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1.
J Vet Med Sci ; 86(3): 285-289, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38233131

RESUMO

Pulmonary aspergillosis occurring in captive penguins living in zoos and aquariums is a fatal disease owing to its high mortality rate. On conducting computed tomography, two gentoo penguins (Pygoscelis papua) with respiratory clinical signs that were housed at an aquarium in Hokkaido, Japan were found to have a certain amount of fluid in their air sacs. This fluid was collected and cultured for bacteria and fungi, the results of which both came back negative. These results enabled us to rule out bacterial infection or aspergillosis and supported our decision not to administer antibacterial and antifungal drugs. Overall, the combination of computed tomography and air sac fluid examination was useful for ruling out bacterial infection or aspergillosis in penguins with respiratory clinical signs.


Assuntos
Aspergilose , Infecções Bacterianas , Spheniscidae , Animais , Sacos Aéreos , Aspergilose/diagnóstico por imagem , Aspergilose/veterinária , Tomografia Computadorizada por Raios X/veterinária , Infecções Bacterianas/veterinária
2.
J Exp Biol ; 227(3)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38230425

RESUMO

A macrourid, Coryphaenoides yaquinae sp. inc., was observed to be attracted to bait and exhibiting normal foraging behaviour during a period of 80 min within view of a baited video camera on the sea floor at 7259 m - the deepest ever observation of a fish species with a swim bladder. The buoyancy provided by an oxygen-filled swim bladder at 74.4 MPa pressure was estimated to be 0.164 N, at a theoretical energy cost of 20 kJ, 200 times less than the cost of equivalent lipid buoyancy. During normal metabolism, 192 days would be required to fill the swimbladder. At these depths, oxygen is very incompressible, so changes in volume during ascent or descent are small. However, swimbladder function is crucially dependent on a very low rate of diffusion of oxygen across the swimbladder wall. The oxygen in the swimbladder could theoretically sustain aerobic metabolism for over 1 year but is unlikely to be used as a reserve.


Assuntos
Sacos Aéreos , Peixes , Animais , Japão , Peixes/metabolismo , Oxigênio/metabolismo
3.
J Acoust Soc Am ; 154(5): 3019-3026, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37955566

RESUMO

Hearing evolved in lampreys with a frequency range of 50-200 Hz. This hearing range is comparable to that of elasmobranchs, most non-teleosts, and lungfish. Elasmobranchs most likely use the saccule and the papilla neglecta (PN) for hearing. In non-teleosts and teleosts, lungfish, and certain tetrapods the saccule is the likely sensor for sound reception while the lagena and the PN are important for gravistatic sensing. Coelacanth and most tetrapods have a basilar papilla (BP) for hearing. In coelacanth and tetrapods, the hair cells of the BP are in contact with a basilar and a tectorial membrane. These membranes transmit mechanical vibrations. A cochlear aqueduct (CA) provides a connection between the cerebrospinal fluid that has a sodium rich space in coelacanth and tetrapods while the potassium rich endolymph is known in vertebrates. A unique feature is known in basic sarcopterygians, the intracranial joint, that never developed in actinopterygians and has been lost in lungfish and tetrapods. The BP in coelacanths is thought to generate pressure with the intracranial joint that will be transmitted to the CA. Lungs or a swim bladder are not forming in Chondrichthyes, structures that have a major impact on hearing in teleosts and tetrapods.


Assuntos
Peixes , Audição , Animais , Som , Sacos Aéreos , Células Ciliadas Auditivas
4.
J Acoust Soc Am ; 154(5): 2928-2936, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37938048

RESUMO

An unmanned surface vehicle (USV; Wave Glider) was deployed to study the coastal soundscape in shallow (less than 30 m) coastal waters off the coast of Cape Canaveral, FL, in July 2020 and January 2022. These surveys documented temporal and seasonal trends in biological sounds across a variety of habitats within an 812-km2 survey area, including sand shoals, sand-mud plains, and natural hardbottom. Among a broader diversity of identifiable and unidentifiable fish choruses recorded during the survey, a distinct and previously unidentified fish chorus was recorded; corroborating evidence suggests it and other sounds with similar spectral properties may be produced by Atlantic midshipman. Putative Atlantic midshipman sounds included an agnostic grunt and a seasonal chorus of persistent hums that peaked 3 h after sunset in the summer survey. While Atlantic midshipman have been demonstrated to have well-developed sonic muscles on their swim bladder, their acoustic behavior has not been previously described. Our use of a mobile passive acoustic platform combined with bottom sampling of fish communities highlights an important opportunity to identify previously undocumented biological sound sources in coastal habitats.


Assuntos
Batracoidiformes , Animais , Areia , Acústica , Sacos Aéreos , Aeronaves
5.
J Avian Med Surg ; 37(2): 144-154, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37733453

RESUMO

Air sac cannulation is used both as an emergency procedure in avian patients with severe upper respiratory compromise, as well as a means of routine ventilation for surgery of the head and neck. The objective of this retrospective study was to describe and quantify the complications associated with air sac cannulation in birds. Medical records were retrieved for all patients that underwent caudal thoracic or abdominal air sac cannulation at a single center between August 2004 and October 2020. Patient signalment, indication for air sac cannulation, location of air sac cannula (ASC) placement, occurrence and category of complications encountered, and survival data were recorded. Eighty-four ASCs were placed in 68 birds across 6 orders; 95.2% (80/84) of cases survived general anesthesia for initial ASC placement. The side and position of ASC placement were known in 33.3% (28/84) and 21.4% (18/84) of cases, respectively. Survival to ASC removal was known in 91.3% (73/80) of cases; 43 (58.9%) of these 73 cases survived to ASC removal. Complications were observed in 32.5% (26/80) of cases, and 11.5% (3/26) of cases died as a direct result of the complication. The most common reported ASC complication was loss of patency in 23.8% (19/80) of cases. Increased likelihoods for complications were seen in cases where exercise intolerance (P = 0.04) or abnormal respiratory sounds (P = 0.04) were reported at presentation. Increased likelihoods for survival to ASC removal were seen with intercostal placements (P = 0.049) and peri-interventional antibiotic therapy (P = 0.005). Decreased likelihood for survival to ASC removal was seen in cases where voice change was reported at presentation (P = 0.02). This study demonstrates a moderate risk of ASC complication, with a guarded overall prognosis for survival to ASC removal.


Assuntos
Sacos Aéreos , Aves , Animais , Estudos Retrospectivos , Registros/veterinária , Cateterismo/veterinária
6.
Sci Rep ; 13(1): 15182, 2023 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-37704690

RESUMO

The lack of data on the species-specific Target Strength (TS) on ancillary species limits the application of acoustic surveys in assessing their abundance and distribution worldwide. The TS values of Scomber colias and Trachurus mediterraneus in use in the Mediterranean Sea rely on studies conducted on other species in the Atlantic and Pacific oceans. Nevertheless, the application of backscattering models offers the possibility to overcome the absence of empirical data handling the parameters that most affect the TS. X-ray scans were performed on 82 specimens to get digital representations of the swimbladder and the fish body which were used as input for the application of the Kirchhoff Ray Mode model to measure the TS as a function of frequency and tilt angle. The morphometric differences between the two species produced divergent relative frequency responses and broadband TS patterns. Moreover, comparing the results with one ex-situ experiment, we found a good agreement considering a mean tilt angle of - 10°, standard deviation = 12°. Our results provide the first theoretical insights into the use of backscattering models as a tool to distinguish between species in the Mediterranean Sea by acoustic method, increasing the knowledge of the acoustic reflectivity of ancillary species.


Assuntos
Acústica , Peixes , Animais , Sacos Aéreos , Conhecimento , Mar Mediterrâneo
7.
Nat Commun ; 14(1): 5630, 2023 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-37699889

RESUMO

The six species of lungfish possess both lungs and gills and are the closest extant relatives of tetrapods. Here, we report a single-cell transcriptome atlas of the West African lungfish (Protopterus annectens). This species manifests the most extreme form of terrestrialization, a life history strategy to survive dry periods that can last for years, characterized by dormancy and reversible adaptive changes of the gills and lungs. Our atlas highlights the cell type diversity of the West African lungfish, including gene expression consistent with phenotype changes of terrestrialization. Comparison with terrestrial tetrapods and ray-finned fishes reveals broad homology between the swim bladder and lung cell types as well as shared and idiosyncratic changes of the external gills of the West African lungfish and the internal gills of Atlantic salmon. The single-cell atlas presented here provides a valuable resource for further exploration of the respiratory system evolution in vertebrates and the diversity of lungfish terrestrialization.


Assuntos
Ascomicetos , Salmo salar , Animais , Aclimatação , Sistema Respiratório , Brânquias , Sacos Aéreos
8.
Dis Aquat Organ ; 155: 21-33, 2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37534719

RESUMO

One possible reason for the European eel (Anguilla anguilla) population decline is the neozoan eel swim bladder nematode Anguillicola crassus. To investigate whether the prevalence of A. crassus and the associated swim bladder pathology is related to eel habitat, growth rate, and age, 728 yellow eels from 6 habitats differing in salinity and located along the German Baltic coast were examined between 2005 and 2009. The prevalence of A. crassus varied between habitats, ranging from 9 to 57%. Infection prevalence and the percentage of eels with a damaged swim bladder were significantly higher in inner coastal waters compared to more saline open coastal water. In infected eels, 1 to 32 adult and preadult individuals of A. crassus were observed. The mean infection intensity varied between habitats from 2 to 7 nematodes per eel but did not significantly differ between inner and open coastal waters. Infection prevalence and intensity decreased significantly with age when all open coastal waters and all habitats were combined. Both the lower prevalence of A. crassus and the swim bladder damage of older eels and of eels originating from open coastal water habitats suggest that these eels have a higher fitness for spawning migrations than eels from inner coastal waters. The present study underlines the importance of eel screening on a sufficiently small geographical scale for the accurate estimation of eel recruitment and the identification of priority areas that are likely to produce healthy silver eels.


Assuntos
Anguilla , Dracunculoidea , Doenças dos Peixes , Animais , Bexiga Urinária , Doenças dos Peixes/epidemiologia , Sacos Aéreos , Ecossistema , Água
9.
J Zoo Wildl Med ; 54(2): 379-386, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37428703

RESUMO

Air sac trematodes (Digenea: Cyclocoelidae) were detected in 23 avian species from eight aviaries in the United States. Most of the infected host species were passeriform birds, but a few species in other orders also were infected. Four species of adult flukes were encountered: Circumvitellatrema momota, Morishitium sp., Psophiatrema greineri, and Szidatitrema yamagutii. Findings from retrospective review of medical records, necropsy records, and author observations are presented. Potential terrestrial snail intermediate hosts were collected from three indoor aviaries. A high prevalence (47%) of larval trematode infections was demonstrated in one species of nonnative snail (Prosopeas achatinacea); one larva was isolated and matched to the adult species (C. momota) from birds using PCR. Problems with introducing potentially infected wild-caught birds into aviaries, and exchanging captive individuals between aviaries where they potentially may carry infections, are discussed.


Assuntos
Trematódeos , Infecções por Trematódeos , Animais , Estados Unidos/epidemiologia , Sacos Aéreos , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/veterinária , Aves , Larva , Caramujos
10.
J Fish Dis ; 46(10): 1029-1047, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37329520

RESUMO

Parasites negatively affect biological processes within their hosts, which may alter for example health, growth, and reproductive ability. Non-native invasive parasites, in particular, may have large effects on the endemic hosts, given that the hosts lack evolved specific defences against such parasites. The swim bladder nematode Anguillicola crassus, an invasive parasite originating from Asia, is found in the European eel (Anguilla anguilla, L. 1758), since the 1980s. We investigated whether A. crassus affected several indicators related to health of the European eel (spleen- and liver size, body fat content and relative condition). Our results indicate that during the continental residency of the eels, infection by A. crassus had no major negative impacts on the investigated health indicators at the generally low infection intensities present in this study (median 2-3 visible parasites). Given that many of the adult eels were found to have swim bladder damage, concerns about their spawning migration through deeper oceanic environments can still be raised. To allow further investigations, we suggest that quantification of swim bladder damage should be implemented in eel-monitoring programs. Compared to other parasite pressure parameters, swim bladder damage provides additional information about past infections and future problems.


Assuntos
Anguilla , Dracunculoidea , Doenças dos Peixes , Parasitos , Animais , Bexiga Urinária , Doenças dos Peixes/parasitologia , Sacos Aéreos/parasitologia
11.
J Acoust Soc Am ; 153(5): 2677, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37130205

RESUMO

My interest in fish bioacoustics was ignited more than 50 years ago and resulted in a zigzag time travel between various interesting problems that were unsettled at the time. The present paper gives a brief overview of the main topics I have worked on in the field of fish hearing, i.e., auditory function of the swim bladder, directional hearing, function of the lateral line system, and infrasound sensitivity. Rather than being a comprehensive review of these issues, the paper is autobiographical and limited. The aim is to show young scientists that experimental science can be exciting, diverse, and rewarding-and open doors to a rich collegial network, collaboration, and friendships.


Assuntos
Peixes , Audição , Animais , Sacos Aéreos
12.
Mar Drugs ; 21(5)2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37233474

RESUMO

As a major component of the extracellular matrix, collagen has been used as a biomaterial for many purposes including tissue engineering. Commercial collagen derived from mammals is associated with a risk of prion diseases and religious restrictions, while fish-derived collagen can avoid such issues. In addition, fish-derived collagen is widely available and low-cost; however, it often suffers from poor thermal stability, which limits its biomedical application. In this study, collagen with a high thermal stability was successfully extracted from the swim bladder of silver carp (Hypophthalmichthys molitrix) (SCC). The results demonstrated that it was a type I collagen with high purity and well-preserved triple-helix structure. Amino acid composition assay showed that the amounts of threonine, methionine, isoleucine and phenylalanine in the collagen of swim bladder of silver carp were higher than those of bovine pericardium. After adding salt solution, swim-bladder-derived collagen could form fine and dense collagen fibers. In particular, SCC exhibited a higher thermal denaturation temperature (40.08 °C) compared with collagens from the swim bladder of grass carp (Ctenopharyngodon idellus) (GCC, 34.40 °C), bovine pericardium (BPC, 34.47 °C) and mouse tail (MTC, 37.11 °C). Furthermore, SCC also showed DPPH radical scavenging ability and reducing power. These results indicate that SCC presents a promising alternative source of mammalian collagen for pharmaceutical and biomedical applications.


Assuntos
Carpas , Colágeno Tipo I , Animais , Bovinos , Camundongos , Colágeno Tipo I/química , Bexiga Urinária/metabolismo , Colágeno/química , Sacos Aéreos/química , Mamíferos/metabolismo
13.
J Exp Biol ; 226(10)2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-37204298

RESUMO

Air sacs are a well-known aspect of insect tracheal systems, but have received little research attention. In this Commentary, we suggest that the study of the distribution and function of air sacs in tracheate arthropods can provide insights of broad significance. We provide preliminary phylogenetic evidence that the developmental pathways for creation of air sacs are broadly conserved throughout the arthropods, and that possession of air sacs is strongly associated with a few traits, including the capacity for powerful flight, large body or appendage size and buoyancy control. We also discuss how tracheal compression can serve as an additional mechanism for achieving advection in tracheal systems. Together, these patterns suggest that the possession of air sacs has both benefits and costs that remain poorly understood. New technologies for visualization and functional analysis of tracheal systems provide exciting approaches for investigations that will be of broad significance for understanding invertebrate evolution.


Assuntos
Sacos Aéreos , Artrópodes , Animais , Filogenia , Insetos , Traqueia
14.
Parasitol Res ; 122(6): 1435-1443, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37071205

RESUMO

Being able to systematically detect parasitic infection, even when no visual signs of infection are present, is crucial to the establishment of accurate conservation policies. The nematode Anguillicola crassus infects the swimbladder of anguillid species and is a potential threat for eel populations. In North America, naïve hosts such as the American eel Anguilla rostrata are affected by this infection. The accidental introduction of A. crassus following restocking programs may contribute to the actual decline of the American eel in Canada. We present a quantitative real time PCR-based method to detect A. crassus infection in final and intermediate hosts. We tested two protocols on samples from different geographical origins in Canada: 1) a general detection of A. crassus DNA in pools of young final hosts (glass eels) or crustacean intermediate hosts 2) a detection at the individual scale by analyzing swim bladders from elvers, or from adult yellow and silver eels. The DNA of A. crassus was detected in one pool of zooplankton (intermediate host) from the Richelieu River (Montérégie-Québec), as well as in individual swim bladders of 13 elvers from Grande and Petite Trinité rivers (Côte-Nord-Québec). We suggest that our qPCR approach could be used in a quantitative way to estimate the parasitic burden in individual swim bladders of elvers. Our method, which goes beyond most of previous developed protocols that restricted the diagnosis of A. crassus to the moment when it was fully established in its final host, should help to detect early A. crassus infection in nature.


Assuntos
Anguilla , Dracunculoidea , Doenças dos Peixes , Animais , Doenças dos Peixes/diagnóstico , Doenças dos Peixes/parasitologia , Anguilla/parasitologia , Sacos Aéreos/parasitologia , Geografia
15.
J Comp Physiol B ; 193(3): 307-313, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37060451

RESUMO

In a recent study, a large number of transport proteins was detected in the transcriptome and proteome of saline perfused rete mirabile tissue of the European eel. In this study, the data set was reanalyzed for the presence of receptor proteins and proteins involved in intracellular signaling pathways. A large number of expressed receptor proteins and proteins involved in intracellular signal transduction was detected. Several G-protein-coupled receptor signal pathways were significantly enriched in their expression level, in particular receptors and signaling pathways involved in the control of blood flow. The enriched signaling pathways also include pathways involved in trafficking of crucial transport proteins like, monocarboxylate transporters, V-ATPase, and aquaporin. The data, therefore, suggest that the rete mirabile has the capacity to control swimbladder function by regulating blood flow and by modifying countercurrent multiplication.


Assuntos
Sacos Aéreos , Anguilla , Animais , Sacos Aéreos/metabolismo , Proteínas de Transporte/metabolismo
16.
Commun Biol ; 6(1): 3, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36650231

RESUMO

Vertebral ribs of the anterior thorax in extant birds bear bony prongs called uncinate processes, which improve the mechanical advantage of mm. appendicocostales to move air through the immobile lung and pneumatic air sacs. Among non-avian archosaurs, broad, cartilaginous uncinate processes are present in extant crocodylians, and likely have a ventilatory function. Preserved ossified or calcified uncinate processes are known in several non-avian dinosaurs. However, whether other fossil archosaurs possessed cartilaginous uncinate processes has been unclear. Here, we establish osteological correlates for uncinate attachment to vertebral ribs in extant archosaurs, with which we inferred the presence of uncinate processes in at least 19 fossil archosaur taxa. An ancestral state reconstruction based on the infer distribution suggests that cartilaginous uncinate processes were plesiomorphically present in Dinosauria and arguably in Archosauria, indicating that uncinate processes, and presumably their ventilatory function, have a deep evolutionary history extending back well beyond the origin of birds.


Assuntos
Evolução Biológica , Dinossauros , Animais , Pulmão , Sacos Aéreos , Fósseis , Aves , Dinossauros/anatomia & histologia
17.
J Fish Dis ; 46(4): 417-431, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36651585

RESUMO

European eel is critically endangered in Europe. Among other stressors, pathogens are well-known to harm eels' fitness. One hundred and eighty-two eels were captured in three Eel Management Units in Andalucía (SE Spain) and analysed for Anguillicoloides crassus, Anguillid herpesvirus 1 (AngHV1), the rhabdovirus Eel Virus European X (EVEX) and the aquabirnavirus Eel Virus European (EVE). A. crassus adults and preadults were isolated and morphometrically identified, and the eel swimbladders were artificially digested to count A. crassus larvae. Also, eel tissues were examined by PCRs for the presence of viruses. EVEX and EVE were not detected in any of the eels. The estimated prevalence (95% confidence limits) was 71 (64-78)% for A. crassus and 35 (28-42)% for AngHV-1, varying these prevalences significantly between and within EMUs. Moreover, A. crassus prevalence was highest in smaller eels, in sites closest to the sea and eels sampled in the autumn. By contrast, AngHV-1 prevalence was highest in biggest eels, in sites far from the sea and sampled in the summer or winter. However, in mixed effects logistic models including site as a random variable, the risk of infection was associated with distance to the sea in both A. crassus and AngHV-1 infections and also to winter sampling in the case of AngHV-1 and not to other variables. These results are evidence that both pathogens are highly endemic in eels from Andalusian habitats. Further studies are needed to better understand the risk factors associated with these pathogens on eel populations.


Assuntos
Anguilla , Aquabirnavirus , Dracunculoidea , Doenças dos Peixes , Rhabdoviridae , Animais , Rhabdoviridae/genética , Espanha/epidemiologia , Doenças dos Peixes/epidemiologia , Sacos Aéreos
18.
Ecotoxicol Environ Saf ; 249: 114363, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36508826

RESUMO

Particle size-dependent biological effects of silver nanoparticles (AgNPs) are of great interest; however, the mechanism of action of silver ions (Ag+) released from AgNPs concerning AgNP particle size remains unclear. Thus, we evaluated the influence of particle size (20, 40, 60, and 80 nm) on the acute 96-h bioaccumulation and toxicity (swim bladder damage) of AgNPs in zebrafish (Danio rerio) larvae, with a focus on the mechanism of action of Ag+ released from differently sized AgNPs. The 40- and 60-nm AgNPs were more toxic than the 20- and 80-nm versions in terms of inflammation and oxidative damage to the swim bladder, as indicated by inhibition of type 2 iodothyroxine deiodinase enzyme activity, mitochondrial injury, and reduced 30-50% adenosine triphosphate content. Furthermore, up-regulation and down-regulation of swim bladder development-related gene expression was not observed for pbx1a and anxa5, but up-regulation expression of shha and ihha was observed with no statistical significance. That 20-nm AgNPs were less toxic was attributed to their rapid elimination from larvae in comparison with the elimination of 40-, 60-, and 80-nm AgNPs; thus, less Ag+ was released in 20-nm AgNP-exposed larvae. Failed inflation of swim bladders was affected by released Ag+ rather than AgNPs themselves. Overall, we reveal the toxicity contribution of Ag+ underlying the observed size-dependent effects of AgNPs and provide a scientific basis for comprehensively assessing the ecological risk and biosafety of AgNPs.


Assuntos
Sacos Aéreos , Nanopartículas Metálicas , Tamanho da Partícula , Prata , Animais , Sacos Aéreos/anormalidades , Sacos Aéreos/efeitos dos fármacos , Proteínas Hedgehog/metabolismo , Larva/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
19.
Sci Rep ; 12(1): 20844, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36494410

RESUMO

The origin of the air sac system present in birds has been an enigma for decades. Skeletal pneumaticity related to an air sac system is present in both derived non-avian dinosaurs and pterosaurs. But the question remained open whether this was a shared trait present in the common avemetatarsalian ancestor. We analyzed three taxa from the Late Triassic of South Brazil, which are some of the oldest representatives of this clade (233.23 ± 0.73 Ma), including two sauropodomorphs and one herrerasaurid. All three taxa present shallow lateral fossae in the centra of their presacral vertebrae. Foramina are present in many of the fossae but at diminutive sizes consistent with neurovascular rather than pneumatic origin. Micro-tomography reveals a chaotic architecture of dense apneumatic bone tissue in all three taxa. The early sauropodomorphs showed more complex vascularity, which possibly served as the framework for the future camerate and camellate pneumatic structures of more derived saurischians. Finally, the evidence of the absence of postcranial skeletal pneumaticity in the oldest dinosaurs contradicts the homology hypothesis for an invasive diverticula system and suggests that this trait evolved independently at least 3 times in pterosaurs, theropods, and sauropodomorphs.


Assuntos
Dinossauros , Animais , Dinossauros/anatomia & histologia , Sacos Aéreos , Coluna Vertebral/anatomia & histologia , Aves , Osso e Ossos , Fósseis , Evolução Biológica , Filogenia
20.
J Exp Biol ; 225(16)2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35916179

RESUMO

Acoustic behavior is widespread across vertebrates, including fishes. We report robust acoustic displays during aggressive interactions for a laboratory colony of Danionella dracula, a miniature and transparent species of teleost fish closely related to zebrafish (Danio rerio), which are hypothesized to be sonic based on the presence of a hypertrophied muscle associated with the male swim bladder. Males produce bursts of pulsatile sounds and a distinct postural display - extension of a hypertrophied lower jaw, a morphological trait not present in other Danionella species - during aggressive but not courtship interactions. Females show no evidence of sound production or jaw extension in such contexts. Novel pairs of size-matched or -mismatched males were combined in resident-intruder assays where sound production and jaw extension could be linked to individuals. In both dyad contexts, resident males produced significantly more sound pulses than intruders. During heightened sonic activity, the majority of the highest sound producers also showed increased jaw extension. Residents extended their jaw more than intruders in size-matched but not -mismatched contexts. Larger males in size-mismatched dyads produced more sounds and jaw extensions compared with their smaller counterparts, and sounds and jaw extensions increased with increasing absolute body size. These studies establish D. dracula as a sonic species that modulates putatively acoustic and postural displays during aggressive interactions based on residency and body size, providing a foundation for further investigating the role of multimodal displays in a new model clade for neurogenomic and neuroimaging studies of aggression, courtship and other social interactions.


Assuntos
Acústica , Peixe-Zebra , Sacos Aéreos/fisiologia , Animais , Corte , Feminino , Masculino , Som
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