Lab 10: Kingdom Animalia: Invertebrates I - Phylum Porifera & Phylum Cnidaria

Vocabulary practice flashcards covering Phylum Porifera and Phylum Cnidaria anatomy, taxonomy, life cycles, and key representatives based on Biology Lab 10.

Parazoa

A subkingdom of animals possessing a cellular level of organization rather than true tissues, exemplified by sponges.

Eumetazoa

A major clade of animals characterized by true tissue-level structure and definite symmetry.

Bilateral Symmetry

A body plan in which both sides around a central axis mirror each other.

Radial Symmetry

A body plan in which body parts radiate outward from a central disc.

Invertebrates

Animals that lack a backbone, make up more than $90\%$ of all living animal species, generally lack a rigid internal skeleton, and include all animals outside subphylum Vertebrata.

Spicules

Sharp skeletal elements that support and construct the body wall of sponges.

Asconoid

The simplest and least folded sponge body form, featuring a simple canal system.

Syconoid

An intermediate sponge body form characterized by folded body walls that form distinct incurrent canals and radial canals.

Leuconoid

The most complex sponge body architecture, characterized by extensively folded canals and numerous flagellated chambers.

Class Calcarea

A class of sponges possessing spicules made of calcium carbonate and exhibiting asconoid, syconoid, or leuconoid body forms.

Class Hexactinellida

A class of sponges characterized by six-rayed spicules made of silica, a syncytial trabecular reticulum, and a syconoid body form.

Class Demospongiae

A class of sponges featuring leuconoid body forms and skeletons consisting of spongin (collagen) networks and siliceous spicules that do not possess six rays.

Cliona celata

The boring sponge; a member of the family Clionaidae that creates round holes up to $5\,\text{mm}$ in diameter in limestone or mollusk shells worldwide.

Spongia officinalis

The commercial sponge; a member of the family Spongiidae that grows in large lobes with small openings and consists of a fibrous mesh, found up to $100\,\text{meters}$ deep in the Mediterranean Sea.

Hippospongia lachne

The sheepswool sponge; a member of the family Spongiidae shaped like a bun with greater horizontal than vertical dimensions, found throughout the Rock Islands, Cuba, Mexico, and Honduras.

Radial Canal

An internal canal within syconoid sponges like Grantia that opens inward to the spongocoel and is lined with flagellated choanocytes.

Incurrent Canal

A canal in syconoid sponges that opens to the outside through ostia to allow water entry.

Ostium

An external pore or opening that allows water to enter into an incurrent canal of a sponge.

Osculum

A large excurrent aperture in sponges through which water is expelled from the central cavity.

Euplectella

A genus of hexactinellid glass sponge known as Venus Flower Basket, featuring an oscular sieve plate, parietal gaps, interlaced siliceous spicules, and a root tuft.

Phylum Cnidaria

A phylum containing approximately $9000$ species of acoelomate, diploblastic eumetazoans exhibiting radial symmetry, an oral-aboral axis, and stinging tentacular cells.

Polyp

A typically sessile, cylindrical cnidarian body form with tentacles and mouth directed upward around the oral axis.

Medusa

A free-floating, umbrella-shaped cnidarian body form with mouth and tentacles oriented downward around the oral axis.

Metagenesis

The alternation of generations between sexual and asexual reproductive stages within the life cycle of certain cnidarians.

Cnidocytes

Specialized stinging cells found in the tentacles of cnidarians that contain stinging capsules termed cnidae or nematocysts.

Nematocyst

A specialized stinging capsule within a cnidocyte that discharges and stings prey when stimulated.

Class Hydrozoa

A cnidarian class containing about $2700$ species that are predominantly colonial and metagenic (such as Obelia and Physalia), with solitary freshwater polyps like Hydra being notable exceptions.

Hydranth

The feeding polyp of a colonial hydrozoan that captures food using tentacles surrounding its mouth.

Gonangium

The reproductive polyp of a colonial hydrozoan that produces medusa buds asexually.

Planula Larva

The ciliated, free-swimming larval stage that develops from a zygote/blastula in metagenic cnidarians like Obelia before settling to form a new colony.

Physalia

A colonial marine hydrozoan known commonly as the Portuguese man-of-war, exhibiting polymorphic polyps and medusoid structures.

Class Scyphozoa

A marine class containing about $200$ species of true jellyfish whose life cycles are dominated by the medusa body form.

Ephyra

An immature, free-swimming juvenile medusa stage of a scyphozoan (such as Aurelia) that develops lappets, radial canals, and rhopalia.

Rhopalium

A specialized marginal sensory structure in scyphozoan jellyfish containing sensory receptors such as eyespots.

Cannonball Jelly

A scyphozoan jellyfish characterized by a dome-shaped bell and the absence of an extended polyp stage in its typical adult display.

Class Anthozoa

A cnidarian class containing approximately $6000$ species (including sea anemones, hard corals, and soft corals) in which the medusa stage is completely absent.

Pedal Disk

The basal muscular plate at the aboral end of sea anemones and polyps used to adhere to solid substrates.

Coenosarc

The common layer of living tissue that interconnects individual polyps across a coral skeleton.

Zooxanthellae

Photosynthetic endosymbiotic dinoflagellates housed within coral polyp tissues that contribute nutrients and assist in skeleton building.