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 Further twists in gastropod shell evolution

2008 ◽  
Vol 4 (2) ◽  
pp. 179-182 ◽  
Author(s):  
Reuben Clements ◽  
Thor-Seng Liew ◽  
Jaap Jan Vermeulen ◽  
Menno Schilthuizen
Keyword(s):  
Evolutionary Biology ◽  
Logarithmic Spiral ◽  
Spiral Growth ◽  
Evolutionary Perspective ◽  
Gastropod Shell ◽  
Form And Function ◽  
Evolutionary Origins ◽  
Taxonomic Groups ◽  
And Function ◽  
Shell Coiling

The manner in which a gastropod shell coils has long intrigued laypersons and scientists alike. In evolutionary biology, gastropod shells are among the best-studied palaeontological and neontological objects. A gastropod shell generally exhibits logarithmic spiral growth, right-handedness and coils tightly around a single axis. Atypical shell-coiling patterns (e.g. sinistroid growth, uncoiled whorls and multiple coiling axes), however, continue to be uncovered in nature. Here, we report another coiling strategy that is not only puzzling from an evolutionary perspective, but also hitherto unknown among shelled gastropods. The terrestrial gastropod Opisthostoma vermiculum sp. nov. generates a shell with: (i) four discernable coiling axes, (ii) body whorls that thrice detach and twice reattach to preceding whorls without any reference support, and (iii) detached whorls that coil around three secondary axes in addition to their primary teleoconch axis. As the coiling strategies of individuals were found to be generally consistent throughout, this species appears to possess an unorthodox but rigorously defined set of developmental instructions. Although the evolutionary origins of O. vermiculum and its shell's functional significance can be elucidated only once fossil intermediates and live individuals are found, its bewildering morphology suggests that we still lack an understanding of relationships between form and function in certain taxonomic groups.

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.

The Relationship of Form and Function of Minute Characters of Lepidopterous Larvae, and its Importance in Life-History Studies

1964 ◽  
Vol 96 (7) ◽  
pp. 991-1004 ◽  
Author(s):  
Margaret Rae MacKay
Keyword(s):  
Life History ◽  
Chemical Control ◽  
Life Histories ◽  
The Other ◽  
Taxonomic Study ◽  
Form And Function ◽  
Morphological Studies ◽  
And Function ◽  
Relationship Of ◽  
The Relationship

AbstractThe information to be obtained from thorough life-history studies is an extremely useful tool, perhaps especially so when ecology is being emphasized, as it is to-day, by the life-table and other mathematical approaches to the study of population processes. This information is desired by workers in many fields of entomology – by the biological and chemical control experts, the biomathematicians, the theorists and even the taxonomists. However, much of the knowledge that these workers require, for instance the fine distinctions of behaviour and environment, has been overlooked in most life-history studies, and I strongly suspect that one of the weaknesses of studies of this nature has been the failure to analyse the mode of living of an insect (or, in the case of Lepidoptera, of the immature forms) in relation to the anatomy on one hand and environmental circumstances on the other. To look for these relationships, I believe that one requires (a) the ability and perseverance to perceive detail as minute as that required for a taxonomic study, and (b) a considerable knowledge of the taxonomic detail that is to be obtained from basic morphological studies. Therefore, in this paper, attention is drawn to pertinent structural characters of lepidopterous larvae and their probable connection with the behaviour and microhabitats of the larvae, in the hope that some guidance may be offered to future students of life-histories, at least in Lepidoptera.

Trophic ecology of terapontid fishes (Pisces: Terapontidae): the role of morphology and ontogeny

2012 ◽  
Vol 63 (2) ◽  
pp. 128 ◽  
Author(s):  
Aaron M. Davis ◽  
Bradley J. Pusey ◽  
Richard G. Pearson
Keyword(s):  
Trophic Ecology ◽  
Dietary Habits ◽  
Form And Function ◽  
Life History Stages ◽  
Selective Pressures ◽  
Intestinal Length ◽  
Mouth Width ◽  
Dietary Variation ◽  
And Function

With the covariation between fish form and function of long-standing interest to fish biologists, ecomorphological research provides a framework for assessing the interaction between the morphology of an organism and their ecology. Whereas ecomorphological studies of Australian fishes are rare, the terapontid grunters are an ideal candidate for study because of their diversity of dietary habits. We examined the morphological correlates of the diet of 21 species of northern Australia’s terapontids and their constituent ontogenetic trophic units. Preliminary analyses focusing on morphology identified the role of allometric growth – in characters such as intestinal length, maxilla length and mouth width – as driving considerable ontogenetic divergence in interspecific morphological trajectories. A significant relationship was identified between diet and morphology across species, although morphology explained only half of the observed dietary variation. Body size, and its relationship to allometric development of several morphological parameters, appears to constrain the trophic habits expressed by many terapontids at different life-history stages. Many of the diet–morphology relationships evident within the Terapontidae parallel those seen in other studies, providing substantial corroboration for the ecomorphological approach. This demonstrates that selective pressures have driven morphology in terapontids to converge morphologically with other ecologically comparable fishes across the globe.

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

scholarly journals Trade-offs among plant reproductive traits determine interactions with floral visitors

2021 ◽  
Author(s):  
Jose B. Lanuza ◽  
Romina Rader ◽  
Jamie Stavert ◽  
Liam K. Kendall ◽  
Manu E. Saunders ◽  
...  
Keyword(s):  
Life History ◽  
Reproductive Traits ◽  
Life History Strategies ◽  
Form And Function ◽  
Plant Life ◽  
Trade Offs ◽  
Floral Visitors ◽  
Plant Form ◽  
And Function ◽  
Plant Pollinator

Plant life-history strategies are constrained by cost-benefit trade-offs that determine plant form and function. However, despite recent advances in the understanding of trade-offs for vegetative and physiological traits, little is known about plant reproductive economics and how they constrain plant life-history strategies and shape interactions with floral visitors. Here, we investigate plant reproductive trade-offs and how these drive interactions with floral visitors using a dataset of 17 reproductive traits for 1,506 plant species from 28 plant-pollinator studies across 18 countries. We tested whether a plant's reproductive strategy predicts its interactions with floral visitors and if the different reproductive traits predict the plant's role within the pollination network. We found that over half of all plant reproductive trait variation was explained by two independent axes that encompassed plant form and function. Specifically, the first axis indicated the presence of a trade-off between flower number and flower size, while the second axis indicated a pollinator dependency trade-off. Plant reproductive trade-offs helped explain partly the presence or absence of interactions with floral visitors, but not differences in visitation rate. However, we did find important differences in the interaction level among floral visitor guilds on the different axes of trait variation. Finally, we found that plant size and floral rewards were the most important traits in the understanding of the plant species network role. Our results highlight the importance of plant reproductive trade-offs in determining plant life-history strategies and plant-pollinator interactions in a global context.

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.

The Development of Form and Function in Fishes and the Question of Larval Adaptation

2004 ◽  
Keyword(s):  
Life History ◽  
Visual Information ◽  
Fish Larvae ◽  
Bright Light ◽  
Developmental Rate ◽  
Motion Sensitivity ◽  
Vertebrate Retina ◽  
Form And Function ◽  
Teleost Retina ◽  
And Function

<em>Abstract.</em>—Although the basic structure of the vertebrate retina is similar across taxa, high variability in specific features of the fish retina reflects the differences in visual microhabitat of these species. The vertebrate retina is the first step in the neural integration of visual information. A great deal of retinal function can be inferred from structure, and as these relationships continue to be revealed, we are gaining new insights into how vision is integrated by the nervous system. Among fishes, the developmental rate and acquisition of retinal structures is highly variable. While some species develop all structures early in embryogenesis, others delay acquisition of the full adult retinal complement of cells until months after hatching. Given the tight relationship between structure and function, differences in the timing of retinogenesis have implications for the visionbased survival skills of the early life history stages and for the overall ecology and fitness of the species. Although much of the observed variation may be related to altricial versus precocial life history strategies, we suggest that protracted retinal development also reflects and separates the constraints imposed by the requirements of foraging and predator avoidance. As evidenced by a typically monochromatic all-cone retina, the eye of early fish larvae is adapted for efficient foraging in bright light. At later stages, an improved ability to identify the presence of predators is acquired via addition of rod photoreceptors for low light vision, as well as multiple cone spectral channels (and regularly geometric cone mosaics) for increased contrast and motion sensitivity. The larval retina of some species exhibits further specializations, such as the pure rod retina of the eel leptocephalus and the pure green cone retina of many marine teleosts. Overall, variation in the development of the teleost retina can be viewed as a continuum from very rapid to greatly delayed. The developmental trajectory of the visual system in any given species represents a product of evolutionary history, developmental constraints, and foraging and predation pressures.

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.

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