scholarly journals Functional morphology of parasitic isopods: understanding morphological adaptations of attachment and feeding structures inNerocilaas a pre-requisite for reconstructing the evolution of Cymothoidae

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2188 ◽  
Author(s):  
Christina Nagler ◽  
Joachim T. Haug

Parasites significantly influence food webs and ecosystems and occur all over the world in almost every animal group. Within crustaceans there are numerous examples of ectoparasites; for example, representatives of the isopod group Cymothoidae. These obligatory parasitic isopods are relatively poorly studied regarding their functional morphology. Here we present new details of the morphological adaptations to parasitism of the cymothoiid ingroupNerocilawith up-to-date imaging methods (macro photography, stereo imaging, fluorescence photography, micro CT, and histology). Central aspects of the study were (1) the morphology of the mouthparts and (2) the attachment on the host, hence the morphology of the thoracopods. The mouthparts (labrum, mandibles, paragnaths, maxillulae, maxillae, maxillipeds) form a distinct mouth cone and are most likely used for true sucking. The mouthparts are tightly “folded” around each other and provide functional rails for the only two moving mouthparts, mandible and maxillula. Both are not moving in an ancestral-type median-lateral movement, but are strongly tilted to move more in a proximal-distal axis. New details concerning the attachment demonstrate that the angular arrangement of the thoracopods is differentiated to impede removal by the host. The increased understanding of morphological adaptation to parasitism of modern forms will be useful in identifying disarticulated (not attached to the host) fossil parasites.

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1002
Author(s):  
Mengzhen Chen ◽  
Wanru Guo ◽  
Sunbin Huang ◽  
Xiaozhu Luo ◽  
Mingyi Tian ◽  
...  

Cave-dwelling ground beetles in China represent the most impressive specific diversity and morphological adaptations of the cavernicolous ground beetles in the world, but they have not been systematically examined in quantitative terms. The present study focuses on the application of geometric morphological methods to address the morphological adaptations of the tribe Trechini, the most representative group in China. We have employed a geometric morphometry analysis of the head, pronotum, and elytra of 53 genera of Trechini, including 132 hypogean and 8 epigean species. Our results showed that the overall morphological variation of cave carabids has gradually specialized from an anophthalmic to semi-aphaenopsian to aphaenopsian type. There were extremely significant differences (p < 0.01) among four different adaptive types including aphaenopsian, semi-aphaenopsian, anophthalmic, and surface-dwelling Trechini when their adaptability to a cave environment was used as the basis for grouping. Furthermore, there were differences in the phenotypic tree of the head, pronotum, and elytra, and an integrated morphology. To the best of our knowledge, this is the first report on the analysis of the head, pronotum, and elytra of four different adaptive types of ground beetles in order to clarify the morphological adaptations of cavernicolous carabids to the cave environment.


2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Ina Schaefer ◽  
Tancredi Caruso

Abstract The early evolution of ecosystems in Palaeozoic soils remains poorly understood because the fossil record is sparse, despite the preservation of soil microarthropods already from the Early Devonian (~410 Mya). The soil food web plays a key role in the functioning of ecosystems and its organisms currently express traits that have evolved over 400 my. Here, we conducted a phylogenetic trait analysis of a major soil animal group (Oribatida) to reveal the deep time story of the soil food web. We conclude that this group, central to the trophic structure of the soil food web, diversified in the early Paleozoic and resulted in functionally complex food webs by the late Devonian. The evolution of body size, form, and an astonishing trophic diversity demonstrates that the soil food web was as structured as current food webs already in the Devonian, facilitating the establishment of higher plants in the late Paleozoic.


2013 ◽  
Vol 3 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Ganapathy Rameshkumar ◽  
Samuthirapandian Ravichandran ◽  
Sartaj Ahmad Allayie

2019 ◽  
Vol 158 ◽  
pp. 100-108 ◽  
Author(s):  
David Wilby ◽  
Tobio Aarts ◽  
Pierre Tichit ◽  
Andrew Bodey ◽  
Christoph Rau ◽  
...  

Author(s):  
Brian Morton ◽  
Sanja Puljas

The functional morphology ofPinna nobilisis described, with special reference to the uniquely pinnid pallial organ, the similarly unique buccal (formerly pallial) gland, the stomach and its contents. The pallial gland produces sulphuric acid which as well as functioning as a shell cleaning swab may be involved in prey capture. The buccal gland discharging into the oesophagus has proteolytic digestive functions while the stomach is adapted for the reception and digestion of captured, mucous-bound, mesozooplanktonic and epi- and endo-benthic, prey items.Pinna nobilisis thus not simply either an accidental or incidental predator of such species but is opportunistic. The buccal glands and stomachs of other Pinnidae are not so specialized as inP. nobilis,possibly indicating that in the particular, oligotrophic, environment of the Mediterranean and Adriatic Seas, and in which it is endemic,P. nobilishas, in addition to being a typical ctenidial suspension feeder, become an opportunistic predator. Although the deep sea representatives of the Septibranchia (Anomalodesmata) and Propeamussidae are obligate predators, this is the first record of any bivalve functioning as an opportunistic predator with unique morphological adaptations to facilitate this.


2019 ◽  
Vol 2 (1) ◽  
pp. 48-50
Author(s):  
Jan Stenis ◽  
William Hogland

Dam disasters occur sometimes frequently around the world as they did recently in 2015 and 2019 in Minas Gerais, Brazil. As a result, hundreds of families were displaced, and many cities suffered from water shortages. The study aimed to reduce ore mining waste pollutions in rivers and ocean currents and therefore mitigate their impact on the food webs. A model based on the equality principle named EUROPE (Efficient Use of Resources for Optimal Production Economy) was used to estimate shadow costs of economic systems. It was applied to ore mining wastes management in order to mitigate their negative impact on rivers and oceans. As a result, it gave a comprehensive picture of that management system in economic, technical as well as environmental terms.


2018 ◽  
Author(s):  
Alexander L. Davis ◽  
Matthew H. Babb ◽  
Brandon T. Lee ◽  
Christopher H. Martin

AbstractBotanical carnivory is a novel feeding strategy associated with numerous physiological and morphological adaptations. However, the benefits of these novel carnivorous traits are rarely tested. Here, we used field observations and lab experiments to test the prey capture function of the marginal spikes on snap traps of the Venus flytrap (Dionaea muscipula). Our field and laboratory results suggested surprisingly inefficient capture success: fewer than 1 in 4 prey encounters led to prey capture. Removing the marginal spikes decreased the rate of prey capture success for moderate-sized cricket prey by 90%, but this effect disappeared for larger prey. The nonlinear benefit of spikes suggests that they provide a better cage for capturing more abundant insects of moderate and small sizes, but may also provide a foothold for rare large prey to escape. Our observations support Darwin’s hypothesis that the marginal spikes form a ‘horrid prison’ that increases prey capture success for moderate-sized prey, but the decreasing benefit for larger prey is unexpected and previously undocumented. Thus, we find surprising complexity in the adaptive landscape for one of the most wonderful evolutionary innovations among all plants. These findings further enrich our understanding of the evolution and diversification of novel trap morphology in carnivorous plants.


Bionomina ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 1-68 ◽  
Author(s):  
ALAIN DUBOIS ◽  
ANNEMARIE OHLER

The Code provides no Rules regarding the taxonomic allocation and nomenclatural validity of class-series nomina (for taxa above the rank superfamily), which results in considerable confusion, arbitrariness and instability in higher zoological nomenclature. Currently, authors are ‘free’ to use any system or no system at all, and the only way to provide clear and unambiguous information about the status of such nomina in a given work is to provide explicit information on the Criteria used. Such Criteria should have a general value over the whole zoological nomenclature and should not be devised on the basis of a limited knowledge of the literature bearing on a single animal group like the amphibians.Several questions related to higher nomenclature are discussed again in detail here: e.g., the acceptance of nomenclatural availability, with their original authorship and date, of class-series nomina introduced as clear scientific names, derived from classical Greek or Latin roots, even in a ‘non-Latin’ form (an unclear concept), or the statement that the rank of a taxon in the work where a new nomen was introduced is a reliable criterion for the assignment of this nomen to a nominal-series only when it concerns the five basic ranks of the Linnean hierarchy, which are the only ones to have always been used for the same position in the taxonominal hierarchy. The proposals made here are not ‘official’, but, as long as no Rules are implemented in the Code in these respects, this also applies to any other proposals, many of which are not even supported by clear statements about consistent Criteria that could be used for higher nomenclature in all animal groups.     These general questions are here discussed based on real examples from amphibian higher nomenclature. Dubois (2004) provided a detailed analysis of the higher nomenclature of recent amphibians. Almost immediately after its publication, Frost et al. (2006) rejected all the conclusions of this work. Although all their arguments were refuted in detail by Dubois in several publications, the widely cited and followed website Amphibian Species of the World (ASW) stuck to their opinions, but without providing replies to these criticisms, without providing a complete and consistent rationale for higher nomenclature, and above all, in the absence of arguments, in repeating factual errors. This is shown in detail here with the examples of the nomina of the two orders of recent amphibians accommodating the frogs and the salamanders. Frost et al. (2006), followed by ASW and by several recent authors and websites, credited the nomina Anura, Urodela, Ecaudata and Caudata to ‘Fischer von Waldheim (1813)’, but it is shown here that this is incorrect, for several reasons: [1] this statement is anachronistic, as Gotthelf Fischer (1771–1853) was granted the nobiliary title ‘von Waldheim’ only in 1835 and never used it in the signature of his publications; [2] the nomina used by Fischer (1813a) for the frogs and the salamanders were not new nomina, but explicit subsequent usages, without any change in rank, of the nomina of Duméril (1805); [3] under a nomenclatural system compatible with the Code, the nomen Urodela Duméril, 1805, instead of Caudata Duméril, 1805, should be considered the valid one for the order of salamanders.Additional examples of widely repeated errors in the citation of the authorship of other amphibian nomina in ASW are pointed out, such as the use of the incorrect transliteration of the name “Татаринов”, the italic writing of “Татаринов” (Tatarinov), as Tamarunov.Finally, we address the question of the use of the ‘principle of authority’ in science.


2013 ◽  
Vol 34 (2) ◽  
pp. 241-247 ◽  
Author(s):  
Pilar López ◽  
Pilar López ◽  
José Martín ◽  
Pilar López ◽  
José Martín ◽  
...  

Morphological adaptations for burrowing, such as an elongated body, and a small head may constrain feeding behaviour in fossorial reptiles. We experimentally examined the effect of prey type on prey capture and handling behaviour of the amphisbaenian Blanus cinereus. This amphisbaenian showed four different handling modes according to the characteristics of each prey type. When prey diameter was narrower than gape-size, prey were consumed without prey processing; when prey diameter was wider than gape-size, B. cinereus shifted handling mode to prey processing. Amphisbaenians scraped or tore off bite-sized pieces of large prey and showed longer handling times for some prey types than most epigean saurians. Flexibility in feeding behaviour may allow amphisbaenians to exploit variable underground trophic resources, overcoming constraints of morphological adaptation to fossoriality.


1978 ◽  
Vol 24 ◽  
pp. 151-182

Professor H. E. Hinton, a distinguished entomologist, Head of the Department of Zoology in the University of Bristol, died on 2 August 1977, aged 64 years. He was born in Mexico of British parents, and went to schools in Mexico and California. His undergraduate work was done at Berkeley and his postgraduate work at Cambridge, where he took the Ph.D. in 1939 and the Sc.D. in 1957. He was an Assistant Keeper at the British Museum (Natural History) 1939-49, then successively Lecturer, Reader, and Professor at the University of Bristol. He published many papers and several books on insects and other animals, principally in the fields of taxonomy, functional morphology, and natural history. Set out in such bare outline, Hinton’s career seems nothing out of the ordinary for these pages. Viewed in more detail, his life was one of exceptional interest, for he was a versatile biologist who visited many parts of the world and worked in several; a tireless investigator with discoveries of wide biological interest to his credit; an independent and unorthodox thinker, given to controversy; an enthusiastic, stimulating, and amusing talker; an outstanding personality in entomological circles in Britain and abroad.


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