Northernmost Distribution Research Articles

First successful nest for the Vulnerable American crocodileCrocodylus acutuspopulation on the west coast of Florida, USA

AbstractThe American crocodileCrocodylus acutusoccurs across the Americas, with its northernmost distribution being in South Florida, USA. This species has undergone severe declines across its range and is categorized globally as Vulnerable on the IUCN Red List and as Threatened on the U.S. Federal Endangered Species List. Long-term monitoring studies in the USA have documented a shift in American crocodile nesting activity and an expansion of its range throughout the southern and eastern coasts of South Florida. However, no successful American crocodile nests have been recorded until now on the west coast of South Florida. Here we document the American crocodile nest monitoring conducted during 1997–2021 at Rookery Bay National Estuarine Research Reserve and the first successful nest from the west coast of South Florida forC. acutus. Marco Airport and McIlvane Marsh are the two main American crocodile nesting areas identified at the Reserve, with 92 nests and 3,586 eggs recorded during 1997–2021. We found most nests at Marco Airport (95.7%) and only four nests (4.3%) at McIlvane Marsh. To date, none of the nests found at Marco Airport have produced successful hatchlings. In contrast, hatchlings have been produced at McIlvane Marsh since nests were first documented there in 2020. We discuss the implications of our findings in terms of the future conservation of the species.

Characterization of the bacterial microbiome of Swedish ticks through 16S rRNA amplicon sequencing of whole ticks and of individual tick organs

BackgroundThe composition of the microbial flora associated with ixodid ticks has been studied in several species, revealing the importance of geographical origin, developmental stage(s) and feeding status of the tick, as well as substantial differences between tissues and organs. Studying the microbiome in the correct context and scale is therefore necessary for understanding the interactions between tick-borne pathogens and other microorganisms as well as other aspects of tick biology.MethodsIn the present study the microbial flora of whole Ixodes ricinus, I. persulcatus and I. trianguliceps ticks were analyzed with 16S rRNA amplicon sequencing. Additionally, tick organs (midguts, Malpighian tubules, ovaries, salivary glands) from flat and engorged I. ricinus female ticks were examined with the same methodology.ResultsThe most abundant bacteria belonged to the group of Proteobacteria (Cand. Midichloria mitochondrii and Cand. Lariskella). 16S amplicon sequencing of dissected tick organs provided more information on the diversity of I. ricinus-associated microbial flora, especially when organs were collected from engorged ticks. Bacterial genera significantly associated with tick feeding status as well as genera associated with the presence of tick-borne pathogens were identified.ConclusionsThese results contribute to the knowledge of microbial flora associated with ixodid ticks in their northernmost distribution limit in Europe and opens new perspectives for other investigations on the function of these bacteria, including those using other approaches like in vitro cultivation and in vitro models.Graphical

Possible northern persistence of Siebold's beech, Fagus crenata, at its northernmost distribution limit on an island in Japan Sea: Okushiri Island, Hokkaido.

Siebold's beech, Fagus crenata, is widely distributed across the Japanese Archipelago and islands in Japan Sea. Similar to the northern limit of the geographical distribution of F. crenata on the mainland of Hokkaido, the northern limit of the distribution of F. crenata on islands in the Japan Sea is observed on Okushiri Island (ca 42°N). To understand the genetic relationships of F. crenata on Okushiri Island, we examined chloroplast (cp) DNA haplotypes and 11 nuclear microsatellite (SSR) loci among 1,838 individuals from 44 populations from Okushiri Island, mainland Hokkaido, and the northern part of the Tohoku region on Honshu Island. We identified 2 cpDNA haplotypes, which represent not only populations on the Japan Sea coast but also those on the Pacific coast and this suggested the Okushiri Island populations might not be formed by single colonization. Genetic diversity of the Okushiri Island populations of nuclear SSR was not lower than the mainland and the STRUCTURE analysis revealed the Okushiri Island individuals were admixed between Hokkaido and Tohoku clusters. Approximate Bayesian computation inferred that divergence between Tohoku and Hokkaido, and admixture between two populations which generated Okushiri populations occurred before the last glacial maximum (LGM), that is, 7,890 (95% hyper probability density (HPD): 3,420 - 9,910) and 3,870 (95% HPD: 431- 8,540) generations ago, respectively. These inferences were well supported by a geological history which suggested an isolation of Okushiri Island from Hokkaido started prior to the Middle Pleistocene. We discuss the possible persistence of F. crenata during the last glacial maximum on northern islands in the Japan Sea such as Okushiri Island.

Northernmost distribution of Indian brown mongoose (Herpestes fuscus)

The Indian brown mongoose, Herpestes fuscus is among the six species of mongoose found in India. The species can be distinguished from other species of mongoose by its dark brown fur, black legs and thick, furry and conical tail. Brown mongoose has a restricted and disjunct distribution, with two populations of the nominate H. f. fuscus in the Western Ghats (Karnataka and Kerala) in Southern India and three other subspecies along the western coast of Sri Lanka. In southern India, brown mongoose has been recorded in wet evergreen forests of the Western Ghats from altitudes ranging between 450 to over 2,000 m a.s.l. Recently it has been recorded from Tadoba-Andheri Tiger Reserve, about 160 km south of Pench, also in Maharashtra.

Novelties in the Anemia elegans Clade (Anemiaceae), with a New Species and Nothospecies from Brazil

Abstract— Anemia is one of the most diverse genera in Brazil, with about 60 species. Unlike many other ferns, species of Anemia are abundant in dry and rocky environments, with many of them being narrow endemics to the mountains of the Central Brazilian Cerrado. Besides its richness, several species of Anemia hybridize, and hybrids and polyploids are fairly common in the genus. During a field trip to the northernmost distribution of the Cerrado, we found an undescribed species that we describe herein ‐ Anemia areniticola. We also describe a new hybrid, Anemia ×pirenopolitana, between two species in the Anemia elegans clade, which is the first record of a hybrid in this clade. We provide morphological descriptions and illustrations, and distribution maps for the new taxa, as well as comparisons with the most similar species. A key is also provided for the species in the Anemia elegans clade.

A New Northernmost Distribution Record of the Reef Coral Duncanopsammia axifuga at Bird’s Head Peninsula, West Papua, Indonesia

Duncanopsammia axifuga (Scleractinia: Dendrophylliidae) is reported for the first time from Indonesia. A population was found in 5-m deep, murky water on a sediment-rich, inshore reef at Bird’s Head Peninsula, West Papua. Some corals were attached to dead coral and others were loose fragments living on sediment. One attached specimen was observed to be damaged as a result of direct contact with an adjacent Goniopora coral. Free-living specimens on sand are more likely able to escape competition for space. These observations may help to better understand the northernmost range limit and the natural environment of D. axifuga, a species that is popular in the international aquarium trade, but has not been studied very well in the field.

Gene expression of a canopy‐forming kelp, Eisenia bicyclis ( Laminariales, Phaeophyceae ), under high temperature stress

Gene expression of a canopy‐forming kelp, <scp> <i>Eisenia bicyclis</i> </scp> ( <scp>Laminariales, Phaeophyceae</scp> ), under high temperature stress

Differentiation within the Drawida ghilarovi complex (Moniligastridae: Annelida) revealed by multigene transcriptomic dataset analysis

Drawida ghilarovi is an earthworm species with the northernmost distribution of all Monilidastridae in Asia. It includes multiple color morphs and has significant genetic diversity. In this study we used transcriptome sequencing to demonstrate that D. ghilarovi consists of three genetic clades that differ on both mitochondrial and nuclear genome levels. Pigmentation in D. ghilarovi appears to be labile, with frequent switching between different morphs. One of the clades of the complex is known from grey morphs only, the other consists of both grey and brown morphs, and the third one also has populations with black pigmentation. Two of the three clades are found only in the very south of the Russian Far East, while the third one has a distribution area that extends 800 km to the north, with the northernmost part of the distribution occupied by the black morph. We demonstrated that it would be phylogenetically unreasonable to divide the complex according to pigmentation, but splitting it according to genetic clades could be sensible.

Vegetation Classification and Distribution Patterns in the South Slope of Yarlung Zangbo Grand Canyon National Nature Reserve, Eastern Himalayas

Yarlung Zangbo Grand Canyon National Nature Reserve has the most complete vertical vegetation belts in China. However, identification and distribution of vertical vegetation belts is still uncertain and in debate. To explore the above issues, 190 plots were surveyed within the reserve from 2019 to 2021. Based on the vegetation plot data, cluster analysis, ordination analysis, and biodiversity statistics were performed to reveal the structure of vertical vegetation belts–the driving factors of vegetation distribution–to describe the main biodiversity patterns. Five vertical vegetation belts were identified by clustering. NMDS ordination showed that the main factor of vegetation distribution is elevation. Based on the results of the analysis and previous literature, a new scheme of vertical vegetation belts in the south slope of the reserve was proposed. There was a lower montane seasonal rainforest belt (600–1100 m), a lower montane evergreen broadleaf forest belt (1100–1800 m), a middle montane semi-evergreen broadleaf forest belt (1800–2400 m), a subalpine evergreen needleleaf forest belt (2400–3800 m), a alpine shrubland and meadow belt (3800–4400 m), an alpine sparse vegetation belt (4400–4800 m), and a nival belt (4800–7782 m). Among them, the seasonal rainforest belts are the northernmost distribution of this type, and the semi-evergreen broadleaf forest belts exist only in the Eastern Himalayas. The study showed a unimodal pattern in plant species diversity, the peak of which is about 1900 m. The middle montane semi-evergreen broadleaf forest belt had the highest species diversity in the reserve. This study settled the issues regarding the vertical vegetation belts, the main drivers of vegetation and assessment of plant species diversity in the south slope of the Yarlung Zangbo Grand Canyon National Nature Reserve. It provides essential support for the management and conservation of these ecosystems in the reserve.

THE STATUS OF BUDDLEJA SESSILIFLORA (SCROPHULARIACEAE) IN ARIZONA: REVISITING A RARE CLIMATE RELICT AT THE NORTHERN EDGE OF ITS RANGE

Rio Grande Butterfly Bush, Buddleja sessiliflora Kunth (Scrophulariaceae), reaches its northernmost distribution in southeast Arizona, and herbarium records document seven historical localities from Pima and Santa Cruz counties. Between 2014–2020, we visited six of the documented historical localities, but could not access the seventh location reported from the Tohono O'odham Nation. We found one of these historical locations is no longer extant. Two recently discovered new sites were also visited. We verified a total of 30 plants, in nine populations, from seven distinct localities during this research, which included the two previously unknown sites. Five of the seven localities were restricted to 6–15 m diameter areas and contained between one and seven plants, while the other two localities each included two disjunct 5 m diameter clusters of plants. We only found two small plants, which are likely seedlings or propagules. It is unclear why these plants rarely reproduce in situ, either sexually or vegetatively. These isolated riparian populations experience environmental stress, including hotter drought, diminishing water resources, anthropogenic habitat disturbance, and invasive plant species. This study resulted in an Arizona state designation for B. sessiliflora of ‘S1: critically imperiled.’ Buddleja sessiliflora may be one of the rarest plants in southern Arizona, and these peripheral populations face an increased extirpation risk.

Genomic signatures for latitudinal selection in the tropical eel Anguilla marmorata.

Selection acting across environmental gradients, such as latitudes, can cause spatial structuring of genomic variants even within panmictic populations. In this study, we focused on the within-generation latitudinal selection between northernmost and southernmost individuals of the North Pacific population of a tropical eel Anguilla marmorata, which shares its northernmost distribution with a temperate eel Anguilla japonica. Whole-genome sequencing data indicated that the northernmost and southernmost individuals of A.marmorata belong to a single panmictic population, as suggested by previous studies. On the contrary, parts of genomic regions across multiple chromosomes exhibited significant genetic differentiation between the northernmost and southernmost individuals, and in these genomic regions, the genotypes of the northernmost individuals were similar to those of A.japonica. These findings suggested within-generation latitudinal selection of A.marmorata, which might have led to genetic closeness between northernmost A.marmorata and A.japonica.

Thermal sum drives abundance and distribution range shift of Panolis flammea in Finland

ABSTRACT Climate change has assisted the northward range expansion of various forest insect pests, increasing the risk of forest damage in Northern Europe. The pine beauty moth, Panolis flammea, is common in European pine stands with cyclical outbreaks that have damaged thousands of hectares. In the 1970s, its Finnish northern distribution limit was reported to be 64°N. We re-evaluated the northernmost distribution limit of P. flammea in Finland and studied the effect of temperature sum on its abundance. We used pheromone-based traps throughout Finland in 2019–2020. The number of individuals caught in each trap was coupled with previous year thermal sums from the same location, and the relationship between them was analysed using a generalised linear mixed model. P. flammea had spread into northern Finland to 68°51’N, at ∼10.2 km/year, 50 years ahead of earlier predictions. We found a non-linear correlation between thermal sums and P. flammea abundance, increasing from cold to warm areas. Given the climate change scenarios for Fennoscandia, its range and population could continue to increase, allowing it to become another widespread coniferous-forest insect pest. Understanding the effects of temperature on its populations will allow us to model their probable future distribution and population dynamics.

Low Population Structure and Genetic Diversity in Rhinolophus blasii at the Northern Limit of Its European Range: Are there Undiscovered Colonies?

The Blasius's horseshoe bat (Rhinolophus blasii) shows a fragmented distribution in the European part of its range, and its populations are threatened by many human-induced factors. The status and distribution of the species in Romania are largely unknown. In recent years, regular bat surveys and monitoring have confirmed the presence of the species in north-western Romania, in Gălăşeni Cave, Pădurea Craiului Mountains, representing the northernmost distribution point of R. blasii in Europe. In our study we investigated whether this northernmost colony is genetically isolated from, or related to, larger populations in south-western Romania. A combined analysis of two mitochondrial (12S, HVII) and two nuclear (RAG2, DBY7) genetic markers was used in order to reveal possible relationships between these populations. The small number of haplotypes, the presence of shared haplotypes and overall low population structure suggest that the south-western and north-western Romanian populations are related through yet unidentified colonies of R. blasii, with continuous migration between them. Our results also indicate that the R. blasii colony from Gălăşeni Cave was established by female individuals migrating not far from their birthplace. To preserve this marginal population in a long term, conservation measures need to be strengthened and properly enforced, in parallel with the search for new R. blasii colonies in the region. To our knowledge, the present work represents the only molecular study of R. blasii in Europe.

Effects of seawater temperature and seasonal irradiance on growth, reproduction, and survival of the endemic Antarctic brown alga Desmarestia menziesii (Phaeophyceae)

Endemic Antarctic macroalgae are especially adapted to live in extreme Antarctic conditions. Their potential biogeographic distribution niche is primarily controlled by the photoperiodic regime and seawater temperatures, since these parameters regulate growth, reproduction, and survival during the entire life cycle. Here we analyzed the upper survival temperature (UST) of juvenile sporophytes and the temperature range for sporophyte formation from gametophytes of Desmarestia menziesii, one of the dominant endemic Antarctic brown algal species. This process is a missing link to better evaluate the full biogeographical niche of this species. Two laboratory experiments were conducted. First, growth and maximum quantum yield of juvenile sporophytes were analyzed under a temperature gradient (0, 5, 10, 12, 13, 14, 15, and 16 °C) in a 16:8 h light:dark (LD) regime (Antarctic spring condition) for 2 weeks. Second, the formation of sporophytes from gametophytes (as a proxy of gametophyte reproduction) was evaluated during a 7 weeks period under a temperature gradient (0, 4, 8, 12, and 16 °C), and two different photoperiods: 6:18 h LD regime simulating winter conditions and a light regime simulating the Antarctic shift from winter to spring by gradually increasing the light period from 7.5:16.5 h LD (late winter) to 18.5:5.5 h LD (late spring). Sporophytes of D. menziesii were able to grow and survive up to 14 °C for 2 weeks without visible signs of morphological damage. Thus, this species shows the highest UST of all endemic Antarctic Desmarestiales species. In turn, gametophyte reproduction solely took place at 0 °C but not at 4–8 °C. The number of emerging sporophytes was six times higher under the light regime simulating the transition from winter to spring than under constant short day winter conditions. There was a negative relationship between the number of sporophytes formed and the gametophyte density at the beginning of the experiment, which provides evidence that gametophyte density exerts some control upon reproduction in D. menziesii. Results strongly indicate that although sporophytes and gametophytes may survive in warmer temperatures, the northernmost distribution limit of D. menziesii in South Georgia Islands is set by the low temperature requirements for gametophyte reproduction. Hence, global warming could have an impact on the distribution of this and other Antarctic species, by influencing their growth and reproduction.

Distribution patterns of vines within the East Asian island chain

The northward dispersal of thermophilic plants along the East Asia island chain is influenced by cold stress, strait barrier and island effect. However, the impact of each parameter is not clear. In this study, we try to clarify the contribution of the above three effects to the geographical patterns of cold-intolerant climbing plants (vines) within the East Asia island chain. We divided the East Asian region into inland, coastal and island chain belts (Belt I, II and III, respectively), and 13/14 latitudinal regions. Distribution patterns of taxa shared by two adjacent belts were compared. We evaluated the impacts of cold stress effects by comparing the northern-most distribution boundary of vines within the island chain with those on the East Asian mainland and matching average January temperature isotherms. We assessed the strait barrier effect by comparing it with non-strait biogeographic lines. The island effect was assessed by quantifying the percentage of discontinuously distributed taxa. The results showed that: The northern-most limit of 54.3% of genera and 63.2% of species shared by Belts II and III coincided with a strait, with 27.2% of genera and 25.0% of species being discontinuously distributed. Cold stress, island effect and strait barrier effects together explained the patterns of 82.1% of genera and 87.7% of species shared by Belts II and III, which was higher than the value explained by cold stress on the mainland (77.7% and 72.4%, respectively). Cold stress, island effect and strait barrier explained 29.6%, 13.6% and 38.9% distribution patterns of taxa at the genus level, and 25.0%, 16.4% and 46.3% at the species level, respectively. Distribution patterns that could not be explained by cold stress were explained by strait barrier and island effect along the East Asian island chain. The East Asian island chain, especially the Ryukyu Islands, might be an efficient avenue for the northward dispersal of terrestrial plants, explaining the low degree of endemism and prevalence of discontinuously distributed taxa in this region.

A New Species and a New Synonymy of the Neotropical Genus Seridentus Osborn (Hemiptera: Reduviidae: Stenopodainae).

Based on the examination of the type specimens, the following new subjective synonymy is proposed in the Neotropical assassin bug genus Seridentus Osborn, 1904: S. denticulatus Osborn, 1904 = Gnathobleda maculosa Haviland, 1931, syn. nov. Lectotypes of the two nominal species are designated. The type depositories of S. denticulatus, obscurely given in the original description of this species, are confirmed to be the C.A. Triplehorn Insect Collection, Ohio State University, Columbus and the California Academy of Sciences, San Francisco. A new species, S. musettiae sp. nov., is described from Cartago, Costa Rica, representing the northernmost distribution record of the genus. A revised key to the species of Seridentus is provided.

The dark-red spider mite, Tetranychus ludeni Zacher (Acari: Tetranychidae): A new pest in Serbian acarofauna

The dark-red spider mite, Tetranychus ludeni Zacher (Acari: Tetranychidae), is a highly polyphagous species and an important pest of economic plants belonging to the families Cucurbitaceae, Malvaceae, Fabaceae and Solanaceae, and growing in tropical and subtropical regions. In the Western Palaearctic, its distribution reports have recently come mostly from the Mediterranean Basin, i.e. Portugal, Spain, Italy and Israel. In a survey conducted in Serbia 2019-2021 (comprising 159 sampling locations), T. ludeni was found at 89 locations on 27 plant species of the families Rosaceae (8), Solanaceae (6), Cucurbitaceae (4), Fabaceae (2), Amaranthaceae (2), Asteraceae (2), Apiaceae (1), Convolvulaceae (1) and Poaceae (1). The dark-red spider mite was found in mixed populations with other spider mites (mostly Tetranychus urticae and T. turkestani) in around half of the sampling locations. Heavy infestation and visible symptoms of injury were observed in several locations. Three Rosaceae plant species, plum (Prunus domestica), blackthorn (Prunus spinosa) and crab apple (Malus sylvestris) were its new hosts. Serbian records of T. ludeni from locations situated at latitudes between 42?N and 46?N were the northernmost distribution records of this species in the Western Palaearctic.

Two New Pseudoscorpion Species of the Coastal Genus Garypus L. Koch, 1873 (Garypidae) and an Updated Checklist of the Pseudoscorpiones of Taiwan.

Pseudoscorpions are predatory microarthropods that feed on even smaller animals, such as mites and springtails. While these organisms are generally considered terrestrial and live in the leaf litter or under barks or rocks, some pseudoscorpions live in the intertidal area, including species in the genera Anagarypus, Anchigarypus, and Garypus in the family Garypidae. This study describes two new species of the genus Garypus L. Koch from Southern Taiwan, Garypus wilsoni Lin & Chang sp. nov. and Garypus sanasai Lin, Huang & Chang sp. nov., reviews the pseudoscorpion fauna of Taiwan, and provides an updated checklist of the country. Specimens of the two new species were collected in seashore habitats and their status as new species were supported by both morphology and molecular phylogenetic analysis. Our discovery marks the first new species of pseudoscorpions reported in Taiwan since 1937, as well as the first records of the family Garypidae in Taiwan and of Garypus in East Asia. Moreover, the discovery of these two new species in Taiwan fills the regional distribution gap between Garypus in Thailand and southward and its closely related genus Anchigarypus in South Korea and Japan. The location where Garypus sanasai Lin, Huang & Chang sp. nov. was found also represents the northernmost distribution of the genus Garypus in the West Pacific.

Hystrix cristata (Mammalia: Rodentia: Hystricidae) newly recorded in South Tyrol (Italy) at its current northernmost distribution limit

Hystrix cristata (Mammalia: Rodentia: Hystricidae) newly recorded in South Tyrol (Italy) at its current northernmost distribution limit

Compositional and functional features of the gut microbiota of the intertidal snail Nerita yoldii along China's coast

AbstractThe gut microbiota plays an important role in animals’ survival in their local environments. The intertidal rocky shore is a key interface of oceanic, atmospheric and terrestrial environments, and the transmission modes of microbes between an intertidal host and the environment are complex and largely ignored. In the present study, we characterized the gut microbiota of the intertidal snail Nerita yoldii, which is experiencing a northward range shift under the combined impacts of climate change and anthropogenic seascape transformation, and also determined the nearby environmental microbiota on the rock and in the seawater at five locations along the snail's distribution range in China. The gut microbial communities were significantly different from the environmental microbial communities, and the dominant phyla were Tenericutes, Cyanobacteria and Bacteroidetes, and Proteobacteria in the gut, rock and seawater microbial communities, respectively. At the genus level, Mycoplasma, with a relative abundance of 48.0 ± 10.2%, was the dominant genus in the gut microbial community, however, the relative abundances of this genus on the rock and in the water were low. These results imply that the gut microbial community of the intertidal snail N. yoldii is relatively independent from the environmental microbial community, and the dominant genus Mycoplasma in the gut, that is rare in the environment, can potentially assist the snail living in the harsh intertidal environment, especially at its northernmost distribution range edge.