Facts and secrets of sea sponges

Sponges are simple animals that lack tissues and organs,found in marine environments, attached to rocks on the seabed.They have been around for a very long time ,over 600 millions of years. They are characterised by a porous body structure with numerous channels and chambers that allow water to flow through them. They come in a wide variety of shapes, sizes, and colours.

Sea sponges are living organisms. They lack organs and true tissues but possess specialised cells that perform various functions such as feeding, reproduction, and structural support. Water is drawn into the sponge through tiny pores called ostia, where food particles and oxygen are filtered out. The filtered water is then expelled through larger openings called the oscula.

The main structural component of sea sponges is a flexible protein called spongin, similar to collagen. Spongin provides the sponge with its shape and flexibility. In addition to spongin, sea sponges also have a skeleton made of mineralized structures called spicules.

Sea sponges constitute the phylum Porifera ,which includes more than 8000 living sponge species.The phylum name Porifera means pore-bearing. Sponges take their name from small holes that cover their bodies.

Sea sponges do not have a backbone, the body of a sponge is supported by a skeleton made of either calcium carbonate or a flexible protein called spongin. The most important structure is the system of canals and channels through which water circulates to bring food and oxygen to the sponge.

Sponges lack anything resembling brains; instead, sponges contain cells that have some of the capabilities of neurons.

Sea sponge digestive system: Sponges lack a complex digestive system,their food is trapped as water passes through the system of canals and channels of their body.

Sea sponges, despite their fascinating biology, do not have eyes or any sensory organs resembling those found in animals with vision. They lack nervous systems and specialised sensory structures, such as eyes, that enable sight.

Sea sponge lifespan varies by species and environment. While some,in shallow marine environments , live only a few years, others, like deep-sea sponges, may endure for centuries. Factors such as predation, competition, and habitat disturbance influence their lifespans.

Sea sponges are filter feeders, which means they primarily feed on tiny particles suspended in the water. These particles can include bacteria, plankton, detritus, and organic matter. Sea sponges have specialised cells lining their internal cavities,these cells have flagella (whip-like structures) that create currents, drawing water into the sponge's body through small pores.

As water passes through the sponge's body, food particles are captured from the water column and direct them into their cell bodies for digestion. The nutrients derived from these particles are then distributed throughout the sponge's body to sustain its metabolic functions and growth.

Essentially, sea sponges filter organic particles from the water, utilising them as a food source. This feeding strategy not only provides sustenance for the sponge but also helps to filter and clean the surrounding marine environment.

Sea sponges are generally considered sessile organisms, meaning they are permanently attached to a substrate and do not move from place to place in the same way that many animals do. Once a sea sponge settles and attaches itself to a suitable surface, it remains anchored in that location for the rest of its life.Overall, while sea sponges are primarily sessile organisms, they may display some limited forms of movement or dispersal during specific stages of their life cycle or in response to environmental cues.

Sea sponges possess a unique respiratory system adapted to their aquatic lifestyle.

Respiration in sponges primarily occurs through diffusion. Oxygen from the surrounding water diffuses across the sponge's body surface into specialised cells These cells line the inner cavities of the sponge and are equipped with whip-like structures that create water currents.This flow of water allows for efficient exchange of gases, with oxygen entering the sponge and carbon dioxide, a waste product of cellular respiration, being released back into the water.

The habitat of sea sponges and their role in marine environment

Sea sponges inhabit various marine environments worldwide, from shallow coastal waters to deep-sea habitats. They are commonly found attached to hard substrates such as rocks, coral reefs, shells, and even the seabed itself.

Sea sponges play crucial roles in marine ecosystems:

Filter Feeding: Sea sponges are filter feeders, meaning they actively pump water through their bodies to capture microscopic food particles suspended in the water column. This process helps to maintain water clarity by removing organic debris and planktonic organisms, contributing to the overall health of the ecosystem.

Habitat and Shelter: The complex structure of sea sponges provides habitat and shelter for a variety of marine organisms , such as crustaceans and mollusks. This makes sea sponges important contributors to biodiversity in marine ecosystems.

Coral Reef Stability: In coral reef ecosystems, certain sponge species play a role in reef stability. By binding sediments and providing a substrate for other organisms to settle on, sponges help build and maintain the structural integrity of coral reefs.

Nutrient Cycling: Sea sponges participate in nutrient cycling within marine environments. They absorb dissolved organic matter and nutrients from the water, which are then incorporated into their tissues.

Biomedical Potential: Sea sponges produce a wide variety of bioactive compounds, some of which have potential pharmaceutical applications. These compounds include antibacterial, antiviral, and anticancer agents. Researchers are exploring the biomedical potential of sea sponge-derived compounds for drug discovery and development.

Sponge farming, also known as sponge aquaculture, involves the cultivation of sea sponges for commercial purposes. This practice has gained attention due to the potential economic benefits and the sustainable production of natural sponges. Sponge farming typically involves the following steps:

Site Selection:Coastal areas with clean water and appropriate environmental conditions are often preferred for sponge cultivation.

Collection of Wild Specimens or Propagation: Depending on the species, sponge farming may involve collecting wild specimens from natural populations or propagating sponges from cultured fragments or larvae.

Sponge Nursery: Cultured sponge fragments or larvae are typically grown in a nursery environment until they reach a suitable size for transplantation. Nursery facilities may include tanks or containers with controlled water flow, temperature, and nutrient levels to optimise sponge growth.

Transplantation: Once the sponges have reached a certain size, they are transplanted onto suitable substrates in the farming area. Substrates may include ropes, frames, or artificial structures designed to support sponge growth.

Maintenance and Management: Sponge farms require regular maintenance and management to ensure optimal growth and health of the cultured sponges.

Harvesting: Depending on the species and market demand, sponges may be harvested once they reach a certain size and maturity.
Sponge farming offers potential benefits such as sustainable harvesting of natural resources, job creation, and economic development in coastal communities.

Types of sea sponges used for bathing and painting.

There are over 8000 types of ocean sponges and from them only around ten types are used for bathing, cleaning or painting purposes:

Harvesting: Sea sponges are typically harvested by divers using specialised equipment such as nets, knives, or scissors. Divers carefully select sponges from the ocean floor, ensuring sustainable harvesting practices to preserve sponge populations and marine ecosystems.

Cleaning and Processing: Once harvested, sea sponges are cleaned to remove any debris, organisms, or sediment that may be clinging to them. This process usually involves rinsing the sponges in seawater or freshwater and gently scrubbing them to remove impurities.

Drying: After cleaning, the sea sponges are laid out to dry in the sun or in a well-ventilated area. Drying helps to remove excess moisture and prevents the growth of mould or bacteria.

Trimming and Shaping: Depending on the intended use, sea sponges may be trimmed and shaped to achieve the desired size and shape,by hand, using scissors.

Turning natural brown colour to yellow: Some clients prefer sponges with yellow colour,which is achieved, with the same traditional method used in Greece the last few hundred years, using household substances of the old times, like lime.

Quality Control: Once trimmed and shaped, the sea sponges undergo quality control inspections to ensure they meet the desired standards for texture, appearance, and overall quality. Any sponges that do not meet the criteria may be discarded or sent for further processing.

Overall, the process of preparing sea sponges for use involves careful handling, cleaning, shaping, and quality control to ensure that the final product meets the standards for performance and appearance.

Natural sea sponge for bathing

Sea sponges for painting

Natural grass sea sponges create stunning, textured effects on walls, adding depth and dimension to any space. Their unique shapes and sizes allow for endless possibilities, from subtle accents to bold statements, making each wall a canvas for your imagination. Make an environmentally conscious choice by opting for natural sea sponges in your wall painting endeavours.

Explore a variety of painting techniques from stippling and dabbing to blending and layering. Whether you're creating a subtle ombré effect or a bold statement wall,natural sponges offer endless possibilities for artistic expression.Ideal types of sea sponges for painting are Mediterranean Honeycomb type and the economical Caribbean grass type.

Craft sponges

Sea sponges bring a unique and organic texture to your arts and crafts creations, adding depth and visual interest to any project. Whether you're painting, stamping, or crafting, the natural texture of sea sponges adds a touch of realism and character. Achieve seamless blending and soft transitions between colours with the help of sea sponges. Their absorbent nature allows for smooth colour blending, creating beautiful gradients and subtle variations in hue. Safe and non-toxic, sea sponges are ideal for arts and crafts projects with children. Let their imagination run wild as they explore different textures and techniques using these natural sponges.

After each use, thoroughly rinse the sea sponge under running water to remove any soap residue, debris, or impurities trapped within its pores. Squeeze the sponge gently to ensure all the dirt is expelled.
If you want to periodically refresh your sponges you may soak in Vinegar Solution by mixing one part white vinegar with three parts water in a bowl. Submerge the sea sponge in this solution and let it soak for 10 to 15 minutes,  rinse well and air dry. Vinegar is a natural disinfectant that helps kill bacteria and remove any odours.    
Store the sea sponge in a clean, dry place away from direct sunlight and moisture.

• What is a sponge?
• Magical mysteries of marine sponges - ScienceDirect
• Sea Sponges: Pharmacies of the Sea | Smithsonian Ocean
• Sea Sponge: Interesting Facts with Pictures - Ocean Info
• Why Sponges are Underrated - Ocean Conservancy
• The cleaning power of sea sponges | Research and Innovation
• Skandalopetra - The Ancient Art Of Kalymnian Sponge Diving
• The sea sponge: a complicated yet simple animal
• Mauritius sea sponge produces chemicals that can kill liver cancer cells – findings are a positive first step