Cnidaria
Also known as cnidarians, cnidarian
thumb|Chrysaora fuscescens|Pacific sea nettles, Chrysaora fuscescens
AI overview
Cnidaria is a group of marine animals that includes jellyfish, sea anemones, and corals, characterized by their stinging tentacles used to capture prey. These animals are important members of ocean ecosystems and some, like corals, form the foundation of diverse underwater habitats that support countless other species.
AI-generated from the Wikipedia summary — may contain errors.
Species
cnidarians
Cnidaria
PHYLUM
- KingdomAnimalia
- PhylumCnidaria
Habitatmarine, brackish, freshwater
刺胞動物門（學名：Cnidaria；/naɪˈdɛəriə/），又名刺絲胞動物門，是一個包含有超過2萬多個动物物种的门 ，皆為生活於水中（包括淡、海水或其他鹹水棲境）， 刺胞動物曾經和櫛水母動物一起組成腔腸動物門，但隨着對這兩種動物的差異的認識，愈來愈多學者同意應該將櫛水母動物從刺胞動物獨立出來。 近期的系统发生学分析支持刺胞動物是一個单系群，而且與两侧对称动物是旁系群關係。在大約5.8億年前形成的岩石中發現了刺胞動物的化石，其他化石表明珊瑚可能在4.9億年前左右才出現，並在幾百萬年後出現多樣化。然而，線粒體基因的molecular clock分析表明，crown group（英语：crown group）的年齡要大得多，估計大約有7.41億年前，在寒武紀以至任何化石出現的時期還要早2億年。 刺絲胞动物门动物有如下特点： 大部分為肉食性，少部分種類獲得能量來自於體內共生生物行光合作用得來的。 其躯干呈辐射对称，水生，大多固着生活 体壁由两层细胞组成，表皮和肠表皮，两者之间有一层凝胶状的中胶层，起支持作用。 有肠腔，有一围口部（Peristom），既是口也是肛门。 有超过20种的刺胞，刺絲胞中含有刺丝囊。刺丝囊一端的鬃样突起的刺针，受刺激时，激起刺丝囊排空。刺絲胞的表面有突出，胞体内有棍状结构。刺胞内有高尔机体分泌物质，在压力作用下会释放。 在肠腔中进行胞外消化 弥散的神经系统/神經網(nerve net)，呈网状 水母体有感觉器官，能感受光和重力 有雌雄同體或異體 水母、珊瑚、海葵、水螅都被歸類為刺絲胞動物。
via GBIF
Research
20,116 papers- Nephrotoxic effects of Cnidaria toxins.ReviewInternational maritime health · 2024Marchelek-Myśliwiec M, Kosik-Bogacka D, Ciechanowski K et al.DOI: 10.5603/imh.102878
Article
29 sectionsContents
- Etymology
- Distinguishing features
- Description
- Basic body forms
- Skeletons
- Main cell layers
- Polymorphism
- Cnidocytes
- Locomotion
- Nervous system and senses
- Feeding and excretion
- Respiration
- Regeneration
- Reproduction
- Sexual
- Asexual
- DNA repair
- Classification
- Ecology
- Evolutionary history
- Fossil record
- Phylogeny
- Interaction with humans
- Notes
- References
- Further reading
- Books
- Journal articles
- External links
thumb|Chrysaora fuscescens|Pacific sea nettles, Chrysaora fuscescens
Cnidaria ( ) is a phylum in kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in freshwater and marine environments (predominantly the latter), including jellyfish, hydroids, sea anemones, corals and some of the smallest marine parasites. Their distinguishing features are an uncentralized nervous system distributed throughout a gelatinous body and the presence of cnidocytes or cnidoblasts, specialized cells with ejectable organelles used mainly for envenomation and capturing prey. Their bodies consist of mesoglea, a non-living, jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick. Many cnidarian species can reproduce both sexually and asexually.