Phylum Mollusca Class Cephalopoda Squid Flashcards

Questions and Answers

What is the phylum of squid?

Arthropoda

Cnidaria

Mollusca (correct)

Annelida

What is the class of squid?

Polyplacophora

Cephalopoda (correct)

Bivalvia

Gastropoda

What is a siphon in the context of a mollusk?

A tubelike structure through which water enters and leaves a mollusk's body.

What are chromatophores?

Pigment cells in the dermis that can disperse or concentrate pigment. Signup and view all the answers

What is the function of the ink sac in cephalopods?

To produce ink ejected from the body to confuse and distract predators. Signup and view all the answers

What are tentacles?

Long, slender, flexible arm-like structures found around the mouth or head of an animal. Signup and view all the answers

What are arms in cephalopods?

Shorter appendages used to manipulate captured prey. Signup and view all the answers

What are lateral fins?

Muscular structures used for swimming and maneuvering. Signup and view all the answers

What is the mantle in a squid?

A body tube encircling the visceral mass forming a hollow chamber. Signup and view all the answers

What is the function of squids' eyes?

Well developed to sense light and dark and form images. Signup and view all the answers

What are ommochromes?

Widely occurring colored molecules of invertebrates. Signup and view all the answers

What is the radula?

A tongue-like organ with rows of backward-facing teeth used for feeding. Signup and view all the answers

What is the role of testes in squid?

To produce sperm. Signup and view all the answers

What does the ovary do in squid?

Passes eggs to the uterus. Signup and view all the answers

What is the systemic heart in squids?

It receives blood from the gill hearts and pumps it to the body of the squid. Signup and view all the answers

What is the primary method of locomotion in a squid?

Jet propulsion. Signup and view all the answers

Why can squid change color faster than other organisms?

They use chromatophores that expand and contract to control skin color. Signup and view all the answers

What is an example of convergent evolution between squid and higher order animals?

Camera eye. Signup and view all the answers

Study Notes

Phylum: Mollusca / Class: Cephalopoda / Species: Squid

Squids belong to the phylum Mollusca and class Cephalopoda.
Their body plan includes distinct features such as tentacles, arms, and fins.

Anatomy and Physiology

Siphon: A tube structure for water entry and exit, aiding in locomotion.
Chromatophores: Pigment cells that enable color changes in response to environmental stimuli.
Ink Sac: An organ that produces ink for defense against predators.
Tentacles: Long, flexible structures used for capturing prey.
Arms: Eight shorter appendages that assist in manipulating prey and swimming.
Lateral Fins: Muscular structures providing propulsion and maneuverability without bony support.
Mantle: Protective layer enveloping the visceral mass, crucial for water propulsion.
Eyes: Highly developed organs capable of forming images and detecting light.

Reproductive Organs

Hectocotylus: A modified arm in males for transferring sperm to females.
Testes: Organs responsible for sperm production.
Spermatophoric Gland: Facilitates the production of sperm cells.
Ovary: Organ that transfers eggs to the uterus.
Oviduct: Connects the ovary with the uterus for egg passage.
Nidamental Gland: A gland involved in secreting eggs or gelatinous egg masses.

Digestive System

Stomach: Oval structure functioning in digestion, adjacent to the caecum.
Cecum: The start of the large intestine, enhancing digestive surface area.

Circulatory System

Systemic Heart: Pumps oxygenated blood received from gill hearts to the squid's body.
Branchial Hearts: Smaller chambers that pump deoxygenated blood to the gills for oxygenation.

Respiratory System

Gills: Respiration organs, feathery in structure, facilitating gas exchange.

Locomotion and Behavior

Jet Propulsion: Squids use jet propulsion by filling their mantle cavity with water and expelling it via the siphon for movement.
Color Change Mechanism: Chromatophores expand and contract through muscle action, allowing rapid color changes for communication and camouflage.

Evolutionary Note

Convergent Evolution: The camera eye of squid has evolved similarly to those found in higher-order animals, showcasing an example of independent evolution of complex traits.

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Description

This quiz includes flashcards focused on the Phylum Mollusca, Class Cephalopoda, and the species Squid. Each card presents key terms and definitions such as siphon and chromatophores, essential for understanding cephalopod biology. Ideal for students looking to enhance their knowledge of marine biology and mollusks.