Farid K. Muzaki, S.Si., M.Si Jurusan BIOLOGI FMIPA – ITS Surabaya THE CNIDARIA Taxonomy of Animalia – SB091321 Characters (1) DilbltiDiploblastic MtMetazoa with ectdtoderm and entdtoderm separatdted by a (primarily) ectodermally derived acellular mesoglea or partly cellular mesenchyme Possess primary radial symmetry, often modified as biradial, quadriradial, or other form; the primary body axis is oral–aboral Possess unique sting ing or adhes ive structures calle d cnidae; each cnida resides in and is produced by one cell, a cnidocyte. The most common cnidae are called nematocysts Musculature formed largely of myoepithelial cells (= epitheliomuscular cells), derived from ectoderm and entoderm (a du lt epidermi s and gastrod ermi s) Cnidarian bauplan Cnidarian bauplan Derivative symmetry on Cnidaria: A. Quadridarial B. Radial C. Biradial D. Biadial Cnidarian bauplan A hydrozoan polyp column wall (cross section) illustrates the basic cnidarian cell and tissue types Characters (2) Ex hibit alterna tion of asexual polypoid and sexual medusoid generations; but there are many variations on this basic theme The entodermallyyg derived gastrovascular cavit y()y (coelenteron) is the only “body cavity.” The coelenteron is saclike, partitioned, or branched, but has only a single opening, which serves as both mouth and anus Without a head, centralized nervous system, or discrete gas exchange, excretory, or circulatory structures Nervous system is a simple nerve net(s), composed of naked and largely nonpolar neurons Typically have planula larvae (ciliated, motile, gastrula larvae) Class 1: HYDROZOA Alternation of generations occurs in most genera (typically asexual benthic polyps alternate with sexual planktonic medusae), although one or the other ggyppgeneration may be suppressed or lacking polyps usually colonial, with interconnected coelenterons Exoskeleton usually of chitin or occasionally calcium carbonate (hydrocorals) coelenteron of polyps and medusae lacks a pharynx and mesenteries mesoglea acellular; tentacles solid or hollow; cnidae occur only in epidermis Hyypdrozoan bauplan Hydra, a solitary Hydrozoan Hyyydra: life cycle Life cycle of Hydra: Sperm produced by the male polyp (a) fertilizes the eggs of the female polyp (b). During cleavage, the eggs secrete a chitinous theca about themselves. After hatching, the embryos (c) grow into polyps that reproduce asexually by budding (d), until environmental conditions again trigger sexual reproduc tion Colonial Hydrozoa A. A thecate hydroid colony. The blastostyles produce either sporosacs or medusae B. A typical leptomedusa Life cycle of Obelia, a colonial Hydrozoa Hydrozoa: Taxonomy & Classification O. Hydroida S.O Anthomedusae, ex: Hydra, Hydractinia S.O Leptomedusae, ex: Obelia, Sertularia O. Trachylina, ex: Rhopalonema, Polypodium O. Sip honop hora, ex: AliApolemia, Physali a O. Chondrophora, ex: Porpita, Velella O. Actinulida, ex: Halammohydra, Otohydra Physalia physalis (Portuguese man of war) Class 2: SCYPHOZOA Medusoid stage predominates; polypoid individuals (scyphistomae) are small and inconspicuous but often long-lived polyps produce medusae by asexual budding (strobilation) coelenteron divided by four longitudinal (oral–aboral) mesenterie medusae acraspedot e (withou t a velum ), typ ica lly with a thic k mesogleal (or collenchymal) layer, distinct pigmentation, filiform or capitate tentacles, and marginal notches producing lappets mouth may or may not be on a manubrium; usually without a ring canal SCYPHOZOAN bauplan Life cycle of Aurelia. TheThe ffertilizedertilized egg (b) is released to develop into a planula larva (c), which settles to ggpyp,row into a polyp, the scyphistoma (d). The scyphistoma either buds off new polyps (()e) or p roduces ephyrae by strobilation (f); ephyra (g) grows into an adult medusae Some of Scyphozoa A. Chrysaora B. Rhopilema C. Aurelia D. Mastigias Scyphozoa: Taxonomy & Classification Stauromedusae, ex: Halyclistis Coronatae, ex: Atolla Semaeostomeae, ex: Cyanea Rhizostomeae, ex: Cassiopea Class 3: Cubozoa polyps each produce a siilngle medusa by complltete metamorphosis (strobilation does not occur) medusa bell nearlyyq square in cross section hollow interradial tentacle(s) hang from bladelike pedalia, one at each corner of umbrella unfrilled bell margin drawn inward to form a velum-like structure (the velarium) into which diverticula of the gut extend Comparison between a cubomedusae (A) and scyphomedusae (B) Some of Cubozoa Chiropsalmus Carybdea Fact sheet Chironex fleckerii has been described as "the most lethal jellyfish in the world", with at least 63 known deaths in Austra lia from 1884 to 1996 Class 4: ANTHOZOA solitary or colonial; without a medusoid stage Coelenteron divided by longitudinal (oral–aboral) mesenteries, the free edges of which form thick, cordlike mesenterial filaments tentacles usually number 8 or occur in multiples of 6 and contain extensions of the coelenteron polyps may reproduce both sexually and asexually Anthozoan bauplan Anatomy of a soft coral polyp Anthozoan bauplan Anatomy of a hard coral polyp Anthozoan life cycle A typical anthozoan sexual life cycle: the adult ppypolyp releases gametes which fuse externally, or fertilized eggs are released, and zygotes develop into a planula larvae; the larvae settle and transform directly into young polyps Anthozoa: Taxonomy & Classification Subclass Octocorallia (Alcyonaria) Order Alcyonacea; Alcyonium, Anthomastus Order Gastraxonacea; Pseudogorgia OdOrder Gorgonacea; Cora llium, Eugorg ia, Eun ice lla Order Helioporacea; Heliopora, Epiphaxum Order Pennatulacea; Anthoptilum, Balticina Order Protoalcyonacea; Haimea, Hartea Order Stolonifera; Tubipora, Clavularia OdOrder TTlelestacea; Coe logorg ia, Para tlttelesto Subclass Hexacorallia (Zoantharia) Subclass Ceriantipatharia Anthozoa: Taxonomy & Classification Subclass Hexacorallia (Zoantharia) Order Actiniaria; Actinia, Stichodactyla, Aiptasia Order Scleractinia; Acropora, Porites, Oculina Order Zoanthidea; Palythoa, Epizoanthus, Zoanthus OdOrder Cora llimorp har ia; Amplexidiscus, Rhodactis Subclass Ceriantipatharia Order Antipatharia; Antipathes Order Ceriantharia; Cerianthus, Arachnanthus Terms in identifyyging hard coral (1) Corallum Æ entire skeleton of a scleractinian coral,,g regardless of whether the animal is solitary or colonial Corallite Æ the skeleton of a single polyp Calyx Æ concave depression that houses the polyp (pl: calices) Theca Æ outer wall of the corallite Septum Æ skeletal plates that radiate into the calyx from the wall (sometimes called scleroseptum); which project inward and support the mesenteries of the ppyp(polyp (pl: sep p)ta) Coenosteum Æ skeletal material between walls of adjacent corallites Costa Æ extensions of the septa outside the wall of the corallite (pl: costae) Terms in identifyyging hard coral (2) Columella Æ central structure of the calyx formed by fusion of the lower elements of the septa Tuberculae Æ larger-than-polyp bumps occurring in the coenosteum Verrucae Æ larger-than-polyp bumps composed of several corallites Papillae Æ smaller-than-polyp, nipple-like bumps on the surface of the skeleton Skeleton of hard coral (Scleractinia) A general anatomy of skeleton of hard coral The arrangement of corallite (1) Solitary Cerioid Phacelloid Hydnophorid Ploco id Dendroid Meandroid Flabello-meandroid The arrangement of corallite (2) Phaceloid Æ koralit memanjang membentuk tabung dan juga mempunyai koralit dengan dinding masing-masing Ex. Galaxea fascicularis Solitary Ex. Fungia horrida The arrangement of corallite (3) CerioidÆ apabila dinding koralit saling menyatu dan membentuk permukaan yang datar Ex. Leptastrea purpurea Plocoid Æ tiap koralit memiliki dindingnya masing-masing yang terhubung oleh coenosteum Ex. The arrangement of corallite (4) DendroidÆ koloni hampir menyerupai pohon yang dijumpai cabang-cabang dan di ujung cabang biasanya dijumpai calix utama Ex. Tubastrea micrantha MeandroidÆ koloni mempunyai koralit yang membentuk lembah dan koralit disatukan oleh dinding-dinding yang saling menyatu dan membentuk alur-alur seperti sungai Ex. Pavona varians The arrangement of corallite (5) HydnophoridÆ koralit terbentuk seperti bukit tersebar pada seluruh permukaan sehingga sangat mudah untuk dikenal Ex. Hyypdnophora rig ida Flabello-MeandroidÆ seperti meandroid, membentuk lembah-lembah memanjang, namun koralit tidak memiliki dinding bersama Ex. Symphillia TiTerima KihKasih.