28.1 Invertebrates: Phylum Porifera Flashcards
What is Porifera?
Phylum containing the sponges; simplest animals.
What are Ostia?
Pores through which water enters the sponge body.
What is an Osculum?
Large opening through which water exits the sponge.
What is the Spongocoel?
Central cavity inside a sponge where water flows.
What are Choanocytes?
Flagellated collar cells that generate water flow and trap food.
What is Mesohyl?
Gelatinous matrix that contains cells and skeletal elements.
What are Spicules?
Structural elements made of silica or calcium carbonate.
What is Spongin?
Proteinaceous material forming supportive fibers.
What are Pinacocytes?
Flattened cells forming the sponge’s outer layer (pinacoderm).
What are Porocytes?
Tubular cells forming pores (ostia) in some species.
What are Amoebocytes (Archaeocytes)?
Mobile cells in mesohyl; functions include transport, spicule and spongin production.
What is Filter Feeding?
Water flows through body for nutrient capture and waste removal.
What does it mean that sponges have No True Tissues or Organs?
Sponges lack true tissues and organs; cellular-level organization.
What type of symmetry do sponges exhibit?
Sponges exhibit asymmetry or radial symmetry.
What does it mean that sponges are Sessile Adults?
Sponges are fixed in place as adults.
What is Hermaphroditism in sponges?
Most sponges produce both eggs and sperm.
What is Asexual Reproduction in sponges?
Budding and fragmentation allow reproduction without gametes.
What are Gemmules?
Resistant structures for surviving unfavorable conditions (freshwater sponges).
What is the Asconoid body form?
Simplest body form; tube-shaped with central cavity lined by choanocytes.
What is the Syconoid body form?
Wall is folded; choanocytes line internal folds (canals).
What is the Leuconoid body form?
Most complex; choanocytes line chambers, not central cavity.
What characterizes the Calcarea class?
Calcium carbonate spicules; includes all three body forms.
What characterizes the Hexactinellida class?
Silica spicules with six rays; mostly syconoid or leuconoid.
