Sycon - Classification, Structure, Habitat and Reproduction

Sycon : Sycon, a marine sponge widely found in shallow waters, belongs to the Phylum Porifera. Typically, these sponges are attached to shells and rocks, and they are mostly stationary. They are primarily found in temperate regions. There are approximately 5000 living species of sponges worldwide, which are classified into three groups based on the presence or composition of spicules or spongin. These groups are Calcaria, Hexactinellida, and Demospongiae. Below are the Sycon NEET Biology Notes .

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Sycon Classification

Mammary Glands

Sycon Habit and Habitat

Habitat

• Sycons are commonly found in shallow waters, usually not exceeding 150 meters in depth.
• They typically attach to solid substrates such as rocks, shells, and coral reefs.
• They thrive in areas with gentle water currents and low tide conditions.
• Some species can even be found growing on seaweed.

Habit

• Sycons are filter feeders, drawing water in through small pores in their body wall and extracting food particles like plankton and bacteria.
• The water flow is facilitated by flagella, which are hair-like structures lining the canals within the sponge.
• Sycons reproduce through both sexual and asexual means.

Okazaki Fragments

Sycon Structure

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Sycon Characteristics

• Sycon sponges typically exhibit a tubular shape, featuring a single opening at the top and microscopic pores along the sides.
• Their size varies by species, ranging from 1 to 3 centimeters in height.

• Sycon sponges commonly appear in hues of white, cream, or yellow.

• These sponges are predominantly found in shallow temperate waters worldwide.
• They tend to attach themselves to rocks, coral reefs, and mollusk shells for stability.

• A distinguishing feature of Sycon is its unique canal system, which enables water flow for feeding and waste removal.
• Water enters through small surface pores and flows through canals lined with specialized choanocytes.
• Choanocytes with flagella that beat continuously draw in water and capture food particles.
• The filtered water exits through a larger opening at the top, the osculum.

• Sycon sponges possess a skeleton comprising microscopic spicules, which may consist of calcium carbonate or silica. These spicules provide support and structure to the sponge's body.

• Sycon sponges reproduce through both sexual and asexual means.
• In sexual reproduction, sperm are released into the water column, fertilizing eggs within other sponges.
• Asexual reproduction can occur through fragmentation, where a fragment breaks off and develops into a new individual.

• Sycon sponges play a crucial role in marine ecosystems by filtering large volumes of water, removing particles, and contributing to water quality maintenance.
• They also serve as a food source and shelter for various marine organisms.

Sexual Reproduction in Flowering Plants

Sycon Canal System

1. Ostia: These are dermal pores lined with thin membranes, with two openings for entry and exit. Myocytes regulate the opening and closing of Ostia for water flow.
2. Spongocoel/Paragastric or Gastral Cavity: The osculum leads to a large central canal, the spongocoel, surrounded by myocytes acting as sphincters. These cells are contractile and control the opening to the outside through the osculum.
3. Radial Canals: These are extensions of the body wall, closed at the outer end and open at the inner end, connecting to the spongocoel via the excurrent canal.
4. Incurrent Canal: This tubular structure is located between two successive radial canals, alternating in arrangement. Ostia are situated on the pore membrane, controlled by contractile myocytes acting as sphincters to regulate the openings.
5. Prosopyles: These are tiny pores located between the radial and incurrent canals, serving as intercellular channels through which incurrent canals open into radial canals, lined by pinacocytes.
6. Apopyles: These openings of the radial canals into the spongocoel are surrounded by contractile myocytes.

Blue Green Algae

Sycon Respiration

1. Water Flow: Small pores on the sponge's outer surface, called ostia, permit water entry. Specialized collar cells (choanocytes) with flagella rhythmically draw water into a system of canals within the sponge.
2. Oxygen Diffusion: Oxygen dissolved in the water diffuses directly into the sponge's cells as the water flows through. This oxygen is crucial for cellular respiration, the process by which cells convert glucose into usable energy (ATP).
3. Carbon Dioxide Removal: Cellular respiration generates carbon dioxide as a byproduct. This carbon dioxide simply diffuses out of the sponge's cells and into the water current, which exits through another set of pores (oscula).

Net Primary Productivity

Sycon Nutrition

• Water current delivery: The sponge's body is covered in small pores called ostia. Water containing microscopic food particles like plankton and bacteria enters through these pores.
• Filter feeding: Specialized collar cells called choanocytes line internal chambers. The flagella on these cells create a current that pulls water through, trapping food particles on their sticky collars.
• Intracellular digestion: Choanocytes engulf the food particles. Digestion occurs inside these cells, breaking down the food into usable nutrients.
• Nutrient distribution: Once digested, the nutrients are passed on to other cells throughout the sponge's body.

Sycon Reproduction