Uptake of DOM by Nemertean Worms: Association of Worms with Arthrodial Membranes

SYNOPSIS. Carcinonemertes errans is a nemertean worm, the juvenilesof which are found as epibionts on the Dungeness crab, Cancermagister, in close association with the arthrodial membranesof the crabs. The juvenile nemerteans appear to have no meansof taking in particulate food but survive for many months onthe surface of the host. We show that the juvenile C. erransare capable of removing amino acids from dilute solution insea water, that the water near the arthrodial membranes wherethe worms are found contains high concentrations of primaryamines, and that there is a low resistance pathway for low molecularweight amino acids across the arthrodial membrane examined invitro.     

Shell characters and taxonomy of Latirus and related fasciolariid groups

The neogastropod family Fasciolariidae contains a complex ofgenera related to Latirus Montfort, 1810, many of which havetraits unusual for the family. In a taxonomic revision of someof these genera, based on shell characters, we restrict Latirusto a mainly Indo-West Pacific group of Pliocene to Recent species,which closely resemble the middle Miocene to Recent pantropicalgenus Hemipolygona Rovereto, 1899. Hemipolygona stenomphalus(Habe & Kosuge, 1966) is synonymized with H. recurvirostris(Schubert & Wagner, 1829). Lathyropsis Oostingh, 1939, basedon a small Pliocene species from Indonesia, is here tentativelysubsumed under Polygona Schumacher, 1817. The latter genus,ranging from the late Oligocene to Recent, occurs mainly inthe New World and eastern Atlantic, and contains at least twospecies groups centered on P. infundibulum Schumacher, 1817(type of genus) and P. angulatus (Röding, 1798). Taxa assignedby many authors to Latirulus Cossmann, 1889, are here reassignedto the new genus Turrilatirus (type species: Voluta turritaGmelin, 1791), from the Pliocene to Recent of the Indo-WestPacific. Latirulus is restricted to Eocene species. We assignvarious early Miocene to Recent species from the western Atlanticand eastern Pacific to the new genus Pustulatirus (type species:Latirus mediamericanus, Hertlein & Strong, 1951a). Taxaformerly assigned to Latirus but here removed from Fasciolariidaeinclude Latirus ewekoroensis Adegoke, 1977; the Eocene RusculaCasey, 1904; Lathyrus granifer and L. compactilis, both of Martin,1931; Latirus kirbyi Clark, 1938; Latirus tortilis var. nanafaliusHarris, 1899; and Latirus quercotillaensis Olsson, 1931. (Received 6 September 2005; accepted 29 May 2006)     

Ecdysteroids in nemerteans: Presence and physiological role

Ecdysteroids were detected in the phylum Nemertea and their physiological role was studied. Radioimmunoassay (RIA) measurements showed ecdysteroid concentrations ranging from 1–47 pg/mg wet weight in several nemertean species from the orders Palaeonemertea, Heteronemertea, and Hoplonemertea. High-performance liquid chromatographic (HPLC) analysis of Paranemertes peregrina displayed peaks of RIA activity with retention times similar to those of authentic ecdysone and 20-hydroxyecdysone standards. Fluctuating ecdysteroid titers were observed in the various life stages of Carcinonemertes errans with the highest concentrations (47 pg/mg wet weight) found in gravid females. RIA of HPLC fractions of Carcinonemertes errans eggs indicated the presence of ecdysteroids (105 pg/mg wet weight). Alterations in the growth of juvenile, male, or female C. errans were not observed when the worms were exposed to 10^–7. 10^–6, or 10^–5 M 20-hydroxyecdysone. However, the eggs of C. errans appeared to be stimulated by 20-hydroxyecdysone. Shorter hatching times were observed in the egg strings exposed to hormone (10^–7 to 10^–5 M) compared to sea water and cholesterol (10^–11 and 10^–9 M) controls. Possible physiological roles and the evolutionary significance of ecdysteroids in nemerteans are discussed.     

Recent bivalve molluscs of the genus Calyptogena (Vesicomyidae)

The genus Calyptogena (Bivalvia: Vesicomyidae) comprises highlyspecialized bivalves living in symbiosis with sulphur-oxidizingbacteria in reducing habitats. In this study, the genus is revisedusing shell and anatomical features. The work is based on typematerial, as well as on the extensive collection of vesicomyidsobtained during twelve expeditions to the Pacific and IndianOceans. Nine Recent species are ascribed to the genus Calyptogena,four of which are new: C. pacifica Dall, 1891, C. fausta Okutani,Fujikura & Hashimoto, 1993, C. rectimargo Scarlato, 1981,C. valdiviae (Thiele & Jaeckel, 1931), C. gallardoi Sellanes& Krylova, 2005, C. goffrediae n. sp., C. starobogatovin. sp., C. makranensis n. sp. and C. costaricana n. sp. Thecharacteristic features of Calyptogena are: shell up to 90 mmin length, elongate-elliptical or elongate; presence of escutcheon;presence of broad posterior ramus (3b) of right subumbonal cardinaltooth as well as right posterior nymphal ridge; absence of pallialsinus as a result of attachment of intersiphonal septal retractorimmediately adjacent to ventral surface of posterior adductor;absence of processes on inner vulva of inhalant siphon; presenceof inner demibranch only, with descending and ascending lamellaewith interlamellar septa not divided into separate tubes. Themost closely related taxa to Calyptogena are probably the genusIsorropodon Sturany, 1896, and the group of species representedby ‘Calyptogena’ phaseoliformis Métivier,Okutani & Ohta, 1986. These groups have several charactersin common, namely absence of pallial sinus, presence of singleinner pair of demibranchs and absence of processes on innervulva of inhalant siphon. The worldwide distribution of thegenus Calyptogena suggests that methane seeps at continentalmargins are the major dispersal routes and that speciation waspromoted by geographical isolation. Recent species diversityand fossil records indicate that the genus originated in thePacific Ocean. Sufficient data to discuss the distribution atspecies level exist only for C. pacifica, which has a remarkablynarrow bathymetric range. Published studies on the physiologyof C. pacifica suggest that adaptation to a specific geochemicalenvironment has led to coexisting vesicomyid genera. The bacteria-containinggill of C. pacifica and other Calyptogena species is one ofthe most specialized in the family Vesicomyidae and may reflectthese ecological adaptations. (Received 23 December 2005; accepted 3 April 2006)     

Carcinonemertes pinnotheridophila sp. nov. (Nemertea,Enopla, Carcinonemertidae) from the branchial chambers of Pinnixa chaetopterana (Crustacea,Decapoda, Pinnotheridae): description,incidence and biological relationships with the host

A new species of Carcinonemertes, C. pinnotheridophila, is described and illustrated. The worms were found in the pinnotherid crab Pinnixa chaetopterana collected from the coasts of New Jersey, North Carolina and Florida. The anatomy of the new species is compared and contrasted with that of other members of the genus Carcinonemertes and an emended generic diagnosis is provided. The nemerteans only inhabit female hosts, crabs being infested with one or two mature female worms but with no more than one ensheathed in each branchial chamber; one or more smaller male nemerteans may be associated with each female. Sheaths are attached to the medial portion of the host branchial exoskeleton, and project through an opening in the floor of the chamber to exit via another aperture in the sternum; the anterior part of the sheath opens in the excurrent canal of the branchial chamber. Female worms cement their oval egg sacs on the pleopods to which the crab's eggs are also attached. Attachment, development and hatching of both host and symbiont eggs are synchronous. The incidence of infestation, reproductive potential of the nemertean, damage to its host and tolerance of the crab's growth cycles are described.     

不同生境源的稻飞虱卵寄生蜂对寄主的选择和寄生特眭

稻飞虱重要卵寄生蜂缨小蜂Anagrus flaveolus、A optabilis和寡索赤眼蜂Oligosita aesopi、O.Naias均能在稻田和稻田周围的非稻田生境中生存。而.Ftaveolus为优势种。不同生境来源的卵寄生蜂有着不同的寄生和选择特性。缨小蜂A.Flaveolus能在飞虱科内转换寄主,但需1～2代的适应期。寄主卵对寡索赤眼蜂O.Aesopi的寄生有较大的影响,用褐飞虱和黑尾叶蝉诱集的O.Aesopi呼;不能交叉寄生。稻田内诱集的寄生蜂选择稻飞虱,而杂草地中诱集的缨小蜂则对飞虱T.Pusanus有一定的选择性。非稻田生境对保护稻飞虱卵寄生蜂有很大的作用,但对其寄生特性有较大的影响。     

松毛虫卵期几种寄生蜂的共寄生现象及其对寄生率的影响

松毛虫赤跟蜂 Trichogramma dendrolimi Matsumura 白跗平腹Pseudanastatusalbitarsis Ashmead松毛虫宽缘金小蜂Pachyneuron olitarium(Harig), 松毛虫黑卵蜂 Telenomus dendrolimusi Chu和大蛾卵跳小蜂Ooenvyrtus Kuwanae(Howard)是松毛虫卵期几种主要寄生蜂。通过对上述几种寄生蜂寄生习性的研究表明：赤眼蜂和平腹小蜂不但能寄生新鲜害虫卵,还可以寄生对方已寄生并巳发育1-3天的寄生卵,但羽化串均不高;松毛虫宽缘金小蜂不寄生新鲜害虫卵,专门寄生赤眼蜂寄生后巳发育1-7,天的寄生卵,其中又以赤眼蜂发育3-5天的卵寄生串和羽化率为最高。除赤眼蜂和平腹小蜂可以混合使用外,其它蜂种混用都不同程度地存在相互排挤的现象。如果先让平腹小蜂寄生尔后再让赤眼蜂寄生或先让赤眼蜂寄生,尔后再让跳小蜂或黑卵蜂寄生,能够提高卵块寄生串和充分发挥各自天敌的作用。     

A new genus and species of monostiliferoidean nemertean (Nemertea: Enopla) found on an egg mass of the anomuran decapod Paralithodes camtschatica

A new genus and species of monostiliferoidean enoplan nemertean from Alaska is described and illustrated. The nemertean, Alaxinus oclairi gen. et sp. nov. , was found on the egg mass of a red king crab, Paralithodes camtschatica.     

双斑截尾寄蝇对寄主种类及草地螟幼虫龄期和寄生部位的选择性

双斑截尾寄蝇Nemorilla maculosa Meigen是草地螟和其他鳞翅类昆虫的重要寄生天敌,但国内外对其寄生行为知之甚少。为了明确双斑截尾寄蝇的寄生行为特征及其对草地螟种群动态的影响,在22℃,光照16 h的条件下就其对不同寄主种类及草地螟幼虫龄期、寄主部位的选择性进行了研究。结果显示：在草地螟、甜菜夜蛾和粘虫3种幼虫同时存在的条件下,双斑截尾寄蝇对草地螟的寄生率显著高于甜菜夜蛾和粘虫,而对甜菜夜蛾的寄生率又显著高于粘虫。另外,幼虫被寄生的平均次数也呈现相同的趋势,表明双斑截尾寄蝇喜选择草地螟。在3, 4, 5龄草地螟幼虫同时存在时,双斑截尾寄蝇对5龄幼虫的寄生率和平均寄生次数均显著高于4龄和3龄幼虫的,表明该寄蝇主要选择5龄幼虫为其寄主。在被寄生的草地螟幼虫中,胸部被寄生的比率（66.4%）和次数（4.2）显著高于头部（23.4%,1.0）和腹部（10.9%,1.1）,而腹部及头部被寄生的比例及卵粒数没有显著差异,表明双斑截尾寄蝇主要选择幼虫的胸部进行寄生。最后,就双斑截尾寄蝇对产卵寄主选择的原因和机理进行了讨论。     

远东地区影响针叶树天然更新的球果种实害虫——球果花蝇（双翅目：花蝇科）

球果花蝇是远东地区的重要球果种实害虫。尤其是在我国东北地区,由于球果花蝇的危害已严重影响了落叶松种子产量,进而影响到落叶松的造林与更新。本文系统地总结了近些年危害落叶松、云杉、冷杉种实的球果花蝇的研究进展及存在的问题。文中还涵括了作者的一些原始研究数据和尚未发表的新结果。     

中国单头螨属一新种(蜱螨亚纲：叶螨科)

中国单头螨属一新种（蜱螨亚纲：叶螨科）谭瑞成,鲁素玲（湖南省林业科学研究所长沙４１０００４）（新疆石河子农学院新疆８３２００３）单头螨属ＡｐｌｏｎｏｂｉａＷＯｍｅｒｓｌｅｙ,１９４０前足体背毛３对,后半体背毛１０对,全部或部分背毛着生在明显结节Ｌ,背...     

HOST-PLANT SWITCHES AND THE EVOLUTION OF CHEMICAL DEFENSE AND LIFE HISTORY IN THE LEAF BEETLE GENUS OREINA

Insect-plant interactions have played a prominent role in investigating phylogenetic constraints in the evolution of ecological traits. The patterns of host association among specialized insects have often been described as highly conservative, yet not all specialized herbivorous insect lineages display the same degree of fidelity to their host plants. In this paper, we present an estimate of the evolutionary history of the leaf beetle genus Oreina. This genus displays an amazing flexibility in several aspects of its ecology and life history: (1) host plant switches in Oreina occurred between plant families or distantly related tribes within families and thereby to more distantly related plants than in several model systems that have contributed to the idea of parallel cladogenesis; (2) all species of the genus are chemically defended, but within the genus a transition between autogenous production of defensive toxins and sequestration of secondary plant compounds has occurred; and (3) reproductive strategies in the genus range from oviparity to viviparity including all intermediates that could allow the gradual evolution of viviparity. Cladistic analysis of 18 allozyme loci found two most parsimonious trees that differ only in the branching of one species. According to this phylogeny estimate, Oreina species were originally associated with Asteraceae, with an inclusion of Apiaceae in the diet of one oligophagous species and an independent switch to Apiaceae in a derived clade. The original mode of defense appears to be the autogenous production of cardenolides as previously postulated; the additional sequestration of pyrrolizidine alkaloids could have either originated at the base of the genus or have arisen three times independently in all species that switched to plants containing these compounds. Viviparity apparently evolved twice in the genus, once without matrotrophy, through a retention of the eggs inside the female's oviducts, and once in combination with matrotrophy. We hypothesize that the combination of autogenous defense and a life history that involves mobile externally feeding larvae allowed these beetles to switch host plants more readily than has been reported for highly conservative systems.     

Photoperiodic Control of Pre-Adult Development and Adult Diapause Induction in Zoophytophagous Bug Dicyphus errans (Wolff) (Heteroptera,Miridae)

Zoophytophagous plant bugs (Heteroptera, Miridae) increasingly attract interest as agents of biological plant protection. In the laboratory experiment, the effects of the day length and temperature on the duration of the pre-adult period and on induction of facultative winter adult diapause were studied in Dicyphus errans (Wolff, 1804) collected in Italy. The experiment demonstrated that at 20°C the duration of the pre-adult period of D. errans significantly depended on the day length. On average, females developed 1.3 days longer than males and, at the same time, the day length equally influenced the duration of the pre-adult period in both sexes. The pre-adult period was the shortest under short-day conditions (10 to 12 h of light per day), reached its maximum at day length of 14 h, but then decreased at 15 h, and at day length of 16 h it was as short as under short-day conditions. Also, a pronounced long-day type photoperiodic response of adult diapause induction was recorded in females of D. errans at 20°C: under short-day conditions (10 to 14 h of light per day) almost all females entered diapause, whereas under long-day conditions (15 and 16 h of light per day) about 90% of females were mature. The threshold of this photoperiodic response was close to 14 h 30 min. The mean (± S.D.) egg load of mature females was 6.3 ± 4.0 eggs per female and did not depend on the day length at which the female was reared before and after the final molt. When photoperiodic response of adult diapause induction was observed at two constant temperatures (20 and 25°C), the proportion of mature females depended significantly on the day length but not on the temperature: the shapes of the photoperiodic response curves of diapause induction were almost the same within the near-threshold zone at 20 and 25°C, i.e., the photoperiodic response was thermostable. The set of two photoperiodic responses manifested at different stages of the species’ life cycle has an obvious adaptive significance. In Central Europe, D. errans has 2 or 3 generations per year and hibernates at the adult stage. Due to the thermostable photoperiodic response, females enter diapause always at the same time at the end of summer, regardless of the weather conditions of a particular year. When oviposition and pre-adult development are extended over a prolonged period in summer, nymphs from the later eggs might not be able to molt to adults in due time and then fully prepare for stable winter diapause. Under such circumstances, the photoperiodic response controlling the rates of pre-adult development acquires apparent adaptive meaning: with an autumnal shortening of the day length to 10–12 h, even under conditions of seasonal decrease in temperature, the rates of nymphal development increase and, thus, the chances of nymphs from the later eggs to molt to adults and properly prepare for overwintering also increase. The new data should be taken into account when analyzing the seasonal cycle of D. errans and developing the programs of mass rearing of this zoophytophagous mirid as an agent of biological plant protection.

     

HAMINAEA EXIGUA (GASTROPODA, OPISTHOBRANCHIA), A NEW CEPHALASPID SPECIES FROM THE MEDITERRANEAN SEA

A new species of the genus Haminaca has been found in samplesfrom the northern Adriatic Sea. The new species is very similarto H. orteai, but may be clearly distinguished by body size,the non-pigmented area around the eyes, number of leaves ofHancock's organ, number of ridges on the gizzard plates andby the morphology of male genital tract. A comparison and adiscussion of the values of the most significant characterswithin the genus Haminaca is provided herein. (Received 19 September 1991; accepted 28 February 1992)     

Revision of the Genus Goodallia (Bivalvia: Astartidae) with the Description of Two New Species

A revision of the Recent species of the genus Goodallia (Astartidae)is presented. Adult shell and prodissoconch morphology of allthe species are described and figured. In total, five speciesare recognized: G. triangularis (Montagu, 1803), G. pusilla(Forbes, 1844), G. macandrewi (Smith, 1881), G. micalii new species,and G. gofasi new species. G. triangularis and G. pusilla are widespreaddistributed in the Atlantic coasts of Europe and North Africa,and in the Mediterranean. G. macandrewi is restricted to thetype locality in the Canary Islands, while what has been calledG. macandrewi from the Mediterranean corresponds to an undescribedspecies here named G. micalii, distributed in the Central andEastern Mediterranean. A second undescribed species from offthe Atlantic Moroccan coast is named G. gofasi, and is knownonly from the type material of station B33 of the expedition CINECA CHARCOT III. The named forms, variability and distributionof G. triangularis are discussed. (Received 30 January 1998; accepted 27 August 1998)     

FURTHER STUDIES ON THE TAXONOMY AND BIOLOGY OF THE OCTOCORAL-FEEDING GENUS PHYLLODESMIUM EHRENBERG, 1831 (NUDIBRANCHIA: AEOLIDOIDEA)

The aeolid nudibranch genus Phyllodesmium (Mollusca: Gastropoda)is reviewed, three new species are described and further informationon the biology, anatomy and distribution on the eight previouslyknown species is reported. The genus Ennoia Bergh, 1896 is considereda synonym of Phyllodesmium and the type species Ennoia briareusredescribed. The genus Phyllodesmium is unique amongst the aeolidsin feeding on octocoral cnidarians. This has led to the evolutionof nudibranch- zooxanthellae symbioses, zooanthellae being obtainedfrom the octocoral prey. The adaptations developed throughoutthe genus are described and possible relationships between thespecies proposed. (Received 6 January 1990; accepted 20 May 1990)     

FOUR NEW SPECIES OF TAMBJA BURN, 1962 (NUDIBRANCHIA: POLYCERIDAE) FROM THE INDO-PACIFIC

The genus Tambja previously included 24 described species. Fournew species, T. tentaculata n. sp., T. gabrielae n. sp., T.zulu n. sp. and Tambja victoriae n. sp., from the Indo-Pacificare described. Tambja tentaculata n. sp., from Guam, is theonly known species in the genus with well developed, dorsolaterallygrooved, oral tentacles. Its inner lateral teeth have a bifidinner cusp with two long, sharp denticles. The oral tentaclesof T. tentaculata are more typical of Roboastra species, whilethe shape of the inner lateral teeth is more typical of Tambja.Nevertheless, the arrangement of the two cusps of the innerlateral teeth and the presence of a rachidian tooth withoutdenticles and with a central notch at the anterior edge, typicalof the species of the genus Tambja, suggest the placement withinthis genus. Tambja gabrielae n. sp., from Indonesia and PapuaNew Guinea, has dark green to dark brown ground colour withbright yellow patches scattered on the body. Tambja zulu n.sp. from Durban, South Africa, is characterized by a black groundcolour with slender yellow longitudinal lines. Tambja victoriaen. sp. is a new species from Papua New Guinea and Australiathat has frequently been misidentified as Roboastra arika, characterizedby its blue body colour and yellow lines. The four species aredistinguishable based on differences in body coloration, ofcharacters of the radula and of the reproductive system. Anoverview on distinguishing features of all known Indo-PacificTambja species is presented. (Received 21 June 2004; accepted 20 January 2005)     

Microanatomical diversification of the zona pellucida in aplochelioid killifishes

This study investigates zona pellucida (ZP) ultrastructure in fertilized eggs of annual killifishes (suborder Aplocheiloidei), a group of highly specialized fishes that are able to survive desiccation for several weeks to months before they hatch. Little is known about ZP or chorionic ultrastructure sustaining these life‐history modes, so scanning electron microscopy (SEM) was used to describe this trait in a large number of aplocheiloids with a focus on the family Rivulidae and the genus Hypsolebias. New images of ZP ultrastructure for 52 aplocheiloid species are provided, more than doubling the number characterized thus far. The evolution of chorionic structure within this group is studied using these new data. Characters were coded into a morphological matrix and optimized onto a consensus phylogeny to assess phylogenetic signal and reconstruct ancestral character states. Although ZP characters seem highly homoplastic and exhibit a large amount of structural convergence among lineages, aplocheiloid killifishes have evolved a number of unique structures associated with the chorion. Some annual species seem to have lost long filaments because eggs are deposited in the soil instead of being adhered to aquatic plants.     

On the Megaspores of Four Species of Lepidostrobus

This paper is an account of the megaspores borne by four speciesof Carboniferous Lycopod cones, referred to the genus Lepidostrobus.The megaspores (assigned to the genus Triletes) have been knownisolated for more than twenty years, but the identities of theirparent cone species have not previously been established. Thisstudy suggests the limits of variation that can reasonably beallowed in a ‘spore species’. Three of the conespecies are emended in the light of their spore content, anda new species (Lepidostrobus allantonensis) is described. Usingthe megaspores as a diagnostic cone character, it has provedpossible to correlate a species of isolated cone (Lepidostrobusdudius Binney) with the tree which bore it (Lepidodendron smileKidst.). A cone previously attributed on doubtful evidence toBothrodendron is shown to bear megaspores indistinguishablefrom those of a species reliably attributed to Lepidodendron,suggesting that the attribution to Bothrodendron is incorrect.     

The peculiar nemertean larva pilidium recurvatum belongs to Riserius sp., a basal heteronemertean that eats Carcinonemertes errans,a hoplonemertean parasite of Dungeness crab

A typical nemertean pilidium larva resembles a hat with ear flaps. But one type, called pilidium recurvatum, looks more like a sock, swimming heel first. This distinctive larva was discovered in 1883 off the coast of Rhode Island and subsequently found in plankton samples from other parts of the world. Despite the long time since discovery, and its significance in discussions of larval evolution, this larva remained unidentified even to the family level. We collected pilidium recurvatum larvae from plankton samples in Coos Bay, OR, and identified them as belonging to the heteronemertean genus Riserius based on juvenile morphology and DNA sequence data. Phylogenetic analysis suggests that two distinct types of pilidium recurvatum from Oregon represent two new species within this currently monotypic genus. We describe the morphology of pilidium recurvatum using confocal microscopy and compare it to that of the typical pilidium, discussing possible implications for larval feeding. We also report our surprising discovery that juveniles of Riserius sp. from Oregon prey on another nemertean, Carcinonemertes errans, an egg predator of Cancer magister (Dungeness crab), a commercially important species. We speculate that the species‐level diversity and geographic distribution of Riserius may be much greater than currently appreciated.