Today we come to comment on a different species to the fish we are used to. It is not a fish that we are going to deal with, but sea sponges. A invertebrate animal which belongs to the edge of the sponges. They live exclusively in aquatic environments and do not present any type of active movement. As its name indicates, it is nothing more than a sponge, but viva. It is among the simplest animals in the evolutionary chain, since they do not have authentic tissues.
Do you want to know all about sea sponges? If you keep reading, you'll find out curious what are these animals?
Key features
As we have mentioned before, sea sponges are very simple animals. These are animals that They do not present defined symmetryTheir bodies do not have a fixed shape, although some species have radial symmetryThe most important characteristic, and the one that gives the name to the porifera phylum, is that the bodies are formed by a network of pores, channels and chambers through which the water passes and, in this way, they achieve food y oxygen.
Not having specialized tissues, sea sponges have a large number of stem cellsThese cells are capable of converting into any cell type the animal needs at a given time. This ability makes them extremely versatile and great regeneration power, even when significant losses of body mass occur.
Although the shape of sponges of different species can vary greatly, they all have a similar structure. They all have a fairly large hole at the top of their body known as kiss. It is through this hole that the water that circulates inside the sponges comes out. The walls of their body are full of pores of different sizes. It is through these pores that water enters and the leak occurs.
A type of cell unique to sea sponges They are the choanocytes. This cell is specialized in filtration. Filtration is the process by which the sponge obtains food. The cells have a flagellum and several microvilli that surround it and are what cause mini water currents through which water enters the sponge.
Basic anatomy: layers and skeleton
The body of a sponge is organized into three main compartments: an external covering called pinacoderm, an inner layer lined by choanocytes called choanoderm and, between them, a gelatinous matrix called mesohylIn the mesohyl are found collagen fibers (spongin), spicules minerals and mobile cells that perform functions of digestion, transport and defense.
The spicules can be of silica or calcium carbonate and come in various shapes and sizes (from megascleras a microscleras). Its combination with spongin determines whether the skeleton is more flexible or more hard, and contributes to protection against predators.
Types of organization of the aquifer system
To optimize their filtration, sponges have evolved three internal organization plans that increase the filtering surface of the choanoderm:
- asconoid: tubular, with a simple central cavity (spongocele) lined by choanocytes.
- Syconoid: thicker and folded wall forming radio channels with flagellated chambers.
- leuconoid: the most complex, with numerous vibrating chambers interconnected and several kisses.
Main cell types
- pinacocytes: They cover the exterior and contribute to protection and flow regulation.
- porocytes: tube-shaped cells that form the inhalant pores (present mainly in calcareous sponges).
- choanocytes: cells with flagellum and collar of microvilli that generate the current y engulf particles.
- Archaeocytes or amoebocytes: totipotent; participate in digestion, transport, excretion y regeneration.
- sclerocytes: produce the spicules of the skeleton.
- spongiocytes: they secrete spongin (collagen) that reinforces the framework.
- myocytes: cells contractile that regulate the diameter of pores and oscula.
Essential physiology
Sponges lack nervous system, digestive system y organs in the style of other animals. Nutrition is based on intracellular digestion (phagocytosis and pinocytosis), gas exchange and excretion are carried out by diffusion, and the coordination of responses (opening or closing of pores) is achieved by chemical signals and cellular contractions.
Taxonomic classification (useful summary)
The edge porifera It brings together four major classes accepted by the specialized literature: Calcarea (calcareous spicules), Hexactinellida (glass sponges with siliceous spicules and syncytial organization), demospongiae (most species, with spongin and/or siliceous spicules) and Homoscleromorpha (group with unique features of its epithelium). This structural diversity explains its wide adaptation to different habitats.
Range and habitat
Although sea sponges are invertebrate animals, they are capable of adapt to different conditions. Facing situations against animals that would be impossible to overcome or survive, she becomes a true survivor. They are able to tolerate water contamination by hydrocarbons quite well, metals or other harmful substances.
They have few natural predators thanks to their skeleton of spicules and its great toxicityThis makes the sea sponge practically in all seas and oceans The most famous sites for the large numbers of sponges harvested in the 20th century are probably the Eastern Mediterranean, the Gulf of Mexico, the Caribbean, and the seas around Japan.
As for the habitat, it is an invertebrate animal sessile. This means that they live fixed on the seabed and do not move actively. They are capable of living in great depths, although they can also be found in more superficial environments. The vast majority of them prefer environments where the sunlight it is not too powerful.
Depth, substrate and inland waters
Most sponges thrive in clean and calm waters, since excess sediment can clog the pores. They are fixed to hard substrates (rock, shells, coral) and some species have developed bases in the form of estate to anchor in soft sediments. Although the vast majority are marine, there are a small number of species in sweet water that inhabits rivers and lakes.
Additional adaptations
In tidal zones, certain species close their pores to prevent drying out when they are exposed. In addition, although they are sessile, some sponges have been documented to very slow movement on the substrate (in the order of millimeters per day) by differential growth and tissue contractions.
Sea sponge feeding
The main food of these animals are organic particles extremely small particles found in the sea that manage to filter through their pores. However, They can feed on plankton and bacteria of small dimensions. Some sponges are capable of establishing a symbiosis with bacteria or other unicellular organisms. This relationship provides them with benefits such as access to organic matter.
There are some animals on the seabed with which you may have some mutualistic relationshipThis type of relationship means that both parties benefit from each other. These relationships involve some invertebrates or fish that use sea sponges as shelter to hide from other large predators. Certain invertebrates can embed themselves in them and help them move while camouflaging themselves. This is a clear example of a mutualistic relationship.
Efficient filtration and dissolved matter
Sponges filter large volumes of water every day. Thanks to the coordinated beating of the choanocytes, capture bacteria, microalgae and dissolved organic matter that other organisms cannot utilize. Some species can process tens of liters daily, acting as real purifiers of the habitat.
Carnivorous sponges
In environments poor in suspended particles (for example, caves or abyssal depths), certain groups such as Cladorhizidae have lost the typical aquifer system and develop hooked spicules to capture small crustaceansThis way of life demonstrates its extraordinary ecological plasticity.
Photosynthetic symbionts
Many sponges host photosynthetic microorganisms (cyanobacteria, zooxanthellae, diatoms) that provide them with products of photosynthesis. In some cases, symbionts can represent a remarkable proportion of the body volume. They periodically expel symbionts and mucous to renew your microbiome and clean your surfaces.
Reproduction
If they are sessile organisms without movement and without symmetry, how do they reproduce? Then They can reproduce both asexually and sexually. The first is thanks to the totipotent cells we saw earlier. It causes them to transform into cells suitable for reproduction. The two common forms of asexual reproduction are buddingSome freshwater species can do this by gemulation.
Because sponges lack some specialized organs for any function, they also lack sexual organs. This can be a problem for reproduction. However, most individuals are hermaphrodites. They need a cross-fertilization to reproduce properly. Both sperm and eggs develop from choanocytes. These are expelled to the outside, and this is where the union between two cells occurs. Therefore, we talk about external fertilization.
The development of sponges is indirectAfter their development, they go through stages larvae before developing into an adult. Four different types of larvae are known, depending on the species.
Modes and phases in more detail
Remember that in addition to the fragmentation (ability to regenerate complete individuals from pieces), in fresh water the gemmules They function as resistance structures against adverse conditions. In sexual reproduction, some species release gametes into the water, while in others the sperm enter another individual's aquifer system and are carried by phorocytes until the ovulesAmong the larval types described, the following stand out: parenchymula, celloblastula, stomoblastula y amphiblastula, all of free life before final settlement.
Curiosities of sea sponges
Although they are not considered, sea sponges synthesize some toxic or antibiotic substances to keep predators away. Many of these substances are used in the pharmaceutical industry and the properties they have are used against some of the most common diseases in our society.
They are also known to have had a relationship with humans due to their usefulness as personal hygiene tool. Currently, the purchase and sale of sponges for personal use is very controlled due to the damage that occurs in their populations.
More striking data
- Amazing genomes: Despite their simplicity, many sponges possess tens of thousands of genes, with parallels to cellular pathways present in vertebrates.
- Genes shared with humans: genes homologous to those involved in have been identified synapse y muscle contraction, which helps to investigate the the origin of complex cellular functions.
- Keys against diseases: part of their genes and Metabolites Secondary are being studied as clues to understanding the cell proliferation and discover compounds antitumor y Antivirals.
- Born survivors: they have resisted episodes of environmental change throughout the history of the planet and colonize from tropical a polar.
- Remarkable longevity: some species can reach very old ages thanks to its slow metabolism and regenerative capacity.
- Subtle locomotion: although sessile, some can move slowly (millimeters per day) modifying its shape and anchor points.
- Tool use in marine fauna: have been documented dolphins that use sponges as protection for their snouts when foraging on sandy bottoms.
Defenses and ecological relationships
There are few animals that feed on sponges because of their toxicity and the framework of spicules. Among the specialized predators are some opisthobranchs, certain fish y echinoderms. On the other hand, numerous invertebrates and fish take advantage of its cavities as a refuge, and the crabs They can carry sponges on their shells to camouflage, offering its “passenger” mobility.
Ecosystem services
The intense filtering capacity of sponges helps to maintain the clear water already recycle nutrientsIn reefs, they transform dissolved organic matter into particles accessible to other organisms, supporting food chains. Therefore, their conservation benefits fisheries and the diversity of the benthos.
Harvest: Sea sponges are usually harvested by divers Using specialized 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 collected, sea sponges are cleaned to remove any debris, organisms, or sediment that may be adhering to them. This process typically involves rinsing the sponges in seawater or freshwater and gently rubbing them to remove impurities.
Drying: After cleaning, the sea sponges are left to dry in the sun or a well-ventilated area. Drying helps remove excess moisture and prevents the growth of mold or bacteria.
Trim and shape: Depending on the intended use, sea sponges can be trimmed and shaped to the desired size and shape, by hand, using scissors.
Convert natural brown color to yellow: Some customers prefer yellow sponges, which are achieved using the same traditional method used in Greece for hundreds of years, using old household substances such as lime.
Sea sponges, oddly enough, are invertebrates. Some scientists claim that they are among the oldest animals on Earth, appearing about 640 million years.
They have been cataloged about 9000 species of sponges, with a wide variety of shapes and colors. Despite all this diversity, their structure is very similar.
They are animals simple, they do not have specific organs and their bodies are made up of pores and channels through which water circulates, allowing them to obtain food and oxygen, transport waste and reproductive cells.
A very important characteristic of sea sponges is their great capacity to regeneration even when they lose much of their body mass. For example, if a sponge is crushed, each of the pieces is capable of forming a new sponge.
The sponge is the only known animal that has this peculiar way of regenerating.
They live attached to the seabed and can do so at great depths as well as in shallower seas.
You can find each other practically in all seas, as they are able to adapt well to very different conditions. However, the places with the greatest number of sponges are the Eastern Mediterranean, the Caribbean, the Gulf of Mexico and Japan.
A little history about the use of sea sponges
It is believed that Egyptians They were the first to use sea sponges, and Cleopatra used them for bathing and absorbing menstrual flow. If you want to learn more about using sponges as menstrual tampons, click here.
The peoples of the Mediterranean have used sponges in many ways. In addition to personal hygiene, the Romans used them for drinking water during their military campaigns, as one of the characteristics of sponges is that they absorb liquid without letting it drip. They also used sponges to protect their bodies from armor. Another interesting fact is that one of the events of the Olympic Games in ancient Rome was the sponge fishing.
Natural sea sponges have long been a household staple, both for general house cleaning and for personal care. Their use was significantly affected with the appearance of synthetic sponges which practically replaced them. Today, we find ourselves in a period of revival of ecological and sustainable products, so important for maintaining the planet's balance.
A traditional and sustainable trade
Of the countless species of sponges that exist, only five are considered viable for sale. All the sponges sold on this page, native to the Mediterranean area - Greece, are the highest quality and softest sponges in the world. They have been cultivated and harvested following traditional natural methods that, far from being an attack on the species, favor its growth and regeneration. This is because divers collect the sponges leaving their base (root) intact and, in addition, they keep the sponges in nets in the sea throughout the capture and movement of the boats, favoring and encouraging their natural reproduction. The capture of natural sponges is a trade that has been practiced for hundreds of years, passed down from father to son and which has taken special care in the maintenance and regeneration of this natural product. 5 reasons to use a sea sponge instead of a synthetic one
Without a doubt, choosing a natural sponge is a win-win option for everyone involved:
the human being, by using a toxin-free product that has no harmful effects on your body;
small producers and all those involved in sponge collection, for continuing their source of income and keeping this traditional trade alive;
the environment, by getting rid of a large amount of non-recyclable waste and all the industrialization that synthetic products entail;
the sea sponges themselves, which are renewed and expand their growth with their harvesting.
The table below shows 5 characteristics that differentiate marine sponges from synthetic ones.
With all this information... Which sponge do you choose for the care and cleaning of your body and that of your family? Visit our store to learn about all the types of natural sea sponges we carry and their different uses.
Sea sponges are simple and extraordinary animals at the same time: they filter and clean the ocean, host life, produce compounds with medical potential and have accompanied humanity as natural resource. Know your biology and support your sustainable use is key to preserving its essential role in marine ecosystems.