Coelomic Invertebrates Flashcards

A comprehensive set of practice questions and answers covering the classification, anatomy, and life cycles of coelomic invertebrates, specifically Phylum Mollusca and Phylum Echinodermata.

What are the three main body regions characteristic of all molluscs?

The head-foot (sensory and locomotor), visceral mass (contains organ systems), and mantle (covers the mass and secretes the shell).

Which type of ciliated larva is shared by both molluscs and annelids?

The trochophore larva.

What is the rasping structure covered with chitinous teeth used for feeding in most molluscs?

The radula.

Which class of Mollusca is characterized by an elliptical body and a shell composed of eight plates?

Class Polyplacophora (chitons).

What is the typical habitat depth range of some deep-water chitons?

As deep as $6,000\,m$ ($20,000\,ft$).

What mineral coats the teeth of a chiton's radula to make them hard?

Magnetite (a hard ferric/ferrous oxide mineral).

In Class Gastropoda, what is the term for the 180-degree twisting of internal organs during development?

Torsion.

Which species is identified as the intermediate host of the liver fluke, Fasciola gigantica?

Limnaea caillaudi.

What are the two intermediate hosts for Schistosoma species mentioned in the notes?

Bulinus truncatus (for S. haematobium) and Biomphalaria alexandrina (for S. mansoni).

What structure do slugs use for respiration, and on which side of the body is it normally located?

The pneumostome (respiratory opening), normally located on the right-hand side.

What are 'byssal threads'?

Strong, elastic thread-like structures secreted by byssal glands in the foot of bivalves like Mytilus to anchor them to rocks.

What is the specialized sensory organ in bivalves like Patella tarentina used to test the quality of the respiratory water current?

Osphradia.

How many hearts does an octopus have, and what are their specific functions?

Three hearts: one systemic heart to circulate blood around the body and two branchial hearts to pump blood through the gills.

What copper-rich protein is used by octopuses to transport oxygen, giving their blood a bluish color?

Haemocyanin.

What is the name of the specialized arm used by male octopuses to transfer spermatophores to females?

Hectocotylus.

Which phylum is characterized by adults with radial symmetry (pentamerism) and a water vascular system?

Phylum Echinodermata.

What is the sequence of the water vascular system in echinoderms starting from the exterior opening?

Madreporite $\rightarrow$ stone canal $\rightarrow$ ring canal $\rightarrow$ radial canals $\rightarrow$ lateral canals $\rightarrow$ ampulla $\rightarrow$ podium (tube feet).

What is the name of the complex jaw apparatus found in sea urchins (Class Echinoidea)?

Aristotle's lantern.

Match the echinoderm class to its larval stage: Asteroidea, Ophiuroidea, Echinoidea, Holothuroidea.

Asteroidea: Bipinnaria; Ophiuroidea: Ophiopluteus; Echinoidea: Echinopluteus; Holothuroidea: Auricularia.

What are 'pedicellariae'?

Small stinging or pincer-like structures on the body surface of some echinoderms used for defense and removing debris.

Which class of echinoderms contains the sea lilies and sea feathers?

Class Crinoidea.

What are the 'respiratory trees' in Class Holothuroidea?

A pair of branched tubules inside the cloaca used for extracting oxygen from water.