A note on the breeding season of three ascidians on coral reefs at Galeta in the Caribbean Sea

Three Caribbean ascidians were sampled from April, 1972 until June, 1973 and the breeding season determined by the presence of larvae in the colonies. In Eudistoma sp. A, larvae occurred from early June until mid-November, in Trididemnum solidum from mid-June until the end of December, and in Didemnum sp. C, throughout the year with occasional interruptions.     

REACH SCALE HYDRAULIC ASSESSMENT OF INSTREAM SALMONID HABITAT RESTORATION1

ABSTRACT: This study investigates the use of a two‐dimensional hydrodynamic model (River2D) for an assessment of the effects of instream large woody debris and rock groyne habitat structures. The bathymetry of a study reach (a side channel of the Chilliwack River located in southwestern British Columbia) was surveyed after the installation of 11 instream restoration structures. A digital elevation model was developed and used with a hydrodynamic model to predict local velocity, depth, scour, and habitat characteristics. The channel was resurveyed after the fall high‐flow season during which a bankfull event occurred. Pre‐flood and post‐flood bathymetry pool distributions were compared. Measured scour was compared to predicted shear and pre‐flood and post‐flood fish habitat indices for coho salmon (Oncorhynchus kisutch) and steelhead trout (O. mykiss) were compared. Two‐dimensional flow model velocity and depth predictions compare favorably to measured field values with mean standard errors of 24 percent and 6 percent, respectively, while areas of predicted high shear coincide with the newly formed pool locations. At high flows, the fish habitat index used (weighted usable area) increased by 150 percent to 210 percent. The application of the hydrodynamic model indicated a net habitat benefit from the restoration activities and provides a means of assessing and optimizing planned works.     

Intraspecific variation of testis size and sperm length in the yellow-pine chipmunk (<Emphasis Type="Italic">Tamias amoenus</Emphasis>): implications for sperm competition and reproductive success

Comparative analyses have found that relative testis size is a strong predictor of the prevalence of sperm competition for many taxa, including mammals, yet underlying this pattern is the assumption that intraspecific variation in testis size is related to individual fitness. Because intraspecific variation in ejaculate investment underlies interspecific patterns, it is critical to understand the causes and consequences of intraspecific variation in ejaculate investment. We examined relationships between ejaculate investment (testis size and sperm length) and reproductive success, body size and condition in the yellow-pine chipmunk (Tamias amoenus), a small ground squirrel in which sperm competition occurs. We examined genetic estimates of male reproductive success from a wild population of yellow-pine chipmunks and determined that males with large testes had higher annual reproductive success than males with small testes. This result provides empirical support for the numerous comparative studies that indicate testis size is associated with the intensity of sperm competition. In addition, males in good condition had relatively larger testes than males in poor condition, but there was no evidence of sperm length being dependent on condition. Finally, contrary to many predictions, males that invested more in sperm production (relatively heavy testes) produced shorter sperm, not longer sperm, than males that invested less.Communicated by P.M. Kappeler     

(<Emphasis Type="Italic">Z,Z</Emphasis>)-11,13-Hexadecadienyl acetate and (<Emphasis Type="Italic">Z,E</Emphasis>)-11,13,15-hexadecatrienyl acetate: synergistic sex pheromone components of oak processionary moth,Thaumetopoea processionea (Lepidoptera: Thaumetopoeidae)

Summary. Our objective was to identify sex pheromone components of the oak processionary moth, Thaumetopoea processionea (Lepidoptera: Thaumetopoeidae), whose larvae defoliate oak, Quercus spp., forests in Eurasia and impact human health. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of pheromone gland extract of female T. processionea revealed two consistently EAD-active compounds. They were identified as (Z,Z)-11,13-hexadecadienyl acetate (Z11,Z13-16:OAc) and (Z,E)-11,13,15-hexadecatrienyl acetate (Z11,E13,15-16:OAc) by comparative GC, GC-MS and GC-EAD analyses of insect-produced compounds and authentic standards. In replicated field experiments (2000, 2001) in Nordbaden, Südbaden and Sachsen-Anhalt (Germany), Z11,Z13-16:OAc and Z11,E13,15-16:OAc in combination, but not singly, attracted significant numbers of male moths. It will now be intriguing to investigate whether Z11,E13,15-16:OAc, or its corresponding alcohol or aldehyde, serves as a pheromone component also in other species of the Thaumetopoeidae.     

Aggressive chemical mimicry of moth pheromones by a bolas spider: how does this specialist predator attract more than one species of prey?

Summary. The bolas spider, Mastophora hutchinsoni, attracts Lacinipolia renigera and Tetanolita mynesalis males by mimicking the female moth sex pheromones. However, as the prey species use completely different pheromone blends we conducted experiments to determine how this is accomplished by the predator. The periodicity of L. renigera mate-seeking activities occurs early in the scotophase, whereas male T. mynesalis are active late at night, corresponding with periods when these moths are captured by the spider. The pheromone blend of early-flying L. renigera interferes with attraction of late-flying T. mynesalis to its pheromone in a dose-dependent manner, suggesting the spider must always produce a single sub-optimal “compromise” blend for both species or that it adjusts its allomonal blend to optimize capture of the respective prey species at different times during the night. We delayed (L. renigera) or advanced (T. mynesalis) the periodicity of male activity through photoperiodic manipulation and found that the bolas spider attracted both prey species outside their normal activity windows. These results support the idea that bolas spiders produce components of both species at all times rather than producing the pheromone of each prey species at different times of the night. However, using coupled gas chromatography-electroantennography, we also demonstrated that the spider decreases its emission of the L. renigera pheromone over the course of the night. This modification should reduce the behavioral antagonism of the L. renigera pheromone on T. mynesalis males and increase the predator's success of attracting T. mynesalis during this prey's normal activity window late at night. Received 13 October 2001; accepted 28 December 2001.     

(<Emphasis Type="Italic">Z</Emphasis>)-9-Pentacosene − contact sex pheromone of the locust borer, <Emphasis Type="Italic">Megacyllene robiniae</Emphasis>

Summary. Male locust borers, Megacyllene robiniae (Förster), responded to females only after contacting them with their antennae, indicating that mate recognition was mediated by a contact sex pheromone. GC-MS analyses of whole-body extracts of males and females determined that the profiles of compounds in the extracts were qualitatively similar, but differed considerably in the ratios of compounds between sexes. Biological activities of reconstructed blends of the most abundant straight-chain (nC₂₃, nC₂₄, nC₂₅, nC₂₆), methyl-branched (3me-C₂₃, 3me-C₂₅), and unsaturated (Z9:C₂₃, Z9:C₂₅, Z9:C₂₇ compounds in extracts from females were assessed in arena bioassays, assessing four distinct steps in the mating behavior sequence of males (orientation, arrestment, body alignment, mounting and attempting to couple the genitalia). Males were unresponsive to freeze-killed, solventwashed females treated with blends of straight-chain and methyl-branched alkanes, but responded strongly to females treated with the blend of alkenes. Further trials determined that the complete sequence of mating behaviors, up to and including coupling the genitalia, was elicited by Z9:C₂₅ alone. Z9:C₂₅ comprised 16.4 ± 1.3% of the total hydrocarbons in whole-body hexane extracts of females and was co-dominant with two other hydrocarbons that were not active. In contrast, in solid phase microextraction (SPME) wipe samples from several areas of the cuticle, Z9:C₂₅ appeared as the single dominant peak, comprising 34.6 – 37.8% of the sampled hydrocarbons. Our data indicate that Z9:C₂₅ is a contact sex pheromone of M. robiniae, being the most abundant hydrocarbon on the surface of the cuticular wax layer of females where it is readily accessible to the antennae of males.     

Phosphogypsum stabilization of bauxite residue: Conversion of its alkaline characteristics

Reduction of the high alkalinity of bauxite residue is a key problem to solve to make it suitable for plant growth and comprehensive utilization. In this study, phosphogypsum, a waste product from the phosphate fertilizer industry, was used to drive the alkaline transformation of the bauxite residue. Under optimal water washing conditions(liquid/solid ratio of 2 mL/g, 30°C, 24 hr), the impact of quantity added, reaction time and reaction mechanism during phosphogypsum application were investigated. Phosphogypsum addition effectively lowered p H levels and reduced the soluble alkalinity by 92.2%. It was found that the concentration of soluble Na and Ca ions in the supernatant increased gradually, whilst the exchangeable Na+and Ca~(2+)in solid phase changed 112 mg/kg and 259 mg/kg, respectively. Ca~(2+)became the dominant element in the solid phase(phosphogypsum addition of 2%, liquid/solid ratio of 2 mL/g, 30°C, 12 hr). X-ray diffraction data indicated that cancrinite and hydrogarnet were the primary alkaline minerals. SEM images suggested that phosphogypsum could promote the formation of stable macroaggregates, whilst the content of Ca~(2+)increased from 5.6% to 18.2% and Na reduced from 6.8% to 2.4%. Treatment with phosphogypsum could significantly promote the transformation of alkalinity cations by neutralization, precipitation and replacement reactions.This research provided a feasible method to promote soil formation of bauxite residue by phosphogypsum amendment.     

畜禽源氨气排放因子估算方法研究

畜禽养殖过程中产生的氨气(NH_3)在人为源NH_3排放中所占的比重较大,对二次气溶胶的形成起重要作用.由于我国畜禽饲养品种多样,各地气候条件和饲养规模存在较大差异,且影响NH_3排放的因素复杂多变,因此,获得准确的畜禽NH_3排放因子较为困难.本文以山西省太原市及其周边地区典型猪场、鸡场、牛场、羊场为实验场所,以杜洛克猪与长白猪的杂交猪、海兰褐蛋鸡、白羽肉鸡、杜泊羊与晋中绵羊的杂交羊、中国黑白花奶牛、金色阿奎丹与西门塔尔杂交肉牛为研究对象,通过3种方法估算它们的NH_3排放因子.结果表明:基于日粮成分和氮代谢沉积率的粗蛋白估算法过程简单、计算便捷、适合所有种类的畜禽,但未考虑NH_3挥发过程中的吸收转化及施肥利用,因而误差较大;基于排泄物含氮率和NH_3挥发率的物质流法涉及粪肥管理的不同阶段,全面考虑了NH_3产生、损失的全过程,与实际情况接近,但参数较多、周期较长、计算过程复杂;基于畜禽舍内NH_3浓度的直接测量法数据来源可靠、参数少,但只能用于相对封闭的环境,不适合牛场和羊场等敞开或半敞开的圈舍,且该方法没有考虑粪尿离开畜禽舍以后的储藏、还田过程,计算结果偏小.通过3种方法的互相印证和比对,猪、奶牛、肉牛、羊、蛋鸡、肉鸡6种实验动物的NH_3排放因子分别为6.90、36.53、22.99、3.94、0.54、0.46 kg·头(只)~(-1)·a~(-1).本研究可以为我国畜禽源NH_3排放因子的本地化测定提供一定的参考,并为准确估算畜禽NH_3排放量、做好农业源NH_3排放清单编制和污染防治工作提供参考.