Allelopathic effects of Alexandrium fundyense (Dinophyceae) on Thalassiosira cf. gravida (Bacillariophyceae): a matter of size

Allelopathic interactions among phytoplankton are well documented. The potency of allelopathic species and responses of target species to allelochemicals are quite variable, however, limiting full understanding of the role these interactions may play in nature. One trait that may influence the sensitivity of an individual to allelochemicals is cell size. The few studies that have examined relationships between cell size and susceptibility to allelochemicals have compared different species and thus could not distinguish between the role of size and species‐specific physiological differences. Culturing an actively sexually reproducing diatom allowed us to focus on the influence of target cell size within a single species. We studied growth and nutrient acquisition by the chain‐forming Thalassiosira cf. gravida Clever in the presence and absence of allelochemicals released by Alexandrium fundyense Balech as a function of T. cf. gravida cell size. Upon exposure to filtrate of A. fundyense, T. cf. gravida cultures “bleached” and both growth and nutrient utilization ceased for up to 4 d. The magnitude of the effect was dependent on filtrate concentration and T. cf. gravida cell surface area:volume ratio. The greatest inhibition was observed on the smallest cells, while T. cf. gravida cultures that had undergone cell enlargement via sexual reproduction were least sensitive to A. fundyense filtrate. These results demonstrate that competitor cell size, independent from taxonomy, may influence the outcome of allelopathic interactions. The findings presented here suggest a potential ecological impact of diatom cell size reduction and sexual reproduction that has not yet been described and that may be important in determining diatom survival and success.     

Phylogeny and revision of the ‘Cubitermes complex’ termites (Termitidae: Cubitermitinae)

The phylogeny of the genus Cubitermes Wasmann was reconstructed using two mitochondrial genes (COI and COII) and a fragment of the nuclear 28S rDNA, including samples of Apilitermes Holmgren, Crenetermes Silvestri, Megagnathotermes Silvestri and Thoracotermes Wasmann. Based on our analyses, we recovered these genera within a paraphyletic Cubitermes clade. Cubitermes species are distributed between five main clades, highly reflective of their enteric valve armatures (EVAs). Consequently, Cubitermes is here divided into five monophyletic genera based on phylogenetic analyses and EVAs: Cubitermes (sensu stricto), Isognathotermes Sjöstedt, Nitiditermes Emerson, Polyspathotermes Josens & Deligne, gen.n. , and Ternicubitermes Josens & Deligne, gen.n. Moreover, the two species of Megagnathotermes included in this study, exhibiting different EVAs, are phylogenetically distant: M. katangensis Sjöstedt belongs in the genus Polyspathotermes, while M. notandus Silvestri remains as a monotypic genus. During the evolution of the Cubitermes complex, sclerotized EVA spatulae appeared twice independently: three or six spatulae in Polyspathotermes (sulcifrons and oblectatus patterns) and two jaw‐like spatulae in Nitiditermes (sankurensis pattern), which is absent in some species (oculatus pattern). Zoobank registration: http://zoobank.org/urn:lsid:zoobank.org:pub:576AAFF8‐63C6‐4962‐A8F5‐75C9317AEA7B .     

Natural establishment of a parasitoid complex on Bactrocera latifrons (Diptera: Tephritidae) in Hawaii

Bactrocera latifrons (Hendel) (Diptera: Tephritidae) is the most recent of four tephritid fruit fly species accidentally introduced into Hawaii. Although parasitoids have been released against other tephritid fruit fly species and have shown partial success in Hawaii, no parasitoids were released until 2004 to suppress populations of B. latifrons. The present study was conducted to document the parasitoid complex that has naturally established against B. latifrons in Hawaii and to assess whether there is a need for improving the biological control of this species. Based on ripe turkeyberry (Solanum torvum Sw) fruit collections over three consecutive years B. latifrons was the dominant tephritid fruit fly infestating turkeyberry at all four sites surveyed, across three major islands in Hawaii. The overall percentage parasitism of B. latifrons ranged from a low of 0.8% (Hana, Maui) to a high of 8.8% (Kahaluu, Oahu). Five primary parasitoid species were recovered from individually held B. latifrons puparia: Fopius arisanus (Sonan), Psyttalia incisi (Silvestri), Diachasmimorpha longicaudata (Ashmead), D. tryoni (Cameron), and Tetrastichus giffardianus Silvestri. F. arisanus was the predominant parasitoid at three of the four sites. Low levels of parasitism suggest that there is a need to improve biological control of B. latifrons, to minimize chances of this species causing economic impacts on crop production in Hawaii. We discuss the possibility of improving biological control of B. latifrons through augmentative releases of F. arisanus or introduction and release of specific and efficient new parasitoid species.     

Stenotaenia Koch, 1847: a hitherto unrecognized lineage of western Palaearctic centipedes with unusual diversity in body size and segment number (Chilopoda: Geophilidae)

Based on morphological evidence, we newly define the genus Stenotaenia Koch, 1847 (=Scnipaeus Bergsøe & Meinert, 1866; =Simophilus Silvestri, 1896; =Onychopodogaster Verhoeff, 1902; =Insigniporus Attems, 1903; =Notadenophilus Verhoeff, 1928; =Bithyniphilus Verhoeff, 1941; =Schizopleres Folkmanova, 1956; =Euronesogeophilus Matic, 1972; all syn. nov. ) as including the following 15 species: Stenotaenia linearis (Koch, 1835) (=Geophilus simplex Gervais, 1835; =Geophilus brevicornis Koch, 1837; =Scnipaeus foveolatus Bergsøe & Meinert, 1866; =Himantarium caldarium Meinert, 1886 syn. nov. ; =Geophilus (Geophilus) linearis var. polyporus Verhoeff, 1896 syn. nov. ; =Geophilus ormanyensis Attems, 1903 syn. nov. , after lectotype designation; =Insigniporus acuneli C?pu?e, 1968 syn. nov. ) from central and northern Europe; Stenotaenia frenum (Meinert, 1870) from northern Africa; Stenotaenia romana (Silvestri, 1895) (=Geophilus silvestrii Verhoeff, 1928 syn. nov. ) and Stenotaenia sorrentina (Attems, 1903) (=Geophilus forficularius Fanzago, 1881 syn. nov. ; =Geophilus linearis abbreviatus Verhoeff, 1925 syn. nov. ) from the Italian peninsula and Sardinia; Stenotaenia antecribellata (Verhoeff, 1898) (=Simophilus albanensis Attems, 1929 syn. nov. ), Stenotaenia cribelliger (Verhoeff, 1898), Stenotaenia palpiger (Attems, 1903), Stenotaenia rhodopensis (Kaczmarek, 1970), and Stenotaenia sturanyi (Attems, 1903) from the Balkan peninsula; Stenotaenia naxia (Verhoeff, 1901) (=Geophilus graecus Verhoeff, 1902) from the Aegean islands; Stenotaenia asiaeminoris (Verhoeff, 1898) and Stenotaenia bosporana (Verhoeff, 1941) from Anatolia; Stenotaenia giljarovi (Folkmanova, 1956) from western Caucasus; Stenotaenia fimbriata (Verhoeff, 1934) and Stenotaenia palaestina (Verhoeff, 1925) from Palestine; with the only exception of S. linearis, all of these binomens are comb. nov. In Stenotaenia, a strongly conserved overall morphology is matched by an unusual interspecific variation in both the body size of fully grown specimens (from 1.7 cm in S. romana to 7.7 cm in S. sturanyi) and the number of leg‐bearing segments (from 43 in male S. romana to 115 in female S. sturanyi). The number of segments correlates with maximum body size. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 153 , 253–286.     

Identification of 21 polymorphic microsatellites in the African parasitoid wasp, Psyttalia lounsburyi (Silvestri) (Hymenoptera: Braconidae)

We have developed 21 dinucleotide repeat microsatellite loci from African populations of Psyttalia lounsburyi (Silvestri) (Hymenoptera: Braconidae), a parasitoid wasp of the olive fruit fly, as part of a study assessing the role of introgression/hybridization in the success of a biological control introduction. We proposed suitable conditions for polymerase chain reaction multiplexing. All 21 loci were polymorphic with two to 21 alleles per locus within the Kenyan and South African populations tested. Most of them were successfully amplified in two other Psyttalia species.     

Ground pearls: a generic revision of the Margarodidae sensu stricto (Hemiptera: Sternorrhyncha: Coccoidea)

The ground pearls comprise the scale insect family Margarodidae s. str., and are subterranean plant sucking parasites on roots of a wide variety of plants. Some ground pearls are serious destructive pests of grape vines, sugar cane, oil palms, cotton or lawn grass around the world. Both female and male development is characterised by an apodous, feeding 2^nd-instar nymph, called a cyst. The cyst is primarily circular and often colourful, shiny, metallic or pearl-like, from which the common name “ground pearls” is derived. Other unique features are the strongly developed prothoracic legs for digging, the construction of a protective test from their own liquid excreta in which the cyst is enclosed and a behavioral adaptation by modification of their life-cycle to survive in adverse environmental conditions.

The 10 genera, currently include 105 species, form a monophyletic group with a worldwide distribution. First-instar nymphs and cysts are feeding instars; however, adults male and females lack mouthparts and do not feed. Species of ground pearls reproduce either bisexually or parthenogenetically, parthenogenesis is facultative in Eurhizococcus brasiliensis. Females undergo three, four or five developmental stages, while male have five. During the cyst stage, one, two or three molts may occur. Most species have a single generation each year, although development in Margarodes vitis requires three years including three instars of cysts. This revision redescribes and illustrates the type species of each genus, including Margarodes vitis (Philippi) and provides a key to the genera based on the morphology of adult females. Lectotypes of Dimargarodes medíterraneus (Silvestri), Heteromargarodes americanus Jakubski, Promargarodes sinensis Silvestri and Termitococcus carrotai Silvestri are designated. A nomenclatural change is proposed, the genus Sphaeraspis Giard, 1894 is considered to be a synonym of Margarodes Guilding, 1829. This work also provides information on the history of the group of Archaeococcoids; on the biology, economic importance and distribution of the margarodids.     

Notocotylidae (Digenea) from the Australian water rat Hydromys chrysogaster Geoffroy, 1804 (Muridae)

Notocotylus johnstoni n. sp., N. imbricatus (Looss, 1893) Szidat, 1935 and Catatropis nicolli n. sp. are described from the large intestine and caecum of the Australian water rat Hydromys chrysogaster (Rodentia: Muridae). The water rat is the only known mammalian host of notocotylids in Australia. N. imbricatus, recorded from Tasmania, is a cosmopolitan species which elsewhere uses birds and bithyniid snails as definitive and intermediate hosts respectively. In Tasmania bithyniid snails are unknown and the only known definitive host is a mammal. In view of this it is possible that the material examined represents a species distinct from N. imbricatus. Catatropis gallinulae Johnston, 1928 is found to have three rows of ventral papillae and thus to belong to the genus Notocotylus. The new combination Notocotylus gallinulae (Johnston, 1928) is a senior homonym of Notocotylus gallinulae El-Naffar & Khalifa, 1983 which is replaced with Notocotylus elnaffari nom. nov.     

Molecular analysis of Southern Ocean skates (Bathyraja) reveals a new species of Antarctic skate

Two regions of mtDNA, cytochrome b and cytochrome c oxidase subunit 1, were sequenced in nine species of Bathyraja from the Southern Ocean and New Zealand. Based on sequence divergence, the species that has been referred to as Bathyraja eatonii from the Antarctic continental shelf and slope is a species distinct from B. eatonii from the Kerguelen Plateau (the type locality) and is a new and undescribed species Bathyraja sp. (cf. eatonii). There was no sequence divergence among samples of Bathyraja sp. (dwarf) from the Ross Sea and the South Atlantic. However, for both Bathyraja sp. (cf. eatonii) and Bathyraja maccaini in the Ross Sea and the South Atlantic Ocean, the DNA sequence divergences indicate differentiation among ocean basins and within Bathyraja sp. (cf. eatonii) divergences are similar to those among recognized species of Bathyraja in the North Pacific Ocean.     

Seven decades of monitoring the aquatic bug fauna of Lake Balaton (Heteroptera: Nepomorpha)

Detailed faunistic data originating from four sampling series of aquatic Heteroptera (Nepomorpha) in the Lake Balaton (the largest shallow lake of Central Europe) between 1928 and 2002 were analysed. A comparative analysis confirmed that the aquatic bug fauna of this great lake can be established with suitable accuracy if it is sampled by different but devoted collectors. So far 26 species of aquatic bugs have been reported from here. The fauna changed considerably during the seven decades. Species lists of the four basins of the lake established during the four sampling periods show characteristic differences. Not only the frequency of four Micronecta species (Micronecta griseola, M. pusilla, M. scholzi, M. minutissima) changed characteristically but there has been a distinct change in the ratio of rare species too. Rare species were present in significantly higher proportion in the period 1928–1930 than in any of the later samplings between 1984 and 2002. All these changes run parallel with the direction of anthropogenic influences.     

Genetic variation in Simocephalus (Anomopoda: Daphniidae) in North America: patterns and consequences

The presumption of intercontinental distributions of many species of Anomopoda has been reinforced by their considerable morphological uniformity and ease of passive dispersal via ephippial eggs. To test the validity of this dogma, genetic variation among taxa in the cladoceran genus Simocephalus was examined on a continental scale. Genetic variability (percentage polymorphic loci = 8.8%, individual heterozygosity = 3.4%) was comparable to that determined on a local scale in Simocephalus and somewhat less than for other zooplankton groups. Four species complexes were distinguished allozymically with unique allelic substitutions found for at least two loci between these taxa. Eight species in North America were differentiated within these complexes (Nei s genetic distance, D>0.30), all of which were clearly separated from two European species. Both S. cf. vetulus and S. cf. serrulatus are broadly distributed in North America, and intraspecific divergence is relatively low. In contrast, S. cf. congener and S. cf. exspinosus represent species complexes, both consisting of several species, differentiated allozymically and morphologically. The concept of generalist species with moderate genetic variation throughout a broad range and specialist species, genetically depauperate, with restricted distributions, is explored.     

Reproduction and larval development of two sympatric Pseudopolydora species (Annelida: Spionidae) in Japan

Pseudopolydora cf. kempi and Pseudopolydora cf. reticulata, which are morphologically similar, are sympatric in Gamo Lagoon, near Sendai on the Pacific eastern coast of Honshu, Japan. Reproduction, larval development, and larval morphology of these two species were compared. The larval developmental pattern of P. cf. kempi was determined to be short-term planktonic with lecithotrophy and adelphophagy, whereas that of P. cf. reticulata was long-term planktonic with planktotrophy. The number of embryos per capsule differed between the two species: 0–16 for P. cf. kempi and 62–405 for P. cf. reticulata. Nurse eggs were only found for P. cf. kempi. The results of this study suggest that some previous studies attributed to P. kempi may have been to P. cf. reticulata or to another species in this complex.     

Life cycle and production of Chironomidae (Diptera) from Lake Banyoles (NE Spain)

1. The life cycles and annual production of the eight most abundant species of chironomids (Prodadius cf. choreus, Tanypus punctipennis, Chironomus bernensis, Chironomus gr. plumosus, Cladopelma virescens, Microchironomus tencr, Tanytarsus gr. lestagei, and Cladotanytarsus atridorsum) were studied from sublittoral and profundal samples taken monthly in Lake Banyoles during 1987 at five sampling stations (depths ranging from 5 to 20 m). 2. The number of generations per year deduced from instar-frequency data varied from one to four, depending on the species, lake basin and depth. Annual temperature range, dissolved oxygen in the stratified period and presence of sulphide are the key factors that may explain the differences in the number of generations. 3. Production estimates were calculated using the size-frequency (SF) method corrected for the number of generations (SFG), and the increment-summation method (IS) when cohorts could be clearly deduced. 4. Production calculated with the SFG method gave results which were comparable with those of the IS method using smoothed-survivorship curves in the three species for which the use of the IS method was possible (C. virescens, M. tener and C. atridorsum). Using these methods production was estimated to range from 23–70 mg AFDW (ash-free dry weight) m^?2 yr^?1 at 12 m to 74–275 mg AFDW m^?2 yr^?1 in the sublittoral zone of the lake (5-m depth). 5. Calculation of production for the other five species using the size-frequency method with the number of generations (SFG) deduced from monthly instar-frequency data gave values ranging from 12 mg AFDW m^?2 yr^?1 (Chironomus bernensis at 20 m depth) to 3.75 g AFDW m^?2 yr^?1(Prodadius cf. choreus at 12 m). 6. Total chironomid production (with the SFG method) varied from 0.8 to 5 g AFDW m^?2 yr^?1 in the profundal and sublittoral, respectively. At each sampling station two species groups accounted for most of the production: Prodadius cf. choreus and Chironomus spp. Annual production/biomass ratio (P/B) varied from very high values for Prodadius (between 11 and 27, as four generations completed each year) to very low values for Chironomus gr. plumosus (2.20), which completed only one generation each year. The annual production of P. cf. choreus in Lake Banyoles is higher than any reported in the literature due to the completion of four generations and to the high densities of this species.     

Identification of a novel member in the family Albulidae (bonefishes)

A novel Caribbean species Albula sp. cf. vulpes in the family Albulidae (bonefishes) was diagnosed through genetic and morphometric study. Phylogenies derived from 16S rRNA sequences revealed deeply separated lineages among Caribbean bonefishes. Mitochondrial DNA sequence divergences indicated a separation between 3·0 and 5·2 million years before present (b.p.). Cytochrome b phylogenies further supported the classification of A. sp. cf. vulpes as a novel albulid. Morphological variability revealed several differences between A. sp. cf. vulpes and other Caribbean species. A microsatellite library was developed to discern hybridization rates among the species. Microsatellite analyses revealed low levels of hybridization between some members in the complex. One instance of backcrossing was found between A. vulpes×A. sp. B and a pure A. sp. B, indicating that hybrids may have reduced fitness or may be reproductively isolated due to temporal–spatial spawning habitat differences.     

杰赞姬蜂属研究(膜翅目:姬蜂科)

该文报道在我国发现的杰赞姬蜂属     

PLEISTOCENE BIRD FAUNA FROM BIR TARFAWI (EGYPTIAN WESTERN DESERT)

Bocheński, Z. 1991. Pleistocene bird fauna from Bir Tarfawi (Egyptian Western Desert). Ostrich 62: 29–34.

At Bir Tarfawi, an archaeological site in the Egyptian Sahara dated to about 135000 years (before present), 202 bone fragments were identified as belonging to 24 bird species or genera. Most of the material is apparently from owl pellets. The birds represent aquatic and terrestrial forms and include different zoogeoraphical elements; Afrotropical species such as Phalacrocorax africanus, Gyps africanus, cf. Neotis denfami, Fulica cristata, Oena capensis and Corvus albus, as well as Indo-African species such as cf. Bubulcus ibis and Turnix cf. sylvatica. The fossil bird remains as well as those of other vertebrates indicate that the Pleistocene “Grey Lake 2” was surrounded by a mosaic of different aquatic and terrestrial biotopes.     

Size scaling of photophysiology and growth in four freshly isolated diatom species from Ryder Bay,western Antarctic peninsula

Diatoms are one of the dominant groups in phytoplankton communities of the western Antarctic Peninsula (WAP). Although generally well‐studied, little is known about size dependent photophysiological responses in diatom bloom formation and succession. To increase this understanding, four Antarctic diatom species covering two orders of magnitude in cell size were isolated in northern Marguerite Bay (WAP). Fragilariopsis sp., Pseudo‐nitzschia cf. subcurvata, Thalassiosira cf. antarctica, and Proboscia cf. alata were acclimated to three different irradiances after which photophysiology, electron transport, carbon fixation, and growth were assessed. The small species Fragilariopsis sp., Pseudo‐nitzschia cf. subcurvata, and large species Proboscia cf. alata showed similar photoacclimation to higher irradiances with a decrease in cellular chlorophyll a and an increase in chlorophyll a specific absorption and xanthophyll cycle pigments and activity. In contrast, pigment concentrations and absorption remained unaffected by higher irradiances in the large species Thalassiosira cf. antarctica. Overall, the small species showed significantly higher growth rates compared to the large species, which was related to relatively high light harvesting capacity and electron transport rates in the smaller species. However, photophysiological responses related to photoinhibition and photoprotection and carbon fixation showed no relationship with cell size. This study supports the dominance of small diatoms at low irradiances during winter and early spring, but does not provide photophysiological evidence for the dominance of large diatoms during the phytoplankton bloom in the WAP. This suggests that other factors such as grazing and nutrient availability are likely to play a major role in diatom bloom formation.     

Temperature‐mediated trade‐offs and changes in life‐history integration in two slipper limpets (Gastropoda: Calyptraeidae) with planktotrophic development

Intraspecific variation in egg size and hatching size, and the genetic and environmental trade‐offs that contribute to variation, are the basis of the evolution of life histories. The present study examined both univariate and multivariate temperature‐mediated plasticity of life‐history traits, as well as temperature‐mediated trade‐offs in egg size and clutch size, in two planktotrophic species of marine slipper limpets, Crepidula. Previous work with two species of Crepidula with large eggs and lecithotrophic development has shown a significant effect of temperature on egg size and hatching size. To further examine the effect of temperature on egg size in Crepidula, the effects of temperature on egg size and hatching size, as well as the possible trade‐offs with other the life‐history features, were examined for two planktotrophic species: Crepidula incurva and Crepidula cf. marginalis. Field‐collected juveniles were raised at 23 or 28 °C and egg size, hatching size, capsules/brood, eggs/capsule, time to hatch, interbrood interval, and final body weight were recorded. Consistent with results for the lecithotrophic Crepidula, egg size and hatching size decreased with temperature in the planktotrophic species. The affects of maternal identity and individual brood account for more than half of the intraspecific variation in egg size and hatching size. Temperature also showed a significant effect on reproductive rate, with time to hatch and interbrood interval both decreasing with increasing temperature. However, temperature had contrasting effects on the number of offspring. Crepidula cf. marginalis has significantly more eggs/capsule and therefore more eggs per brood at 28 °C compared to 23 °C, although capsules/brood did not vary with temperature. Crepidula incurva, on the other hand, produced significantly more capsules/brood and more eggs per brood at the lower temperature, whereas the number of eggs/capsule did not vary with temperature. The phenotypic variance–covariance matrix of life‐history variables showed a greater response to temperature in C. incurva than in C. cf. marginalis, and temperature induced trade‐offs between offspring size and number differ between the species. These differences suggest that temperature changes as a result of seasonal upwelling along the coast of Panama will effect the reproduction and evolution of life histories of these two co‐occurring species differently. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.