Adult Morphology Research Articles

Reproductive fitness consequences of progenesis: Sex-specific pay-offs in safe and risky environments.

Progenesis is considered to have an important role in evolution because it allows the retention of both a larval body size and shape in an adult morphology. However, the cost caused by the adoption of a progenetic process in both males and females remains to be explored to explain the success of progenesis and particularly its biased prevalence across the sexes and environments. Here, through an experimental approach, we used a facultative progenetic species, the palmate newt (Lissotriton helveticus) that can either mature at a small size and retain gills or mature after metamorphosis, to test three hypotheses for sex-specific pay-offs of progenesis in safe versus risky habitats. Goldfish were used because they caused a higher decline in progenetic than metamorphic newts. We determined that progenetic newts have a lower reproductive fitness than metamorphic newts. We also found that, when compared to metamorphs, progenetic males have lower reproductive activity than progenetic females and that predatory risk affects more progenetic than metamorphic newts. By identifying ultimate causes of the female-biased sex ratios found in nature, these results support the male escape hypothesis, that is the higher metamorphosis rate of progenetic males. They also highlight that although progenesis is advantageous in advancing the age at first reproduction, it also brings an immediate fitness cost and this, particularly, in hostile predatory environments. This means that whereas some environmental constraints could favour facultative progenesis, some others, such as predation, can ultimately counter-select progenesis. Altogether, these results improve our understanding of how developmental processes can affect the sexes differently and how species invasions can impair the success of alternative developmental phenotypes.

Developmental organization of central neurons in the adult Drosophila ventral nervous system.

We have used MARCM to reveal the adult morphology of the post embryonically produced neurons in the thoracic neuromeres of the Drosophila VNS. The work builds on previous studies of the origins of the adult VNS neurons to describe the clonal organization of the adult VNS. We present data for 58 of 66 postembryonic thoracic lineages, excluding the motor neuron producing lineages (15 and 24) which have been described elsewhere. MARCM labels entire lineages but where both A and B hemilineages survive (e.g., lineages 19, 12, 13, 6, 1, 3, 8, and 11), the two hemilineages can be discriminated and we have described each hemilineage separately. Hemilineage morphology is described in relation to the known functional domains of the VNS neuropil and based on the anatomy we are able to assign broad functional roles for each hemilineage. The data show that in a thoracic hemineuromere, 16 hemilineages are primarily involved in controlling leg movements and walking, 9 are involved in the control of wing movements, and 10 interface between both leg and wing control. The data provide a baseline of understanding of the functional organization of the adult Drosophila VNS. By understanding the morphological organization of these neurons, we can begin to define and test the rules by which neuronal circuits are assembled during development and understand the functional logic and evolution of neuronal networks.

Craniofacial Growth Studies and Craniofacial Growth

Current understandings of human craniofacial growth are based on multiple historic longitudinal growth studies. The extent to which regional variation in growth patterns is present among the various growth studies even within the United States, however, is not well understood. The aim of this study is to compare growth patterns across six of the nation's largest growth studies.Lateral cephalographs were examined from the historical archives of the Denver Growth Study, Iowa Growth Study, and Oregon Growth Study (available via the AAOF Legacy Collection) as well as the Fels Longitudinal Study, the Michigan Growth Study, and the Bolton‐Brush Growth Study. A set of 44 two‐dimensional landmarks were collected on longitudinal series from participants 6–22 years old. A total of 5,622 cephalographs from 726 males and 5,514 cephalographs from 723 females were assessed. Fifth order polynomials were used to evaluate growth of 11 linear craniofacial measures for each growth study and by sex. Rates of growth and associated growth milestones were calculated from polynomial models and compared across study and by sex. In addition, geometric morphometric analyses were used to assess ontogenetic shape differences among studies using a regression of the shape variables on log centroid size, pooled by study, with subsequent evaluation of residual variation.Growth curves for the separate studies roughly parallel each other yet show differences in the timing of growth milestones and adult morphology. In general, for each linear trait participants in the Denver study are smaller and participants in the Iowa and Michigan studies are larger than participants in other studies at the same chronological age. Timing of onset and peak growth is similar in all 11 craniofacial measures, although trait values at those growth milestones differ by study. Preliminary results from the geometric morphometric analysis identify a common ontogenetic pattern shared across studies but demonstrate that, for a given size, individuals from the Denver study are more advanced along the common shape trajectory relative to other studies. Although ontogenetic trajectories are roughly similar, overall shape differences are present between study populations.Variations in growth and overall morphology among these six longitudinal growth study populations demonstrate regional differences in the rate and timing of growth that may be attributable to the ancestry and environmental conditions of study participants. Further study of the mechanisms for these differences in growth will improve the accuracy of craniofacial growth predictions, thereby improving the efficacy of growth modification interventions in pediatric craniofacial treatment.Support or Funding InformationFunding: NIH/NIDCR R03‐DE021435; NIH/NIDCR R01 DE024732This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Differential growth of seals and sea lions with paedomorphic and peramorphic adult skull morphologies

Links between behavior and skull morphology have been widely demonstrated in carnivorans. The skulls of more‐aggressive species tend to be more peramorphic, with greater crest development for the emplacement of muscles, compared to the more paedomorphic rounded skulls of less‐aggressive species. Are these two endpoints the result of differential growth patterns in dimorphic species?To answer this, we looked at skulls of seals and sea lions (n = 58, including 22 males, 14 females and 22 unknowns, usually juveniles) across 8 species. We categorized the individuals into ages from immature (teeth erupting, less fused sutures, smaller size), sub‐adult (teeth erupted but not worn, more sutural fusion), and adult (teeth with wear, fully‐fused sutures, and larger size). We compared these individuals by observing the placement of 26 bony landmarks using a geometric morphometric approach.We found that paedomorphic adults have juvenile‐looking skulls, e.g., a short or absent sagittal and nuchal crest, a narrow zygomatic width, and shorter skull length between the braincase and rostrum. Peramorphic adults had more growth resulting in traits including taller sagittal and nuchal crests, a wider zygomatic width, and a longer skull length. The brain case varied little between paedomorphic and peramorphic end points. The increase in skull length happens first through growth, and the width of the zygomatic arch and height of crests increases later, likely in response to the increase of size of the jaw‐closing muscles.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Transatlantic discovery of Notocotylus atlanticus (Digenea: Notocotylidae) based on life cycle data.

Digenean parasites feature a series of stages with a distinct appearance, reproduction mode, and lifestyle that together constitute their well-known, complex life cycle. Species descriptions of Digenea have always been based on one of these stages-the marita, or sexually reproducing adult in the final host. However, in some cases, data on the life cycle are essential for the differential diagnosis of closely related species. Here, we present the case of Notocotylus atlanticus, where different stages of its life cycle were discovered for the first time since the species description, and across the Atlantic. We used a material from a naturally infected intertidal marine snail, Ecrobia ventrosa, and several waterfowl species and also carried out infection experiments. For morphological studies, we employed light microscopy, SEM, and CLSM; molecular data obtained include sequences of ITS1 and 28S rRNA gene. We demonstrate that N. atlanticus adult worm morphology is barely sufficient to distinguish it from several other species. Cercariae morphology and identity of the first intermediate hosts provide crucial additional information. According to our preliminary phylogenetic reconstructions, two notocotylid lineages are associated with two major gastropod lineages-the Caenogastropoda and the Heterobranchia. The traditional character to identify notocotylid genera (structure of ventral organs) fails to explain the phylogeny and thus requires reassessment. Further reliable morphological, life cycle and molecular data on other species are likely to reveal more patterns in notocotylid systematics, host specificity, and evolution.

Towards resolving and redefining Amphipyrinae (Lepidoptera, Noctuoidea, Noctuidae): a massively polyphyletic taxon

AbstractAmphipyrinae have long been a catchall taxon for Noctuidae, with most members lacking discernible morphological synapomorphies that would allow their assignment to one of the many readily diagnosable noctuid subfamilies. Here data from seven gene regions (> 5500 bp) for more than 120 noctuid genera are used to infer a phylogeny for Amphipyrinae and related subfamilies. Sequence data for 57 amphipyrine genera – most represented by the type species of the genus – are examined. We present here the first large‐scale molecular phylogenetic study of Amphipyrinae and the largest molecular phylogeny of Noctuidae to date; several proposed nomenclatural changes for well‐supported results; and the identification of areas of noctuid phylogeny where greater taxon sampling and/or genomic‐scale data are needed. Adult and larval morphology, along with life‐history traits, for taxonomic groupings most relevant to the results are discussed. Amphipyrinae are significantly redefined; many former amphipyrines, excluded as a result of these analyses, are reassigned to other noctuid subfamily‐level taxa. Four genera, Chamaeclea Grote, Heminocloa Barnes & Benjamin, Hemioslaria Barnes & Benjamin and Thurberiphaga Dyar, are transferred to the tribe Chamaecleini Keegan & Wagner tribe n. in Acontiinae. Stiriina is elevated to Stiriinae rev. stat., Grotellina is elevated to Grotellinae rev. stat. and Annaphilina is elevated to Annaphilini rev. stat. Acopa Harvey is transferred to Bryophilinae, Aleptina Dyar is transferred to Condicinae, Leucocnemis Hampson and Oxycnemis gracillinea (Grote) are transferred to Oncocnemidinae, Nacopa Barnes & Benjamin is transferred to Noctuinae and Narthecophora Smith is transferred to Stiriinae. Azenia Grote (and its subtribe Azeniina), Cropia Walker, Metaponpneumata Möschler, Sexserrata Barnes & Benjamin and Tristyla Smith are transferred to Noctuidae incertae sedis. Hemigrotella Barnes & McDunnough (formerly in subtribe Grotellina) is retained in Amphipyrinae. Argentostiria Poole and Bistica Dyar are retained in Stiriini but removed from incertae sedis position.This published work has been registered on ZooBank: http://zoobank.org/urn:lsid:zoobank.org:pub:4A140782‐31BA‐445A‐B7BA‐6EAB98ED43FA.

New microhylid frog genus from Peninsular India with Southeast Asian affinity suggests multiple Cenozoic biotic exchanges between India and Eurasia

Anurans in Peninsular India exhibit close biogeographical links with Gondwana as well as Laurasia, often explainable by the geological history of the Indian subcontinent; its breakup from Gondwanan landmasses followed by long isolation that resulted in diversification of endemic lineages, and subsequent land connections with Asia that enabled dispersal of widespread groups. Although widely distributed, the frog subfamily Microhylinae mostly comprises of geographically restricted genera found either in Southeast and East Asia or Peninsular India and Sri Lanka. Here we report a previously unknown microhylid from the Western Ghats in Peninsular India with closest relatives found over 2,000 km away in Southeast Asia. Based on integrated evidence from mitochondrial and nuclear DNA, adult and tadpole morphology, hand musculature, male advertisement call, and geographical distance, we recognize this enigmatic frog as a distinct new species and genus endemic to the Western Ghats. The discovery of Mysticellus franki gen. et sp. nov. and its close evolutionary relationship with the Southeast Asian genus Micryletta also provide insights on the biogeography of Microhylinae. Genus-level divergences within the subfamily suggest multiple Cenozoic biotic exchange events between India and Eurasia, particularly through postulated Eocene land bridges via Southeast Asia prior to accretion of the two landmasses.

A New Species of Pseudopaludicola Miranda-Ribeiro, 1926 (Anura: Leptodactylidae: Leiuperinae) from an Amazonia-Cerrado Transitional Zone, State of Tocantins, Brazil

Abstract The Neotropical genus Pseudopaludicola includes 24 species distributed throughout South America. Herein, we formally describe the 25th member of this Neotropical clade as a new species: Pseudopaludicola jazmynmcdonaldae sp. nov. from an Amazon-Cerrado transitional zone in Brazil. The recognition of this new species is supported by adult morphology, advertisement call, and molecular data. It is diagnosed mainly by the following characters: small size; upper eyelids smooth, with no palpebral tubercles; heel smooth, with no enlarged conical tubercle; terminal phalanges knobbed, with no T-shaped terminal phalanges or expanded toe tips; relatively short hind limbs (tibiotarsal articulation just reaching the corner of the mouth); single, subgular, smooth, dark vocal sac in life, with no warty texture; and an advertisement call composed of regular series of short multipulsed notes, emitted at high rate.

The influence of land cover and within-pool characteristics on larval, froglet, and adult wood frogs along a rural to suburban gradient

Urbanization is known to extirpate many species, but far less is known about how suburbanization may affect amphibian populations. We studied wood frogs (Lithobates sylvaticus) to test the effects of site characteristics (within-pool conditions and land cover indicative of suburbanization within 1000 m) and larval morphology on newly emerged froglets and post-breeding males across a suburbanization gradient in 15 pools in greater Bangor, Maine, USA. We raised field-captured larvae in microcosms and examined froglet morphology and locomotor performance at emergence and one month post-emergence. Larval mass was positively correlated with 50% of froglet responses (survival, size, and locomotor performance) but was negatively associated with adult size. Among site characteristics, egg density had the most salient influence with negative effects on larval survival and morphology as well as on 11 of 14 froglet responses. Vegetation, hydrology, and suburban-associated cover near pools also influenced froglet performance, and hydrology and suburban-associated cover was associated with larger and smaller adult morphology. However the influence of suburban-associated cover on froglet performance and adult morphology was small compared to that of within-pool characteristics. Specifically, our findings support the idea that within-pool conditions experienced by larvae can influence terrestrial stages with potentially life-long consequences. Nevertheless, in suburban landscapes where there is evidence of population declines, it is likely that suburbanization has the greatest impact on populations via direct effects on terrestrial stages. We encourage planners to maintain high-quality habitat for aquatic and terrestrial stage wood frogs in suburbanizing landscapes to avoid extirpation.

Further studies on Melitaea arduinna (Esper, [1873]) (Lepidoptera: Nymphalidae), with observations on early stages and host-plants, from the Levant populations in Upper Galilee and the Samarian Desert, Israel

The life history and host-plants of two populations of Melitaea arduinna from Israel are described and illustrated. Their final instar larvae, adult wing morphology and wingspans are compared with those of the same species from Russia, the Caucasus and the Balkans. The taxonomic position of the Levant populations is discussed.

Two new day-flying species of Agrotis Ochsenheimer (Lepidoptera: Noctuidae) from the alpine summit of the Maunakea Volcano.

Two new endemic Hawaiian species of Agrotis Ochsenheimer (Noctuidae) are described: A. helela and A. kuamauna. Both species are day-flying and occur at high-elevations. Observations of adult and larval morphology and biology are included, as well as illustrations of adult moths and genitalia for both sexes.

<p class="Body" align="left">Contribution to the knowledge of the oribatid mite genus Antarctozetes (Acari, Oribatida, Punctoribatidae)

A new species of Antarctozetes (Oribatida, Ceratozetoidea) is described from the soil in New Zealand based on adult morphology. Antarctozetes mariehammerae sp. nov. differs from Antarctozetes intermedius (Hammer, 1967) by the short rostral setae, very short stalks of bothridial setae, and bidentate lamellar cusps. A revised generic diagnosis is given, Antarctozetes is maintained in Punctoribatidae, although knowledge of juvenile instars is lacking. The relationship of Antarctozetes, Anellozetes, Africoribates and Kilimabates is discussed. Data on habitat and an identification key to known species of Antarctozetes in New Zealand are provided.

Redescription of Porrocaecum semiteres (Zeder, 1800) (Nematoda: Ascaridida) from the Song Thrush Turdus philomelos (Passeriformes: Turdidae).

Porrocaecum semiteres (Zeder, 1800) (Ascaridida: Ascaridoidea) occurs frequently in various birds in Europe. However, the knowledge of the morphology of this species remains insufficient. Light and scanning electron microscopy were used to study the detailed morphology of adults of P. semiteres based on newly collected specimens from Turdus philomelos in the Czech Republic. Some previously unreported morphological features were revealed, including the presence of a medio-apical notch, 70-80 small conical denticles and one pair of submedial pores on each lip, the absence of caudal alae, the presence of four pairs of postcloacal papillae, and a single, medio-ventral precloacal papilla.

Archaeomalthus-(Coleoptera, Archostemata) a ‘ghost adult’ of Micromalthidae from Upper Permian deposits of Siberia?

ABSTRACT Archaeomalthus synoriacos gen. et sp. nov. from the Upper Permian Babiy Kamen` locality indicates a remarkable evolutionary stability. Herein we report the oldest record of the family Micromalthidae, Archaeomalthus synoriacos gen. et sp. nov., which demonstrates several plesiomorphic character states, but generally retains most of the apomorphies of Micromalthidae. Archaeomalthus suggests that a distinct simplification of the morphology of adults already evolved in the late Paleozoic, suggesting and early reduction of the role of adults in the life cycle of the group. Despite the marked differences between Archaeomalthus and Micromalthus, the former already show a distinct and apparently very stable degree of deviation from the ground plan of Coleoptera s.str. and s.l. The remarkable series of reductional features shared by the Permian fossil and the extant species include a lightly sclerotized body without distinct surface sculpture, a head lacking dorsal protuberances, shortened and apparently thin elytra, exposed membranous areas behind the procoxae and between at least two basal visible abdominal sternites, and the reversal of the invagination of the terminal abdominal segments. It is likely that the reduced role of adults of Micromalthidae was a syndrome of simplified, vestigial adult morphology characters acquired at least 255 million years ago.

Three-Dimensional Soft-Tissue Facial Morphometry in Caucasian Obese Adults

Objective: To evaluate the facial morphology of Caucasian obese adults in relation to normal weight peers, and to study the association between three-dimensional soft-tissue facial measurements and cardiometabolic risk factors. Material and Methods: Nineteen Caucasian obese subjects aged 25 to 73 years underwent anthropometric measurements, blood samples and a stereophotogrammetric facial scan. Soft-tissue facial linear distances, angles, and volumes were obtained and compared to those collected on normal weight subjects by computing z-scores. Spearman correlation was used to assess the associations between facial measurements and metabolic parameters. Logistic regression analysis adjusted for sex and age was used to assess the risk of metabolic syndrome associated to the facial measurements. Results: Overall, when compared to normal weight persons, obese adults had a wider face in the horizontal dimension, with a middle face (maxilla) that was larger both in absolute value and relatively to the lower face (mandible), and a larger right side gonial angle (Wilcoxon test, p < 0.01). Only the mean (left and right) gonial angle was positively associated to serum triglycerides level, while the other facial measurements were associated with none of the cardiometabolic parameters. Moreover, none of the facial measurements was associated with the risk of metabolic syndrome. Conclusion: Despite larger facial dimensions and altered mandible/maxilla volume ratio, three-dimensional soft-tissue facial morphometry in Caucasian obese adults is not related to cardiometabolic risk factors. The actual association between morphological facial characteristics and clinical information on the health conditions of patients is still to be investigated.

A new species of Teleogryllus (Teleogryllus) Chopard, 1961 from Yunnan, China (Orthoptera: Gryllidae: Gryllinae).

There are six species of genus Teleogryllus Chopard, 1961 recorded from China prior to this study. They belong to either subgenus Macroteleogryllus or subgenus Brachyteleogryllus. We describe a new species, Teleogryllus (Teleogryllus) albipalpus He sp. nov. belonging to subgenus Teleogryllus from Yunnan, China. The morphology of adults and nymphs in different instars, songs and COI gene are provided. The type specimens are deposited in Museum of Biology, East China Normal University (ECNU).

Wing morphology in migratory North American monarchs: characterizing sources of variation and understanding changes through time

Abstract Monarch butterfly wing morphology varies substantially throughout their global range, both between resident and migratory populations and also within the migratory North American population. Here, we use a dataset comprising more than 1800 North American individuals collected between 1878-2017 to characterize the factors shaping continent-wide patterns of wing morphological variation. North American overwintering butterflies have forewings that are approximately 4.4% larger than those collected in summer breeding areas. Monarchs overwintering in Mexico have forewings that are approximately 1.8% larger than monarchs overwintering in California, conducive to the idea that migration distance is positively correlated with wing area. We find evidence for a latitudinal cline within North America, such that butterflies collected at higher latitudes have significantly larger and more elongated forewings. We also find a significant increase of approximately 4.9% in forewing area between 1878-2017, but no difference through time in wing elongation. This result is corroborated by a reanalysis of a recently published dataset of more than 600 butterflies from Mexican overwintering sites. We discuss possible reasons for this increase in wing size through time, including northward shifts in the monarch’s breeding range and changes in relative abundance of milkweed hosts, and present experimental data addressing the influence of larval host plant on adult wing morphology. Our analysis suggests that (1) migration is indeed an important selective force for monarch wing morphology; (2) wing size has increased through time in North America; (3) factors such as host plant identity must be considered to fully understand monarch wing morphological variation.

A New Species ofFritzianaMello-Leitão 1937 (Amphibia: Anura: Hemiphractidae) from the Atlantic Forest, Brazil

Abstract We describe a new species of the genus Fritziana, historically identified as Fritziana fissilis or F. aff. fissilis. Using adult and tadpole morphology, as well as molecular analyses, we found the new species to be characterized by having the following traits: a mucronate snout tip, a black stripe on the wrist, round subarticular tubercles on the fingers and toes, a closed dorsal egg-pouch in females, tadpoles deposited in bromeliads, and a different mitochondrial transfer RNA gene order, when compared to the general orders already recognized for anurans. This new species occurs in the Atlantic Forest of Brazil, in the states of Sao Paulo, Parana, Santa Catarina, and Rio Grande do Sul, and has the largest geographic distribution recorded for a species of Fritziana.

A new species of Pseudopaludicola (Anura, Leptodactylidae, Leiuperinae) from the state of Minas Gerais, Brazil

The genus of Neotropical frogs Pseudopaludicola Miranda-Ribeiro, 1926 includes 23 species, which occur throughout South America. Herein we describe a new species of Pseudopaludicola from the central region of the state of Minas Gerais (southeastern Brazil). This new species is distinguished by the adult morphology, the advertisement call, and molecular data. It is diagnosed mainly by its small size, terminal phalanges knobbed (lack of any expansion of the digital tips), proportionally short hind limbs, and its advertisement call composed of series of two-pulsed notes, emitted at a high repetition rate. In addition, we report the occurrence of the new species in the southern foothills of the Serra do Cipó National Park, at elevations lower than 800 m above sea level (a.s.l). The sister species of this new taxon is P. mineira Lobo, 1994, which occurs in rupestrian grasslands above 1200 m a.s.l. at the Serra do Cipó National Park and in Serra do Cabral, both in the state of Minas Gerais, Brazil. We also redescribe the advertisement call of P. mineira based on recordings from topotypical males and compare it to calls of related species.

Three Species of Andricus Hartig (Hymenoptera: Cynipidae) Inducing Similar Galls in East Asia, with Description of a New Species and the Asexual Generation of A. Pseudocurvator, and Redescription of A. Moriokae

The sexual generation of Andricus wuhanensis Ide, Abe, Su and Zhu, new species is described from Mainland China. The gall of this species is similar to the sexual generation galls of A. pseudocurvator Tang and Melika and A. moriokae Monzen, but the adult wasps of the three species differ morphologically. The asexual generation gall of A. pseudocurvator was previously reported as that of A. moriokae from Japan, but the adult morphology has not yet been described; therefore, we here describe the asexual generation adult of A. pseudocurvator for the first time. Andricus pseudocurvator is here first recorded from Mainland China and Japan.