Functional morphology of the pretarsus in larval Thysanoptera

1972 ◽  
Vol 50 (6) ◽  
pp. 751-766 ◽  
Author(s):  
B. S. Heming
Keyword(s):  
Blood Pressure ◽  
Functional Morphology ◽  
Form And Function ◽  
Pull Out ◽  
Depressor Muscle ◽  
And Function

Legs of larval thrips differ in form and function from those of the adults. The tarsal depressor muscle and tibial gland of the adult are absent, the trochanter and tarsus are fused to the femur and tibia, respectively, and the relative sizes and shapes of the remaining parts differ.Contraction of the pretarsal depressor muscle elevates and flattens the unguitractor plate and flexes the ungues laterally and downward. Extenders associated with the bases of the ungues rotate outward and pull out and spread the arolium. This subsequently inflates with blood pressure. When the depressor muscle relaxes, the recoil of two stretched restraining tendons originating on the tibiotarsal walls and inserting proximally into the unguitractor apodeme returns the unguitractor plate to its resting position. The ungues approach each other anteriorly and the extenders flip back into the pretarsus, pulling the arolium within the unguitractor plate as the latter rolls up longitudinally. Minor differences in pretarsal function existing between larvae of the two suborders are indicated.Replacement of the first- by the second-instar pretarsus is described and an explanation is offered for the origin of the divergence between larval and imaginal mechanisms.

Functional morphology of the thysanopteran pretarsus

1971 ◽  
Vol 49 (1) ◽  
pp. 91-108 ◽  
Author(s):  
B. S. Heming
Keyword(s):  
Blood Pressure ◽  
Functional Morphology ◽  
Depressor Muscle

The functional morphology of the unique pretarsal mechanism of adult Thysanoptera is described. The components of each pretarsus are homologous with those of other insects, but changes in their relative sizes and shapes have arisen through modifications in their function. Among these are the enlargement of the arolium into a protrusible bladder; the reduction of the ungues into spoon-shaped, laterally ensheathing plates; the development of a tibial gland opening to the surface of the arolium through three fine ducts; and the evolution of two elastic "restraining" tendons each inserting into the "head" of the unguitractor apodeme and originating laterally on the walls of the distal end of the tibia.The contraction of the pretarsal depressor muscle causes the ungues to rotate outward on the unguifer and blood pressure, increased by abdominal contraction, everts the arolium. When the depressor muscle relaxes, the restraining tendons contract and the arolium is withdrawn between the closing ungues by sclerites and filaments associated with each. The adults of species in all five families of the order have this mechanism.

Virtual Functional Morphology: Novel Approaches to the Study of Craniofacial Form and Function

2012 ◽  
Vol 39 (4) ◽  
pp. 521-535 ◽  
Author(s):  
Paul O’Higgins ◽  
Laura C. Fitton ◽  
Roger Phillips ◽  
JunFen Shi ◽  
Jia Liu ◽  
...  
Keyword(s):  
Functional Morphology ◽  
Form And Function ◽  
Novel Approaches ◽  
And Function

Section 2 Summary—Functional Morphology and Ecology of Larval Forms

2018 ◽  
Keyword(s):  
Life History ◽  
Functional Morphology ◽  
Morphological Variation ◽  
Aquatic Environment ◽  
Molecular Variation ◽  
Form And Function ◽  
Life History Stages ◽  
Taxonomic Groups ◽  
And Function ◽  
Exogenous Nutrients

Larvae are intermediate life history stages between embryos and juvenile and/or reproductive stages, but this characteristic is about the only feature that unites the incredible diversity of larval forms. The majority of larval forms evolved in the sea and exhibit tremendous morphological, physiological, and molecular variation, many of which are potential adaptations to match form and function in the context of the aquatic environment. The three chapters in this section review how larvae from different taxonomic groups sort through and ingest exogenous nutrients and how environmental variation elicits morphological variation....

scholarly journals Melding Modeling and Morphology: A Call for Collaboration to Address Difficult Questions about the Evolution of Form and Function

2020 ◽  
Vol 60 (5) ◽  
pp. 1188-1192
Author(s):  
Lindsay D Waldrop ◽  
Jonathan A Rader
Keyword(s):  
Functional Morphology ◽  
The Other ◽  
Form And Function ◽  
Interdisciplinary Collaborations ◽  
And Function

Synopsis The nascent field of evolutionary biomechanics seeks to understand how form begets function, and researchers have taken two tacks toward this goal: inferring form based on function (comparative biomechanics) or inferring function based on form (functional morphology). Each tack has strengths and weaknesses, which the other could improve. The symposium, “Melding modeling and morphology—integrating approaches to understand the evolution of form and function” sought to highlight research stitching together the two tacks. In this introduction to the symposium’s issue, we highlight these works, discuss the challenges of interdisciplinary collaborations, and suggest possible avenues available to create new collaborations to create a unifying framework for evolutionary biomechanics.

scholarly journals Anatomy, functional morphology, evolutionary ecology and systematics of the invasive gastropod Cipangopaludina japonica (Viviparidae: Bellamyinae)

2016 ◽  
Vol 85 (2) ◽  
pp. 235-263 ◽  
Author(s):  
Bert Van Bocxlaer ◽  
Ellen E. Strong
Keyword(s):  
Functional Morphology ◽  
Evolutionary Ecology ◽  
Distribution Patterns ◽  
Reproductive Organs ◽  
Japanese Species ◽  
Shell Size ◽  
High Fecundity ◽  
Form And Function ◽  
Morphometric Analyses ◽  
And Function

The anatomy, functional morphology and evolutionary ecology of the Viviparidae, and the subfamily Bellamyinae in particular, are incompletely known. Partly as a result, genealogical relationships within the family remain poorly understood. Because of this lack in knowledge, few informed hypotheses exist on ancestral states, how differences in body plans between the subfamilies evolved, and how the peculiar biogeographic distribution patterns of viviparids have arisen. Here we document the anatomy, morphology, life history and systematics of Cipangopaludina japonica, a Japanese species that has been introduced into North America, to resolve taxonomic confusion and to improve our understanding of how form and function are related in bellamyines. Anatomical and histological examinations demonstrate marked differences between C. japonicaand other bellamyines in the radula, salivary gland, kidney, nerve ring and reproductive organs. Substantial differences also exist between male and female body organization, but conchological differences between sexes in semi-landmark morphometric analyses are limited. The volume of the brood pouch of females, and hence body and shell size, appear to be good predictors of reproductive success, and the species’ ecological versatility may relate to high fecundity and the ability to alternate between feeding modes. Comparing our observations on C. japonicawith other viviparids and basal Architaenioglossa, we identify several persistent misinterpretations in the literature on how form and function are related in viviparids, not in the least as to female reproductive anatomy. Our reinterpretations improve understanding of the evolution of Viviparidae and its subfamilies, and hopefully will allow future workers to isolate key traits that shaped the evolution of viviparids at the taxonomic levels of their interest for more detailed studies.

First Carboniferous thylacocephalan from Europe and its significance for the understanding of functional morphology of Concavicarididae Schram, 2014

Crustaceana ◽  
2018 ◽  
Vol 91 (3) ◽  
pp. 265-285 ◽  
Author(s):  
Štěpán Rak ◽  
Krzysztof Broda ◽  
Tomáš Kumpan
Keyword(s):  
New Species ◽  
Functional Morphology ◽  
Fossil Record ◽  
Free Swimming ◽  
Lower Carboniferous ◽  
Form And Function ◽  
Mode Of Life ◽  
Moravian Karst ◽  
And Function ◽  
Evolutionary Aspects

Thylacocephala Pinna, Arduini, Pesarini & Teruzzi 1982 are among the most enigmatic arthropods. Their fossil record is very patchy both geographically and stratigraphically. In this paper we describe the first thylacocephalan known from the Carboniferous (Mississippian) of Europe, Concavicaris viktoryni sp. nov. Until now Carboniferous representatives of Thylacocephala were know exclusively from the U.S.A. We discuss the stratigraphic and geological context of occurrence of this new species as well as form and function of the unique carapace micro- and macro-ornamentation. A shape and assumed function of the characteristic lirae on the C. viktoryni sp. nov. carapace present an important supporting argument for the supposed free-swimming or pelagic mode of life in thylacocephalans. Palaeobiogeographical and evolutionary aspects of surprisingly rich but local occurrence of thylacocephalans in the Lower Carboniferous of the Moravian karst are discussed. Possible sympatric evolution from its predecessor Concavicaris incola is also pointed out.

Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

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