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1.
Sci Rep ; 14(1): 8218, 2024 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589432

RESUMO

Flies belonging to the Sarcophagidae family play a significant role in forensic investigations by aiding in the estimation of post-mortem interval through the assessment of the developmental time of their immature stages and/or the succession patterns of species on carcasses and cadavers. In this regard, this study aimed to investigate the ecological succession of these flies on pig carcasses within Cerrado of Brazil. The progression of fly succession was examined over a 10-day period using the Threshold Indicator Taxa Analysis (TITAN) approach. Six Z + species (Oxysarcodexia thornax (Walker), Peckia (Sarcodexia) lambens (Wiedemann), Peckia (Euboettcheria) collusor (Curran & Walley), Ravinia belforti (Prado & Fonseca), Tricharaea (Sarcophagula) canuta (Wulp) and Tricharaea (Sarcophagula) occidua (Fabricius)) were identified, with change points ranging from 2.5 to 3 days during the dry season and 2.5 to 5.5 days during the rainy season. Two Z- species (Dexosarcophaga carvalhoi (Lopes) and Peckia (Sarcodexia) tridentata (Hall)) were present, with a change point of 6.5 days during the rainy season. This study provides a continuous analysis of the temporal succession of flies, enabling an investigation into species progression based on their change points and directions (Z + and Z- ), thereby offering methodological advancements to avoid the arbitrary categorization of inherently continuous data.


Assuntos
Dípteros , Hidrozoários , Sarcofagídeos , Animais , Suínos , Brasil , Autopsia
2.
Methods Mol Biol ; 2784: 77-85, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38502479

RESUMO

In situ hybridization allows the detection of nucleic acid sequences in fixed cells and tissues. The gelatinous nature of cnidarians and Hydractinia demands extensive and exhausting protocols to detect RNA transcripts with traditional methods (e.g., colorimetric in situ hybridization). Signal amplification by exchange reaction (SABER) fluorescence in situ hybridization (FISH) enables simplifying and multiplex imaging of RNA targets in a rapid and cost-effective manner. In one enzymatic reaction, SABER-FISH uses a strand-displacing polymerase and catalytic DNA hairpin to generate FISH probes with adjustable signal amplification, allowing highly sensitive detection of nucleic acids and reducing the number of required probes. Here I describe the methodology to detect transcripts within the cells of Hydractinia by SABER-FISH in whole-mount samples.


Assuntos
Hidrozoários , Ácidos Nucleicos , RNA , Hibridização in Situ Fluorescente/métodos
3.
Genome Biol Evol ; 16(3)2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38502059

RESUMO

Siphonophores (Cnidaria: Hydrozoa) are abundant predators found throughout the ocean and are important constituents of the global zooplankton community. They range in length from a few centimeters to tens of meters. They are gelatinous, fragile, and difficult to collect, so many aspects of the biology of these roughly 200 species remain poorly understood. To survey siphonophore genome diversity, we performed Illumina sequencing of 32 species sampled broadly across the phylogeny. Sequencing depth was sufficient to estimate nuclear genome size from k-mer spectra in six specimens, ranging from 0.7 to 2.3 Gb, with heterozygosity estimates between 0.69% and 2.32%. Incremental k-mer counting indicates k-mer peaks can be absent with nearly 20× read coverage, suggesting minimum genome sizes range from 1.4 to 5.6 Gb in the 25 samples without peaks in the k-mer spectra. This work confirms most siphonophore nuclear genomes are large relative to the genomes of other cnidarians, but also identifies several with reduced size that are tractable targets for future siphonophore nuclear genome assembly projects. We also assembled complete mitochondrial genomes for 33 specimens from these new data, indicating a conserved gene order shared among nonsiphonophore hydrozoans, Cystonectae, and some Physonectae, revealing the ancestral mitochondrial gene order of siphonophores. Our results also suggest extensive rearrangement of mitochondrial genomes within other Physonectae and in Calycophorae. Though siphonophores comprise a small fraction of cnidarian species, this survey greatly expands our understanding of cnidarian genome diversity. This study further illustrates both the importance of deep phylogenetic sampling and the utility of k-mer-based genome skimming in understanding the genomic diversity of a clade.


Assuntos
Cnidários , Genoma Mitocondrial , Hidrozoários , Animais , Cnidários/genética , Filogenia , Hidrozoários/genética , Genômica , Tamanho do Genoma
4.
Sci Rep ; 14(1): 3065, 2024 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321132

RESUMO

Clinically, rosacea occurs frequently in acne patients, which hints the existence of shared signals. However, the connection between the pathophysiology of rosacea and acne are not yet fully understood. This study aims to unveil molecular mechanism in the pathogenesis of rosacea and acne. We identified differentially expressed genes (DEGs) by limma and weighted gene co-expression network analysis and screened hub genes by constructing a protein-protein interaction network. The hub genes were verified in different datasets. Then, we performed a correlation analysis between the hub genes and the pathways. Finally, we predicted and verified transcription factors of hub genes, performed the immune cell infiltration analysis using CIBERSORT, and calculated the correlation between hub genes and immune cells. A total of 169 common DEGs were identified, which were mainly enriched in immune-related pathways. Finally, hub genes were identified as IL1B, PTPRC, CXCL8, MMP9, CCL4, CXCL10, CD163, CCR5, CXCR4, and TLR8. 9 transcription factors that regulated the expression of hub genes were identified. The infiltration of γδT cells was significantly increased in rosacea and acne lesions and positively linked with almost all hub genes. These identified hub genes and immune cells may play a crucial role in the development of rosacea and acne.


Assuntos
Acne Vulgar , Hidrozoários , Rosácea , Humanos , Animais , Biologia Computacional , Fatores de Transcrição
5.
Toxicon ; 237: 107556, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38072317

RESUMO

Cnidarians thriving in biofouling communities on aquaculture net pens represent a significant health risk for farmed finfish due to their stinging cells. The toxins coming into contact with the fish, during net cleaning, can adversely affect their behavior, welfare, and survival, with a particularly serious health risk for the gills, causing direct tissue damage such as formation of thrombi and increasing risks of secondary infections. The hydroid Ectopleura larynx is one of the most common fouling organisms in Northern Europe. However, despite its significant economic, environmental, and operational impact on finfish aquaculture, biological information on this species is scarce and its venom composition has never been investigated. In this study, we generated a whole transcriptome of E. larynx, and identified its putative expressed venom toxin proteins (predicted toxin proteins, not functionally characterized) based on in silico transcriptome annotation mining and protein sequence analysis. The results uncovered a broad and diverse repertoire of putative toxin proteins for this hydroid species. Its toxic arsenal appears to include a wide and complex selection of toxin proteins, covering a large panel of potential biological functions that play important roles in envenomation. The putative toxins identified in this species, such as neurotoxins, GTPase toxins, metalloprotease toxins, ion channel impairing toxins, hemorrhagic toxins, serine protease toxins, phospholipase toxins, pore-forming toxins, and multifunction toxins may cause various major deleterious effects in prey, predators, and competitors. These results provide valuable new insights into the venom composition of cnidarians, and venomous marine organisms in general, and offer new opportunities for further research into novel and valuable bioactive molecules for medicine, agronomics and biotechnology.


Assuntos
Incrustação Biológica , Hidrozoários , Toxinas Biológicas , Animais , Peçonhas , Proteínas , Transcriptoma
6.
Cladistics ; 40(2): 107-134, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38112464

RESUMO

Capitate hydrozoans are a morphologically and ecologically diverse hydrozoan suborder, currently including about 200 species. Being grouped in two clades, Corynida and Zancleida, these hydrozoans still show a number of taxonomic uncertainties at the species, genus and family levels. Many Capitata species established symbiotic relationships with other benthic organisms, including bryozoans, other cnidarians, molluscs and poriferans, as well as with planktonic dinoflagellates for mixotrophic relationships and with bacteria for thiotrophic ectosymbioses. Our study aimed at providing an updated and comprehensive phylogeny reconstruction of the suborder, at modelling the evolution of selected morphological and ecological characters, and at testing evolutionary relationships between the symbiotic lifestyle and the other characters, by integrating taxonomic, ecological and evolutionary data. The phylogenetic hypotheses here presented shed light on the evolutionary relationships within Capitata, with most families and genera being recovered as monophyletic. The genus Zanclea and family Zancleidae, however, were divided into four divergent clades, requiring the establishment of the new genus Apatizanclea and the new combinations for species in Zanclea and Halocoryne genera. The ancestral state reconstructions revealed that symbiosis arose multiple times in the evolutionary history of the Capitata, and that homoplasy is a common phenomenon in the group. Correlations were found between the evolution of symbiosis and morphological characters, such as the perisarc. Overall, our results highlighted that the use of genetic data and a complete knowledge of the life cycles are strongly needed to disentangle taxonomic and systematic issues in capitate hydrozoans. Finally, the colonization of tropical habitat appears to have influenced the evolution of a symbiotic lifestyle, playing important roles in the evolution of the group.


Assuntos
Hidrozoários , Humanos , Animais , Filogenia , Hidrozoários/genética , Hidrozoários/anatomia & histologia , Simbiose/genética , Ecossistema
7.
PeerJ ; 11: e16265, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38077448

RESUMO

Planktonic lifestyle of polyps in representatives of Margelopsidae are very different from all other species in the hydrozoan clade Aplanulata. Their evolutionary origin and phylogenetic position have been the subject of significant speculation. A recent molecular study based only on COI data placed Margelopsidae as a sister group to all Aplanulata, an unexpected result because margelopsid morphology suggests affiliation with Tubulariidae or Corymorphidae. Here we used multigene analyses, including nuclear (18S rRNA and 28S rRNA) and mitochondrial (16S rRNA and COI) markers of the hydroid stage of the margelopsid species Margelopsis haeckelii and the medusa stage of Margelopsis hartlaubii to resolve their phylogenetic position with respect to other hydrozoans. Our data provide strong evidence that M. haeckelii, the type species of Margelopsis, is a member of the family Corymorphidae. In contrast, M. hartlaubii is sister to Plotocnide borealis, a member of Boreohydridae. These results call into question the validity of the genus Margelopsis and the family Margelopsidae. The systematic position of M. haeckelii is discussed in light of the phylogeny of Corymorphidae.


Assuntos
Hidrozoários , Animais , Filogenia , RNA Ribossômico 16S , Hidrozoários/anatomia & histologia , Evolução Biológica , RNA Ribossômico 18S/genética
8.
PLoS Biol ; 21(12): e3002435, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38127832

RESUMO

Blastema formation is a crucial process that provides a cellular source for regenerating tissues and organs. While bilaterians have diversified blastema formation methods, its mechanisms in non-bilaterians remain poorly understood. Cnidarian jellyfish, or medusae, represent early-branching metazoans that exhibit complex morphology and possess defined appendage structures highlighted by tentacles with stinging cells (nematocytes). Here, we investigate the mechanisms of tentacle regeneration, using the hydrozoan jellyfish Cladonema pacificum. We show that proliferative cells accumulate at the tentacle amputation site and form a blastema composed of cells with stem cell morphology. Nucleoside pulse-chase experiments indicate that most repair-specific proliferative cells (RSPCs) in the blastema are distinct from resident stem cells. We further demonstrate that resident stem cells control nematogenesis and tentacle elongation during both homeostasis and regeneration as homeostatic stem cells, while RSPCs preferentially differentiate into epithelial cells in the newly formed tentacle, analogous to lineage-restricted stem/progenitor cells observed in salamander limbs. Taken together, our findings propose a regeneration mechanism that utilizes both resident homeostatic stem cells (RHSCs) and RSPCs, which in conjunction efficiently enable functional appendage regeneration, and provide novel insight into the diversification of blastema formation across animal evolution.


Assuntos
Hidrozoários , Animais , Células-Tronco , Células Epiteliais
9.
Sci Rep ; 13(1): 18819, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37914720

RESUMO

Epithelial wound healing involves the collective responses of many cells, including those at the wound margin (marginal cells) and those that lack direct contact with the wound (submarginal cells). How these responses are induced and coordinated to produce rapid, efficient wound healing remains poorly understood. Extracellular ATP (eATP) is implicated as a signal in epithelial wound healing in vertebrates. However, the role of eATP in wound healing in vivo and the cellular responses to eATP are unclear. Almost nothing is known about eATP signaling in non-bilaterian metazoans (Cnidaria, Ctenophora, Placozoa, and Porifera). Here, we show that eATP promotes closure of epithelial wounds in vivo in the cnidarian Clytia hemisphaerica (Clytia) indicating that eATP signaling is an evolutionarily ancient strategy in wound healing. Furthermore, eATP increases F-actin accumulation at the edges of submarginal cells. In Clytia, this indicates eATP is involved in coordinating cellular responses during wound healing, acting in part by promoting actin remodeling in cells at a distance from the wound. We also present evidence that eATP activates a cation channel in Clytia epithelial cells. This implies that the eATP signal is transduced through a P2X receptor (P2XR). Phylogenetic analyses identified four Clytia P2XR homologs and revealed two deeply divergent major branches in P2XR evolution, necessitating revision of current models. Interestingly, simple organisms such as cellular slime mold appear exclusively on one branch, bilaterians are found exclusively on the other, and many non-bilaterian metazoans, including Clytia, have P2XR sequences from both branches. Together, these results re-draw the P2XR evolutionary tree, provide new insights into the origin of eATP signaling in wound healing, and demonstrate that the cytoskeleton of submarginal cells is a target of eATP signaling.


Assuntos
Hidrozoários , Animais , Filogenia , Cicatrização , Transdução de Sinais , Trifosfato de Adenosina
10.
Mar Pollut Bull ; 196: 115610, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37804672

RESUMO

Application of oil toxicity modelling for assessing the risk of spills to coral reefs remains uncertain due to a lack of data for key tropical species and environmental conditions. In this study, larvae of the coral Acropora millepora were exposed to six aromatic hydrocarbons individually to generate critical target lipid body burdens (CTLBBs). Larval metamorphosis was inhibited by all six aromatic hydrocarbons, while larval survival was only affected at concentrations >2000 µg L-1. The derived metamorphosis CTLBB of 9.7 µmol g-1 octanol indicates larvae are more sensitive than adult corals, and places A. millepora larvae among the most sensitive organisms in the target lipid model (TLM) databases. Larvae were also more sensitive to anthracene and pyrene when co-exposed to ecologically relevant levels of ultraviolet radiation. The results suggest that the application of the phototoxic TLM would be protective of A. millepora larvae, provided adequate chemical and light data are available.


Assuntos
Antozoários , Hidrocarbonetos Aromáticos , Hidrozoários , Animais , Larva , Raios Ultravioleta , Recifes de Corais , Hidrocarbonetos Aromáticos/farmacologia , Lipídeos/farmacologia
11.
J Exp Biol ; 226(18)2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37655651

RESUMO

Siphonophores are ubiquitous and often highly abundant members of pelagic ecosystems throughout the open ocean. They are unique among animal taxa in that many species use multiple jets for propulsion. Little is known about the kinematics of the individual jets produced by nectophores (the swimming bells of siphonophores) or whether the jets are coordinated during normal swimming behavior. Using remotely operated vehicles and SCUBA, we video recorded the swimming behavior of several physonect species in their natural environment. The pulsed kinematics of the individual nectophores that comprise the siphonophore nectosome were quantified and, based on these kinematics, we examined the coordination of adjacent nectophores. We found that, for the five species considered, nectophores located along the same side of the nectosomal axis (i.e. axially aligned) were coordinated and their timing was offset such that they pulsed metachronally. However, this level of coordination did not extend across the nectosome and no coordination was evident between nectophores on opposite sides of the nectosomal axis. For most species, the metachronal contraction waves of nectophores were initiated by the apical nectophores and traveled dorsally. However, the metachronal wave of Apolemia rubriversa traveled in the opposite direction. Although nectophore groups on opposite sides of the nectosome were not coordinated, they pulsed with similar frequencies. This enabled siphonophores to maintain relatively linear trajectories during swimming. The timing and characteristics of the metachronal coordination of pulsed jets affects how the jet wakes interact and may provide important insight into how interacting jets may be optimized for efficient propulsion.


Assuntos
Ecossistema , Hidrozoários , Animais , Fenômenos Biomecânicos , Natação
12.
PLoS One ; 18(9): e0291503, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37738222

RESUMO

The plasticity of some coral-associated microbial communities under stressors like warming and ocean acidification suggests the microbiome has a role in the acclimatization of corals to future ocean conditions. Here, we evaluated the acclimatization potential of coral-associated microbial communities of four Hawaiian coral species (Porites compressa, Porites lobata, Montipora capitata, and Pocillopora acuta) over 22-month mesocosm experiment. The corals were exposed to one of four treatments: control, ocean acidification, ocean warming, or combined future ocean conditions. Over the 22-month study, 33-67% of corals died or experienced a loss of most live tissue coverage in the ocean warming and future ocean treatments while only 0-10% died in the ocean acidification and control. Among the survivors, coral-associated microbial communities responded to the chronic future ocean treatment in one of two ways: (1) microbial communities differed between the control and future ocean treatment, suggesting the potential capacity for acclimatization, or (2) microbial communities did not significantly differ between the control and future ocean treatment. The first strategy was observed in both Porites species and was associated with higher survivorship compared to M. capitata and P. acuta which exhibited the second strategy. Interestingly, the microbial community responses to chronic stressors were independent of coral physiology. These findings indicate acclimatization of microbial communities may confer resilience in some species of corals to chronic warming associated with climate change. However, M. capitata genets that survived the future ocean treatment hosted significantly different microbial communities from those that died, suggesting the microbial communities of the survivors conferred some resilience. Thus, even among coral species with inflexible microbial communities, some individuals may already be tolerant to future ocean conditions. These findings suggest that coral-associated microbial communities could play an important role in the persistence of some corals and underlie climate change-driven shifts in coral community composition.


Assuntos
Antozoários , Hidrozoários , Microbiota , Humanos , Animais , Concentração de Íons de Hidrogênio , Água do Mar , Aclimatação , Mudança Climática , Morte , Viverridae
13.
PLoS One ; 18(8): e0290667, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37624787

RESUMO

The impact of the Amazon River freshwater plume on planktonic cnidarians over neritic and oceanic provinces is unknown. To provide further knowledge we took advantage of an oceanographic cruise performed in October 2012 in the Western Atlantic off the North Brazilian coast (8°N, 51°W-3.5°S, 37°W). A complex and dynamic system was observed, with strong currents and eddies dispersing the plume over a large area. Our results show that the Amazon River shapes marine habitats with a thin highly productive surface layer compressed by a deeper oxygen minimum zone both over the shelf and in the open ocean. We hypothesized that such habitat structure is particularly advantageous to planktonic cnidarians, which have low metabolic rates, being able to survive in hypoxic zones, resulting in high species richness and abundance. Over the shelf, distinctions were sharp and the area under the influence of the plume presented a diverse assemblage occurring in large abundance, while outside the plume, the hydromedusa Liriope tetraphylla was dominant and occurred almost alone. Divergences in the oceanic province were less pronounced, but still expressive being mostly related to the abundance of dominant species. We concluded that Amazon River plume is a paramount physical feature that profoundly affects the dynamics of the mesoscale habitat structure in the Western Equatorial Atlantic Ocean and that such habitat structure is responsible for shaping planktonic cnidarian assemblages both in neritic and oceanic provinces.


Assuntos
Hidrozoários , Rios , Animais , Água Doce , Oceano Atlântico , Brasil , Plâncton
14.
Dermatologie (Heidelb) ; 74(9): 715-724, 2023 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-37594512

RESUMO

Rosacea is a common chronic inflammatory dermatosis of the face, clinically characterized by erythema, telangiectasia, papules, pustules, and rhinophyma. In January 2022, the updated guideline on rosacea was published. Groundbreaking innovations include the new clinical classification according to phenotypes, extended diagnostic and therapeutic recommendations for ocular rosacea and implications of the gut microbiome on rosacea. Furthermore, the guideline encompasses a new chapter on the psychosocial aspects of rosacea and detailed recommendations for approved and off-label therapies.


Assuntos
Dermatite , Hidrozoários , Rinofima , Rosácea , Animais , Rosácea/diagnóstico , Vesícula
15.
Proc Biol Sci ; 290(2004): 20230851, 2023 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-37528709

RESUMO

Sampling in multiple localities, coupled with molecular barcoding, has shown that nominal species with wide geographical distribution often harbour local cryptic species in allopatry. Cryptic species in sympatry, however, can be easily missed if they have different seasonality, because they can be identified only through long-term frequent sampling (i.e. sampling through time of the same species in the same location). This is especially true in planktonic invertebrates that exhibit strong seasonality. By integrating mitochondrial 16S sequences of eight species of Hydrozoa (Cnidaria) collected weekly for a year in one Gulf of Mexico region, with sequences gathered globally, we investigate the presence of cryptic species within a temporal gradient (regionally) and on a spatial (worldwide) scale. We find that eight species of Hydrozoa are composed of 28 cryptic species, with 16 of them appearing in sympatry but with non-overlapping seasonality. The high number of sympatric cryptic species could only be discovered through extensive and prolonged regional sampling efforts. The bi-dimensional cryptic diversity (in time and space) highlighted in this study is essential for understanding processes of evolution, biogeography dispersal in the sea, and for more realistic biodiversity assessments.


Assuntos
Hidrozoários , Animais , Filogenia , Biodiversidade , Simpatria , Golfo do México
16.
Zootaxa ; 5315(5): 401-455, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37518418

RESUMO

A catalogue of Eumeninae occurring in Oceania is presented, the first in more than a century.


Assuntos
Hidrozoários , Himenópteros , Vespas , Animais , Distribuição Animal
17.
Zootaxa ; 5264(4): 490-504, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37518035

RESUMO

In this paper, we study material belonging to the hydroid genera Egmundella Stechow, 1921 and Cyclocanna Bigelow, 1918 collected off the coast of Northwest Africa, from Morocco to Guinea Bissau, between 2004 and 2012, during several international surveys. Currently, the genus Egmundella is included in the family Campanulinidae Hincks, 1869, but its taxonomic status is doubtful, since most of the life cycles of its species are unknown. A total of four species have been identified: E. grimaldii Leloup, 1940, E. modesta Millard & Bouillon, 1975, E. superba Stechow, 1921 and E. ansini n. sp. Egmundella grimaldii is found for the first time since its original description, and fertile material is described herein. Its gonotheca is morphologically similar to that of C. producta (G.O. Sars, 1874), suggesting that both species could be congeneric. A description of specimens of C. producta collected along the NW African coast is also provided.


Assuntos
Hidrozoários , Animais , Inquéritos e Questionários
18.
PeerJ ; 11: e15423, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37273545

RESUMO

The brown alga Sargassum provides a natural substrate occupied by hydrozoans in shallow marine waters. A global count in 2007 listed 39 epibiotic species of Hydrozoa growing on Sargassum, but more studies have been published since, therefore, an update is timely, particularly due to the increased abundance of Sargassum in the Caribbean. This review, based on a recent literature survey and new records from Mexico, includes 133 publications of epibiotic hydrozoans on Sargassum spanning 220 years, from 1802 to 2022. A total of 131 hydrozoan species were recorded on 26 species of Sargassum, most belonging to the subclass Hydroidolina (130), with only one record of a trachyline medusa (Gonionemus vertens, subclass Trachylinae). Most publications centered on the Tropical Atlantic, where the greatest number of hydrozoan species (67 species) were recorded. All hydrozoan species possess a hydrorhiza, except one hydromedusae species that attach to Sargassum via adhesive tentacles. Most of the hydrozoan species associated with Sargassum exhibited a benthic life cycle (93 species) and are comprised of erect, branched colonies (67 species) and large hydrothecae (69 species). Although the number of studies of epibiotic hydrozoans on Sargassum has increased since the mid-20th century, nevertheless hydrozoan richness has not reached an asymptote. Therefore, more sampling of Sargassum species would likely identify more hydrozoan species associated with Sargassum, especially among benthic Sargassum, and might help reveal potential biogeographical and ecological patterns between Sargassum and hydrozoan epibionts.


Assuntos
Hidrozoários , Sargassum , Animais , Estágios do Ciclo de Vida , Região do Caribe , México
19.
Curr Biol ; 33(11): R434-R436, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37279662

RESUMO

How do animals replace all their worn-out cells to maintain their tissues? A new study shows that, in the cnidarian Hydractinia symbiolongicarpus, a single adult stem cell is sufficient to generate the entire repertoire of somatic and germ line cells.


Assuntos
Células-Tronco Adultas , Hidrozoários , Animais , Células-Tronco
20.
Sci Rep ; 13(1): 9760, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37328506

RESUMO

Ephyrae, the early stages of scyphozoan jellyfish, possess a conserved morphology among species. However, ontogenetic transitions lead to morphologically different shapes among scyphozoan lineages, with important consequences for swimming biomechanics, bioenergetics and ecology. We used high-speed imaging to analyse biomechanical and kinematic variables of swimming in 17 species of Scyphozoa (1 Coronatae, 8 "Semaeostomeae" and 8 Rhizostomeae) at different developmental stages. Swimming kinematics of early ephyrae were similar, in general, but differences related to major lineages emerged through development. Rhizostomeae medusae have more prolate bells, shorter pulse cycles and higher swimming performances. Medusae of "Semaeostomeae", in turn, have more variable bell shapes and most species had lower swimming performances. Despite these differences, both groups travelled the same distance per pulse suggesting that each pulse is hydrodynamically similar. Therefore, higher swimming velocities are achieved in species with higher pulsation frequencies. Our results suggest that medusae of Rhizostomeae and "Semaeostomeae" have evolved bell kinematics with different optimized traits, rhizostomes optimize rapid fluid processing, through faster pulsations, while "semaeostomes" optimize swimming efficiency, through longer interpulse intervals that enhance mechanisms of passive energy recapture.


Assuntos
Hidrozoários , Cifozoários , Animais , Natação , Fenômenos Biomecânicos , Metabolismo Energético
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