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1.
Zootaxa ; 5104(4): 577-585, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35391018

RESUMO

Investigation of the male calling signals of Limotettix (Limotettix) striola (Falln, 1806) in populations from central and southern European Russia, Northern Caucasus, and West Tien Shan, Kyrgyzstan demonstrated that they belong to the same species. Males of L. striola from West Tien Shan have a somewhat different penis shape and belong to a separate subspecies, L. striola ferganensis Dubovskiy, 1966. L. striola ferganensis from West Tien Shan differs from L. ferganensis sensu Hamilton (1983, 1994) from the Nearctic in the shape of penis in dorsal view. Apparently, L. ferganensis sensu Hamilton (1983, 1994) is a separate, possibly, undescribed Nearctic taxon.


Assuntos
Hemípteros , Distribuição Animal , Estruturas Animais/anatomia & histologia , Animais , Hemípteros/anatomia & histologia , Masculino
2.
Zootaxa ; 5092(3): 273-290, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35391205

RESUMO

Two new snapping shrimps associated with gobies are described from the tropical waters of the western Pacific. Alpheus thompsoni sp. nov. is described based on a single adult female from Madang, Papua New Guinea. Alpheus sciolii sp. nov. is described based on several specimens of both sexes from the Solomon Islands, Australia and Vietnam. Both species are part of a larger species complex, which also includes A. djeddensis Coutire, 1897, A. djiboutensis De Man, 1909, A. bellulus Miya Miyake, 1969, A. macellarius Chace, 1988, A. fenneri Bruce, 1994 and A. mannarensis Purushothaman, Abhilash, Kumar Lal, 2021, but can be distinguished from each of them by a combination of morphological characters, and from the latter four species also by the very different colour patterns.


Assuntos
Decápodes , Distribuição Animal , Estruturas Animais/anatomia & histologia , Animais , Decápodes/anatomia & histologia , Feminino , Humanos , Masculino
3.
Zootaxa ; 5115(4): 511-531, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35391354

RESUMO

We describe Gehyra wongchan sp. nov. from Tham Khao Chan (Khao Chan Cave), Tha Luang District, and Wat Khao Wong, Kok Samrong District, in Lopburi Province, central Thailand. The new species differs from all currently recognized Gehyra by the following combination of morphological characters and dorsal color pattern: maximal known snoutvent length of 52.4 mm, 810 supralabials, 7680 dorsal and 4850 ventral scale rows around midbody, absence of skin folds on limbs, 17 or 18 preanofemoral pores in males in a continuous series extending to mid-length of femur (pores absent in females), tail not- to moderately widened behind vent in adults, a single row of widened subcaudals, digits and toes unwebbed, 7 or 8 divided subdigital lamellae on 4th toe, and a dorsal pattern with white spots as large or larger than adjacent crescentic black markings on a beige to light-brown background.


Assuntos
Carbonato de Cálcio , Lagartos , Distribuição Animal , Estruturas Animais/anatomia & histologia , Animais , Cavernas , Ecossistema , Feminino , Lagartos/anatomia & histologia , Masculino , Filogenia , Tailândia
4.
Zootaxa ; 5099(1): 1-45, 2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-35391428

RESUMO

Based on the specimens deposited in Guangxi Normal University, the paper mainly deals with Capnogryllacris and reports one new species and four new subspecies, viz. Capnogryllacris sequestris Liu, Lu Bian sp. nov. (Chinese name: ), Capnogryllacris erythrocephala maculates Liu, Lu Bian ssp. nov. (Chinese name: ), Capnogryllacris nigromarginata hainanensis Liu, Lu Bian ssp. nov. (Chinese name: ), Capnogryllacris nigromarginata rectispina Liu, Lu Bian ssp. nov. (Chinese name: ) and Capnogryllacris xichou flavifrons Liu, Lu Bian ssp. nov. (Chinese name: ). The next-generation sequencing technology was used to sequence the mitochondrial genomes of 13 specimens of Gryllacrididae, and the characteristics of newly obtained mitogenomes were introduced. The gene arrangements are completely consistent with other known orthopteran insects, and there is a long IGS of 166 bp217 bp between trnK and cox2 genes in three individuals of C. erythrocephala maculatis ssp. nov.. Meanwhile, fourteen specimens of Capnogryllacris were delimited using COI barcode by constructing NJ tree and two distance-based barcoding methods (ABGD and jMOTU). Among the three methods, C. erythrocephala maculatis, C. rufonotata and C. spinosa can be correctly identified, but C. nigromarginata shows some differences in morphological and genetic distance, and Capnogryllacris melanocrania is divided into two clades. The Bayesian inference (BI) and Maximum likelihood (ML) trees based on the 13 protein-coding genes data supported the division of Gryllacrididae into two groups according to whether the male ninth abdominal tergite with median furrow or split along the midline or not.


Assuntos
Ortópteros , Distribuição Animal , Estruturas Animais/anatomia & histologia , Animais , Teorema de Bayes , Tamanho Corporal , China , Humanos , Masculino , Tamanho do Órgão , Filogenia
5.
Zootaxa ; 5094(3): 409-434, 2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35391444

RESUMO

The current work presents the description of a new species for the genus Arachnopsita Desutter-Grandcolas Hubbell, 1993 from caves in the municipality of Raxruh, Alta Verapaz, Guatemala. The morphology of the phallic complex was used as the main criterion for distinguishing the species. In addition, we present the additional description for Arachnopsita cavicola (Saussure, 1897) and Arachnopsita uncinata Desutter-Grandcolas, 1997 from a new analyzed material. Finally, we present some ecological remarks for all the studied species as well as a brief discussion on troglomorphic traits for the genus.


Assuntos
Gryllidae , Ortópteros , Distribuição Animal , Estruturas Animais/anatomia & histologia , Animais , Guatemala , Fenótipo
6.
Zootaxa ; 5094(2): 288-300, 2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35391451

RESUMO

A new stomatopod-associated species of the alpheid shrimp genus Athanas Leach, 1814 is described based on several specimens collected in shallow waters of northern New Caledonia. Athanas philippei n. sp. differs from all of its congeners by a unique combination of morphological characteristics, as well as a diagnostic colour pattern. All specimens of A. philippei n. sp. were collected from burrows, including one with its host, a large tiger mantis shrimp, Lysiosquillina maculata (Fabricius, 1793) (Lysiosquillidae). Thus, the new species represents the fifth species of Athanas known or presumed to be associated with the spacious burrows of stomatopods.


Assuntos
Decápodes , Distribuição Animal , Estruturas Animais/anatomia & histologia , Animais , Crustáceos , Nova Caledônia
7.
Zootaxa ; 5093(4): 465-482, 2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35391474

RESUMO

Herein we describe a new species of Cyrtodactylus from Lunglei District in the state of Mizoram, India. Based on morphology and ND2 gene sequences, the species was found to be a member of the Cyrtodactylus khasiensis group. The species can be identified by its moderate size (adult SVL 64.975.1 mm) with rounded, bluntly conical and feebly keeled dorsal tubercles in 2428 longitudinal rows; 3240 paravertebral tubercles between the level of the axilla and the level of the groin; 3743 mid-ventral scale rows; 35 precloacal pores in males and 57 pitted precloacal scales in females; 1618 subdigital lamellae under IV toe; no single row of transversely enlarged subcaudal scales; dorsal markings are dark brown, irregular and distinct; tail with alternating dark and light bands.


Assuntos
Lagartos , Distribuição Animal , Estruturas Animais/anatomia & histologia , Animais , Ecossistema , Feminino , Índia , Lagartos/anatomia & histologia , Lagartos/genética , Masculino , Cauda
8.
Zoolog Sci ; 39(1): 147-156, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35107002

RESUMO

Acoels, belonging to Xenacoelomorpha, are small worms with a relatively simple body plan and are considered a critical clade for understanding the evolution of bilaterians. Despite acoels' importance, however, many undiscovered species are predicted to be present worldwide. Here, we describe a new marine acoel species, Amphiscolops oni sp. nov., based on materials collected from the intertidal and subtidal zones of rocky shores at several localities along the Japanese Pacific coast. The new species is approximately 3 mm long and shows typical characteristics of the family Convolutidae, such as the presence of eyespots, symbiosis with algae, position of the gonopores, morphology of the bursal nozzles, lack of central singlet microtubules in the axonemes of spermatozoa, and funnel-like posture of the anterior end. Based on morphology and the results of molecular phylogenetic analyses, we assign this species to the genus Amphiscolops. Interestingly, these worms show unique behaviors such as swimming by flapping the lateral sides and actively capturing prey by swinging the anterior funnel. Furthermore, they possess a dorsal appendage-a characteristic previously unreported in Xenacoelomorpha-representing an evolutionary novelty acquired by this species.


Assuntos
Estruturas Animais/anatomia & histologia , Sensação , Animais , Masculino , Filogenia
9.
Cells ; 10(10)2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34685746

RESUMO

Postcopulatory sexual selection is credited as a principal force behind the rapid evolution of reproductive characters, often generating a pattern of correlated evolution between interacting, sex-specific traits. Because the female reproductive tract is the selective environment for sperm, one taxonomically widespread example of this pattern is the co-diversification of sperm length and female sperm-storage organ dimension. In Drosophila, having testes that are longer than the sperm they manufacture was believed to be a universal physiological constraint. Further, the energetic and time costs of developing long testes have been credited with underlying the steep evolutionary allometry of sperm length and constraining sperm length evolution in Drosophila. Here, we report on the discovery of a novel spermatogenic mechanism-sperm cyst looping-that enables males to produce relatively long sperm in short testis. This phenomenon (restricted to members of the saltans and willistoni species groups) begins early during spermatogenesis and is potentially attributable to heterochronic evolution, resulting in growth asynchrony between spermatid tails and the surrounding spermatid and somatic cyst cell membranes. By removing the allometric constraint on sperm length, this evolutionary innovation appears to have enabled males to evolve extremely long sperm for their body mass while evading delays in reproductive maturation time. On the other hand, sperm cyst looping was found to exact a cost by requiring greater total energetic investment in testes and a pronounced reduction in male lifespan. We speculate on the ecological selection pressures underlying the evolutionary origin and maintenance of this unique adaptation.


Assuntos
Estruturas Animais/anatomia & histologia , Drosophila/anatomia & histologia , Drosophila/fisiologia , Espermatozoides/fisiologia , Animais , Evolução Biológica , Masculino , Filogenia , Maturidade Sexual/fisiologia , Especificidade da Espécie , Testículo/anatomia & histologia
10.
Acta Biomater ; 134: 513-530, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34329785

RESUMO

Biological tissues may exhibit graded heterogeneities in structure and mechanical properties that are crucial to their function. One biological structure that shows variation in both structure and function is the molluscan radula: the organ comprises a chitinous membrane with embedded teeth and serves to process and gather food. The tooth morphologies had been well studied in the last decades, but the mechanical properties of the teeth are not known for the vast majority of molluscs. This knowledge gap restricts our understanding of how the radula is able to act effectively on a target surface whilst simultaneously resisting structural failure. Here we employed nanoindentation technique to measure mechanical properties (hardness and Young's modulus) on distinct localities of individual radular teeth from 24 species of African paludomid gastropods. These species have distinct ecological niches as they forage on algae on different feeding substrates. A gradual distribution of measured properties along the teeth was found in species foraging on solid or mixed feeding substrates, but soft substrate feeders exhibit teeth almost homogeneous in their biomechanical properties. The presence or absence of large-scale gradients in these taenioglossan teeth could directly be linked with their specific function and in general with the species ecology, whereas the radular tooth morphologies do not always and fully reflect ecology. STATEMENT OF SIGNIFICANCE: African Lake Tanganyika is well known for harbouring endemic and morphologically distinct genera. Its paludomid gastropods form a flock of high interest because of its diversity. As they show distinct radular tooth morphologies hypotheses about potential trophic specializations had always been at hand. Here we evaluated the mechanical properties Young's modulus and hardness of 9027 individual teeth from 24 species along the tooth by nanoindentation and related them with the gastropods' specific feeding substrate. We find that hard substrate feeders have teeth that are hard at the tips but much less stiff at the base and thus heterogeneous with respect to material properties, whereas soft substrate feeders have teeth that are flexible and homogenous with respect to material properties.


Assuntos
Estruturas Animais/anatomia & histologia , Gastrópodes , Animais , Ecossistema , Módulo de Elasticidade , Gastrópodes/anatomia & histologia
11.
Acta Biomater ; 134: 490-498, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34293506

RESUMO

Insect cuticle can reach a wide range of material properties, which is thought to be the result of adaptations to applied mechanical stresses. Biomechanical mechanisms behind these property variations remain largely unknown. To fill this gap, here we performed a comprehensive study by simultaneous investigation of the microstructure, sclerotization and the elasticity modulus of the specialized cuticle of the femora of desert locusts. We hypothesized that, considering their different roles in jumping, the femora of fore-, mid- and hind legs should be equipped with cuticles that have different mechanical properties. Surprisingly, our results showed that the hind femur, which typically bears higher stresses, has a lower elasticity modulus than the fore and mid femora in the longitudinal direction. This is likely due to the lower sclerotization and different microstructure of the hind femur cuticle. This allows for some deformability in the femur wall and is likely to reduce the risk of mechanical failure. In contrast to both other femora, the hind femur is also equipped with a set of sclerotized ridges that are likely to provide it with the required stiffness to withstand the mechanical loads during walking and jumping. This paper is one of only a few comprehensive studies on insect cuticle, which advances the current understanding of the relationship between the structure, material property and function in this complex biological composite. STATEMENT OF SIGNIFICANCE: Insect cuticle is a biological composite with strong anisotropy and wide ranges of material properties. Using an example of the femoral cuticle of desert locusts, we measured the elasticity modulus, microstructure and sclerotization level of the cuticle. Our results show that, although the hind femur withstands most of the stress during locomotion, it has a lower elasticity modulus than the fore and mid femora. This is likely to be a functional adaption to jumping, in order to allow small deformations of the femur wall and reduce the risk of material failure. Our results deepen the current understanding of the structure-material-function relationship in the complex insect cuticle.


Assuntos
Estruturas Animais/anatomia & histologia , Gafanhotos , Animais , Fenômenos Biomecânicos , Módulo de Elasticidade , Gafanhotos/anatomia & histologia , Insetos , Estresse Mecânico
12.
Mar Drugs ; 19(5)2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063509

RESUMO

Marine biodiversity has been yielding promising novel bioproducts from venomous animals. Despite the auspices of conotoxins, which originated the paradigmatic painkiller Prialt, the biotechnological potential of gastropod venoms remains to be explored. Marine bioprospecting is expanding towards temperate species like the dogwhelk Nucella lapillus, which is suspected to secrete immobilizing agents through its salivary glands with a relaxing effect on the musculature of its preferential prey, Mytilus sp. This work focused on detecting, localizing, and testing the bioreactivity of cysteine-rich proteins and peptides, whose presence is a signature of animal venoms and poisons. The highest content of thiols was found in crude protein extracts from the digestive gland, which is associated with digestion, followed by the peribuccal mass, where the salivary glands are located. Conversely, the foot and siphon (which the gastropod uses for feeding) are not the main organs involved in toxin secretion. Ex vivo bioassays with Mytilus gill tissue disclosed the differential bioreactivity of crude protein extracts. Secretions from the digestive gland and peribuccal mass caused the most significant molecular damage, with evidence for the induction of apoptosis. These early findings indicate that salivary glands are a promising target for the extraction and characterization of bioactive cysteine-rich proteinaceous toxins from the species.


Assuntos
Secreções Corporais/química , Cisteína/química , Cisteína/toxicidade , Gastrópodes/química , Estruturas Animais/anatomia & histologia , Estruturas Animais/química , Animais , Bivalves/anatomia & histologia , Cisteína/análise , Dano ao DNA/efeitos dos fármacos , Gastrópodes/anatomia & histologia , Gastrópodes/metabolismo , Brânquias/anatomia & histologia , Toxinas Marinhas/análise , Toxinas Marinhas/química , Toxinas Marinhas/toxicidade , Glândulas Salivares/química
13.
Zoology (Jena) ; 147: 125941, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34126327

RESUMO

Flamingos inhabit specialized habitats and breed in large colonies, building their nests on islands that limit the access of terrestrial predators. Many aspects of their uropygial gland are still unknown. The uropygial gland, a sebaceous organ exclusive to birds, shares some histological features among species such as the presence of a capsule, adenomers with stratified epithelium and secondary and primary chambers. We found that the uropygial gland of the Chilean Flamingo (Phoenicopterus chilensis) displays most of these characteristics but lacks a primary storage chamber. This absence may be an adaptation to their aquatic environment. The uropygial secretion of this species has a variety of glycoconjugates while its lipid moiety is largely dominated by waxes and minor amounts of triacylglycerols and fatty acids. Mass spectrometry analysis of the preen wax showed branched fatty acids of varied chain length and unbranched fatty alcohols, resulting in a complex mixture of wax esters and no differences between sexes were observed. The glycoconjugates present in the preen secretion could play a role as antimicrobial molecules, as suggested for other bird species, while the absence of diester waxes in flamingos might be related with their nesting habits and limited exposure to predation. Our results were evaluated according to physiological and ecological aspects of the flamingo's biology.


Assuntos
Estruturas Animais/fisiologia , Aves/fisiologia , Secreções Corporais/química , Estruturas Animais/anatomia & histologia , Animais , Secreções Corporais/fisiologia , Feminino , Masculino , Tamanho do Órgão , Especificidade da Espécie
14.
Integr Comp Biol ; 61(2): 655-667, 2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34038530

RESUMO

Spines are ubiquitous in both plants and animals, and while most spines were likely originally used for defense, over time many have been modified in a variety of ways. Here we take an integrative approach to review the form, function, and evolution of spines as a defensive strategy in order to make new connections between physical mechanisms and functional behavior. While this review focuses on spines in mammals, we reference and draw ideas from the literature on spines in other taxa, including plants. We begin by exploring the biomechanics of defensive spines, their varied functions, and nondefensive modifications. We pay particular attention to the mechanics involved in passive puncture and the ways organisms have overcome limitations associated with the low energy input. We then focus on the ecological, physiological, and behavioral factors that promote the evolution of spiny defenses, including predator- and habitat-mediated hypotheses. While there is considerable evidence to support both, studies have generally found that (1) defensive spines are usually effective against one class of attacker (e.g., larger predators) but ineffective against or even facilitate predation by others and (2) species that are more visible or exposed to predators are under much stronger selection to evolve defensive spines or some other robust defense. What type of defensive morphology that evolves, however, is less predictable and probably strongly dependent on both the dominant source of predation and the habitat structure of the organism (e.g., arboreal, terrestrial, and fossorial). We then explore traits that often are correlated with defensive spines and armor, potentially forming armor syndromes, suites of traits that evolve together with body armor in a correlated fashion. In mammals, these include aposematic warning coloration, locomotion style, diet, metabolic rate, and relative brain size. Finally, we encourage integration of mechanistic, behavioral, and evolutionary studies of defensive spines and suggest future avenues of research in the biomechanics, evolution, and behavior of spines and spiny organisms.


Assuntos
Estruturas Animais/anatomia & histologia , Evolução Biológica , Mamíferos/anatomia & histologia , Comportamento Predatório , Animais , Fenômenos Biomecânicos , Ecossistema , Fenótipo
15.
Zootaxa ; 4965(1): zootaxa.4965.1.8, 2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33903500

RESUMO

The genus Arachnomimus Saussure, 1897 is one of the 13 genera of Phalangopsidae present in India. A total of 11 species belongs to this genus, of which, 9 are grouped in the subgenus Arachnomimus Saussure, 1897 with their distribution on the Indian subcontinent. One species occurs in Brazil and another in Euarachnomimus Gorochov, 1996 known from Southeast Asia. India hosts two species, Arachnomimus (Arachnomimus) lepidus Chopard, 1969 and Arachnomimus (Arachnomimus) maindroni (Chopard, 1969). In the present paper, we describe a new subgenus, Indimimus Desutter-Grandcolas Jaiswara and a new species Indimimus jayanti Jaiswara under genus Arachnomimus. Identification keys for all the three subgenera and three species from India are proposed.


Assuntos
Ortópteros , Distribuição Animal , Estruturas Animais/anatomia & histologia , Animais , Índia , Ortópteros/anatomia & histologia , Ortópteros/classificação , Especificidade da Espécie
16.
Toxins (Basel) ; 13(4)2021 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918654

RESUMO

Spiders are one of the most successful groups of venomous animals, but surprisingly few species have been examined in sufficient detail to determine the structure of their venom systems. To learn more about the venom system of the family Araneidae (orb-weavers), we selected the wasp spider (Argiope bruennichi) and examined the general structure and morphology of the venom apparatus by light microscopy. This revealed morphological features broadly similar to those reported in the small number of other spiders subject to similar investigations. However, detailed evaluation of the venom duct revealed the presence of four structurally distinct compartments. We propose that these subunits facilitate the expression and secretion of venom components, as previously reported for similar substructures in pit vipers and cone snails.


Assuntos
Estruturas Animais/anatomia & histologia , Venenos de Aranha/metabolismo , Aranhas/anatomia & histologia , Estruturas Animais/metabolismo , Animais , Via Secretória , Picaduras de Aranhas , Aranhas/metabolismo
17.
Philos Trans R Soc Lond B Biol Sci ; 376(1825): 20200155, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-33813897

RESUMO

The byssus is a structure unique to bivalves. Byssal threads composed of many proteins extend like tendons from muscle cells, ending in adhesive pads that attach underwater. Crucial to settlement and metamorphosis, larvae of virtually all species are byssate. By contrast, in adults, the byssus is scattered throughout bivalves, where it has had profound effects on morphological evolution and been key to adaptive radiations of epifaunal species. I compare byssus structure and proteins in blue mussels (Mytilus), by far the best characterized, to zebra mussels (Dreissena polymorpha), in which several byssal proteins have been isolated and sequenced. By mapping the adult byssus onto a recent phylogenomic tree, I confirm its independent evolution in these and other lineages, likely parallelisms with common origins in development. While the byssus is superficially similar in Dreissena and Mytilus, in finer detail it is not, and byssal proteins are dramatically different. I used the chromosome-scale D. polymorpha genome we recently assembled to search for byssal genes and found 37 byssal loci on 10 of the 16 chromosomes. Most byssal genes are in small families, with several amino acid substitutions between paralogs. Byssal proteins of zebra mussels and related quagga mussels (D. rostriformis) are divergent, suggesting rapid evolution typical of proteins with repetitive low complexity domains. Opportunities abound for proteomic and genomic work to further our understanding of this textbook example of a marine natural material. A priority should be invasive bivalves, given the role of byssal attachment in the spread of, and ecological and economic damage caused by zebra mussels, quagga mussels and others. This article is part of the Theo Murphy meeting issue 'Molluscan genomics: broad insights and future directions for a neglected phylum'.


Assuntos
Dreissena/anatomia & histologia , Genoma , Mytilus/anatomia & histologia , Proteoma , Estruturas Animais/anatomia & histologia , Animais , Dreissena/genética , Mytilus/genética
18.
Proc Natl Acad Sci U S A ; 118(10)2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33658360

RESUMO

Located in the forelegs, katydid ears are unique among arthropods in having outer, middle, and inner components, analogous to the mammalian ear. Unlike mammals, sound is received externally via two tympanic membranes in each ear and internally via a narrow ear canal (EC) derived from the respiratory tracheal system. Inside the EC, sound travels slower than in free air, causing temporal and pressure differences between external and internal inputs. The delay was suspected to arise as a consequence of the narrowing EC geometry. If true, a reduction in sound velocity should persist independently of the gas composition in the EC (e.g., air, [Formula: see text]). Integrating laser Doppler vibrometry, microcomputed tomography, and numerical analysis on precise three-dimensional geometries of each experimental animal EC, we demonstrate that the narrowing radius of the EC is the main factor reducing sound velocity. Both experimental and numerical data also show that sound velocity is reduced further when excess [Formula: see text] fills the EC. Likewise, the EC bifurcates at the tympanal level (one branch for each tympanic membrane), creating two additional narrow internal sound paths and imposing different sound velocities for each tympanic membrane. Therefore, external and internal inputs total to four sound paths for each ear (only one for the human ear). Research paths and implication of findings in avian directional hearing are discussed.


Assuntos
Estruturas Animais , Meato Acústico Externo , Gryllidae , Audição/fisiologia , Membrana Timpânica , Estruturas Animais/anatomia & histologia , Estruturas Animais/fisiologia , Animais , Meato Acústico Externo/anatomia & histologia , Meato Acústico Externo/fisiologia , Gryllidae/anatomia & histologia , Gryllidae/fisiologia , Membrana Timpânica/anatomia & histologia , Membrana Timpânica/fisiologia
19.
Toxins (Basel) ; 13(2)2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33540609

RESUMO

Predator-prey interactions are thought to play a driving role in animal evolution, especially for groups that have developed venom as their predatory strategy. However, how the diet of venomous animals influences the composition of venom arsenals remains uncertain. Two prevailing hypotheses to explain the relationship between diet and venom composition focus on prey preference and the types of compounds in venom, and a positive correlation between dietary breadth and the number of compounds in venom. Here, we examined venom complexity, phylogenetic relationship, collection depth, and biogeography of the Terebridae (auger snails) to determine if repeated innovations in terebrid foregut anatomy and venom composition correspond to diet variation. We performed the first molecular study of the diet of terebrid marine snails by metabarcoding the gut content of 71 terebrid specimens from 17 species. Our results suggest that the presence or absence of a venom gland is strongly correlated with dietary breadth. Specifically, terebrid species without a venom gland displayed greater diversity in their diet. Additionally, we propose a revision of the definition of venom complexity in conoidean snails to more accurately capture the breadth of ecological influences. These findings suggest that prey diet is an important factor in terebrid venom evolution and diversification and further investigations of other understudied organisms, like terebrids, are needed to develop robust hypotheses in this area.


Assuntos
Estruturas Animais/metabolismo , Carnivoridade , Dieta , Venenos de Moluscos/metabolismo , Comportamento Predatório , Caramujos/metabolismo , Estruturas Animais/anatomia & histologia , Animais , Perfilação da Expressão Gênica , Venenos de Moluscos/genética , Caramujos/anatomia & histologia , Caramujos/genética , Especificidade da Espécie , Transcriptoma
20.
Arthropod Struct Dev ; 61: 101029, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33607463

RESUMO

Ambrosia beetles from the genus Xyleborus are important vectors of fungal pathogens in forest and agricultural systems, yet the influence of temperature on their morphological development has been poorly studied. Because host colonization and ambrosial fungi cultivation is mostly restricted to females, it is possible to speculate on strong sexual dimorphism expression in secondary sexual characters and ecological segregation between sexes. Here, we determined the effect of different growing temperatures (17, 23, 26 and 29 °C) on mandible ontogeny of larvae and adult individuals of X. affinis, and sexual dimorphism in adults, in shape and size variation using geometric morphometrics. Mandible shape change showed significant differences in magnitude and direction through larval ontogeny among temperature treatments. Sexual shape and size dimorphism were found in adult mandibles, and the degree of sexual dimorphism was dependent on growth temperature, with a significant effect of the interaction between temperature and sex on mandible shape and size variation. Higher morphological differences were observed at the base of mandibles among temperature treatments in adults and a gradual narrowing trend with temperature increments. These findings could have consequences on feeding performance and fungus cultivation inside colonies, potentially influencing their ability to establish populations in new geographical areas.


Assuntos
Temperatura , Gorgulhos , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Feminino , Masculino , Caracteres Sexuais , Gorgulhos/anatomia & histologia , Gorgulhos/crescimento & desenvolvimento
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