Porifera and Sponge Biology Flashcards

Vocabulary flashcards covering the study questions and key terminology for sponges (Phylum Porifera).

Porifera

The phylum of basal multicellular animals lacking true tissues, commonly known as sponges.

Choanocytes

Flagellated collar cells in sponges that generate water currents and capture food particles for filter feeding.

Spicules

Microscopic structural skeletal elements in sponges made of calcium carbonate or silica that provide support.

Monoecious

The condition of having both male and female reproductive structures within the same individual organism.

Archaeocytes

Amoeboid, totipotent cells in the mesohyl of sponges responsible for digestion, nutrient transport, and cell differentiation.

Sclerocytes

Specialized cells in sponges responsible for secreting mineral spicules.

Spongocytes

Specialized cells in sponges that secrete collagenous spongin fibers.

Collencytes

Sponge cells that secrete collagen to maintain structural support within the mesohyl.

Mesohyl

The gelatinous extracellular matrix lying between the outer pinacoderm and inner choanoderm cell layers in sponges.

Ostia

Small incurrent pores on the outer surface of sponges through which water enters the body.

Osculum

A large excurrent opening through which filtered water exits the sponge body.

Spongocoel

The central internal cavity of a sponge into which water flows before exiting through the osculum.

Pinacocytes

Thin, flat, epithelial-like cells forming the outer protective layer (pinacoderm) of sponges.

Calcarea

A traditional class of sponges characterized by spicules composed entirely of calcium carbonate ($CaCO_3$).

Hexactinellida

A class of sponges known as glass sponges, characterized by six-rayed siliceous spicules.

Demospongiae

The largest class of sponges, characterized by skeletons composed of spongin fibers, siliceous spicules, or both.

Filter feeders

Organisms that obtain nutrients by straining suspended organic particles from water pumped through their bodies.

Sessile

Permanently attached directly at the base to a substrate and non-motile in adult form.

Canal systems

Internal anatomical pathways (asconoid, syconoid, leuconoid) that route water through sponges for feeding, respiration, and excretion.

Eumetazoa

A clade of multicellular animals possessing true tissues, excluding sponges (Porifera).

Bilateria

A major clade of animals displaying bilateral symmetry and three germ layers, distinct from sponges.

Heterotrophic

A mode of nutrition in which organisms cannot synthesize their own food and must consume organic matter.

Spongin

A fibrous collagenous protein that forms the flexible skeletal network in demosponges.

Asconoid

The simplest sponge canal system, where water enters ostia directly into a large choanocyte-lined spongocoel.

Syconoid

A sponge canal system featuring folded body walls that form choanocyte-lined radial canals.

Leuconoid

The most complex sponge canal system, characterized by highly branched canals and flagellated chambers.

Skeletal elements

Structural components of sponges consisting of mineral spicules (calcareous or siliceous) and organic spongin fibers.

Sponge reproduction

The reproductive strategies of sponges including asexual methods (budding, gemmules) and sexual reproduction.

Ecological relationships of sponges

Interactions between sponges and ecosystems, including providing habitat for marine life, water filtration, and symbiotic associations.

Sponge interactions with humans

Positive and negative human relationships with sponges, such as commercial harvesting for bath sponges, biofouling, and pharmaceutical applications.

Phylogeny of sponges

The evolutionary position of sponges (Porifera) as the basal lineage or earliest-diverging group of animals.

Morphology of sponges

The anatomical structure of sponges, defined by cellular organization, lack of true tissues/organs, and a system of pores and channels.

Development in sponges

The embryological and larval processes in sponges, typically involving free-swimming ciliated larvae that settle into sessile adults.