone treatment at weaning on reproductive performance of sows: altering effects of season and parity

Azaperone treatment can control aggression and decrease stress due to weaning, re-grouping and hierarchical fighting of gilts and sows. However, the effects of this butyrophenone neuroleptic and sedative administered at weaning on pig reproductive function are poorly characterized. In this year-long study, a total of 619 cross-bred sows (Polish Large White×Polish Landrace) kept on a commercial farm received an i.m. injection of azaperone (Stresnil®; 2 mg/kg BW) just before weaning and were artificially inseminated during the ensuing estrus with 3×10⁹ spermatozoa per dose of an inseminate; 1180 sows served as untreated controls. Immediately after weaning, the sows were moved to four pens of seven to nine animals each. A teaser boar was used twice daily to check for estrus and sows were bred at heat detection. Subsequently, all sows stayed in individual stalls until pregnancy testing on day 30 post-artificial insemination and were then re-grouped until farrowing. The proportion of pigs that were in estrus within 6 days post-weaning was significantly lower in azaperone-treated groups of animals than in controls (71.4% v. 84.2%). Overall, the azaperone-treated sows had a significantly longer weaning-to-estrus interval (WEI; 8.7±10.1 v. 6.3±8.1 days; mean±SD) and a significantly larger litter size (LS: 11.8±3.0 v.11.3±3.2; azaperone-treated v. control sows). Treatment of the winter-farrowing sows was associated with increased LS (12.8±2.6 and 11.3±3.1 piglets/sow, respectively; P<0.05) and longer (P<0.05) weaning-to-effective-service intervals (11.7±19.3 and 8.4±12.3 days, respectively) as well as farrowing intervals (155.7±19.7 and 152.2±16.1 days, respectively) compared with untreated controls. In the summer months, significantly longer WEIs (12.1±21.0 v. 8.4±16.9 days) were accompanied by a significant decline in LS only in azaperone-treated sows that were inseminated within 6 days post-weaning (10.8±2.9 v. 11.5±3.3 piglets/sow; azaperone-treated v. controls). Azaperone-treated second parity sows had greater LS (P<0.001) along with prolonged WEIs (P<0.05) in comparison to their respective controls, regardless of the timing of estrus. An application of azaperone at weaning increased the annual piglet productivity of winter-farrowing animals and of second parity sows but depressed it significantly in summer. The extra cost and labor due to delayed onset of estrus may cancel out any reproductive benefits of azaperone treatment.     

Effects of temperature, feeding position and crop growth stage on the population dynamics of the rose grain aphid, Metopolophium dirhodum (Hemiptera: Aphididae)

The population dynamics of Metopolophium dirhodum were studied on winter wheat seedlings at constant (10°C, 15°C, 20°C, 25°C and 30°C) and fluctuating (12(night)-22(day)°C) temperatures, and during booting to early inflorescence, and anthesis to early milky ripe stage, at 19°C. The pre-reproductive development time was decreased by increasing the temperature from 10°C to 25°C. It was significantly shorter when the aphids were feeding during booting to early inflorescence than during anthesis to early milky ripe stage but was similar when the aphids were feeding on the flag, second or third leaves. The total number of nymphs produced/apterous adult was not significantly affected by temperature from 10°C to 25°C but adult reproductive lifespan was reduced by increasing temperature from 10°C and 12–22°C to 15°C, 20°C and 25°C. The daily intrinsic rate of increase changed from 0.11 to 0.25, and the cohort generation time decreased from 31 to 12 days, with increase of temperature from 10°C to 25°C. Reproductive rate was similar when the aphids were feeding on the flag, second or third leaves during booting to early inflorescence at 19°C. The reproductive rate was higher when the aphids fed from mid-inflorescence to mid-milky ripe stage than from mid-milky to early ripe stage. These results were compared with those from other studies. Predictions from a simulation model using development and reproductive rates from this study and literature were compared and the former rates resulted in a more accurate prediction of field observations in 1979, an outbreak year.     

Nesting Phenology and Clutch Characteristics of Captive Siamese Crocodiles (Crocodylus siamensis) in Cambodia

The Siamese crocodile (Crocodylus siamensis) is considered one of the least studied and most critically endangered crocodilians in the world. Although few wild populations remain, more than 700,000 C. siamensis are held on commercial crocodile farms in Southeast Asia. Despite conservation concerns, many aspects of C. siamensis life history remain poorly known, particularly with regards to its reproductive biology. We studied nesting phenology, clutch characteristics, and other aspects of C. siamensis reproductive biology on crocodile farms in Cambodia during 2000 and 2001. Oviposition among captive crocodiles began in February and continued into early June. The mean (±1 SD) oviposition date based on pooled data from 2000 and 2001 was 5 April ± 24 days. Mean oviposition date differed significantly between 2000 and 2001, possibly as a result of annual variability among nesting cues. The mean incubation period was 72 ± 3 days and eggs hatched from 5 May to 18 August. Mean clutch size (25.0 ± 8.8 eggs; n = 183) differed significantly between years, possibly resulting from the >2.5‐fold increase in sample size during 2001. There was no correlation between clutch size and oviposition date during either 2000 or 2001. A single female produced two clutches during 2001, complimenting previous reports of double‐clutching among C. siamensis. The mean length and width of 515 eggs were 78.2 ± 4.9 and 48.1 ± 2.5 mm, respectively; mean egg mass was 90.8 ± 16.5 g (n = 471). One unpipped egg contained a set of twins. Zoo Biol 31:534‐545, 2012. © 2011 Wiley Periodicals, Inc.     

荒漠植物准噶尔无叶豆结实、结籽格局及其生态适应意义

连续2a采用野外记录的方式对荒漠植物准噶尔无叶豆的结实、结籽格局进行了比较研究。结果表明:植株内花序生成格局表现为不同大小的花序在总花序中的比重与其结实率存在显著正相关,其中含有中等花数目的花序所占的比重及其结实率均最高,此种分布格局能够最大程度的保证繁殖成功;果序内果实生成格局表现为单花着生位置(从近柄端算起)与其结实量占总结实量的比例成线性负相关,花序基部的结实比例最高,顶部结实比例近为0;荚果内种子生成格局表现为:中间位置的胚珠败育率最低。另外,年际间荚果内仅有(1.08±0.03)粒和(1.07±0.03)粒种子能够完全成熟,此种结籽格局是准噶尔无叶豆保证后代质量的最佳策略。     

Ranging and parental care of the raccoon dogNyctereutes procyonoides during pup rearing

Three pairs of raccoon dogsNyctereutes procyonoides (Gray, 1834) were observed by continuous radio-tracking (one 24-h session, once a week) during the first six weeks after parturition. Males spent noticeably more time (40.5% ±11.7 SD) alone with the pups than females (16.4% ±8.5 SD). Females had noticeably larger home ranges (95% kernel: 98.24 ha ±51.71 SD) than males (14.73 ha ±8.16 SD) and moved much longer daily distances (7368 m ±2015 SD) than males (4094 m ±2886 SD) in six weeks postpartum. The raccoon dogs left the breeding den in the 6th week after the birth of the pups.In situ video observation showed that the male carried prey to the den to provide the female and the litter with food. A clear division of labour took place among parents during the period in which the pups were nursed: males guarded the litter in the den or in close vicinity of it, while the females foraged to satisfy their increased energy requirements.     

Seed characteristics and testa textures of Pratensis, Orobon, Lathyrus, Orobastrum and Cicercula sections from Lathyrus (Fabaceae) in Turkey

The seed morphologies and testa textures of 23 taxa belonging to the Pratensis, Orobon, Lathyrus, Orobastrum and Cicercula sections of Lathyrus that can widely be found in Turkey were analysed. The findings obtained in this study and previous findings (34 taxa in total) were compared and interpreted at the level of the sections. Morphological properties including seed size, general shape, surface shape, colour, hilum length and width were measured under stereomicroscopy. The seeds were of spheroidal, subprolate and prolate (P/E = 0.90–1.58) types and medium in size. The smallest seeds belonged to Lathyrus inconspicuus var. inconspicuus (P = 2.19 ± 0.25 mm, E = 2.08 ± 0.16 mm) and the largest to L. sativus (P = 5.88 ± 0.74 mm, E = 5.36 ± 0.57 mm). The smallest hilum belonged to L. inconspicuus var. stenophyllus (0.38 ± 0.04 mm) and the largest to L. sylvestris (4.50 ± 0.58 mm). Testa textures such as papillae shape, dense, ribbing and presence or absence of a waxy layer were examined using scanning electron microscopy (SEM). In addition, some photographs included in this study were taken via stereomicroscopy and SEM.     

Diet Composition and Intensity of Feeding of Tenualosa ilisha (Hamilton, 1822) Occurring in the Northern Bay of Bengal,India

Feeding intensity and diet composition of Hilsa Shad (Tenualosa ilisha) from Northern Bay of Bengal were studied between June 2010 and March 2011. The stomach contents of 320 fishes were analyzed from the northern part of the Bay of Bengal to understand the food items of this species. The major constituents of food are organic debris (26.06 ± 5.19 % SD), diatoms (31.22 ± 11.97 % SD), other algae (12.41 ± 2.62 % SD), and crustaceans (3.50 ± 1.28 % SD). The most abundant species of diatoms were Coscinodiscus, Pleurosigma, Bacillaria, Nitzschia, Biddulphia, Diatoma and Asterionella. The stomach of Hilsa was found to be almost empty during June to October while it was almost full during November to March. Significant positive correlation among feeding intensity, chlorophyll-A concentration and salinity of the ambient water indicated that feeding in T. ilisha is influenced by a number of factors. Strong positive correlation between percentage occurrence of diatoms and intensity of feeding indicated their preference for diatom–food.     

Morphological study of the reproductive system and ovarian growth of the univoltine bamboo borer,Omphisa fuscidentalis (Hampson, 1896) (Lepidoptera: Crambidae)

ABSTRACT

The female reproductive system and protein deposition in the ovaries during development have never been examined in the bamboo borer Omphisa fuscidentalis Hampson. The aim of this study was thus to study the morphology of the female reproductive system of each stage of development. The female reproductive system of the borer consists of a pair of ovary, oviduct and accessory glands. Each ovary is composed of four polytrophic ovarioles that connect to lateral oviducts, fused with a common oviduct. The size of the ovary in diapausing larvae for 9 months was determined. The length and width of the ovaries were the smallest in September larvae (0.343 ± 0.03 and 0.071 ± 0.01 mm, respectively). The ovaries were the largest during ovarian development in May (0.752 ± 0.08 mm long and 0.084 ± 0.01 wide). Additionally, ovarian size was significantly larger in adults than in pupae. The ovarian protein concentration of larvae in May was 0.59 ± 0.06 mg/ml and increased to 16.61 ± 7.5 and 37.42 ± 5.5 mg/ml in pupae (June) and adults (July), respectively. The results showed ovarian development in all life stages of this holometabolous insect, which has a longer life cycle than other lepidopterans.

Abbreviation: TEM: transmission electron microscope