Converse Bergmann cline in a Eucalyptus herbivore,Paropsis atomaria Olivier (Coleoptera: Chrysomelidae): phenotypic plasticity or local adaptation?

Aim  To measure latitude-related body size variation in field-collected Paropsis atomaria Olivier (Coleoptera: Chrysomelidae) individuals and to conduct common-garden experiments to determine whether such variation is due to phenotypic plasticity or local adaptation.
Location  Four collection sites from the east coast of Australia were selected for our present field collections: Canberra (latitude 35°19' S), Bangalow (latitude 28°43' S), Beerburrum (latitude 26°58' S) and Lowmead (latitude 24°29' S). Museum specimens collected over the past 100 years and covering the same geographical area as the present field collections came from one state, one national and one private collection.
Methods  Body size (pronotum width) was measured for 118 field-collected beetles and 302 specimens from collections. We then reared larvae from the latitudinal extremes (Canberra and Lowmead) to determine whether the size cline was the result of phenotypic plasticity or evolved differences (= local adaptation) between sites.
Results  Beetles decreased in size with increasing latitude, representing a converse Bergmann cline. A decrease in developmental temperature produced larger adults for both Lowmead (low latitude) and Canberra (high latitude) individuals, and those from Lowmead were larger than those from Canberra when reared under identical conditions.
Main conclusions  The converse Bergmann cline in P. atomaria is likely to be the result of local adaptation to season length.     

Metazoan parasites of Sebastes capensis from two localities in northern Chile as tools for stock identification

Examination of 290 red rockfish Sebastes capensis from two fishing grounds in northern Chile (Coquimbo 71°30' W; 30°0' S and Antofagasta 70°40' W; 23°30' S) revealed 8770 metazoan parasites, belonging to 18 taxa: Udonella caligorum (Udonellidae); Interniloculus chilensis , Paramicrocotyle sp. and Neobenedenia melleni (Monogenea); larval Gnathia sp., Cirolana sp. and Rocinela sp. (Isopoda); Helicometrina nimia , Diphtherostomum sp., Lecithochirium sp. and Pseudopecoelus sp. (Digenea); Ascarophis sebastodis , Anisakis sp. and larval Hysterothylacium sp. (Nematoda); Caligus cheilodactylus , Lepeophtheirus chilensis and Trifur tortuosus (Copepoda); larval Corynosoma australe (Acanthocephala). Ten species were found only in Coquimbo and three were found only in Antofagasta, species common to both localities were Pseudopecoelus sp., C. australe , Anisakis sp. and A. sebastodis . Evidence, based on qualitative differences between the parasite faunas of the red rockfish, suggests the existence of two discrete stocks.     

A first record of Isistius plutodus in the north‐eastern Atlantic

One specimen of the largetooth cookiecutter shark Isistius plutodus was caught in the north‐eastern Atlantic at 43°58' N; 28°32' W. This is the first record of this rare species in the north‐eastern Atlantic and the northernmost point of its known distribution.     

Interactive controls of herbivory and fluvial dynamics on landscape vegetation patterns on the Tanana River floodplain, interior Alaska

Aim  We examined the interactive effects of mammalian herbivory and fluvial dynamics on vegetation dynamics and composition along the Tanana River in interior Alaska.
Location  Model parameters were obtained from field studies along the Tanana River, Alaska between Fairbanks (64°50.50' N, 147°43.30' W) and Manley Hot Springs (65°0.0' N, 150°36.0' W).
Methods  We used a spatially explicit model of landscape dynamics (ALFRESCO) to simulate vegetation changes on a 1-year time-step. The model was run for 250 years and was replicated 100 times.
Results  Increases in herbivory decreased the proportion of early successional vegetation and increased the proportion of late successional vegetation on the simulated landscape. Erosion and accretion worked as antagonists to herbivory, increasing the amount of early successional vegetation and decreasing the amount of late successional vegetation. However, the interactive effects of herbivory and erosion/accretion were especially important in determining system response, particularly in early seral vegetation types. High erosion rates, when coupled with low herbivory, greatly increased the proportion of willow on the landscape. When coupled with high herbivory, however, they greatly increased the proportion of alder on the landscape. At low levels of herbivory, alder abundance peaked at intermediate levels of erosion/accretion.
Main conclusions  Neither erosion/accretion nor herbivory produced consistent landscape patterns that could be predicted independently of the other. These findings underscore the importance of the interactive effects of biotic and abiotic disturbances in shaping large-scale landscape vegetation patterns in boreal floodplain ecosystems – systems traditionally thought to be driven primarily by abiotic disturbance alone.     

First record of Polyprion oxygeneios(Perciformes: Polyprionidae) for the south‐west Atlantic and a northernmost range extension

The occurrence of Polyprion oxygeneios (Perciformes: Polyprionidae) is recorded for the first in the south‐west Atlantic. Twenty specimens were caught off Rio Grande do Sul (33°41·8'–34° 15·3' S, 370–854 m depth) during winter cruises of the commercial fishing fleet.     

Energy balance and temperature relations of Azorella compacta, a high-elevation cushion plant of the central Andes

The environmental relationships and ecophysiology of Azorella compacta, a giant cushion plant, were investigated in Parque Nacional Lauca, Chile (18°10'–18°25' S and 69°16' W, 4400 m asl). The diurnal temperature range can reach 42 °C on some days of the year. The surface temperature of A. compacta was 13 °C below that of the air temperature of −7 °C at dawn, but from midmorning to late afternoon, the plant surface temperature remained within a few degrees of the air temperature. Soil surface temperatures did not differ between north- and south-facing slopes, but a model showed an increase in radiation reception by north-facing slopes throughout most of the year. Gas exchange measurements of A. compacta measured at the onset of the wet season ranged from −0.6662 to 11.4 μmol·m⁻²·s⁻¹, and maximum stomatal conductance (Gs) was 410 mmol·m⁻²·s⁻¹. The estimated light compensation point was 89 μmol·m⁻²·s⁻¹ and estimated light saturation occurred at about 1280 μmol·m⁻²·s⁻¹. Diurnal water potential measurements for A. compacta ranged from −1.67 to −2.65 MPa. This is one of the first ecophysiological studies of a tropical alpine cushion plant.     

Species richness, composition and abundance of fruit-feeding butterflies in the Brazilian Atlantic Forest: comparison between a fragmented and a continuous landscape

Aim  To evaluate frugivorous butterflies as indicators of forest disturbance in the Brazilian Atlantic Forest.
Location  The study area is located in the municipality of Cotia, São Paulo State, south-eastern Brazil (23°35'−23°50' S, 46°45'−47°15' W).
Methods  Sampling was done at four sites inside a large forest block, the Morro Grande State Reserve, and in five forest fragments in an adjacent fragmented landscape. Butterflies were sampled with portable traps, baited with a fermented mixture of banana and sugar cane juice. Sampling was carried out during the period most favourable for the capture of frugivorous butterflies in south-eastern Brazil.
Results  All richness-related results indicated no effect of forest fragmentation on the frugivorous butterfly guild, concurring with the suggestion of appreciable resistance of Atlantic Forest butterflies to habitat modification. However, species composition discriminated between the two landscapes, indicating that fragmentation may have effects beyond simple species richness. When species were analysed individually, clear patterns of distribution emerged, with some species that were very abundant in the fragmented landscape being practically absent in the continuous landscape, and vice versa. This pattern seems consistent even for some subfamilies.
Main conclusion  Our findings support the usefulness of the frugivorous butterfly guild as a biological indicator of forest disturbance effects in one of the world's most threatened ecosystems.     

Delayed egg production and a possible group effect in the blowfly Calliphora vicina

Abstract .Protein-fed Calliphora vicina , F₁ offspring of wild flies in two cages with lower and higher fly densities showed variable delay in starting oocyte vitellogenesis at ambient semi-natural temperatures in warm July–August weather in 1996 and 1997 at Durham in northern England (54°45' N). The high-density flies in 1996 showed no delay, in that the thermal sum (degree-days) experienced was 133, comparable to 18°C constant, assuming the lower threshold for egg maturation to be 5°C. Low-density cages and flies in a large outdoor cage (2 m³) in both years showed delays in production of first eggs of 34 days (thermal sum 293 degree-days) in 1996 and 32 days (396 degree-days) in 1997, and longer delays for other individuals. Delays in egg production at low densities relative to high densities seem to be a group effect of unknown mechanism.     

Evidence for a lacustrine faunal refuge in the Larsemann Hills, East Antarctica, during the Last Glacial Maximum

Aim  There is no previous direct evidence for the occurrence of lacustrine refuges for invertebrate fauna in Antarctica spanning the Last Glacial Maximum (LGM). In the absence of verified LGM lacustrine refuges many species are believed to result from Holocene dispersal from sub-Antarctic islands and continents further north. If freshwater lake environments were present throughout the LGM, extant freshwater species may have been associated with Antarctica prior to this glacial period. This study looked at faunal microfossils in a sediment core from an Antarctic freshwater lake. This lake is unusual in that, unlike most Antarctic lakes, the sediment record extends to c . 130,000 yr bp , i.e. prior to the LGM.
Location  Lake Reid, Larsemann Hills, East Antarctica (76°23' E; 69°23' S).
Methods  Palaeofaunal communities in Lake Reid were identified through examination of faunal microfossils in a sediment core that extended to c . 130,000 yr bp .
Results  Ephippia and mandibles from the cladoceran Daphniopsis studeri and loricae of the rotifer Notholca sp. were found at all depths in the sediment, indicating that these two species have been present in the lake for up to 130,000 years. Copepod mandibles were also present in the older section of the core, yet were absent from the most recent sediments, indicating extinction of this species from Lake Reid during the LGM.
Main conclusion  The presence of D. studeri and Notholca sp. microfossils throughout the entire Lake Reid core is the first direct evidence of a glacial lacustrine refugium for invertebrate animals in Antarctica, and indicates the presence of a relict fauna on the Antarctic continent.     

Are green turtles globally endangered?

Aim  To examine the exploitation, recovery and current status of green turtles ( Chelonia mydas ) nesting at Ascension Island.
Location  Ascension Island (UK) (7°57' S, 14°22' W), South Atlantic Ocean.
Methods  We analysed records of the harvest of green turtles nesting at Ascension Island between 1822 and 1935, illustrating the decline in numbers over this period. Using a deterministic age-class structured model we predict the initial number of breeding females present in the population prior to the recorded harvest and compare this to our estimate of the current population based upon our recent annual surveys (1999–2004).
Results  Prior to 1822 we estimate the nesting population of green turtles to have been at least 19,000–22,000 individuals in order for the population to have survived the level of harvest recorded. From recent data (1999–2004), we estimate the current breeding population of green turtles at this site to be 11,000–15,000 females. Our results illustrate a dramatic recovery of the population, which is still increasing exponentially and shows no evidence of slowing, suggesting it has not reached 50% of its carrying capacity.
Main conclusions  We estimate that, since the 1970s, the Ascension Island population of green turtles has increased by 285% and question the recent listing of this species as endangered by the IUCN (World Conservation Union), in particular in the Atlantic Ocean, where 75% of the populations assessed by the IUCN are increasing. Indeed, we estimate the global population of this species to be in excess of 2.2 million individuals. We suggest that the IUCN's global listing process detracts attention from those populations that are truly threatened with extinction and should not, in its present form, be applied to globally distributed long-lived species such as marine turtles.     

Towards a monophyletic genus Albinaria (Gastropoda, Pulmonata): the first molecular study into the phylogenetic position of eastern Albinaria species

Recent molecular phylogenetic studies of the terrestrial snail genus Albinaria have caused a radical reassessment of its taxonomy. These studies, however, were limited to western species. This paper examines mitochondrial 12S sequences and nuclear ITS1 & 2 sequences of both eastern and western species, and demonstrates that Albinaria, in its most recent definition, is not monophyletic. Both molecular datasets place ' Albinaria ' hedenborgi from Lebanon in a well-supported clade with species of the genus Cristataria , distributed south-east of the vicariant range of Albinaria . The remaining species from Cyprus, Turkey and Greece constitute a well-supported monophyletic group. These two clades form geographical clusters, whereas Albinaria in the current definition (including ' A. '  hedenborgi ) has a disjunct distribution. ' A.' hedenborgi should therefore be classified with Cristataria , together with the morphologically similar and geographically close ' A. '  nadimi .  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 531−542.     

Influence of rainfall seasonality on African lowland vegetation during the Late Quaternary: pollen evidence from Lake Masoko, Tanzania

Aim  To determine if changes in the key bioclimatic parameters associated with rainfall seasonality can be quantified from fossil sequences and to distinguish them from changes in the total annual rainfall.
Location  Lake Masoko, southern Tanzania (9°20' S, 33°45' E, 840 m a.s.l.).
Methods  Fossil pollen was extracted from a long and well-dated sedimentary sequence spanning the period 45,000–4400 cal. yr bp . The modern habitat, geographical distribution and climatic range (mean annual rainfall and temperature, and length of the dry season) of selected East African plants were used to infer past rainfall attributes for the most characteristic fossil pollen taxa identified from the sediments of Lake Masoko.
Results  In the Masoko pollen sequence it has been possible to identify changes in the length/severity of the dry season during the last 45,000 cal. yr bp , which are interpreted to reflect shifts in the mean position of the Intertropical Convergence Zone (ITCZ) over the southern tropics. We suggest that this bioclimatic parameter has been the main driver of the vegetation dynamics in this area. The major inferred change occurred at the Younger Dryas–Holocene transition c . 11,800 cal. yr bp , when semi-deciduous forest disappeared, being replaced in the lake catchment by woodland, which persists to the present day in spite of locally high rainfall.
Main conclusions  In tropical regions under the influence of the ITCZ, the position and strength of which determine the distribution of rainfall through the year, more attention must be paid to the impact of the length and intensity of the dry season on the modern and past distribution and dynamics of the vegetation. This climatic parameter is as important as the total annual amount of rainfall, and probably one of the most relevant in lowland areas.     

The Indochinese–Sundaic faunal transition at the Isthmus of Kra: an analysis of resident forest bird species distributions

Aim  To establish the geographical position of the biogeographical transition between Indochinese and Sundaic faunas using distributional data for the best-documented taxon, the birds.
Methods  Distributional data of 544 resident forest and forest edge bird species of Thailand and the Thai–Malay peninsula were examined at 45 sites spanning 15° of latitude from northern-most Thailand to the southern peninsular Malaysia. Sites were grouped into 23 degree or half-degree latitudinal zones and avifaunal similarity coefficients were calculated between each zone.
Results  A Mantel test revealed a significant transition between northern Indochinese and southern Sundaic (Indomalay) avifauna assemblages just north of the Isthmus of Kra (10°30' N). Northern and southern range limits of 152 species (> 269 species and subspecies combined) lie between 11° and 13° N.
Main conclusions  This transition between zoogeographical subregions is not coincident with the widely recognized transition between floristic provinces which is traditionally placed 400–500 km further south at the Kangar–Pattani line, but is associated with a change from wet seasonal evergreen dipterocarp rain forest to mixed moist deciduous forest north of the Isthmus of Kra in the northern Thai–Malay peninsula. Climatological and ecological factors associated with the distribution of forest types today are reviewed and it is hypothesized that the avian transition tracks the northern phytogeographical boundary. Palaeogeographical factors, including hypothetical Neogene seaways, which may account for the historical development of both phytogeographical and avifaunal transitions are also described.     

Contrasting water relations of three coastal tree species with different exposure to salinity

This field study examined the ecophysiological responses of three tree species to salinity in the Austin Bay Nature Reserve, adjacent to the Peel-Harvey Estuary in Western Australia (115°46' E 32°37' S). The area is at increased risk of flooding with saline water during storm surges due to the construction of a channel between the estuary and Indian Ocean in 1994. Banksia attenuata R.Br. occurs on small sandy ridges adjacent to a seasonal wetland, while Melaleuca cuticularis Labill. and Casuarina obesa Miq. occur in a seasonally flooded wetland. Landscape position determined exposure to salinity, with M. cuticularis and C. obesa experiencing high soil and groundwater salinity during summer (electrical conductivity, EC, up to 70 dS m⁻¹) while B. attenuata was not exposed to soil or groundwater with EC greater than 20 dS m⁻¹. B. attenuata had relatively stable leaf water status throughout the year and did not osmotically adjust as root-zone salinity increased. By contrast, M. cuticularis and C. obesa had large variation in stem water potential and exhibited osmotic adjustment during summer. Whereas the sap flow rates of M. cuticularis and C. obesa remained high throughout the year, sap flow of B. attenuata decreased during summer which may have limited uptake of salt. The three species also exhibited differences in traits associated with tissue-level salt tolerance, as M. cuticularis and C. obesa produced compatible organic solutes (methyl proline in M. cuticularis and proline in C. obesa ), whereas B. attenuata did not. The distributions of these species within the Austin Bay Nature Reserve are determined in part by their tolerance to salinity, which will influence their responses to hydrological disturbance.     

Rapid cold-hardening of Drosophila melanogaster in a field setting

Abstract.  Although laboratory studies demonstrate that cooling to ecologically relevant temperatures and/or at ecologically relevant rates induces rapid cold-hardening (RCH) in a variety of insects, little is known of the induction of RCH in nature. In the present study, caged Drosophila melanogaster (1–2 days posteclosion) from a colony established with flies collected locally are placed in a field setting (i.e. in approximately 4-cm deep leaf litter beneath an apple tree in Mount Pleasant, Michigan) during late afternoon (18.00 h EST; 05.00 h GMT). As the cage temperature falls from 22.1 ± 0.8 to 10.1 ± 0.1 °C between 18.00 and 06.00 h, the proportion of flies surviving a transfer to –6 °C for 1 h increases from 10.0 ± 6.2% to 68.1 ± 7.2%. When obtained from field cages, and then cooled from 23 °C at approximately 0.33 °C min⁻¹, more female flies remain behaviourally responsive (clinging to surfaces, exhibiting an active righting response, and/or climbing) at temperatures of 8–12 °C (24.00 h samples) or 7–12 °C (06.00 h samples), than do those sampled from cages kept in an incubator (23 °C). Field cooling reduces chill coma temperature from 8.7 ± 0.2 °C at 06.00 h to 7.1 ± 0.2 °C at 24.00 h, and to 6.6 ± 0.2 °C at 06.00 h. These data demonstrate that, in a recently collected culture of D. melanogaster , natural changes in microenvironmental temperature induce RCH that can benefit the organism at temperatures encountered in nature.     

Adaptative significance of a temperature induced diapause in a cosmopolitan parasitoid of Drosophila

Abstract. 1. We have previously demonstrated pre-pupal diapause in a tropical population of Leptopilima boulardi Barbotin, Carton and Kelner-Pillault (Cynipidae, Hymenoptera), a larval parasitoid of Drosophila melanogaster Meigen. Prepupal diapause was induced by low temperature (17.5°C) but absent at 25°C; it was independent of photoperiod.
2. Four populations which originated from different latitudes (4°S to 44°N) exhibit the same response to temperature without any major genetic geographical variation.
3. In temperate areas, this diapause may permit a phenological and temporal coincidence between the parasitoid and its host whose larval growth is only possible for temperatures above 13°C.
4. The significance of the persistence of this diapause in tropical areas is discussed.     

Age, growth and reproduction of the black scorpionfish, Scorpaena porcus (Pisces, Scorpaenidae), on the Black Sea coast of Turkey

Age, growth and reproduction of the black scorpionfish, Scorpaena porcus were studied in specimens from the coast of the Sinop Peninsula (Black Sea) between March 2002 and April 2003 in order to characterize these population parameters in comparison to specimens from populations of nearby regions. A total of 1086 specimens was captured by beam trawl at the depths between 0 and 30 m. The total number of females (510) was significantly higher than that of males (373). Total length of males and females ranged between 5.7 and 23.6 cm, and 4.9 and 31.7 cm, respectively. The length–weight relationship showed a positive allometric growth. Females grew faster and reached a larger size at age than males ( L _∞ = 111.9 cm, K  = 0.035 year⁻¹, φ' = 2.64 for females, and L _∞ = 74.6 cm, K  = 0.054 year⁻¹, φ' = 2.49 for males). The age range estimated was up to 8 years for females and 5 years for males. Reproduction likely occurs between June and September. Sex ratio varied greatly with season, perhaps indicating different seasonal migratory patterns in adults of different sex. An inverse correlation between gonadosomatic index (GSI) and hepatosomatic index (HSI) was evident during the reproduction seasons. The mean size at first sexual maturity was 17.5 cm TL for females, and 16.7 cm TL for males.     

The upper critical thermal limits for alevins of Arctic charr from a Norwegian lake north of the Arctic circle

Mean values ±95% CL of the upper incipient (T_IL) and ultimate (T_UL) lethal temperatures, determined at five acclimation temperatures ( T_A ), increased for T_IL from 19.2 ± 0.4° C ( T_A 0.5° C) to 21.0 ± 0.4° C ( T_A 20° C), and for T_UL from 22.6 ± 0.1° C ( T_A 0.5° C) to 26.6 ± 0.4° C ( T_A 20° C). Mean values were close to those obtained for Arctic charr alevins from Windermere (north-west England). These comparative data for alevins, and previous data for 0+ year parr, indicate negligible geographical variation in the thermal limits of Arctic charr.     

Revision of the Australian species of Hyalobathra Meyrick (Lepidoptera: Pyraloidea: Crambidae: Pyraustinae) based on adult morphology and with description of a new species

Abstract The genus Hyalobathra Meyrick is redefined based on five Australian species including the type  species. The four named Australian species, H. archeleuca Meyrick, H. unicolor (Warren) , H. miniosalis (Guenée) and H. minialis (Warren), are redescribed and a new species, H. crenulata sp. n., is described . Hyalobathra unicolor is removed from synonymy with H. illectalis (Walker), and lectotypes are designated for H. archeleuca , H. minialis and for H. rhodoplecta Turner, a synonym of H. miniosalis . The presence of H. paupellalis (Lederer) in Australia could not be confirmed, but its genitalia are figured. Two previously included species, ' Hyalobathra ' aequalis (Lederer) and ' H .'  brevialis (Walker), are excluded from Hyalobathra, as they lack its generic apomorphies, but cannot at present be assigned to any other genus.     

Temperature- and salinity-dependent development of a Nordic strain of Ichthyophthirius multifiliis from rainbow trout

During the twentieth century evidence was presented which suggested the presence of various strains and races of the parasite Ichthyophthirius multifiliis Fouquet. However, ecological profiles of various parasite isolates from different climatic zones are sparse. Such stringent characterizations of parasite development at defined abiotic conditions could provide valuable criteria for the different races; profile comparison from various localities is one way to differentiate these strains. Baseline investigations were therefore performed on the associations between abiotic factors (temperature/salinity) and the development of theronts in tomocysts of I. multifiliis isolated from rainbow trout in a Danish trout farm. It was shown that tomocyst formation and theront development took place between 5 and 30°C. Development rates and sizes of theronts were clearly affected by temperature: theronts escaped tomocysts already after 16–27 h at 25°C and 30°C, whereas this process took 8–9 days at 5°C. Likewise, theront size decreased steadily from a maximum of 57.4 × 28.6 μm at 5°C to 28.6 × 20.0 μm at 30°C. This size variation was only partly associated with the number of theronts that appeared at different temperatures. The lowest number of theronts escaping from one tomocyst was indeed found at 5–7°C (mean 329–413). At 11.6, 17.0 and 21°C, the highest number of theronts appeared (mean 546–642). However, at 25 and 30°C, the number decreased (458 and 424, respectively). Additional studies on the salinity dependent development of the parasite (at 11.6°C) showed that salinities above 5 p.p.t. totally inhibited development. Even at 5 p.p.t. the developmental time significantly increased and the number of theronts produced from one tomocyst decreased.