Transfer function between surface sediment diatom assemblages and sea-surface temperature and salinity of the Labrador Sea

Q-mode factor analysis (CABFAC) of 38 diatom species in 66 surface sediment samples from the Labrador Sea allowed the definition of six assemblages explaining 95.69% of the total variance. The first assemblage (40.12% of the total variance) is represented by Thalassiothrix longissima, a species characteristic of the Irminger Current and associated with the West Greenland Current. The second assemblage (34.52% of the total variance) is represented by Thalassiosira gravida (resting spores), a cold water species associated with the Labrador Current. A third assemblage (11.43% of the variance) represented by Chaetoceros spp. is concentrated in the northeastern section of the Labrador Sea and associated with upwelling and high productivity. The fourth, the fifth and the sixth assemblages, represented, respectively, by Coscinodiscus marginatus, Coscinodiscus oculus iridis, and Coscinodiscus divisus, and Nitzschia frigida, are less significant and account, respectively, for 4.95, 2.62 and 2.04% of the total variance. Transfer functions derived by relating factor assemblages to surface water temperature and salinity (August and February) give standard errors of estimate of ±0.93°C (August) and ±0.64°C (February) for temperature, and of ±0.58‰ (August) and ±0.45‰ (February) for salinity. High correlations between the measured and estimated parameters confirm the validity of the paleoecological equations for the reconstruction of the Labrador Sea paleoclimate.     

Ostracods from the cruise of the R.R.S.John Murray, 1969 in the Tyrrhenian Sea

Gravity cores and grab samples collected during the 1969 cruise of the R.R.S.John Murray in the Tyrrhenian Sea have been sampled for ostracods. The ostracod assemblages are recent in age and separate into an Offshore Assemblage from approximately 100–120 m, an Abyssal Assemblage associated with the canyons from 800–1200 m and an Abyssal Assemblage from 1200–3000 m water depth. No psychrospheric ostracods were found thus confirming that the last major open connection with the Atlantic was in the Pliocene.     

The distribution of Recent benthic foraminifera in the Polar Front region, southwest Atlantic

Twenty-five core-top samples from the Maurice Ewing Bank (MEB) and Islas Orcadas Rise (IOR) were examined to determine the distribution of benthic foraminifera in the vicinity of the Polar Front in the southwest Atlantic Ocean. The Polar Front has a subsurface expression that effects the areal and depth distribution of benthic foraminifera in this region.Three faunal assemblages were identified by Q-mode factor analysis. The shallowest assemblage, dominated by Bulimina aculeata, is present from 1500 to 2600 m on the Maurice Ewing Bank and is associated with potential temperatures of 1.71-0.50°C, salinities of 34.74-34.70‰ and potential density values of 45.84–46.04 sigma-4. A second assemblage, dominated by Uvigerina peregrina, occurs in water depths from 2600 to 3100 m and is associated with potential temperatures of 0.40-0.26°C, salinities of 34.70-34.69‰ and potential density values of 46.05–46.07 sigma-4. The third assemblage is dominated by Nuttallides umbonifera, Ehrenbergina trigona and secondarily by Oridorsalis umbonatus and Pullenia bulloides (the N. umbonifera-E. trigona assemblage) is present form 2770 to 3120 m on the Islas Orcadas Rise. This assemblage is associated with potential temperatures of 0.36-0.14°C, salinities of 34.69-34.68‰, and potential density values of 46.06–46.09 sigma-4. Although the U. peregrina assemblage and the N. umbonifera-E. trigona assemblage overlap bathymetrically, they are present in waters of slightly different properties. The Bulimina aculeata assemblage is within the core of the Lower Circumpolar Deep Water (LCDW), while the other two assemblages occur within transition zones between the LCDW and Weddell Sea Deep Water (WSDW).The difference in the benthic foraminiferal assemblages at similar depths on the Islas Orcadas Rise and the Maurice Ewing Bank is the result of different water-mass regimes separated by the Polar Front.     

The effects of glacio-eustatic sea-level change on Pleistocene cold-water ostracod assemblages from the Japan Sea

The Pleistocene palaeo-habitats and the extinction history of cold-water ostracods in the Japan Sea are recorded in its coastal strata. The presence of now-extinct species in the Omma Formation of central Japan (1.5 Ma) indicates that such species predominated in a shallow, open sea environment. The tolerance ranges of these species as to water temperature and salinity are inferred to have been narrower than those of most extant cold-water species in the same families that live in shallow open water, as well as in brackish inner bays. The horizons in the Omma Formation with peak relative abundances of now-extinct species differ from the horizons with peak abundances of living Japan Sea species. We therefore suggest that the now-extinct species were adapted to optimum temperature and salinity conditions that differ from those in the modern Japan Sea. The observation that few now-extinct species survived after 0.4 Ma may be explained by the hypothesis that physicochemical properties of the water masses changed. We argue that, during the glacial periods with increased amplitude (0.9–0.4 Ma), the salinity decreased as the result of glacio-eustatic changes and the closure of shallow straits owing to low sea levels, causing the extinctions.     

Palaeobiogeography of Early Cretaceous (Berriasian–Barremian) calcareous nannoplankton

In order to assess Early Cretaceous nannoplankton biogeography, we studied a series of sites which provide a north–south transect across the Atlantic Ocean, supplemented by sections from the North Sea Basin, Barents Sea, Falkland Plateau, Weddell Sea (Antarctica), Argo Abyssal Plain (NW of Australia) and Neuquén Basin (Argentina). Quantitative assemblage data were gathered from each site for seven time-slices within the Berriasian to Barremian interval, each horizon being determined by a nannofossil datum. Trends in species relative abundance and measures of diversity, evenness and richness provide revealing biogeographic information. A broad, low- to mid-palaeolatitude zone (50°N–50°S) is flanked in both Northern and Southern Hemispheres by distinct high-palaeolatitude zones. Major changes in assemblage abundance and composition occur across a sharp biogeographic ‘front’ at around 50°N and S palaeolatitude. High-palaeolatitude assemblages are lower in species richness and diversity and characterised by the presence of abundant, typically bipolar, taxa (e.g. Crucibiscutum salebrosum). A less distinct biogeographic boundary at 40°N is distinguished by the presence/absence of rarer, but biogeographically significant, taxa, many of which have previously been assigned to Boreal or Tethyan provinces. Continental shelf sites are characterised by lower-diversity assemblages with common to dominant diagnostic taxa, which vary with palaeolatitude: Nannoconus and Micrantholithus at low palaeolatitudes, and Biscutum constans and Zeugrhabdotus spp. at higher palaeolatitudes. The latter two taxa are considered to be indicative of elevated surface-water fertility and the former two may have been similarly adapted. The genus Watznoueria is ubiquitously dominant, giving the populations an unevenness, which appears to be a common feature throughout coccolithophore history.     

Late Pleistocene and Holocene distribution of Mytilus edulis in the Barents Sea region and its palaeoclimatic implications

Aim For decades, subfossil shells of the bivalve Mytilus edulis Linnaeus, 1758 in Svalbard have been taken as evidence of higher surface temperatures during the early Holocene because the modern northern occurrence of this mollusc was, until recently, in the southern Barents Sea. Here, we elucidate and discuss the spatial and temporal Late Pleistocene and Holocene distribution of the species within the entire Barents Sea region. Location The Barents Sea region. Methods Radiocarbon dates of Mytilus shells from the Barents Sea region and information about the present distribution of the species were compiled, including two new radiocarbon dates from north‐eastern Spitsbergen. The dataset was divided into time slices, each covering 1000 years, and compared with Holocene temperature variations, ocean current systems and present‐day temperature patterns. Results Maps show the Late Pleistocene and Holocene spatial and temporal distribution of Mytilus edulis in the Barents Sea region. M. edulis was already present in northern Norway about 14,000 cal. yr bp . It appeared at western Spitsbergen about 11,000 cal. yr bp , and slowly spread to the rest of the archipelago. The maximum distribution in the region was reached 10,000–7000 cal. yr bp , coinciding with the Holocene climatic optimum. The species gradually disappeared in the late Holocene and became absent from the northern and eastern parts of the region 3000–1000 cal. yr bp . Today, M. edulis lives in the southern part and has begun to recolonize the northern parts. Main conclusions The time slices illustrate strong connections between the ocean current regimes, the climate and the distribution of M. edulis. The species settled in the southern part of the Barents Sea region several thousand years before it spread to the northern part during the Holocene climatic optimum. It may even have been completely absent from the region for a short time during the late Holocene cold period. The Holocene distribution of Mytilus implies that the underlying pattern of coastal sea surface temperatures in the region was very stable.     

Prorocentrum minimum (Dinophyceae) in the Baltic Sea: morphology, occurrence—a review

The potentially toxic dinoflagellate Prorocentrum minimum (Pavillard) Schiller has successfully established in the Baltic Sea in the last two decades. A review of the invasion history is presented as well as new data on the spatial and inter-annual variability of this species and its relation to salinity, temperature, and nutrient concentrations. A short literature review of the morphological characters of the Baltic P. minimum is also included.From 1993 to 2002, P. minimum was a regular component of the summer and autumn plankton flora of the Baltic Sea proper and the Gulf of Finland. Its abundance varied considerably inter-annually and did not show any clear trends during the period. Abundance of P. minimum was significantly higher in the nutrient-enriched Bay of Mecklenburg (German coast) and the southern Baltic proper than in the central and northern Baltic proper and the Gulf of Finland, where its abundance was mostly sparse. In coastal waters P. minimum occasionally reached densities of several million cells per litre and dominated phytoplankton biomass (>90%).Abundance of the Baltic P. minimum was generally not related to salinity or temperature. It could be a dominant species at both high and low salinity (over 15 and 4.8 PSU), and its temperature range was broad (from 2.7 to 26.4 °C). However, dense populations usually occurred from July to October at temperatures above 10 °C.Further, there appears to be a positive correlation between the success of P. minimum in the Baltic Sea and high concentrations of total phosphorus and nitrogen.This tolerant and morphologically variable dinoflagellate seems to be a morphospecies without subtaxa, which can expand its range in the Baltic Sea, especially in nutrient-rich coastal waters.     

Seed germination and dormancy in the medicinal woodland herbs Collinsonia canadensis L. (Lamiaceae) and Dioscorea villosa L. (Dioscoreaceae)

We used a double germination phenology or “move-along” experiment (sensu Baskin and Baskin, 2003) to characterize seed dormancy in two medicinal woodland herbs, Collinsonia canadensis L. (Lamiaceae) and Dioscorea villosa L. (Dioscoreaceae). Imbibed seeds of both species were moved through the following two sequences of simulated thermoperiods: (a) 30/15 °C→20/10 °C→15/6 °C→5 °C→15/6 °C→20/10 °C→30/15 °C, and (b) 5 °C→15/6 °C→20/10 °C→30/15 °C→20/10 °C→15/6 °C→5 °C. In each sequence, seeds of both species germinated to high rates (>85%) at cool temperatures (15/6 and 20/10 °C) only if seeds were previously exposed to cold temperatures (5 °C). Seeds kept at four control thermoperiods (5, 15/6, 20/10, 30/15 °C) for 30 d showed little or no germination. Seeds of both species, therefore, have physiological dormancy that is broken by 12 weeks of cold (5 °C) stratification. Morphological studies indicated that embryos of C. canadensis have “investing” embryos at maturity (morphological dormancy absent), whereas embryos of D. villosa are undeveloped at maturity (morphological dormancy present). Because warm temperatures are required for embryo growth and cold stratification breaks physiological dormancy, D. villosa seeds have non-deep simple morphophysiological dormancy (MPD). Neither species afterripened in a 6-month dry storage treatment. Cold stratification treatments of 4 and 8 weeks alleviated dormancy in both species but C. canadensis seeds germinated at slower speeds and lower rates compared to seeds given 12 weeks of cold stratification. In their natural habitat, both species disperse seeds in mid- to late autumn and germinate in the spring after cold winter temperatures alleviate endogenous dormancy.     

Effect of Temperature on the Life History of Cirrospilus sp. near lyncus (Hymenoptera: Eulophidae), a Parasitoid of Phyllocnistis citrella (Lepidoptera: Gracillariidae)

The effect of four constant temperatures on the life history of Cirrospilus sp. near lyncus was examined in the laboratory. This species is one of the most abundant generalist indigenous parasitoids of the citrus leafminer, Phyllocnistis citrella Stainton, in Spain. Adult lifespan of C. sp. near lyncus decreased from 50.2 to 9.1 days as temperatures increased from 15 to 30°C, respectively. Both gross fecundity and host-feeding were highest at 20°C (170.48 eggs and 32.33 hosts). Oviposition rates were optimal at higher temperatures (5.22 eggs per day at 25°C and 4.79 eggs per day at 30°C) and were dependent on female age. In contrast, host-feeding rates for a given temperature did not depend on age. Generation time decreased with increasing temperatures from 68.05 days at 15°C to 12.19 days at 30°C. Net reproduction peaked at 20°C (68.86 viable females per female). Intrinsic rate of increase doubled from 15°C (0.059 females per female per day) to 20°C (0.127 females per female per day) and almost doubled again from 20 to 30°C (0.210 females per female per day). Given these parameters, C. sp. near lyncus could perform optimally in the area occupied by P. citrella in the Mediterranean region.     

An autecological study of the potentially toxic dinoflagellate Alexandrium affine isolated from Vietnamese waters

The potentially toxic dinoflagellate species Alexandrium affine isolated from Ha Long Bay (Tonkin Gulf), Vietnam was cultured and maintained for morphological, physiological and toxicological studies. Classical morphological examinations including plate pattern were in good agreement with the international nomenclature of the species. The fine structure of A. affine, including morphology of its developmental stages during vegetative and sexual reproduction was found to be typical of other species in the genus. Two general trends in growth of A. Affine from Vietnamese waters were apparent: (1) growth rates were low at low salinities (10 and 15 psu) in all experimental temperatures (21–27 °C); (2) growth rates were high at salinities 25, 30, and 35 psu in all temperatures. There were no significant differences in growth rates at different salinities at low temperature (21 °C), and the most significant difference in growth rate was between high temperature–high salinity and high temperature–low salinity. The optimum temperature and salinity for growth were 24 °C and 30 psu. Maximum division rates per day (0.5–0.7) were at salinities 30 and 35 psu and at temperatures 24 and 27 °C. But the best conditions for division rate were 21 and 24 °C at salinities 30 and 35 psu. Toxicity analyses indicated A. affine to be both toxic and non-toxic at certain times. In the former case, toxicity was very low, 2.28 fmol  per cell; the toxicity component of A. affine was compared with that of A. leei and the mussel Perna viridis including neoSTX, STX, and GTX₁–GTX₄.     

Cryotolerance and Cold Adaptation in Lactococcus lactis Subsp. lactis IL1403

The physiology of the cold-shock response in Lactococcus lactis subsp. lactis IL1403 at a subzero temperature, and cold-induced adaptation to heat shock, were investigated. Preincubation of cells at 8°C led to the development of cryotolerance, i.e., an enhanced capacity to survive exposure to freezing temperature (-20°C). Pretreatment with chemicals considered to be chaotropic agents did not induce cryotolerance or, in contrast, led to a decrease in survival capacity at -20°C. Interestingly, preincubation at 8°C led also to thermololerance to a 52°C challenge, but preincubation of cells at 42°C for 30 min did not improve their capacity to survive freezing-thawing exposure. These results demonstrate that cold- and heat-shock responses are physiologically linked by a complex relation. Furthermore, food processing at low temperature before subzero or heat treatment may need to be reconsidered.     

Genetic diversification of the Kanehira bitterling Acheilognathus rhombeus inferred from mitochondrial DNA,with comments on the phylogenetic relationship with its sister species Acheilognathus barbatulus

The Kanehira bitterling, Acheilognathus rhombeus, is a freshwater fish, discontinuously distributed in western Japan and the Korean Peninsula. Unusually among bitterling it is an autumn-spawning species and shows developmental diapause. Consequently, the characterization of its evolutionary history is significant not only in the context of the fish assemblage of East Asia, but also for understanding life-history evolution. This study aimed to investigate the phylogeography of A. rhombeus and its sister species Acheilognathus barbatulus, distributed in China, using a mitochondrial analysis of the ND1 gene from 311 samples collected from 50 localities in Japan and continental Asia. Phylogenetic analysis revealed that A. barbatulus is included in A. rhombeus and genetically closer to Japanese A. rhombeus than to Korean A. rhombeus. Divergence of Korean A. rhombeus and A. barbatulus from Japanese A. rhombeus was estimated to be from the late Pliocene (3.44 Mya) and the early Pleistocene (1.98 Mya), respectively. Each event closely coincided with the time of the Japan Sea opening. Japanese A. rhombeus comprised seven lineages: three in Honshu and four in Kyushu. One lineage in central Kyushu was genetically closer to the Honshu lineages than to other lineages in northern Kyushu. Divergence of Japanese lineages was estimated to be from the early to middle Pleistocene (0.55–0.93 Mya), during a period of geological and paleoclimatic change, including volcanic activity. Population expansion in the late Pleistocene (<0.10 Ma) was suggested in many of the lineages, which accords with other freshwater fishes. Biogeographically the ancestral A. rhombeus/A. barbatulus was likely to have repeatedly colonized Japan from the continent through land bridges in the late Pliocene and the early Pleistocene. However, the close genetic relationship between Japanese A. rhombeus and A. barbatulus suggests another possibility, with the second colonization occurring in reverse, from Japan to China. The small genetic distance between them indicates that the colonization occurred later than colonization events of other freshwater fishes, including other bitterling species.     

Comparison study of the modern ostracod associations in the Kara and Laptev seas: Ecological aspects

Recent ostracod assemblages were investigated from coretop sediment samples collected in the eastern Kara Sea from water depths down to 300 m. A total of 45 species were identified, 27 of them were reported for the Kara Sea for the first time. The Kara Sea data were compared with our results on the distribution of ostracods in the eastern Laptev Sea. The spatial distribution of recent taxa and the ecological groupings demonstrate a clear relation to dominant environmental factors which range from estuarine to full-marine conditions. Four assemblages related to average summer bottom water salinities were established: (1) a freshwater assemblage from the inner estuaries of the Ob' and Yenisei rivers with salinities less than 2 and from thermokarst lagoons of the southern Laptev Sea coast with strong salinization in winter; (2) a brackishwater assemblage of the outer estuaries of the Ob' and Yenisei rivers with salinities up to 26; (3) a mixed euryhaline–marine assemblage dominated by euryhaline species Paracyprideis pseudopunctillata and Heterocyprideis sorbyana from the inner shelf river-affected zone of the Kara and Laptev seas, where salinities range between 26 and 32; (4) a taxonomically diverse marine assemblage dominated by shallow-water marine taxa from the northern parts of the Kara and Laptev shelves and upper continental slope with stable bottom environments and a salinity higher than 32. Abundant euryhaline species found at greater water depths are identified as part of an ice-rafted assemblage. They are possibly entrained into the newly formed fast ice during autumn storms and freeze-up period and then transported to the distal open-sea areas during summer.     

Aspects of the Cryobiology of the Intertidal Harpacticoid CopepodTigriopus brevicornis(O. F. Müller)

Cold-resistance studies of marine invertebrates have concentrated on intertidal sedentary organisms, which are often subjected to subzero air temperatures in winter. Mobile rock pool inhabitants have been rarely studied because such habitats are thought to buffer environmental variation. However, it is not uncommon for small upper-shore rock pools (2 by 1 cm) to become completely frozen. Such supralittoral habitats are subject to extreme physicochemical fluctuations especially in salinity (0 to 300‰) and temperature (−1 to +32°C) due to evaporation and dilution. The dominant invertebrate in such habitats is the harpacticoid copepodTigriopus brevicornis.Aspects of the cryobiology ofT. brevicorniswere investigated using differential scanning calorimetry (DSC). Thermograms obtained from DSC allowed determinations of freeze-onset (supercooling point, SCP), melt-onset, and melt-peak (melting point, MP) temperatures, together with estimation of the proportion of water freezing in the samples. The effects of acclimation salinity, temperature, starvation, and reproductive state on these cryobiological parameters were investigated. Acclimation to increasing salinity depressed the SCP, with the highest salinity (70‰) producing the lowest SCP, melt-onset, and MP temperatures at −27.5, −15.2, and −9.5°C respectively. The highest acclimation temperature (20°C) produced the lowest SCP (−23.4°C). Starvation significantly increased the SCP, melt-onset, and MP temperatures in comparison to fed individuals acclimated to the same salinity. The presence of eggs or ovaries in individual copepods elevated the SCP compared to nongravid females and males. LT₅₀studies showed that acclimation to high salinity improved the ability ofT. brevicornisto survive in frozen seawater. Seventy parts per thousand acclimated individuals had an LT₅₀of 64.9 h compared with just 1.4 h for 5‰ acclimated individuals in frozen seawater at −5°C. The study shows that the cold-resistance capabilities ofT. brevicorniscan be affected by several different factors, and the link between the osmoconforming nature of this species and its cold resistance is discussed.     

Germination responses of Discopodium penninervium Hochst. to temperature and light

The germination responses of Discopodium penninervium were tested at different constant and alternating temperature regimes as well as under various light conditions both in the laboratory and glasshouse. Seeds incubated at 10, 15, 20, 25 and 30 °C failed to germinate. When the seeds were incubated at alternating temperatures of 20/12 °C and 30/12 °C under continuous light, germination was 89 and 61%, indicating that the species requires alternating temperatures as a cue for germination. However, germination declined as the amplitude of alternating temperatures increased from 8 °C and was completely inhibited at an amplitude of 23 °C, suggesting that the optimum amplitude is around 8 °C. Germination was less than 10% in light and nil in darkness at 20 °C in the laboratory. In contrast, seeds incubated at 20/12 °C germinated to 96 and 86% in light and darkness, respectively. Seeds incubated under leaf shade in the glasshouse failed to germinate whereas those incubated under direct daylight and darkness germinated to 44 and 50%, respectively, 30 days after sowing. When seeds incubated under leaf shade and in darkness were exposed afterwards to light, final percent germination was 83% from seeds incubated initially under direct daylight, 79% from those incubated under leaf shade and 86% from those incubated in darkness. The requirement for alternating temperatures and light rich in red:far red ratio to break the dormancy of seeds of D. penninervium could restrict germination to gaps in the vegetation. The results conform with the ecology of the species.     

Temperature effects on growth and cell size in the marine calcareaous dinoflagellate Thoracospaera heimii

Growth experiments were carried out on the marine calcareous dinoflagellate Thoracosphaera heimii. Two strains (A603, GeoB 86) of the phototrophic, predominantly vegetative coccoid T. heimii were cultured at different temperature and nutrient levels. For the temperature experiment a gradient box was developed to allow the simultaneous testing of a wide range of temperatures on phytoplankton. During the investigations T. heimii was growing from 14 to 27°C. Exponential growth rates do not show an unimodal response curve vs. temperature: values rise with increasing temperatures toward maximal growth rates around 27°C. At low temperatures exponential growth is extremely long (over 50 days). In f/2 culture medium T. heimii (A603) is less efficient at high temperatures than at low temperatures, final yield was about five times higher at 16°C than at 27°C. Growth rate and final yield at 27°C are approximately the same for all experiments, despite different nutrient levels. Mean shell diameters show no clear relation to growth temperature. Calcification of T. heimii shells is inversely related to temperature.     

Late Albian dinoflagellate cyst paleobiogeography as indicator of asymmetric sea surface temperature gradient on both hemispheres with southern high latitudes warmer than northern ones

Late Albian temperature sensitive dinoflagellate cysts are characterized in order to better understand mid-Cretaceous sea surface temperature gradients. Distribution maps of thirty-seven species recovered from one hundred fifty outcrops and deep sea drilling holes (ODP, DSDP) Sites located from low and high paleolatitudes over the two hemispheres (75°N–70°S) are encountered. Fifty years of published data available in eighty-seven articles have been considered and synthesized using a database coupled with a Geographical Information System (GIS). The continuous and disjoint biogeographic patterns of dinocyst species along latitudes define seven climatic belts, four in the northern hemisphere (high, mid-high, mid-low, low latitude belts) and three in the southern hemisphere (low, mid-low, mid-high latitude belts). Dinocysts restricted along latitudes are temperature sensitive species. Limit ranges of temperature sensitive dinocysts of mid-low and mid-high latitude belts reveal mixing belts, located at 40–45°N and 50°–70°S. They represent major palaeofrontal systems as paleosubtropical fronts with strongly mixed water column. The northern frontal system (40–45°N) was located as in the modern ocean. The large southern frontal system (50°S–70°S) was 10°–20° poleward to Antarctica. Semi-quantitative temperature range limits for mid-Cretaceous dinoflagellates and SST gradients in the two hemispheres are suggested by setting dinocyst climatic belts against estimated δ¹⁸O temperature curve from fish teeth. A paleoecological classification is suggested. Latitudinal distribution of extant temperature sensitive dinoflagellate cysts follows the asymmetric modern temperature gradient. Asymmetric latitudinal ranges of Late Albian dinocyst species of mid-low latitude belts restricted between 45°N and 70°S demonstrate asymmetric temperature gradients with southern high latitudes being warmer than northern high latitudes.     

Effect of cold storage on survival, reproduction and development of adults and eggs of Franklinothrips vespiformis (Crawford)

Cold storage effects on both female adults and eggs of the predatory thrips Franklinothrips vespiformis (Crawford) (Thysanoptera: Aeolothripidae) were investigated. The effect of low temperatures (5.5, 7.0, 8.5, 10.0 and 12.5 °C) on survival of F. vespiformis adults was firstly recorded. Survival times were significantly reduced at the lower temperatures tested, whereas storage at 10.0 and 12.5 °C provided the longest survival. Life-history consequences of exposing adults to moderately low temperatures were examined in terms of pre-oviposition period, oviposition rate, egg viability and survival after storage. Adults stored at 7.0 °C showed longer pre-oviposition period and shorter longevity than unstored females but other reproductive attributes were not significantly affected by storage regime. Low temperature and storage period affected egg viability and subsequent development of pre-imaginal stages. No eggs hatched after a 20-day period of storage at 5.5 and 7.0 °C, whereas eggs stored at 12.5 °C hatched significantly faster than ones stored at 10.0 °C and unstored eggs. Increasing the egg storage period from 10 to 20 and 30 days decreased the oviposition rate of adults and egg viability. An essential component in the successful mass rearing and distribution of these predators is the development of a reliable storage schedule of eggs and adults. Long-term storage was unsatisfactory, however their short-term storage (3.5 weeks at 10.0 and 12.5 °C for adults and 4–5 weeks at 12.5 °C for eggs) gave satisfactory results, which suggest the efficacy of such storage during the mass production of the biocontrol agent.     

Two macaque fossil teeth from the Japanese Pleistocene

Two fossil teeth of the Pleistocene macaque of Japan are stated to be those ofMacaca cf.fuscata. One of them is a lower canine tooth found in the Shiriya mine in northern Japan. It has been thought that the fossil assemblage of the Shiriya mine is of the late Pleistocene. The canine concerned is not distinguishable from the lower right one of the living female Japanese monkey. The other is a lower molar taken from the Ando quarry in western Japan. The fossil assemblage from the Ando quarry or from sites neighbouring the quarry indicates that the age of the molar can be traced back to the middle Pleistocene. The molar concerned has a somewhat buccolingually depressed crown as compared with that of the living Japanese monkey (Macaca fuscata).     

Taxonomy and sexual dimorphism of a new species of Loxoconcha (Podocopida: Ostracoda) from the Pleistocene of the Japan Sea

A new ostracod, Loxoconcha kamiyai sp. nov. in the Family Loxoconchidae, is described from the Pleistocene Omma Formation of Japan. Its geological and geographical distributions suggest that this species was once endemic to the Japan Sea, where it would have evolved until the Pliocene. Since the early Pleistocene, this species would have become extinct within this marginal sea during glacial maxima, probably due to its narrower salinity tolerances and geographical distributions than those of extant species inhabiting the euryhaline environments in other seas. The distributional patterns of pore systems in this species strongly suggest its closest phylogenetic affinities to a living species, Loxocorniculum mutsuense . These two species show a unique adult sexual dimorphism in the anterior element of the hingement. Taking the female hingement morphology as a standard, the male hingement can be explained in terms of heterochrony, i.e. paedomorphosis. Sexual hingement dimorphism with paedomorphosis occurs in only one phylogenetic group of the genus Loxoconcha , which is distinguished by the ontogenetic distributional patterns of pore systems. This morphology may represent relict primitive characters of ancient ostracods and could be an important character for evaluating the history of sexual dimorphism in ostracods since the Palaeozoic.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 239–251.