Farid K. Muzaki, S.Si., M.Si
Jurusan BIOLOGI FMIPA – ITS Surabaya
THE CNIDARIA
Taxonomy of Animalia – SB091321 Characters (1)
DilbltiDiploblastic MtMetazoa with ec tdtoderm an d en tdtoderm separat tded 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 (ad ult epidermi s and gast rod 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)
Exhibit alternati on of asexual pol ypoid and sexual med usoid generations; but there are many variations on this basic theme
The entodermallyyg derived gastrovascular cavity 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 reproducti on 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 acrasped ot e (withou t a ve lum ), 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 fertilizedfertilized 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 produces 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 Coralli morp 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 ri gida
Flabello-MeandroidÆ seperti meandroid, membentuk lembah-lembah memanjang, namun koralit tidak memiliki dinding bersama Ex. Symphillia
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