Associations between gelatinous zooplankton and hyperiid amphipods (Crustacea: Peracarida) in the Gulf of California

Hyperiid amphipods are pelagic crustaceans that live associated with gelatinous zooplankton including medusae, ctenophores, siphonophores, and salps. Standard plankton sampling disrupts natural associations, so the most reliable way to determine an association is through direct observation of the organisms in their environment. The planktonic fauna of the Gulf of California dwelling between 10 and 3000 m was surveyed using SCUBA diving and a remotely operated submersible (ROV) during March 2003. Here we report our observations on a total of 14 symbiotic associations found between the hyperiid amphipods and various taxa of gelatinous zooplankton. We found parental care behavior in a group of amphipods (Oxycephalidae) in which this phenomenon has not been previously reported. For two hyperiid species, Euthamneus rostratus and Vibilia australis, we present the first information on their symbiotic relations. Additional hosts were discovered for other well-known and widely distributed hyperiid species (i.e. Brachyscelus crusculum, Hyperoche medusarum). Photographic evidence of some of these interactions is included in this contribution. This is the first survey of these relationships in the Gulf of California, and many aspects of the ecology and biology of these symbioses remain to be studied.     

A review of cnidarians and ctenophores feeding on competitors in the plankton

Predation among pelagic cnidarians and ctenophores is reviewed. The diets of semaeostome scyphomedusae and hydromedusae commonly include other gelatinous zooplanktivores. However, few species of siphonophores and ctenophores are known to consume other gelatinous species. Most of these species can be said to exhibit intraguild predation, since they consume species that potentially compete with them for food. In addition, some hydromedusan and ctenophore species may consume other gelatinous zooplanktivores exclusively. Characteristics of cnidarians and ctenophores as predators and as prey of other gelatinous species are discussed.     

长江口及邻近海域浮游水螅水母、管水母和栉水母的丰度分布与季节变化

依据2002—2003年长江口及邻近海域(29°00'—32°00'N、122°00—123°30'E)4个季节的海洋调查资料,探讨了该水域小型水母(含水螅水母、管水母和栉水母)总丰度的空间分布特征及季节差异。结果显示,该海域共出现小型水母41种,其中水螅水母28种,管水螅11种,栉水母2种。主要优势种包括管水母大西洋五角水母(Muggiaea atlantica)、双生水母(Diphyes chamissonis)和气囊水母(Physophora hydrostatica)以及水螅水母四叶小舌水母(Liriope tetraphylla)、两手筐水母(Solmundella bitentaculata)和短柄和平水母(Eirene brevistylus),其中大西洋五角水母为冬、春季第一优势种,双生水母则为夏、秋季第一优势种。该水域小型水母总丰度呈明显季节差异,夏季丰度最高((337.33±55.68)个/m~2),春、秋季次之(分别为(142.09±67.71)个/m~2和(132.84±35.17)个/m~2),冬季最低((113.69±32.72)个/m~2)。水温是影响调查区小型水母总丰度季节变化的主要环境因子,小型水母丰度与表层温度显著正相关(P0.01)。盐度是影响小型水母平面分布格局的主要环境因子,春季小型水母丰度与底层盐度正相关(P0.05),夏季与10 m层盐度正相关(P0.01),全年则是与10 m层盐度正相关(P0.01)。此外,调查水域小型水母丰度与其饵料——小型桡足类亦存在显著正相关关系(P0.01)。     

Keratodont formulae in anuran tadpoles: proposals for a standardization1

The various systems proposed to describe concisely, in the form of a formula, the number and arrangement of keratodont rows in the oral disk of anuran tadpoles, are reviewed and classified. A distinction is made between individual and collective keratodont formulae. The different systems are compared and evaluated, and proposals are made to standardize the use of various signs, numerals and letters in keratodont formulae. Nine standardized systems (seven all-cardinal and two cardinal-ordinal systems) are finally retained: these should cover all needs according to the kind of use and the level of precision required.     

前额蚤灰獭亚种幼虫形态的描述

本文对前额蚤灰獭亚种Frontopsylla frontalis baibacina Ji, 1979的幼虫形态进行了描述,并与同属似升额蚤介中亚种和无棘鬃额蚤的幼虫形态作了比较,其结果有共同点也有异点。     

Keratodont formulae in anuran tadpoles: proposals for a standardization

The various systems proposed to describe concisely, in the form of a formula, the number and arrangement of keratodont rows in the oral disk of anuran tadpoles, are reviewed and classified. A distinction is made between individual and collective keratodont formulae. The different systems are compared and evaluated, and proposals are made to standardize the use of various signs, numerals and letters in keratodont formulae. Nine standardized systems (seven all-cardinal and two cardinal-ordinal systems) are finally retained: these should cover all needs according to the kind of use and the level of precision required.     

Protistan epibionts of the ctenophore Mnemiopsis mccradyi Mayer

Mnemiopsis mccradyi, a common coastal ctenophore, was observed to bear two distinct, exclusive assemblages of protistan epibionts. The mobiline peritrich, Trichodina ctenophorii (Estes et al., 1997), and small Flabellula-like gymnamoebae inhabited only the surface of the comb plates. By contrast, small Vexillifera-like gymnamoebae and large Protoodinium-like dinoflagellates were found on the ectoderm. The relationship of the epimicrobial protists with their host varied from possible mutualism (vexilliferids) to commensalism (trichodinids) to parasitism (flabellulids and protoodinids). Trichodinids may benefit from comb plate attachment by enhanced food capture. Although they did not obviously impair comb plate beating, they did distort the surface and appear to produce fissures in the comb plate surface, which could provide inroads for more severe comb plate damage by amoebae. By contrast, when flabellulid amoebae occurred in very high surface densities (up to 5000 mm^–2), they clearly damaged comb plates by eroding the surface. Where flabellulid pseudopodia invaded the comb plate, we observed local degradation of comb plate cilia, as evidenced by central pair disorientation and plasma membrane perturbation and overt phagocytosis of comb plate cilia. Ectodermal vexilliferids, which occurred at much lower densities, did not appear to have any degradative impact on the ctenophore. By contrast, clusters of ectodermal protoodinids were found in localized depressions most likely caused by invasive phagocytosis. The impact of the protistan assemblages on ctenophore populations is unclear, but under conditions of severe infestation they might depress ctenophore population density.     

Isolation and Identification of the Characteristic Sweet-aroma Compounds in Refinery Final Molasses

The characteristic sweet-aroma components in refinery final molasses were isolated by using a combination of sensory evaluation, column chromatography and gas chromatography, and were identified by infrared spectrometry, mass spectrometry and color reactions. Identified were ethyl n-hexanoate, ethyl phenylacetate, phenylacetic acid, n-butyl benzoate, isopropyl benzoate, l(+)-pantolactone, benzoic acid, o-toluic acid, m-toluic acid, β-phenylpropionic acid, succinic anhydride, maltol, isomaltol, and 2-methyl-5-hydroxy-6-ethyl-γ-pyrone.

The aroma of the mixture of these compounds and vanillin and vanillic acid was similar to that of refinery molasses by sensory evaluation. The results indicate that these compounds are important in producing of sweet molasses aroma.     

Comparative reproduction of <Emphasis Type="Italic">Varroa destructor</Emphasis> in different types of Russian and Italian honey bee combs

Earlier studies showed that Russian honey bees support slow growth of varroa mite population. We studied whether or not comb type influenced varroa reproduction in both Russian and Italian honey bees, and whether Russian bees produced comb which inhibited varroa reproduction. The major differences found in this study concerned honey bee type. Overall, the Russian honey bees had lower (2.44 ± 0.18%) levels of varroa infestation than Italian honey bees (7.20 ± 0.60%). This decreased infestation resulted in part from a reduced number of viable female offspring per foundress in the Russian (0.85 ± 0.04 female) compared to the Italian (1.23 ± 0.04 females) honey bee colonies. In addition, there was an effect by the comb built by the Russian honey bee colonies that reduced varroa reproduction. When comparing combs having Russian or Italian colony origins, Russian honey bee colonies had more non-reproducing foundress mites and fewer viable female offspring in Russian honey bee comb. This difference did not occur in Italian colonies. The age of comb in this study had mixed effects. Older comb produced similar responses for six of the seven varroa infestation parameters measured. In colonies of Italian honey bees, the older comb (2001 dark) had fewer (1.13 ± 0.07 females) viable female offspring per foundress than were found in the 2002 new (1.21 ± 0.06 females) and 1980s new (1.36 ± 0.08 females) combs. This difference did not occur with Russian honey bee colonies where the number of viable female offspring was low in all three types of combs. This study suggests that honey bee type largely influences growth of varroa mite population in a colony.     

白蚁菌圃真菌多样性研究进展

白蚁菌圃存在于白蚁巢中,具有硬而脆的多孔结构,是特殊的真菌生存环境。当有白蚁在白蚁巢内活动时,蚁巢伞Termitomyces是菌圃上的优势菌;当白蚁巢被废弃,炭角菌Xylaria成为菌圃上的优势真菌。菌圃中还存在其他微生物如无性型真菌（anamorphic fungi）和酵母等。菌圃中的真菌很多具有潜在药用价值或其他经济价值。从蚁巢伞、炭角菌等主要真菌类群出发,结合分子生态学研究菌圃真菌多样性的方法,综述了白蚁菌圃真菌多样性的研究进展,揭示了目前的研究热点及存在的问题,并针对这些问题提出可能的发展方向。     

唇腭裂矫形修复中的美学研究

本文介绍用双重牙列修复唇腭裂患者面中1/3缺陷,其特点是方法简便、效果明显和患者乐意接受。并提出评判唇腭裂患者的面容面貌改善不能单纯以正常美貌人群中面部指数为标准,而应在介于正常人与唇腭裂患者之间寻找一个能协调、柔和、均衡、匀称的面部指娄作为评判标准。     

Does male secondary sexual trait size reveal fertilization efficiency in Australian Drosophila bipectinata Duda (Diptera: Drosophilidae)?

Males developing relatively large, costly sexually selected traits may be of superior body condition compared to small-ornamented males. Thus, males developing the largest secondary sexual trait in a given environment may also be able to augment their investment into ejaculate quality, and fertilize a larger proportion of a female's eggs. We tested the prediction that the degree of expression of a condition-dependent secondary sexual trait, the male sex comb, in a Cape Tribulation (northeastern Australia) population of Drosophila bipectinata Duda, reveals male ability to fertilize eggs in the absence of sperm competition. This test permitted us also to evaluate whether pre-copulatory sexual selection and fertilization efficiency might act additively to influence male reproductive success because a previous study of the same population demonstrated a positive association between comb size and copulation probability. The results obtained indicate that, although genotypes developing smaller sex combs collectively had a significantly higher rate of insemination failure compared to larger comb genotypes, the hatch rate and the number of eggs laid by females inseminated by the two genotypic categories were not statistically different. The results fail to support the prediction that comb size reveals noncompetitive fertilization efficiency of males in this Australian population.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 406–413.