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Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.2Lab #5 - Biological Sciences 102 – Animal BiologyClassification of the Radiate AnimalsPhylum CnidariaClass Hydrozoa (hy-dro-zo'a) (Gr. hydra, water serpent, + zoon, animal).Both polyp and medusa stages represented, although one type may besuppressed; medusa with a velum; found in fresh and marine water. Thehydroids. Examples: Hydra, Obelia, Gonionemus, Tubularia, PhysaliaHydraClass Scyphozoa (sy-fo-zo'a) (Gr. skyphos, cup, + zoon, animal). Solitary; medusa stage emphasized;polyp reduced or absent; enlarged mesoglea; medusa without a velum. The true jellyfish. Examples:Aurelia, Rhizostoma, CassiopeiaClass Cubozoa (ku'bo-zo'a) (Gr. kybos, a cube, + zoon, animal). Solitary; polyp stage reduced; bellshapedmedusae square in cross section, with a tentacle or group of tentacles at each corner; marginwithout velum but with velarium; all marine. Examples: Carybdea, ChironexClass Anthozoa (an-tho-zo'a) (Gr. anthos, flower, + zoon, animal). All polyps, no medusae;gastrovascular cavity subdivided by mesenteries (septa).Subclass Hexacorallia (hek-sa-ko-ral'e-a) (Gr. hex, six, +korallion, coral) (Zoantharia). Polyp with simple, unbranchedtentacles; septal arrangement hexamerous; skeleton, whenpresent, external. Sea anemones and stony corals. Examples:Metridium, Tealia, AstrangiaSubclass Ceriantipatharia (se-re-an-tip' a-tha' ri-a)(combination of Ceriantharia and Antipatharia, from typegenera). With simple, unbranched tentacles; mesenteriesunpaired. Tube anemones and black or thorny corals.Examples: Cerianthus, AntipathesCross section through ahexacorallianSubclass Octocorallia (ok'to-ko-ral'e-a) (L. octo, + Gr. korallion, coral) (Alcyonaria). Polyp witheight pinnate tentacles; septal arrangement octamerous. Soft and horny corals. Examples:Gorgonia, Renilla, AlcyoniumPhylum CtenophoraClass Tentaculata (ten-tak'yu-la'ta) (L. tentaculum, feeler, + ata, group suffix). Withtentacles; tentacles may have sheaths into which they retract; some types flattened inoral-aboral axis for creeping; others compressed in tentacular plane to a band-likeform; in some the comb plates may be confined to the larva. Examples: Pleurobrachia,Cestum.Class Nuda (nu-da) (L. nudus, naked). Without tentacles, but flattened in tentacularplane; wide mouth and pharynx; gastrovascular canals much branched. Example:BeroeA Ctenophore (Beroe)

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.3Lab #5 - Biological Sciences 102 – Animal BiologyBasic Animal Life Cycles & Development (Embryology)On the chalkboard, your instructor will diagram a basic, generalized animal lifecycle to introduce thefollowing terms related to animal life cycles and development. Your instructor will then review withyou the basic life cycle of the cnidarians, Obelia sp. and Aurelia aurita as specific examples.EARLY ANIMAL DEVELOPMENT (see diagrams from board)‣ sperm = the male gamete (haploid = N)‣ ovum (egg) = the female gamete (haploid = N)‣ fertilization = the species specific binding of the sperm to the egg and fusion of the sperm cellnucleus with the egg cell nucleus to create a diploid zygote‣ zygote = fertilized egg (diploid = 2N)‣ cleavage = the mitotic cell divisions of an animal zygote; the first cell divisions that occur tocreate a morula from the zygote‣ morula = a solid ball of cells that froms from the mitotic divisions of the zygote‣ blastula = the next embryonic stage that marks the end of early cell division during animaldevelopment; an embryo that look like a hollow ball of cells‣ gastrula = the next embryonic stage resulting from the division of the early cells into threemajor tissue types during early animal development. The gastrula may have two (endoderm &ectoderm only) or three tissue layers (ectoderm, mesoderm, & endoderm)‣ gastrulation = the process that leads to the formation of a gastrula‣ ectoderm = the outer layer of three embryonic cell layers in a gastrula; forms the skin of thegastrula and gives rise to the epidermis and nervous system of the adult‣ mesoderm = the middle layer of the three embryonic cell layers in a gastrula; gives rise tomuscles, bones, the dermis of the skin, and many other organs in the adult‣ endoderm = the innermost of three embryonic cell layers in a gastrula; forms the gut of thegastrula and gives rise to the innermost linings of the digestive tract and other hollow organs(e.g. lungs) in the adult‣ larvae = an immature animal life stage that is significantly different from the adult and usuallyincapable of sexual reproduction‣ metamorphosis = a drastic change in form during postembryonic development from the larvalstage to another form, usually the adult‣ adult = the sexually mature form of an animalCleavage, the earliest stage in embryonic development, consists of a succession of regular mitotic celldivisions that partition the egg into a multitude of small cells clustered together. In lower animals,cleavage is so rapid that hundreds, sometimes thousands, of cells are produced in a matter of hours.In animals such as sponges and cnidarians, cleavage is irregular and seemingly disorganized; egg

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.4Lab #5 - Biological Sciences 102 – Animal Biologycytoplasm is partitioned randomly into daughter cells of highly variable size and shape with noapparent relevance to future cell fates. As the metazoa evolved cleavage began to follow precisepatterns and rhythms. In virtually all animal groups above the cnidarians, cleavage is regular; the eggcytoplasm is segregated into specific cells called blastomeres(Gr. blastos, bud, + meros, part) occupying discrete positions and having specific developmental fates.Patterns of regular cleavage depend greatly on amount and distribution of yolk in the egg. In eggshaving a large amount of yolk, cleavage may be either complete (= holoblastic), as in amphibians, orincomplete (= meroblastic), as in birds and reptiles. In birds and reptiles with extreme telolecithal(Gr. telos, end, + lekithos, yolk) eggs, cleavage is restricted to a small disc of cytoplasm on the animalpole; this type of cleavage is called discoidal. The eggs of most insects follow another pattern ofcleavage called superficial. In these the nuclei divide mitotically into hundreds or thousands of "free"nuclei, which later migrate to the egg surface. Only then do cleavage furrows form, rapidly partitioningthe cytoplasm into a superficial layer of cells.In most invertebrates, eggs have little yolk (= isolecithal ["equal-yolk"]), and cleavage is complete(holoblastic) and equal. Two major kinds of holoblastic cleavage exist: spiral and radial (see text page156, fig 8-7). The first two cleavages are the same in both kinds of eggs:the cleavage planes are along the animal-vegetal axis, producing a quartet of cells. At the thirdcleavage, however, these two patterns, spiral and radial, can be distinguished from each other by thegeometric positioning of the cells.In radial cleavage, the third cleavage is perpendicular to the first two, yielding two quartets of cells,with the upper quartet lying directly on top of the lower. In spiral cleavage, the third cleavage planesare oblique to the polar axis and typically produce an upper quartet of smaller cells that come to liebetween the furrows of the lower quartet of larger cells.There are other important differences between these two cleavage patterns. Spiral cleavage istypically mosaic, meaning that the embryo is constructed as a mosaic, with each cell fitting into itspredetermined location in the larval body. If cells of the embryo are experimentally separated at thisearly stage, each cell will develop into partial or defective larvae because the developmental fate of eachcell has already been determined. Spiral cleavage is found in several phyla, including annelids, manymolluscs, some flatworms, and ribbon worms(nemerteans). All groups showing spiral cleavage belong to the grouping of animal phyla called theProtostomia, in which the embryonic blastopore forms the mouth.Radial cleavage is characteristically regulative becausecell fate does not become fixed until after the first fewcleavages. Radial cleavage is found in eggs of echinodermsand many chordates, especially protochordates,amphibians, and mammals. (As mentioned earlier, eggs ofbirds and reptiles, as well as many fishes, show discoidalcleavage.) All of these belong to the Deuterostomia, agroup of phyla in which the mouth is formed from asecondary embryonic opening.(mitosis)Early Embryonic Development - Cell Cleavages

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.6Lab #5 - Biological Sciences 102 – Animal BiologyLAB PROCEDURENAME:LAB SCORE:Class HydrozoaBasic Body PlanWhile the dominant life stage of both Physalia and Velella exist as pneustonic (living at the air-waterinterface) polyp stage, Physalia is a floating colony of polyps exhibiting extensive polymorphism whilethe polyp stage of Velella is actually solitary.‣ Observe the specimens and/or diagrams of the species listed below.‣ Record the descriptive information requested at the end of the lab for each species.Aglaophenia latirostris (common name = Ostrich Plume Hydroid)Physalia physalia (common name = Portugeuese Man-of-War)Vellela velella (common name = By-the-Wind Sailor)

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.7Lab #5 - Biological Sciences 102 – Animal BiologyUsing the preserved, prepared slides identify the following structures of Obelia sp.‣ Below, draw and label the Obelia sp. (polyp colony) with hydranths and gonangia with clearlabels for each of the structures listed below.‣ Use the internet and textbook to assist you in your drawings.‣ coenosarc‣ perisarc‣ gonangiumo medusae in gonangium‣ hydrantho hydrothecao moutho tentacles

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.8Lab #5 - Biological Sciences 102 – Animal Biology‣ Draw and CLEARLY label the Obelia sp. medusa from a prepared slide.‣ Use the internet and textbook to assist you in your drawing.‣ tentacles‣ radial canals‣ manubrium‣ gonads‣ How many gonads are observed in this species?Feeding Demonstration in a HydrozoanHydra, a Solitary HydroidPhylum CnidariaClass HydrozoaOrder HydroidaSuborder AnthomedusaeGenus Hydra, Pelmatohydra, or ChlorohydraHydras are found in pools, quiet streams and ponds often on the underside of aquatic vegetation.Your instructor will prepare a slide of hydra for your observation. The hydra may be contracted at firstand then extend. Small ciliated protozoans which are symbionts of hydras are sometimes seen glidingover the body and tentacles.Your instructor will add a drop of Daphnia or similar food to the slide. Some extracellular digestionoccurs within the gastrovascular cavity via enzymes released by gland cells. Food particles are thenengulfed by cells of the gastrodermis and digestion is completed intracellularly. Undigested food isregurgitated as there is no anus.‣ Observe and briefly describe the feeding reaction of the hydra below:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.9Lab #5 - Biological Sciences 102 – Animal BiologyClass ScyphozoaBasic Body Plans & Life Cycles‣ Clearly label the stages of the life cycle of Aurelia aurita shown below.‣ Use the internet and textbook to assist you in with the labels.

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.10Lab #5 - Biological Sciences 102 – Animal Biology‣ Look at the prepared slides of the following life stages of a life cycle for Aurelia aurita.‣ Make drawings and clearly label them to complete the diagram below.‣ Use the internet and textbook to assist you in your drawings.‣ scyphistoma‣ strobila‣ ephyra

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.11Lab #5 - Biological Sciences 102 – Animal BiologyClass Cubozoa‣ Observe the specimen and/or diagram of Carybdea sp.‣ Record the descriptive information requested at the end of the lab for this species.Class AnthozoaSubclass Hexacorallia‣ Observe the specimens and/or diagrams of the following species.‣ Record the descriptive information requested at the end of the lab for these species.‣ Balanophyllia elegansNote that the scleractinian hexacorallians (stony corals) synthesize a consolidated calciumcarbonate skeleton while anemones do not.‣ Anthopleura sola‣ What accounts for the green color often present in this species?Feeding Demonstration in an AnthozoanAs available, your instructor may feed a small piece of mussel to one of the anemones on display in thelab.‣ Briefly describe the feeding behavior of the anemone:Cnidocytes and Examination of Nematocyst DischargeCnidocytes are cells found in the epidermis between epitheliomuscular cells of cnidarians.Cnidocytes have nematocysts which are tiny capsules composed of material similar to chitin andcontain a coiled tubular filament which is a continuation of the narrowed end of the capsule. This endof the cnidocyte is covered by the operculum. The base of the filament may have spines are barbs.The filament and barbs may contain a poison. The cnidocytes in anthozoans do not have the triggerlikecnidocil. The cnidocil is a modified cilium. In anthozoans a modified ciliary-likemechanoreceptor is involved in triggering nematocyst discharge.

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.13Lab #5 - Biological Sciences 102 – Animal BiologyFor the live specimens available for observation in the lab, record the requestedinformation.Be sure to include descriptions of any live members of the Phylum Ctenophora if theyare available.Phylum CnidariaClass HydrozoaScientific name: Aglaophenia latirostrisCommon name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.14Lab #5 - Biological Sciences 102 – Animal BiologyPhylum CnidariaClass HydrozoaScientific name: Physalia physaliaCommon name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.15Lab #5 - Biological Sciences 102 – Animal BiologyPhylum CnidariaClass HydrozoaScientific name: Vellela velellaCommon name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.16Lab #5 - Biological Sciences 102 – Animal BiologyPhylum CnidariaClass ScyphozoaScientific name: Aurelia auritaCommon name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.17Lab #5 - Biological Sciences 102 – Animal BiologyPhylum CnidariaClass CubozoaScientific name: Carybdea sp.Common name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.18Lab #5 - Biological Sciences 102 – Animal BiologyPhylum CnidariaClass AnthozoaSubclass HexacoralliaScientific name: Balanophyllia elegans or other hexacorallianCommon name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.19Lab #5 - Biological Sciences 102 – Animal BiologyPhylum CnidariaClass AnthozoaSubclass HexacoralliaScientific name: Anthopleura solaCommon name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.20Lab #5 - Biological Sciences 102 – Animal BiologyPhylum CnidariaClass AnthozoaSubclass CeriantipathariaOrder CerianthariaScientific name: Pachycerianthus fimbriatusCommon name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.21Lab #5 - Biological Sciences 102 – Animal BiologyPhylum CnidariaClass AnthozoaSubclass OctocoralliaScientific name: Lophogorgia chilensisCommon name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.22Lab #5 - Biological Sciences 102 – Animal BiologyPhylum CnidariaClass AnthozoaSubclass OctocoralliaScientific name: Renilla kollikeri or other octocorallianCommon name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.23Lab #5 - Biological Sciences 102 – Animal BiologyPhylum Ctenophora (if available)Class:Scientific name:Common name:General dimensions of specimen:Color of specimen:Life stage present (observed):Solitary or colonial:Benthic, planktonic or pneustonic:Unique structures or features:Draw a simple sketch to remind you of the basic structure of this species and any uniquecharacteristics observed.Notes & observations to help you remember and distinguish this group/species:

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.24Lab #5 - Biological Sciences 102 – Animal BiologyLABORATORY NOTES:Actiniae by HaeckelErnst Haeckel (1834 – 1919) was an eminent German biologist, naturalist, philosopher, physician,professor and artist who discovered, described and named thousands of new species, mapped agenealogical tree relating all life forms, and coined many terms in biology, including phylum,phylogeny, ecology and the kingdom Protista. Haeckel promoted and popularized Charles Darwin'swork in Germany and developed the controversial recapitulation theory ("ontogeny recapitulatesphylogeny") claiming that an individual organism's biological development, or ontogeny, parallels andsummarizes its species' entire evolutionary development, or phylogeny.

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.25Lab #5 - Biological Sciences 102 – Animal BiologyLABORATORY NOTES:Peromedusae by HaeckelDiscomedusae by HaeckelTrachomedusae by Haeckel

Phyla Cnidaria and Ctenophora, Basic Animal Development &Introduction to Nervous Systems 5.26Lab #5 - Biological Sciences 102 – Animal BiologyLABORATORY NOTES: