Porifera (Sponges) Flashcards

Questions and Answers

Porifera are also known as?

Sea Anemones

Sponges (correct)

Corals

Jellyfish

Do sponges have true embryonic tissues?

False

What does it mean for a sponge to have cells that are totipotent?

The cells change form and function and are mobile throughout the body

Are sponges found in marine waters or freshwaters?

True Signup and view all the answers

What is a group of sponges known as?

A sleeze Signup and view all the answers

What are the three classes of sponges?

CALCAREA, DEMOSPONGIAE, HEXACTINELLIDA Signup and view all the answers

What are the spicules of CALCAREA composed of?

Calcium Carbonate Signup and view all the answers

Do CALCAREA sponges typically live in marine water or freshwater?

False Signup and view all the answers

CALCAREA are considered the least primitive of the three classes of sponges.

False Signup and view all the answers

What is one defining characteristic of CALCAREA that helps you identify them?

CALCAREA are usually dull colors Signup and view all the answers

Would I be correct in assuming a sponge I found is probably of the class Demospongiae?

I would probably be correct because DEMOSPONGIAE make up 95% of the extant species of sponge. Signup and view all the answers

What are the spicules of DEMOSPONGIAE made of?

The spicules of DEMOSPONGIAE are siliceous (hydrated SiO2) Signup and view all the answers

DEMOSPONGIAE are found exclusively in marine waters at shallow depths.

False Signup and view all the answers

Sponges of the class HEXACTINELLIDA are also known as what?

Glass sponges Signup and view all the answers

What are the spicules of HEXACTINELLIDA made of?

The spicules of HEXACTINELLIDA are siliceous (hydrated SiO2) Signup and view all the answers

What is unique about the spicules of the HEXACTINELLIDA?

The spicules of HEXACTINELLIDA are six-rayed Signup and view all the answers

HEXACTINELLIDA are typically found in shallow depths of freshwater.

False Signup and view all the answers

What does it mean for a sponge to be an aquiferous system?

Water is pumped through the sponge such that O2 and nutrients are brought in and CO2 and wastes are removed Signup and view all the answers

What structures does a sponge have that provides each cell with the appropriate nutrients and gas exchange?

Sponge walls have pores and chambers so that each cell is in close proximity to water Signup and view all the answers

What is the body structure of sponges if the sponge does not have true tissues?

The sponge has layers of cells with specific functions that contribute to the aquiferous system, food uptake, and support Signup and view all the answers

What is mesohyl? Is it cellular? What is found in the mesohyl?

Mesohyl is noncellular and contains spicules and many types of ameboid cells. Signup and view all the answers

What type of cells make up the PINACODERM?

PINACOCYTES Signup and view all the answers

What is the PINACODERM?

The PINACODERM is the outer layer of the sponge body that is perforated with small pores where water enters. Signup and view all the answers

What are PINACOCYTES?

PINACOCYTES are flattened and overlapping cells that are epithelial in function and are probably phagocytic. PINACOCYTES also aid in osmoregulation in freshwater sponges Signup and view all the answers

What defines a pore as a DERMAL PORE?

A DERMAL PORE is if the pore is composed of more than one cell Signup and view all the answers

What defines a pore as an OSTIA?

An OSTIA is if the pore is composed of only one, tube-like cell Signup and view all the answers

What are these OSTIA cells called?

POROCYTES, which are cylindrical and contractile Signup and view all the answers

What type of cells is the CHOANODERM made up of?

CHOANOCYTES Signup and view all the answers

What is the function of the CHOANODERM?

The CHOANODERM is a surface of flagellated cells that create water currents. Signup and view all the answers

What does a CHOANOCYTE look like?

A CHOANOCYTE has a main body, with a cone-like collar made up of MICROVILLI and a FLAGELLUM in the middle. Signup and view all the answers

How does the COLLAR of the CHOANOCYTE aid in obtaining food?

The COLLAR has mucus to trap food particles Signup and view all the answers

What are the three general body types for the CALCEROUS and DEMOSPONGES?

ASCONOID, SYNCONOID, LEUCONOID Signup and view all the answers

What does the ASCONOID body type look like?

Small and simple vase shape Signup and view all the answers

What do the PINACODERM and CHOANODERM look like in ASCONOIDs?

Simple sheets Signup and view all the answers

Where does the POROCYTE in the ASCONOID lead to?

The SPONGOCOEL Signup and view all the answers

What class of sponges can the ASCONOID body type be found?

All juvenile and some adult CALCAREOUS Signup and view all the answers

What is the osculum in the ASCONOID?

The OSCULUM is the big opening at the top of the animal. Signup and view all the answers

Identify the path that water flows in the ASCONOID body type.

Ostia, Porocyte, Spongocoel, Osculum Signup and view all the answers

What does a SYNCONOID body plan look like?

A SYNCONOID body plan has various degrees of infolding to create FLAGELLATED CHAMBERS containing CHOANOCYTES Signup and view all the answers

Is the MESOHYL thickened or reduced in SYNCONOIDS?

True Signup and view all the answers

Is the incurrent opening a dermal pore or an ostia?

True Signup and view all the answers

What is the opening into the flagellated chamber called in SYNCONOIDS?

PROSOPYLE Signup and view all the answers

What is the opening to the SPONGOCOEL called?

APOPYLE Signup and view all the answers

What sponges can you find the body type of a SYNCONOID in?

SYNCONOID body plans are found in many calcareous sponges. Signup and view all the answers

Identify the path of water flow in SYNCONOIDS.

Dermal pore, Incurrent canal, Prosopyle, Flagellated chamber, Apopyle, Spongocoel, Osculum Signup and view all the answers

What distinguishes the LEUCONOID from the SYNCONOID and the ASCONOID?

Further infolding of the PINACODERM and CHOANODERM to create FLAGILLATED CHAMBERS that are discreet chambers Signup and view all the answers

What does the SPONGOCOEL look like in LEUCONOIDS?

The SPONGOCOEL is a series of EXCURRENT (or EXHALENT) canals Signup and view all the answers

How does flagellated chambers in the LEUCONOID benefit the organism?

This decreases water velocity to maximize gas and nutrient exchange Signup and view all the answers

What class of sponges might you find with LEUCONOID body plans?

Most CALCAREOUS and all DEMOSPONGES have a LEUCONOID body plan Signup and view all the answers

Identify the path of water flow in the LEUCONOID body plan.

Dermal pore, Incurrent canal, Prosopyle, Flagellated chamber, Apopyle, Excurrent canal, Osculum Signup and view all the answers

HEXACTINELLIDS do not have a PINACODERM. What do they have instead?

A dermal membrane with no discreet cell structure and simple holes for pores Signup and view all the answers

What does the inside of the HEXACTINELLIDS look like?

Cellular material forms a TRABECULAR NETWORK with INTERNAL cavities called SUBDERMAL LACUNAE Signup and view all the answers

How are flagellated chambers supported in the HEXACTINELLIDS?

Flagellated chambers are supported by the TRABECULAR NETWORK Signup and view all the answers

What structure brings water from the lacunae to the chambers?

The PROSOPYLES bring water from the lacunae to the chambers Signup and view all the answers

Choanocyte chambers and the trabecular network are SYNCITIAL. What does this mean?

There are no discrete cells; the majority of cells are fused, resulting in one large multi-nucleated mega-cell Signup and view all the answers

Identify the path of water flow in HEXACTINELLIDS.

Prosopyle, Subdermal lacunae, Flagellated chamber Signup and view all the answers

How do sponges support themselves?

COLLAGEN and SPICULES Signup and view all the answers

What types of cells secrete COLLAGEN?

COLLENCYTES, LOPHOCYTES, SPONGOCYTES Signup and view all the answers

What distinguishes a LOPHOCYTE?

LOPHOCYTES are motile and have a band of COLLAGEN behind them Signup and view all the answers

What distinguishes a COLLENCYTE?

COLLENCYTES secrete thin intercellular COLLAGEN Signup and view all the answers

What distinguishes a SPONGOCYTE?

SPONGOCYTES secrete SPONGIN, a supportive COLLAGEN Signup and view all the answers

Which class is TRUE SPONGIN found in?

TRUE SPONGIN is found only in DEMOSPONGES Signup and view all the answers

What are the two different compounds that SPICULES can be made of?

CaCO3 or SiO2 Signup and view all the answers

Where are SPICULES found?

MESOHYL Signup and view all the answers

What cells produce the SPICULES?

SCLEROCYTES produce SPICULES by collecting Ca or Si and deposit it Signup and view all the answers

What use are SPICULES for us as biologists?

SPICULES are useful in identifying sponges Signup and view all the answers

What are the two general types of SPICULES?

There are either MEGASCLERES or MICROSCLERES Signup and view all the answers

Which type of SPICULES are found in CALCAREOUS sponges?

Only MEGASCLERES spicules Signup and view all the answers

What type of SPICULES are found in DEMOSPONGES and HEXACTINELLIDS?

Both types of spicules Signup and view all the answers

How do sponges feed intracellularly?

By PHAGOCYTOSIS and PINOCYTOSIS Signup and view all the answers

Which cells capture small particles for sponges?

Small particles are captured by ARCHEOCYTES (small amoeboid cells) in the lining of inhalent canals Signup and view all the answers

Where does digestion occur?

Digestion occurs in food vacuoles Signup and view all the answers

What is another method of collecting food particles for sponges?

Water driven through the collar of CHOANOCYTES helps the CHOANOCYTES trap food particles Signup and view all the answers

What happens to food particles captured by CHOANOCYTES?

The food particles are partially digested by the CHOANOCYTE and then passed on to the ARCHEOCYTES Signup and view all the answers

What are three methods of asexual reproduction of sponges?

Fragmentation, Budding, Gemmules Signup and view all the answers

What are GEMMULES and what type of sponges use this method of asexual reproduction?

GEMMULES are a tough-coated dormant cluster of embryonic cells produced by a freshwater sponge for development in more favorable conditions. Signup and view all the answers

Most sponges are sequential hermaphrodites, but some are GONOCHORISTIC.

True Signup and view all the answers

What cells produce the eggs and sperm?

CHOANOCYTES or ARCHAEOCYTES produce sperm and eggs Signup and view all the answers

What structure are sperm produced in?

Sperm are produced in SPERMATIC CYSTS Signup and view all the answers

Where are eggs kept?

Eggs are kept in the mesohyl Signup and view all the answers

Where does fertilization occur?

Most sponges release egg and sperm into water. Fertilization is typically external Signup and view all the answers

A few sponges release sperm but retain eggs. What cells take up the sperm?

Sperm is taken up by the CHOANOCYTE and transferred to the egg. Signup and view all the answers

After fertilization, the zygote may spend time in the maternal sponge.

True Signup and view all the answers

What type of cleavage does the embryo experience?

Holoblastic cleavage into a coeloblastula Signup and view all the answers

What are the 3 larval types of sponges?

Coeloblastula, Parenchymula, Amphiblastula Signup and view all the answers

Sponge larvae are motile (they swim and creep), and are also LECITHOTROPHIC. What does this mean?

LECITHOTROPHIC means the yolk of an egg provides all the nourishment for the larvae Signup and view all the answers

Demosponges typically do not incubate embryos.

False Signup and view all the answers

What is odd about CALCAREA larvae and how they develop?

CALCAREA larvae typically turn inside out as they develop into sponges. Signup and view all the answers

Study Notes

Porifera (Sponges) Overview

Porifera is the scientific classification for sponges, known as the simplest multicellular organisms.
Sponges are characterized as parazoans and lack true embryonic tissues.

Cellular Characteristics

Sponge cells are totipotent, meaning they can change form and function, and are mobile.
They absorb water through a unique aquiferous system that facilitates gas exchange and nutrient uptake.

Habitats and Classifications

Sponges are found in both marine and freshwater environments.
They are grouped into three main classes:
- Calcarea (calcium carbonate spicules)
- Demospongiae (siliceous spicules)
- Hexactinellida (glass sponges with six-rayed spicules)

Spicule Composition

Calcarea spicules are made of calcium carbonate, while Demospongiae spicules are siliceous and may include collagen structures.
Hexactinellida spicules are also siliceous and distinctive due to their six-ray structure.

Body Types

Sponges exhibit three general body types:
- Asconoid: simple and small vase-like shape.
- Syconoid: more complex, with infoldings creating flagellated chambers.
- Leuconoid: highly folded, resulting in discrete flagellated chambers for efficient nutrient exchange.

Anatomical Structures

Pinacoderm is the outer layer composed of pinacocytes that provide structure and regulate water flow.
Choanoderm consists of choanocytes, which generate water currents and capture food through phagocytosis.
Mesohyl is a noncellular matrix that contains spicules and various cells for support and digestion.

Water Flow Pathways

Water enters through ostia and dermal pores, leading to the spongocoel and then out through the osculum.
Each body type has a specific water flow path, adapted for efficient feeding and gas exchange.

Reproductive Strategies

Sponges can reproduce asexually through fragmentation, budding, or gemmules (dormant clusters in unfavorable conditions).
Most sponges are sequential hermaphrodites, possessing both male and female reproductive structures.
Sperm production occurs in spermatic cysts, while eggs are retained in the mesohyl.

Development and Larval Stages

Fertilization often occurs externally in the water, with the potential for some sponges to retain embryos.
Embryos undergo holoblastic cleavage into a coeloblastula, which features three types of larvae: coeloblastula, parenchymula, and amphiblastula.
Sponge larvae are motile and lecitotropic, meaning they depend on yolk for nourishment.

Key Identifying Features

Spicules are crucial for sponge identification, comprising either megascleres (in calcareous sponges) or both megascleres and microscleres (in demosponges and hexactinellids).
Each cell type within sponges has specialized roles, from maintaining structural integrity to facilitating nutrition and reproduction.

By understanding these facets of Porifera, one can appreciate their biological significance and adaptability within various ecosystems.

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Description

Test your knowledge about Porifera, commonly known as sponges, with these flashcards. This quiz covers essential characteristics, anatomical features, and habitats of sponges, including their cellular structure and totipotent abilities. Suitable for biology students and enthusiasts alike!