Two Gonostomatid Ciliates from the Soil of Lombardia,Italy; including Note on the Soil Mapping Project

Two gonostomatid ciliates, Gonostomum paronense n. sp. and G. strenuum, isolated from the soil sample of paddy field, Lombardia, Italy, were investigated using live observation and protargol impregnation. Gonostomum paronense n. sp. is mainly characterized by a tailed body, frontoventral cirri arranged in pairs, and presence of pretransverse and transverse cirri. Morphologically and morphometrically, the new species is similar to Gonostomum namibiense in having a tailed body and frontoventral cirral pairs; however, it differs mainly in the number of frontoventral cirral pairs (seven vs. three). Phylogenetic analyses based on the SSU rDNA sequences show that the new species is more closely related to G. namibiense than to G. strenuum, supporting the morphological classification based on the cirral pattern and the tailed body. However, due to the poor nodal support and absence of gene sequence of the type species Gonostomum, a more robust phylogeny of this group still remains unresolved. The biometric data of the Italian population of Gonostomum strenuum overlap with those from other known populations. Both species were collected from the industrial area of Parona, in the framework of the “Soil Mapping, Lombardia” project in which, for the first time in Italy, soil ciliates were used as bioindicators of soil quality.     

New species, observations, and a list of new records of brown algae (Phaeophyceae) from the Hawaiian Islands

Two new species of brown algae (Phaeophyceae), Padina moffittiana Abbott et Huisman, sp. nov. and Cutleria irregularis Abbott et Huisman, sp. nov., are described from the Hawaiian Islands (between 19°04′N, 155°35′W and 28°25′N, 178°20′W). In addition, the new combination Cutleria canariensis is proposed for Aglaozonia canariensis. New observations are presented on Nereia intricata Yamada, a species described 67 years ago and known only from its type specimen. New records of a further 14 species are given for the Hawaiian Islands. These 17 taxa bring the total number of species of brown algae recorded for the Hawaiian Islands to 55, an increase of 28%. Of the 15 new records, two are recent ‘accidental’ introductions: Dictyota flabellata (Collins) Setchell et Gardner and Sargassum muticum (Yendo) Fensholt from California. Six records are notable because of their great distances from previously known collections: Nereia intricata Yamada from the Ryukyu Is., Japan; Discosporangium mesarthrocarpum (Meneghini) Hauck, from the Adriatic, Mediterranean, warm Atlantic and southern Australia; Distromium flabellatum Womersley, Spatoglossum macrodontum J. Agardh, and Sporochnus moorei Harvey, from Australia; Desmarestia ligulata (Lightfoot) Lamouroux from temperate and colder waters in the Pacific and Atlantic. A comparison with some Japanese species of Padina confirms that Padina japonica Yamada should be subsumed with Padina sanctae‐crucis Børgesen, as proposed earlier.     

Species of Gonostomum and Paragonostomum (Ciliophora, Hypotrichida, Oxytrichidae) from the Valley of Flowers, India, with descriptions of Gonostomum singhii sp nov, Paragonostomum ghangriai sp nov and Paragonostomum minuta sp nov

Soil samples taken from the Valley of Flowers, a component of the Nanda Devi Biosphere Reserve in the Himalayan regions of India showed the presence of twenty two free living species of ciliates. There is a preponderance of species which exhibit oral ciliature and ontogenesis in the Gonostomum pattern. Of the four species of the genus Gonostomum, three viz., G affine, G gonostomoida and G kuehnelti are similar to described species; Gonostomum singhii is new. The two species of genus Paragonostomum viz., P minuta and P ghangriai are new. The three new species are described in the present paper. All these species show prominent hypertrophied ciliary structures. Their paroral membranes reveal characteristic differences with respect to their position, number of constituent cilia and the distance between adjacent cilia. It is proposed that such species specific features of the paroral membrane have a bearing in exercising different food organism preferences as they co-exist at many sites. This single factor has possibly played an important role in species diversification of this group of hypotrichs in this isolated habitat.     

Tonnacypris glacialis (Ostracoda, Cyprididae): taxonomic position, (palaeo-) ecology, and zoogeography

Abstract. The freshwater ostracod Tonnacypris glacialis (Sars, 1890) is reported from the European Pleistocene for the first time. The historical allocation of the species is discussed, and the species composition and characteristics of Tonnacypris Diebel & Pietrzeniuk (1975) and its phylozoogeography are considered. The significance of T. glacialis is reviewed, particularly from the viewpoint of the possible implications of parthenogenesis (and occasional-male production) for the Quaternary history of the genus, and for the use of the species in palaeoenvironmental reconstruction. It is suggested that the Pleistocene fossil occurrence of T. glacialis in modern temperature latitudes is a robust indicator of mean summer temperatures of 6°C.     

Heat stress responses and population genetics of the kelp Laminaria digitata (Phaeophyceae) across latitudes reveal differentiation among North Atlantic populations

To understand the thermal plasticity of a coastal foundation species across its latitudinal distribution, we assess physiological responses to high temperature stress in the kelp Laminaria digitata in combination with population genetic characteristics and relate heat resilience to genetic features and phylogeography. We hypothesize that populations from Arctic and cold‐temperate locations are less heat resilient than populations from warm distributional edges. Using meristems of natural L. digitata populations from six locations ranging between Kongsfjorden, Spitsbergen (79°N), and Quiberon, France (47°N), we performed a common‐garden heat stress experiment applying 15°C to 23°C over eight days. We assessed growth, photosynthetic quantum yield, carbon and nitrogen storage, and xanthophyll pigment contents as response traits. Population connectivity and genetic diversity were analyzed with microsatellite markers. Results from the heat stress experiment suggest that the upper temperature limit of L. digitata is nearly identical across its distribution range, but subtle differences in growth and stress responses were revealed for three populations from the species’ ecological range margins. Two populations at the species’ warm distribution limit showed higher temperature tolerance compared to other populations in growth at 19°C and recovery from 21°C (Quiberon, France), and photosynthetic quantum yield and xanthophyll pigment responses at 23°C (Helgoland, Germany). In L. digitata from the northernmost population (Spitsbergen, Norway), quantum yield indicated the highest heat sensitivity. Microsatellite genotyping revealed all sampled populations to be genetically distinct, with a strong hierarchical structure between southern and northern clades. Genetic diversity was lowest in the isolated population of the North Sea island of Helgoland and highest in Roscoff in the English Channel. All together, these results support the hypothesis of moderate local differentiation across L. digitata's European distribution, whereas effects are likely too weak to ameliorate the species’ capacity to withstand ocean warming and marine heatwaves at the southern range edge.     

Effect of temperature and dark pretreatment on the germination of three species of Jamesonia (Pteridaceae,Polypodiopsida)

To study the influence of temperature on the germination ability of three species of Jamesonia (Jamesonia imbricata, Jamesonia scammaniae and Jamesonia rotundifolia), spores were cultured at 10°C, 15°C and 20°C. A temperature of 15°C was selected as representative of the natural annual average temperature of the paramo environment that Jamesonia species inhabit. In addition, a dark pretreatment of 2 days was tested to verify if germination was enhanced. The results indicated that germination of Jamesonia, considering the three species as a whole, is affected by temperature, but is independent of the dark treatment. All species showed higher and faster germination at 20°C, and exhibited a threshold minimum temperature around 10°C, below which germination is avoided or extremely low and delayed. This could suggest that spore germination in Jamesonia is adapted to establish gametophyte populations during frost‐free periods.     

THE EFFECTS OF TEMPERATURE ON THE PHOTOSYNTHETIC PARAMETERS AND RECOVERY OF TWO TEMPERATE BENTHIC MICROALGAE,AMPHORA CF. COFFEAEFORMIS AND COCCONEIS CF. SUBLITTORALIS (BACILLARIOPHYCEAE)1

Temperature and irradiance are the most important factors affecting marine benthic microalgal photosynthetic rates in temperate intertidal areas. Two temperate benthic diatoms species, Amphora cf. coffeaeformis (C. Agardh) Kütz. and Cocconeis cf. sublittoralis Hendey, were investigated to determine how their photosynthesis responded to temperatures ranging from 5°C to 50°C after short‐term exposure (1 h) to a range of irradiance levels (0, 500, and 1,100 μmol photons · m^?2 · s^?1). Significant differences were observed between the temperature responses of maximum relative electron transport rate (rETRmax), photoacclimation index (E_k), photosynthetic efficiency (α), and effective quantum yield (ΔF/F_m’) in both species. A. coffeaeformis had a greater tolerance to higher temperatures than C. sublittoralis, with nonphotochemical quenching (NPQ) activated at temperatures of 45°C and 50°C. C. sublittoralis, however, demonstrated a more rapid rate of recovery at ambient temperatures. Temperatures between 10°C and 20°C were determined to be optimal for photosynthesis for both species. High temperatures and irradiances caused a greater decrease in ΔF/F_m’ values. These results suggest that the effects of temperature are species specific and that short‐term exposure to adverse temperature slows the recovery process, which subsequently leads to photoinhibition.     

Temperature requirements for the growth of young sporophytes of Undaria pinnatifida and Undaria undarioides (Laminariales, Phaeophyceae)

The relative growth rate of young sporophytes of Undaria pinnatifida (Harvey) Suringar and Undaria undarioides (Yendo) Okamura was examined in order to understand the difference in distribution of these two species around the coast of Japan. The optimal temperature for growth of both species was similar at 20°C and the upper critical temperature for growth was also similar, at 27°C for U. pinnatifida and 26°C for U. undarioides. Therefore, the optimal and upper critical temperatures for growth of the young sporophytes are not the main factors determining the distribution of each species. Next, the lower critical temperatures for growth were examined. For the young sporophytes of U. pinnatifida, the lower limit was less than 5°C while for those of U. undarioides it was 15°C. Thus, the difference in the lower critical temperature for growth between the two species was approximately 10°C. During the period of young sporophyte growth in the field, the temperature at the mouth of Ise Bay, Japan, where U. pinnatifida occurs, ranges from 12.7°C in December to 13.1°C in April, with a minimum of 7.9°C in February. Our experiments indicate that young sporophytes are able to grow throughout this period. The temperature off Hamajima, Japan, where U. undarioides occurs, ranges from 19.1°C to 14.8°C during the same time period. Again, young sporophytes are able to growth throughout this period, although minimum winter temperatures are only just high enough for growth. These natural temperature ranges during the growth season of the sporophytes agree well with the experimentally determined temperature requirements for growth of each species. Therefore, the difference between the two species in the critical temperature required for growth of the young sporophytes, especially in the low temperature range, is one of the major factors determining the distribution pattern of each species.     

Ectothermic vertebrates (Actinopterygii,Allocaudata, Urodela,Anura, Crocodylia,Squamata) from the Miocene of Sandelzhausen (Germany,Bavaria) and their implications for environment reconstruction and palaeoclimate

The Early to Middle Miocene fossil locality Sandelzhausen has yielded 48 species of ectothermic vertebrates and thus represents one of the most diverse ectotherm faunas of Miocene age. Thirty-five taxa of fishes, amphibians and reptiles, including three new species: Pelobates fahlbuschi nov. sp. (Pelobatidae, the most abundant vertebrate), Tropidophorus bavaricus nov. sp. (Lygosominae) and Bavaricordylus molassicus nov. sp. (Cordylidae), are described. Three additional species are new, but are not named yet: Ranidae indet. nov. gen. et sp., Anguidae gen. indet. sp. nov. and Palaeoblanus sp. nov. (Amphisbaenidae). In order to reconstruct the palaeoenvironment and past hydrologic conditions, a new methodology (the tooth replacement method, TRM) is introduced, which allows for the detection of autochthonous components within freshwater fish taphocoenose. TRM is tested on 45 localities from the Upper Freshwater Molasse and gives reasonable results in agreement with other analytical approaches. It is therefore viewed as a reliable method to distinguish perennial from seasonal water conditions at the Sandelzhausen locality. Using the TRM it was demonstrated that the palaeohydrology of Sandelzhausen is characterized by a change from temporary water to permanent water conditions. During the period of temporary water conditions (units B to D1, lower part) the ecosystem was driven by seasonal inundations, and the remaining riparian pools have yielded no autochthonous fish population, but acted as spawning places for amphibians (amphibian pool). A mostly open habitat in the close vicinity, with sandy and non-groundwater-affected soils during the dry season, is suggested based on the absolute dominance of the spadefoot Pelobates fahlbuschi nov. sp. This ecosystem changed up-section (late part of unit D1 and during D2 and E) due to the establishment of permanent water conditions of riparian pond type, preserving an autochthonous Palaeocarassius/Channa fish population (fish pond). The reconstructed precipitation values suggest that the observed change in hydrologic conditions was probably driven by climate. The lower part of the section gives semi-arid/sub-humid values, with 571 mm mean annual precipitation (MAP), whereas the upper part yields sub-humid/humid values of 847 mm MAP. The increase in precipitation by about 280 mm was perhaps caused by a less seasonal precipitation regime with concomitant higher regional groundwater tables during units D2 and E. Based on the occurrence of several thermophilous reptile species, and in agreement with palaeobotanical and oxygen isotope data, the climate of Sandelzhausen is interpreted as subtropical with mean annual temperatures from 18°C to 20.8°C, mean cold month temperatures from 12.6°C to 13.3°C and mean warm month temperatures from 25.1°C to 28.1°C.     

Temperature requirements for the growth and maturation of the gametophytes of Undaria pinnatifida and U. undarioides (Laminariales, Phaeophyceae)

Gametophytes of two Undaria species, U. pinnatifida and U. undarioides (Laminariales, Phaeophyceae), were studied to determine their water temperature requirements in order to understand their different distributions in Mie Prefecture, Japan. The optimal temperature for growth was 20°C for gametophytes of both species, and the upper critical temperature for growth was also the same for both species at 28°C. Therefore, the optimal and critical temperatures for growth of the gametophytes are not the main factors determining distribution. The optimal temperature for maturation of U. pinnatifida was approximately 10–15°C, whereas it was closer to 20–21°C for U. undarioides, a difference between these species of at least 5°C. In autumn and early winter, the seawater temperature at the mouth of Ise Bay, where U. pinnatifida is distributed, ranges from 21.6°C (October) to 12.7°C (December), and off Hamajima, where U. undarioides is found, the range is from 22.7°C (October) to 19.1°C (December). The seawater temperatures from October to December, which is the maturation season for the gametophytes, agreed well with the optimal temperature requirements for maturation of the gametophytes of both species. Thus the difference in the maturation temperature range of the gametophytes is a major factor determining distribution of these Undaria species along the Japanese coast.     

Lack of metabolic temperature compensation in the intertidal gastropods,Littorina saxatilis (Olivi) and L. obtusata (L.)

Two intertidal snails, Littorina saxatilis (Olivi, 1972) (upper eulittoral fringe/maritime zone) and Littorina obtusata (Linnaeus, 1758) (lower eulittoral) were collected from a boulder shore on Nobska Point, Cape Cod, Massachusetts, in July and acclimated for 15–20 days at 4 ° or 21 °C. Oxygen consumption rate (Vo₂) was determined for 11–15 subsamples of individuals at 4 °, 11 ° and 21 °C with silver/platinum oxygen electrodes. Multiple factor analysis of variance (MFANOVA) of lo₁₀ transformed values of whole animal Vo₂ with log₁₀ dry tissue weight (DTW) as a covariant revealed that increased test temperature induced a significant increase in Vo₂ in both species (P<0.00001). In contrast, MFANOVA revealed that temperature acclimation did not affect Vo₂ in either L. saxatilis (P= 0.35) or L. obtusata (P= 0.095). Thus, neither species displayed a capacity for the typical metabolic temperature compensation marked by an increase in Vo₂ at any one test temperature in individuals acclimated to a lower temperature that is characteristic of most ectothermic animals. Lack of capacity for metabolic temperature acclimation has also been reported in other littorinid snail species, and may be characteristic of the group as a whole. Lack of capacity for respiratory temperature acclimation in these two species and other littorinids may reflect the extensive semi-diurnal temperature variation that they are exposed to in their eulittoral and eulittoral fringe/maritime zone habitats. In these habitats, any metabolic benefits derived from longer-term temperature compensation of metabolic rates are negated by extreme daily temperature fluctuations. Instead, littorinid species appear to have evolved mechanisms for immediate metabolic regulation which, in L. saxatilis and L. obtusata and other littorinids, appear to centre on a unique ability for near instantaneous suppression of metabolic rate and entrance into short-term metabolic diapause at temperatures above 20–35 °C, making typical seasonal respiratory compensation mechanisms characteristic of most ectotherms of little adaptive value to littorinid species.     

Temperature requirements for growth and maturation of the warm temperate kelp Eckloniopsis radicosa (Laminariales,Phaeophyta)

The annual kelp Eckloniopsis radicosa is distributed along Japanese coasts and occurs within the area with a February isotherm ranging 15–18°C and August isotherm ranging 25–28°C. In this study, the effects of temperature on the gametophyte growth and maturation, and the young sporophyte growth of E. radicosa were examined and the results are discussed in relation to the distribution of other warm‐adapted kelp species and the potential effects of climate change. The optimal temperature ranges for growth of male and female gametophytes were 23–27°C and 20–26°C, respectively. The upper survival temperature for gametophyte growth was 31°C for males and 30°C for females, respectively. The optimal temperature range for maturation of female gametophytes was ≤23°C. The optimal temperature range for growth of young sporophytes was 14–22°C. It was clarified that E. radicosa has the most warm‐adapted characteristics for growth and maturation of gametophytes among members of the Laminariales studied so far. The natural seawater temperature ranges during the growth and maturation seasons for gametophytes of E. radicosa, as well as the growth season for young sporophytes near to the northern and southern distribution limits (Izu‐Oshima: 14.9–24.5°C, Ichiki‐kushikino: 17.1–29.6°C), agreed with the experimentally determined temperature requirements. The warm‐adapted gametophyte stage and annual lifecycle are major factors enabling survival of E. radicosa in warm waters near tropical regions along the Japanese coast.     

Growth energetics in relation to temperature for larvae of four species of necrophagous flies (Diptera: Calliphoridae)

The growth characteristics of the larvae of the major members of a necrophagous fly guild in Tasmania (Lucilia cuprina, Calliphora stygia, Calliphora vicina and Calliphora hilli) were measured to assess their competitive ability. The measurements were made at temperatures between 10 and 45°C, to cover the range of temperatures that would be encountered by larvae in carrion or myiasis under field conditions. The characteristics measured were net production and respiration. The indices K_2i (instantaneous growth efficiency), K_2c (cumulated growth efficiency) and M_i (instantaneous cost of maintenance) were calculated. Generally K_2c and K_2i are highest and M_i lowest at 25°C for all the species. A sinusoidal response in K_2c, K_2i and M_i against temperature is seen for L. cuprina, C. stygia and C. vicina. This response is‘cold’adapted in the Calliphora species and‘warm’adapted in L. cuprina. Egg size, egg caloric density and the energy content of the eggs are discussed in relation to the‘fitness’and reproductive strategies of the four species. The thermal tolerance range of L. cuprina determined here suggests that carrion may provide a significant number of this fly particularly in areas where Chrysomya spp. do not occur, and in large carcasses where temperatures are elevated.     

Telltale eyes: the lateral visual systems of Rhenish Lower Devonian eurypterids (Arthropoda,Chelicerata) and their palaeobiological implications

The compound eyes of three taxa of Rhenish Lower Devonian eurypterids are examined and compared with those known from other eurypterids and the extant horseshoe crab Limulus polyphemus. The lateral eyes of the small species Rhenopterus diensti, a phylogenetically basal representative of the stylonurine clade, are characterized by a comparatively low number of lenses and high interommatidial angle Δφ (2.8°). The comparatively limited visual capacities of R. diensti are more similar to L. polyphemus than to its closer relatives of the eurypterine clade and perhaps this reflects a progression of lateral eye structure in the evolution of eurypterids as a whole. The number of eye facets in Adelophthalmus sievertsi is higher than that in the supposed ambush predator Acutiramus cummingsi, but lower than that in other ‘swimming’ eurypterids (Eurypterina). Due to poor preservation, no other eye parameters could be analysed in this species, but further morphological attributes and geographical distribution designate the mid‐sized A. sievertsi as an able swimmer. A low interommatidial angle Δφ of less than 1° confirms that the visual capacities of Jaekelopterus rhenaniae are in line with an interpretation of this giant species as an active high‐level predator. The inferred lifestyles of adult individuals of these three, co‐occurring Rhenish eurypterids indicate niche differentiation avoiding to some degree the competition for food in their marginal marine to delta plain transitional habitats.     

Phytogeography, range size and richness of Australian endemic Sauropus (Euphorbiaceae)

Aim To investigate the distribution of Australian species of Sauropus. The information obtained is used to (1) identify areas of highest richness and centres of endemism, (2) investigate latitudinal gradients of richness and range size, (3) determine the types of rarity shown, and (4) provide hypotheses on historical biogeography of the genus within Australia. Location Australia. Methods Specimens from 17 herbaria and field searches were examined and label and field information collated on distribution, habit and habitat. Distribution information was used to map all species within 784 grid cells of 1° × 1° and within the 97 Australian ‘ecological regions’. Morphometric cluster analysis of species was conducted using Kulczynski association and flexible UPGMA on 23 character states. Simple regression was used to correlate species richness, density and range size to changes in latitude. CLIMEX is used to match the climate of the region of highest richness in Australia with other areas of the world. Results Species richness was highest within the tropical north of Australia, and most species were associated with tropical savanna woodlands. Two areas were identified as centres of endemism and these corresponded closely to areas of high species richness. Four morphological groups were identified. One species (Sauropus trachyspermus) was found to be widespread, however all other species had small geographical ranges. Species richness and range size were significantly correlated with changes in latitude. Ten species were found to be of the rarest type, warranting conservation initiatives. Main conclusions Two regions of high richness and endemism of Sauropus occur, Thailand and Australia. Within Australia, the Kakadu‐Alligator River and the Cairns‐Townsville areas were identified as centres of endemism and high species richness for Sauropus. Australian Sauropus in general occur in similar communities and climates as other members of the genus elsewhere. Ten of the 27 species of Australian endemic Sauropus are extremely rare and warrant conservation initiatives. Correlations of latitude to species richness are potentially due to Sauropus radiating from the climatically stable top end of Australia. Increasing range size in more southern latitudes may also be due to stability of climates in the top end or because there is more available land area at these latitudes. Sauropus micranthus, the only non‐endemic species, is probably a more recent invader from the Tertiary period when tropical rain forests where more extensive and congruent with those of New Guinea.     

DISTINCTION OF SOUTH AMERICAN HAPLOGLOIA ANDERSONII AND CHORDARIA LINEARIS (PHAEOPHYCEAE) BASED ON DIFFERENCES IN SEXUAL REPRODUCTION,MORPHOLOGY, ECOPHYSIOLOGY,AND DISTRIBUTION1

Haplogloia andersonii (Farlow) Levring is an anti-tropical species that occurs on cold and warm-temperate Pacific coasts of both Americas. In its habit it resembles the subantarctic species Chordaria linearis (Hooker et Harvey) Cotton. Culture studies show that the species differ in morphology and ecophysiology of their microscopic gametophytes and in gamete behavior. Details of sporophyte anatomy are presented that also allow the distinction of field plants. In South America, H. andersonii occurs only on the Pacific coast, from central Perú (14°S) to southern Chile (50°S). Chordaria linearis occurs on the Pacific coast from Chiloé Island (43°S) to Cape Horn (56°S). In the shared area the species may co-occur. On the Atlantic coast, C. linearis was newly collected at a locality in northern Patagonia (41°S). In addition, C. linearis occurs in Antarctica. Haplogloia moniliformis Richer, recently described from Macquarie Island, is probably synonymous with Chordaria linearis.     

Congruence of electrical properties in two Antarctic and two middle-latitude marine species of Euplotes (Ciliata, Hypotrichida)

Electric membrane properties and motor behaviour of two Antarctic and two middle-latitude species of Euplotes were compared. Membrane potential fluctuations and whole-cell currents were measured using the whole cell clamp. The electrical properties of both of the Antarctic species between themselves and of both of the middle-latitude species are nearly identical. Furthermore, after warming up to 22°C, the Antarctic species grown at 4°C show the same pattern of spontaneous potential fluctuations, induced potential oscillations and membrane currents as the middle-latitude species grown and measured at 22°C. After cooling down to 4°C, the middle-latitude species grown at 22°C show the same electrical properties as the Antarctic species grown and measured at 4°C. The congruence of the temperature-dependent electrical properties in Euplotes species from completely different habitats is presumably based on a universal mechanism of temperature dependence of ionic conductances, indicating the close physiological relationship among the species. Received: 29 October 1997 / Accepted: 20 April 1998     

New Host and Locality Records for the Ixodes Auritulus (Acari: Ixodidae) Species Group, with a Review of Host Relationships and Distribution in the Neotropical Zoogeographic Region

New Neotropical records are presented for ticks belonging to the Ixodes auritulus Neumann, 1904, species group, together with a review of hosts and localities from which members of this complex have previously been collected. The range of the I. auritulus species group is now understood to include Colombia, and 15 bird species are listed as new hosts. From Guatemala to southern Argentina and Chile, specimens of the I. auritulus group have been found on birds belonging to the orders Ciconiiformes, Columbiformes, Falconiformes, Galliformes, Passeriformes, Piciformes, Procellariiformes and Tinamiformes. Passeriform birds are probably the principal hosts, sustaining tick populations throughout the Neotropics. Collection data have yielded four areas – southern South America (from 56° S to 51° S), southern Brazil (25° S–22° S), south-central Peru (14° S–10° S) and Central America (10° N–15° N) – where the I. auritulus group appears to commonly parasitize birds, but additional collections may show that the range of this complex is less discontinuous than currently perceived. Several morphological differences are described for ticks within and among these areas, but it is still unclear whether the I. auritulus group comprises more than one species.     

The effects of productivity and seasonality on life history: comparing age at maturity among moose (Alces alces) populations

The productivity hypothesis in respect of an animal species’ geographical range predicts that whereas higher productivity at the equatorial periphery of a species’ range favours superior competitors, lower productivity at the centre of a species’ range favours high reproduction and reduced competitive traits. I test whether life‐history patterns follow this hypothesis, using demographic data from 15 Canadian moose (Alces alces) populations. Two models are contrasted; the first assumes that intraspecific variation in age at maturity is explained proximately by density and juvenile mortality. Age at maturity was found to increase with decreasing juvenile mortality (P = 0.01) and increasing density (P = 0.006). To test the productivity hypothesis, the second model additionally included primary productivity and seasonality as geographical explanatory variables that would ultimately influence age at maturity via juvenile mortality and density. Path analysis indicated that including productivity and seasonality improved the model predictions of variation in age at maturity (R_a² 0.56 and 0.85). In bivariate comparisons, seasonality was negatively associated (P = 0.01) with age at maturity. In the best model, however, primary productivity was the environmental variable that explained 25% of the variance in age at maturity, and forest cover replaced seasonality as an explanatory variable. The positive association between primary productivity and age at maturity is consistent with the productivity hypothesis. Relative to populations that lived at the centre of the species’ range (51°N), moose populations living in relatively high productivity and low seasonality environments (equatorial periphery of species’ range; 48°N) experienced less juvenile mortality, more variable year‐to‐year density, higher relative density and slower life history (slower growth rate, later age at maturity, lower fecundity).