Short Appendages Research Articles

Assessing Ecogeographic Rules in Two Sigmodontine Rodents along an Elevational Gradient in Central Chile.

Bergmann's and Allen's rules are two classic ecogeographic rules concerning the physiological mechanisms employed by endotherm vertebrates for heat conservation in cold environments, which correlate with adaptive morphological changes. Thus, larger body sizes (Bergmann's rule) and shorter appendages and limbs (Allen's rule) are expected in mammals inhabiting cold environments (higher latitudes). Both rules may also apply to elevational gradients, due to the decrease in external temperature as elevation increases. In this study, we evaluated whether these patterns were true in two coexisting sigmodontine rodents across an elevational gradient in central Chile. We analyzed whether the size of the skull, body, and appendages of Abrothrix olivacea (n = 70) and Phyllotis darwini (n = 58) correlated with elevation, as predicted by these rules in a range between 154 and 2560 m. Our data revealed weak support for the Bergmann and Allen predictions. Moreover, we observed opposite patterns when expectations of Bergmann's rules were evaluated, whereas Allen's rule just fitted for ear size in both rodent species. Our results suggest that morphological changes (cranial, body, and appendage sizes) may play a minor role in the thermoregulation of these two species at high elevations, although behavioral strategies could be more critical. Other ecological and environmental variables could explain the morphological trends observed in our study. These hypotheses should be assessed in future studies to consider the relative contribution of morphology, behavior, and physiological mechanisms to the thermal adaptation of these two rodent species at high elevations.

Erysipheneelamensis, a new powdery mildew fungus (Ascomycota: Erysiphaceae) from Azad Jammu and Kashmir, Pakistan

A new powdery mildew species, Erysiphe neelamensis, was found on Celtis eriocarpa in Azad Jammu and Kashmir, Pakistan. The identification was based upon morpho‐anatomical features and results of a molecular sequence analysis. This species is morphologically distinguished from phylogenetically allied Erysiphe species by having chasmothecia with fewer, shorter appendages and a small number of asci and ascospores. A phylogenetic analysis of the nrDNA of ITS region of E. neelamensis supports the involvement of a novel species of the genus Erysiphe. The new species is described, illustrated and compared with all allied species, along with a phylogram showing its inferred phylogenetic position.

Appendage abnormalities in spiders induced by an alternating temperature protocol in the context of recent advances in molecular spider embryology.

In the literature there are numerous reports of developmental deformities in arthropods collected in their natural habitat. Since such teratogenically affected individuals are found purely by chance, the causes of their defects are unknown. Numerous potential physical, mechanical, chemical, and biological teratogens have been considered and tested in the laboratory. Thermal shocks, frequently used in teratological research on the spider Eratigena atrica, have led to deformities on both the prosoma and the opisthosoma. In the 2020/2021 breeding season, by applying alternating temperatures (14 °C and 32 °C, changed every 12 h) for the first 10 days of embryonic development, we obtained 212 postembryos (out of 3,007) with the following anomalies: oligomely, heterosymely, bicephaly, schistomely, symely, polymely, complex anomalies, and others. From these we selected six spiders with defects on the prosoma and two with short appendages on the pedicel for further consideration. The latter cases seem particularly interesting because appendages do not normally develop on this body part, viewed as the first segment of the opisthosoma, and appear to represent examples of atavism. In view of the ongoing development of molecular techniques and recent research on developmental mechanisms in spiders, we believe the observed phenotypes may result, at least in part, from the erroneous suppression or expression of segmentation or appendage patterning genes. We consider "knockdown" experiments described in the literature as a means for generating hypotheses about the sources of temperature-induced body abnormalities in E. atrica.

Vanilla cameroniana (Orchidaceae, Vanilloideae), a new species from French Guiana and new records from the Guiana Shield

In this study, a new species of Vanilla from French Guiana is described with detailed illustrations, photographs, and distribution. Vanilla cameroniana honors Kenneth M. Cameron, a distinguished professor at the University of Wisconsin-Madison, for his contributions to our understanding of the subfamily Vanilloideae. The new species is placed within Vanilla subgenus Xanata, due to its distinctive penicillate callus and lip margins connate to the column. Vanilla cameroniana can be distinguished from V. appendiculata, a morphologically similar species by the broader leaves up to 12 cm wide (vs. 5.9 cm), axillary inflorescence (vs. apical), narrow linear petals, 0.2–0.3 cm wide (vs. narrowly lanceolate, 0.5–0.8 cm), unlobed lip (vs. trilobed), and sub-quadrate apex (vs. sub-acute) with a trullate-shaped structure close to the apex made of short appendages (vs. long lombricoid appendages). Detailed morphological comparisons are provided for other superficially similar species. Additionally, based on herbarium collections V. sprucei, and V. dressleri are newly recorded from the Guiana Shield, and a geographic range expansion is proposed for Vanilla corinnae. Our findings highlight the importance of conservation efforts of fragile ecosystems such as swamps in the Guiana Shield.

Complementarity in Allen’s and Bergmann’s rules among birds

Biologists have long noted that endotherms tend to have larger bodies (Bergmann’s rule) and shorter appendages (Allen’s rule) in colder environments. Nevertheless, many taxonomic groups appear not to conform to these ‘rules’, and general explanations for these frequent exceptions are currently lacking. Here we note that by combining complementary changes in body and extremity size, lineages could theoretically respond to thermal gradients with smaller changes in either trait than those predicted by either Bergmann’s or Allen’s rule alone. To test this idea, we leverage geographic, ecological, phylogenetic, and morphological data on 6,974 non-migratory terrestrial bird species, and show that stronger family-wide changes in bill size over thermal gradients are correlated with more muted changes in body size. Additionally, we show that most bird families exhibit weak but appropriately directed changes in both traits, supporting the notion of complementarity in Bergmann’s and Allen’s rules. Finally, we show that the few families that exhibit significant gradients in either bill or body size, tend to be more speciose, widely distributed, or ecologically constrained. Our findings validate Bergmann’s and Allen’s logic and remind us that body and bill size are simply convenient proxies for their true quantity of interest: the surface-to-volume ratio.

Fathers & Sons

Fathers & Sons Joshua Doležal (bio) Click for larger view View full resolution Photo by Julian Ortiz [End Page 118] I When my wife and I scheduled an ultrasound during her third pregnancy, I expected another girl. The odds were pretty much fifty-fifty, but after watching the coin fall the other way two times previously, I had come to think of myself—and with some relief—as a father to daughters. One does not expect to be struck down on the road to Thebes by one’s daughter, for instance. But it might also have been that the cultural narratives available to me translated more readily into mentoring girls and young women who might imagine every avenue open to them. Masculinity had become a dark energy to guard against, the systemic foil to every plot in the Rebel Girls podcast series my daughters loved. In fact, I had been redefining my own understanding of manhood for many years and wasn’t sure I had firm enough footing on that ground to point a boy in the right direction. Perhaps that was why my first thought, when the nurse drew an arrow to a [End Page 119] short appendage on the screen, was Oh, no, the poor girl has only half an arm. When the knowledge that we’d be having a boy hardened into certainty, I felt a curious swirl of elation and panic. I can’t say exactly why the stakes felt higher in raising a son. Maybe it was that my likeness in my daughters felt a step removed, more figurative than literally true. A father does not think to name a daughter Junior, even if she is the spitting image of himself as a child. I felt that a boy would seek to emulate me more thoroughly than my girls had and that this carried a unique responsibility to offer a worthy prototype for the person my son might become. Over the next few months, I searched my memory for guidance, and I was dismayed to remember only one conversation about what it meant to be a father. It was not wisdom imparted by my own father or even advice given directly to me but an exchange relayed secondhand by one of my high school basketball teammates on one of our long road trips. It was late at night, pitch dark but for the headlights from oncoming traffic. The bus reeked of sweat, socks, and the turkey club sandwiches we’d dispatched after our game, and several of us were huddled in the back listening to the team captain’s version of the Bloody Mary story. If you chanted her name, he said, while staring into a mirror, she would appear. And if her eyes were red, you were sure to die. As we sat there laughing but inwardly horrified that we might glimpse red taillights in our rearview mirrors later that night, my coach called back to us, and my friend Scott left to speak with him. Scott’s girlfriend was pregnant, and they planned to keep the child. Our coach, whom I’ll call Coach Taylor, had just learned the news, and he wanted to share something of his own experience at his eldest’s birth. When Scott returned to the back of the bus, he repeated what Coach Taylor had said, that holding your own flesh and blood in your hands was the most powerful thing you would ever feel. A hush fell over us then. We knew we’d brushed against a sacred truth and that none of us, including Scott, were anywhere near ready to face its full weight. I forgot all about Bloody Mary and sat enveloped in awe of my coach for knowing something of this mystery, and of Scott, who would soon know it for himself. The men in my life rarely speak of these things at night, and never in the daytime. And the sad truth is that not one of the fathers in my family—not my father or either of my grandfathers or my four uncles— shared anything with me about how they felt holding their newborns [End Page 120] or how they went about...

Food resources and competition rather than eco-geographic rules explain trait variations in two contrasting rat species: Implications for future climate change

Understanding how morphological traits are influenced by temperature, resource availability and competition is critical for predicting future ecosystem resilience to climate change. Here we tested the effects of biotic and abiotic factors, on the morphology of two contrasting Muridae species (Chinese white-bellied rats Niviventer confucianus [n = 565; 57.1 g] and Edwards's long-tailed giant rats Leopoldamys edwardsi [n = 45; 459.5 g]) in relation to Bergmann’s, Allen’s, Hesse’s and Geist’s eco-geographical rules along a 2900-m elevational gradient. Specifically, we tested the “body size threshold” theory, which posits that animals heavier than 0.16 kg are more likely to follow Bergmann’s rule. We measured body length and mass, appendage lengths and heart mass for 610 adult specimens from 115 localities, and used principal components analysis to quantify food resource availability. Linear mixed models were employed to test these eco-geographical rules, along with the effects of associated biotic and abiotic factors. We found that for N. confucianus (< 0.16 kg), colder temperatures were associated with smaller body-size, contrary to Bergmann’s rule, and with greater interspecific competition and food abundance (supporting Geist’s rule). There was no support for Allen's rule, except for a contrary effect on snout length among females; however, greater intraspecific competition and lesser food abundance were associated with shorter snout length, supporting Geist’s rule. Heart size increased with colder temperatures, but only among females, partly supporting Hesse’s rule, and decreased with greater intraspecific competition for both sexes. L. edwardsi (> 0.16 kg) did not conform with any eco-geographic rules, and so we found no support for the “body size threshold” theory. Our study proposes that food resource abundance and inter- and intraspecific competition mediated variations in morphological traits in these rodent species to a greater extent than any reduction in temperature alone, giving little support for ecogeographical rule effects. We interpret that where food supply can meet energetic demands, even under colder conditions, then any selective pressure for thermal/energy efficiency through larger body size and shorter appendages will be alleviated. Considering the full range of inter-related factors that are affected by temperature, rather than just the bio-physics of heat loss, is important to better predict future climate change responses.

Ant communities in disturbed subtropical landscapes: is climate more important than stochastic processes?

Functional trait-based approaches have provided advances in the understanding of community assembly rules. Broad generalisations remain, however, limited due to the idiosyncratic nature of taxa and ecosystems, especially in tropical regions. We use fine scale resolution (30m grid) environmental variables and community surveys from nearly 100 secondary tropical forest sites to study niche-based or neutral assembly mechanisms in ground dwelling ants. This provides a unique opportunity for understanding fine scale drivers of taxonomic, functional and phylogenetic diversity in a region characterized by large topographic and climatic differences on a relatively small geographic scale. Precipitation emerged as the most consistent environmental correlate, in shaping taxonomic, phylogenetic and functional aspects of the communities. Functional diversity was weakly associated with topography and temperature related variables. The fourth corner model revealed that femur, scape and mandible length were key traits in response to precipitation, and that communities showed a functional homogenization towards shorter appendages at wetter sites. Our results suggest that neutral and deterministic assembly processes act in concert to shape the taxonomic, phylogenetic and functional aspects of leaf litter ant assemblages. The use of multiple complementary metrics and approaches along environmental gradients are powerful to reveal the subtilities of assembly processes and provide insight into the ways future communities might change.

Knockdown of Ecdysone-Induced Protein 93F Causes Abnormal Pupae and Adults in the Eggplant Lady Beetle.

Ecdysone-induced protein 93F (E93) plays triple roles during post-embryonic development in insects whose juvenile instars are more than four. However, it only acts as a specifier of adult structures in Drosophila flies whose larval instars are fixed at three. In this study, we determined the functions of E93 in the eggplant lady beetle (Henosepilachna vigintioctopunctata), which has four larval instars. We uncovered that E93 was abundantly expressed at the prepupal and pupal stages. A precocious inhibition of the juvenile hormone signal by RNA interference (RNAi) of HvKr-h1 or HvHairy, two vital downstream developmental effectors, at the penultimate instar larval stage increased the expression of E93, Conversely, ingestion of JH by the third-instar larvae stimulated the expression of HvKr-h1 but repressed the transcription of either HvE93X1 or HvE93X2. However, disturbance of the JH signal neither drove premature metamorphosis nor caused supernumerary instars. In contrast, depletion of E93 at the third- and fourth-instar larval and prepupal stages severely impaired pupation and caused a larval-pupal mixed phenotype: pupal spines and larval scoli were simultaneously presented on the cuticle. RNAi of E93 at the pupal stage affected adult eclosion. When the beetles had suffered from a dsE93 injection at the fourth-instar larval and pupal stages, a few resultant adults emerged, with separated elytra, abnormally folded hindwings, a small body size and short appendages. Taken together, our results suggest the larval instars are fixed in H. vigintioctopunctata; E93 serves as a repressor of larval characters and a specifier of adult structures during the larval-pupal-adult transition.

Thermal adaptation best explains Bergmann’s and Allen’s Rules across ecologically diverse shorebirds

Bergmann’s and Allen’s rules state that endotherms should be larger and have shorter appendages in cooler climates. However, the drivers of these rules are not clear. Both rules could be explained by adaptation for improved thermoregulation, including plastic responses to temperature in early life. Non-thermal explanations are also plausible as climate impacts other factors that influence size and shape, including starvation risk, predation risk, and foraging ecology. We assess the potential drivers of Bergmann’s and Allen’s rules in 30 shorebird species using extensive field data (>200,000 observations). We show birds in hot, tropical northern Australia have longer bills and smaller bodies than conspecifics in temperate, southern Australia, conforming with both ecogeographical rules. This pattern is consistent across ecologically diverse species, including migratory birds that spend early life in the Arctic. Our findings best support the hypothesis that thermoregulatory adaptation to warm climates drives latitudinal patterns in shorebird size and shape.

Challenging ecogeographical rules: Phenotypic variation in the Mountain Treeshrew (Tupaia montana) along tropical elevational gradients.

Bergmann’s and Allen’s rules were defined to describe macroecological patterns across latitudinal gradients. Bergmann observed a positive association between body size and latitude for endothermic species while Allen described shorter appendages as latitude increases. Almost two centuries later, there is still ongoing discussion about these patterns. Temperature, the common variable in these two rules, varies predictably across both latitude and elevation. Although these rules have been assessed extensively in mammals across latitude, particularly in regions with strong seasonality, studies on tropical montane mammals are scarce. We here test for these patterns and assess the variation of several other locomotory, diet-associated, body condition, and thermoregulatory traits across elevation in the Mountain Treeshrew (Tupaia montana) on tropical mountains in Borneo. Based on morphological measurements from both the field and scientific collections, we found a complex pattern: Bergmann’s rule was not supported in our tropical mountain system, since skull length, body size, and weight decreased from the lowest elevations (<1000 m) to middle elevations (2000–2500 m), and then increased from middle elevations to highest elevations. Allen’s rule was supported for relative tail length, which decreased with elevation, but not for ear and hindfoot length, with the former remaining constant and the latter increasing with elevation. This evidence together with changes in presumed diet-related traits (rostrum length, zygomatic breadth and upper tooth row length) along elevation suggest that selective pressures other than temperature, are playing a more important role shaping the morphological variation across the distribution of the Mountain Treeshrew. Diet, food acquisition, predation pressure, and/or intra- and inter-specific competition, are some of the potential factors driving the phenotypic variation of this study system. The lack of variation in body condition might suggest local adaptation of this species across its elevational range, perhaps due to generalist foraging strategies. Finally, a highly significant temporal effect was detected in several traits but not in others, representing the first phenotypic variation temporal trends described on treeshrews.

Phyllactinia himalayensis, a new species on Juglans regia from Pakistan

A powdery mildew fungus of the genus Phyllactinia was found on leaves of Juglans regia in Pakistan. This species is well characterized by having large-sized chasmothecia, rather short appendages and small ascospores. Sequences retrieved from this species formed a separate clade distant from the clade constituted by Phyllactinia juglandis, a common species on different hosts of the Juglandaceae in Asia. On account of biological and morphological differences from phylogenetically related species, the new species is described and illustrated as Phyllactinia himalayensis sp. nov.

Initial Experience and Results of Combined Treatment for Atrial Fibrillation: Catheter Ablation with High-Power Short Duration Ablation and Left Atrial Appendage Closure

Introduction: Long-term freedom from atrial fibrillation (AF) after catheter ablation and, consequently, the potential for stroke reduction remain unpredictable. Recently, left atrial appendage closure (LAAC) became an effective mechanical alternative to oral anticoagulation (OAC) for stroke prevention in AF patients. Objective: This study aims to evaluate the feasibility and safety of combined treatment for AF with catheter ablation (CA) with the high-power short duration technique associated with LAAC in one single procedure. Methods: Patients with non-valvular AF who underwent combined CA and LAAC procedure were included in the retrospective observational study. Between April 2018 and October 2020, 13 patients with AF were included, eight (61,54%) males, eight (61.54%) with persistent AF (PersAF), mean age 68.54 (65–84) years old, mean time from AF diagnosis to treatment 13.08 (3–33) months, mean CHA2VASC2 5.08 (3–7), all patients with coronary or vascular disease, 12 (92.31%) with hypertension, five (38.46%) with left ventricular dysfunction, four (30.77%) prior strokes using OAC and four (30.77%) patients with diabetes. Indications for LAAC included history of contraindication to OAC because of severe bleeding in eight (61.54%), previous stroke in four (30.77%) and two (13.08%) patients with LAA thrombus, despite the use of two different OAC (one associated with bleeding). One patient had a pseudoaneurysm in femoral artery, and two patients died of non-procedure complications after 30 days. At six months, angiotomography showed successful complete sealing of the LAA in seven (77.72%) of nine patients evaluated, and the two patients without it had a leak of less than 2 mm. After mean follow-up of 14 months (five to 33), 10 (90.91%) of the 11 patients were in sinus rhythm. Three (27.27%) patients, one in blanking period, recovered sinus rhythm after amiodarone. No cardioembolic or bleeding events occurred. Conclusion: In this small observational study, we showed the feasibility and safety of the combined therapy with AF catheter ablation with LAAC with a high rate of sinus rhythm and no cardioembolic event.

A new species of Podosphaera sect. Sphaerotheca subsect. Sphaerotheca from India—first report of powdery mildew causing wilting and ultimately death of leaves of Filipendula vestita

Podosphaera filipendulensis, a new teleomorph of powdery mildew was discovered on living leaves of Filipendula vestita (Rosaceae). It is the first species of powdery mildew that causes wilting and ultimately death of apical infected leaves of F. vestita. It is described, illustrated and compared with other Podosphaera species reported on Rosaceae and a key to all species reported on Rosaceae is provided. The phylogeny of this species has been inferred from internal transcribed spacer (ITS) rDNA sequence data. Phylogenetically, P. filipendulensis is close to P. ferruginea var. ferruginea and P. macularis but differs in having larger chasmothecia, smaller peridium cells, shorter, narrower and aseptate appendages, 8-spored asci and smaller ascospores.

Accounting for clinal variation and covariation in the assessment of taxonomic limits: why we should remember the ‘rules’

Accounting for clinal variation and covariation in the assessment of taxonomic limits: why we should remember the ‘rules’

Temperature drives caste-specific morphological clines in ants.

The morphology of organisms relates to most aspects of their life history and autecology. As such, elucidating the drivers of morphological variation along environmental gradients might give insight into processes limiting species distributions. In eusocial organisms, the concept of morphology is more complex than in solitary organisms. Eusocial insects such as ants exhibit drastic morphological differences between reproductive and worker castes. How environmental selection operates on the morphology of each caste, and whether caste-specific selection has fitness consequences is largely unknown, but is potentially crucial to understand what limits ant species' distributions. Here we aimed to examine whether ant shape and body size covaries with climate at the scale of an entire continent, and whether such relationship might be caste specific. We used 26,472 georeferenced morphometric measurements from 2,206 individual ants belonging to 32 closely related North American species in the genus Formica to assess how ant morphology relates to geographic variation in the abiotic environment. Although precipitation and seasonality explained some of the geographic variation in morphology, temperature was the best predictor. Specifically, geographic variation in body size was positively related to temperature, meaning that ants are smaller in cold than in warm environments. Moreover, the strength of the relationship between size and temperature was stronger for the reproductive castes (i.e. queens and males) than for the worker caste. The shape of workers and males also varied along these large-scale abiotic gradients. Specifically, the relative length of workers' legs, thoraxes and antennae positively related to temperature, meaning that they had shorter appendages in cold environments. In contrast, males had smaller heads, but larger thoraxes in more seasonal environments. Overall, our results suggest that geographic variation in ambient temperature influences the morphology of ants, but that the strength of this effect is caste specific. In conclusion, whereas ant ecology has traditionally focused on workers, our study shows that considering the ecology of the reproductive castes is imperative to move forward in this field.

NAUTILUS BERCANGKANG RAPUH DARI TELUK TOMINI KABUPATEN PARIGI MOUTONG SULAWESI TENGAH, INDONESIA

Nautilus bercangkang rapuh termasuk dalam kelas Cephalopoda, famili Argonautidae. Tujuan dari penelitan ini adalah untuk mengidentifikasi jenis Nautilus bercangkang rapuh yang ditemukan di perairan Teluk Tomini Kabupaten Parigi Moutong. Sampel paper Nautilus ditangkap pada kedalaman 1000 m. Hasil penelitian memperlihatkan bahwa sampel yang berhasil dikoleksi selama bulan Maret hingga bulan Desember hanya sebanyak 6 spesimen pada kedalaman 70-80 m, dengan 4 spesimen yang bertelur dan 2 spesimen tanpa telur. Dari 6 spesimen yang ditemukan, diketahui ada 2 jenis yaitu Argonauta argo dengan rerata panjang cangkang= 34,05 mm, lebar cangkang= 22,20 mm dan lebar aperture= 11,15 mm. A. argo memiliki 8 tentakel dengan 4 tentakel panjang dan 2 pendek. Warna cangkangnya lebih cerah dari cangkang A. hians, cangkangnya lebih pipih dengan dua baris duri kecil yang sangat berdekatan di sepanjang sisi dorsal dan halus, sepanjang sisi ventral ujung tebal dan meruncing. Serta A. hians yang memiliki rerata panjang cangkang 47,02 mm, lebar cangkang 33,07 mm dan lebar aperture 21,30 mm, memiliki duri yang lebih besar dan tumpul, di sepanjang sisi dorsal yang lebar, sepanjang sisi lateral aperture melebar dan tidak membentuk seperti sayap. Garis rusuk yang terdapat di sisi lateral lebih tebal dan renggang. Jenis Nautilus bercangkang rapuh yang ditemukan di Teluk Tomini, yaitu A. argo dan A. hians.

&lt;p&gt;&lt;strong&gt;&lt;em&gt;Nepenthes putaiguneung&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt; (Nepenthaceae), a new species from highland of Sumatra, Indonesia&lt;/strong&gt;&lt;/p&gt;

A new species of Nepenthes—Nepenthes putaiguneung—from the highlands of Sumatra (Indonesia) is described and illustrated. This new species is morphologically similar with N. Singalana from which differs in having narrowly spathulate leaves, more gracile upper pitchers with a finely ribbed peristome, lacking teeth on its inner edge, lid with a basal crest and a short tooth-like triangular appendage near the apex on the underside (not lacking such appendages), the lid glands of lower pitcher confined to the midline (not scattered evenly over the whole surface), and pedicel of lower male flowers usually with minutely short bracteole. N. putaiguneung is also similar to N. mikei but differs in having narrowly spathulate leaves with obtuse apex, lower pitcher with slender infundibulate shape below and cylindrical above, peristome of lower pitcher with short and denser distinct ribs, lid of lower and upper pitcher with a prominent glandular crest at the base of midrib, several distinct glands on the lid of lower pitcher that clustered along the midrib; and pedicel of lower male flowers that usually with minutely short bracteole.

ICTV Virus Taxonomy Profile: Spiraviridae.

The family Spiraviridae includes viruses that replicate in hyperthermophilic archaea from the genus Aeropyrum . The non-enveloped, hollow, cylindrical virions are formed from a coiling fibre that consists of two intertwining halves of a single circular nucleoprotein filament. A short appendage protrudes from each end of the cylindrical virion. The genome is circular, positive-sense, single-stranded DNA of 24 893 nucleotides. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) report on the family Spiraviridae, which is available at ictv.global/report/spiraviridae.

The interplay between habitat use, morphology and locomotion in subterranean crustaceans of the genus Niphargus

Locomotion is an important, fitness-related functional trait. Environment selects for type of locomotion and shapes the morphology of locomotion-related traits such as body size and appendages. In subterranean aquatic arthropods, these traits are subjected to multiple, at times opposing selection pressures. Darkness selects for enhanced mechano- and chemosensory systems and hence elongation of appendages. Conversely, water currents have been shown to favor short appendages. However, no study has addressed the variation in locomotion of invertebrates inhabiting cave streams and cave lakes, or questioned the relationship between species’ morphology and locomotion. To fill this knowledge gap, we studied the interplay between habitat use, morphology and locomotion in amphipods of the subterranean genus Niphargus. Previous studies showed that lake and stream species differ in morphology. Namely, lake species are large, stout and long-legged, whereas stream species are small, slender and short-legged. We here compared locomotion mode and speed between three lake and five stream species. In addition, we tested whether morphology predicts locomotion. We found that the stream species lie on their body sides and move using slow crawling or tail-flipping. The species inhabiting lakes move comparably faster, and use a variety of locomotion modes. Noteworthy, one of the lake species almost exclusively moves in an upright or semi-upright position that resembles walking. Body size and relative length of appendages predict locomotion mode and speed in all species. We propose that integrating locomotion in the studies of subterranean species might improve our understanding of their morphological evolution.